Mammals of South America, Volume 2: Rodents 9780226169606

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Mammals of South America, Volume 2

Mammals of South America, Volume 2 Rodents Edited by James L. Patton, Ulyses F. J. Pardiñas, and Guillermo D’Elía

The University of Chicago Press Chicago and London

James L. Patton is professor emeritus of integrative biology and curator of mammals at the Museum of Vertebrate Zoology, University of California, Berkeley. Ulyses F. J. Pardiñas is senior scientist at the Centro Nacional Patagónico, Puerto Madryn, Argentina. Guillermo D’Elía is professor in the Instituto de Ciencias Ambientales y Evolutivas at the Universidad Austral de Chile, Valdivia. The University of Chicago Press, Chicago 60637 The University of Chicago Press, Ltd., London © 2015 by The University of Chicago All rights reserved. Published 2015. Printed in the United States of America 24 23 22 21 20 19 18 17 16 15

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ISBN-13: 978-0-226-16957-6 (cloth) ISBN-13: 978-0-226-16960-6 (e-book) DOI: 10.7208/chicago/9780226169606.001.0001 Library of Congress Cataloging-in-Publication Data Mammals of South America / edited by Alfred L. Gardner. p. cm. Includes bibliographical references and index. ISBN-13: 978-0-226-28240-4 (cloth : alk. paper) ISBN-10: 0-226-28240-6 (cloth : alk. paper) 1. Mammals—South America. 2. Mammals—South America— Classification. I. Gardner, Alfred L. QL725.AI.M36 2007 599.098—dc22 2007017496 This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper).

t h i s vo l u m e i s d e d i c a t e d t o t h o s e s c h o l a rs o f m a m m a l s i n a c a d e m i c institutions, governmental agencies, and nongovernmental organizations in countries of the South American continent. At a pivotal point in the worldwide biodiversity crisis, these individuals have rightly assumed the mantle for the exploration, discovery, description, and conservation of the mammals of their continent through the programs they have developed, the academic institutions and professional organizations they have established and populated, the front rank publication series they have initiated and are supporting, and the students they have trained and who will train those of future generations. There has been remarkable growth in these programs, especially over the past two to three decades, with an energy level and commitment to discovering, archiving, and understanding mammalian diversity in South America that is currently unsurpassed anywhere else in the world.

Contents

Sections and Authors Introduction

ix

xvii

Acronyms and Abbreviations Acknowledgments

xxv

Taxonomic Accounts Literature Cited Gazetteer

xxi

1

1049

1209

List of Taxa

1277

Contributors 1287 Index of Scientific Names

1291

Sections and Authors

Class Mammalia Linnaeus, 1758

1

Order Rodentia Bowdich, 1821: by James L. Patton Suborder Sciuromorpha Brandt, 1855 Infraorder Sciurida Carus, 1868

1

1

1

Family Sciuridae G. Fischer, 1817: by Mario de Vivo and Ana Paula Carmignotto 1 Subfamily Sciurillinae Moore, 1959 3 Genus Sciurillus Thomas, 1914

3

Subfamily Sciurinae G. Fischer, 1817 9 Genus Guerlinguetus Gray, 1821

9

Genus Hadrosciurus J. A. Allen, 1915

15

Genus Microsciurus J. A. Allen, 1895

24

Genus Notosciurus J. A. Allen, 1914

32

Genus Simosciurus J. A. Allen, 1915

43

Genus Syntheosciurus Bangs, 1902

47

Suborder Castorimorpha Wood, 1955: by James L. Patton Infraorder Geomorpha Thaler, 1966

48

48

Superfamily Geomyoidea Bonaparte, 1845

48

Family Geomyidae Bonaparte, 1845: by Mark S. Hafner Genus Orthogeomys Merriam, 1895

49

49

Family Heteromyidae Gray, 1868: by Robert P. Anderson Genus Heteromys Desmarest, 1817

51

52

Suborder Myomorpha Brants, 1855: by James L. Patton 58 Infraorder Myodonta Schaub, in Grassé and Dekeyser, 1955 Superfamily Muroidea Illiger, 1811

58

58

Family Cricetidae G. Fischer, 1817 58 Subfamily Neotominae Merriam, 1894

60

Genus Isthmomys Hooper and Musser, 1964: by James L. Patton Genus Reithrodontomys Giglioli, 1874: by Elizabeth Arellano Subfamily Sigmodontinae Wagner, 1843: by Guillermo D’Elía and Ulyses F. J. Pardiñas 63 Sigmodontinae incertae sedis: by Guillermo D’Elía 70 Genus Abrawayaomys F. Cunha and Cruz, 1979: by Ulyses F. J. Pardiñas, Pablo Teta, and Guillermo D’Elía 73 Genus Andinomys Thomas, 1902: by Jorge Salazar-Bravo and Jorge Pablo Jayat 75

61

60

x Mammals of South America

Genus Chinchillula Thomas, 1898: by Jorge Salazar-Bravo Genus Delomys Thomas, 1917: by Robert S. Voss

78

79

Genus Euneomys Coues, 1874: by Janet K. Braun and Ulyses F. J. Pardiñas 83 Genus Irenomys Thomas, 1919: by Pablo Teta and Ulyses F. J. Pardiñas 89 Genus Juliomys E. M. González, 2000: by Enrique M. González, João A. de Oliveira, and Pablo Teta 92 Genus Neomicroxus Alvarado-Serrano and D’Elía, 2013: by Diego F. Alvarado-Serrano and Guillermo D’Elía 96 Genus Neotomys Thomas, 1894: by Pablo E. Ortiz and Jorge Pablo Jayat 99 Genus Phaenomys Thomas, 1917: by Alexandre R. Percequillo Genus Punomys Osgood, 1943: by James L. Patton

101

103

Genus Wilfredomys Avila-Pires, 1960: by Enrique M. González, João A. de Oliveira, and Ulyses F. J. Pardiñas 105 Tribe Abrotrichini D’Elía, Pardiñas, Teta, and Patton, 2007: by Guillermo D’Elía, Ulyses F. J. Pardiñas, and Pablo Teta 107 Genus Abrothrix Waterhouse, 1837: by Bruce D. Patterson, Margaret F. Smith, and Pablo Teta 109 Genus Chelemys Thomas, 1903: by Pablo Teta, Ulyses F. J. Pardiñas, and Guillermo D’Elía 127 Genus Geoxus Thomas, 1919: by Pablo Teta, Ulyses F. J. Pardiñas, and Guillermo D’Elía 132 Genus Notiomys Thomas, 1890: by Pablo Teta and Ulyses F. J. Pardiñas 135 Genus Pearsonomys B. D. Patterson, 1992: by Guillermo D’Elía

138

Tribe Akodontini Vorontsov, 1959: by Guillermo D’Elía and Ulyses F. J. Pardiñas 140 Genus Akodon Meyen, 1833: by Ulyses F. J. Pardiñas, Pablo Teta, Diego F. Alvarado-Serrano, Lena Geise, Jorge Pablo Jayat, Pablo E. Ortiz, Pablo R. Gonçalves, and Guillermo D’Elía 144 Genus Bibimys Massoia, 1979: by Ulyses F. J. Pardiñas, Guillermo D’Elía, and Pablo Teta 204 Genus Blarinomys Thomas, 1896: by Pablo Teta and Ulyses F. J. Pardiñas 208 Genus Brucepattersonius Hershkovitz, 1998: by Júlio Fernando Vilela, Pablo R. Gonçalves, and João A. de Oliveira 211 Genus Deltamys Thomas, 1917: by Ulyses F. J. Pardiñas and Pablo Teta 219 Genus Gyldenstolpia Pardiñas, D’Elía, and Teta, 2009: by Ulyses F. J. Pardiñas and Alexandra M. R. Bezerra 222 Genus Juscelinomys Moojen, 1965: by Louise H. Emmons 225 Genus Kunsia Hershkovitz, 1966: by Alexandra M. R. Bezerra

228

Sections and Authors xi

Genus Lenoxus Thomas, 1909: by James L. Patton

231

Genus Necromys Ameghino, 1889: by Ulyses F. J. Pardiñas, Pablo Teta, Pablo E. Ortiz, Jorge Pablo Jayat, and Jorge Salazar-Bravo 232 Genus Oxymycterus Waterhouse, 1837: by João A. de Oliveira and Pablo R. Gonçalves 247 Genus Podoxymys Anthony, 1929: by Ulyses F. J. Pardiñas and Pablo Teta 268 Genus Scapteromys Waterhouse, 1837: by Guillermo D’Elía and Ulyses F. J. Pardiñas 269 Genus Thalpomys Thomas, 1916: by Ulyses F. J. Pardiñas and Pablo Teta 274 Genus Thaptomys Thomas, 1916: by Pablo Teta, Ulyses F. J. Pardiñas, and Guillermo D’Elía 277 Tribe Ichthyomyini Vorontsov, 1959: by Robert S. Voss Genus Anotomys Thomas, 1906

279

281

Genus Chibchanomys Voss, 1988

282

Genus Ichthyomys Thomas, 1893

284

Genus Neusticomys Anthony, 1921

287

Tribe Oryzomyini Vorontsov, 1959: by Marcelo Weksler

291

Genus Aegialomys Weksler, Percequillo, and Voss, 2006: by Alexandre R. Percequillo 293 Genus Amphinectomys Malygin, 1994: by Marcelo Weksler and Michael Valqui 298 Genus Cerradomys Weksler, Percequillo, and Voss, 2006: by Alexandre R. Percequillo 300 Genus Drymoreomys Percequillo, Weksler, and Costa, 2011: by Alexandre R. Percequillo and Marcelo Weksler 308 Genus Eremoryzomys Weksler, Percequillo, and Voss, 2006: by Alexandre R. Percequillo 310 Genus Euryoryzomys Weksler, Percequillo, and Voss, 2006: by Alexandre R. Percequillo 312 Genus Handleyomys Voss, Gómez-Laverde, and Pacheco, 2002: by Marcela Gómez-Laverde, Robert S. Voss, and Víctor Pacheco 321 Genus “Handleyomys”: by Marcelo Weksler

323

Genus Holochilus Brandt, 1835: by Pablo R. Gonçalves, Pablo Teta, and Cibele R. Bonvicino 325 Genus Hylaeamys Weksler, Percequillo, and Voss, 2006: by Alexandre R. Percequillo 335 Genus Lundomys Voss and Carleton, 1993: by Robert S. Voss

346

Genus Melanomys Thomas, 1902: by Marcelo Weksler and Simone Lóss 348 Genus Microakodontomys Hershkovitz, 1993: by Roberta Paresque and J. Delton Hanson 354 Genus Microryzomys Thomas, 1917: by Michael D. Carleton 355

xii Mammals of South America

Genus Mindomys Weksler, Percequillo, and Voss, 2006: by Alexandre R. Percequillo 360 Genus Neacomys Thomas, 1900: by Marcelo Weksler and Cibele R. Bonvicino 361 Genus Nectomys Peters, 1861: by Cibele R. Bonvicino and Marcelo Weksler 369 Genus Nephelomys Weksler, Percequillo, and Voss, 2006: by Alexandre R. Percequillo 377 Genus Nesoryzomys Heller, 1904: by Robert C. Dowler

390

Genus Oecomys Thomas, 1906: by Michael D. Carleton and Guy G. Musser 393 Genus Oligoryzomys Bangs, 1900: by Marcelo Weksler and Cibele R. Bonvicino 417 Genus Oreoryzomys Weksler, Percequillo, and Voss, 2006: by Alexandre R. Percequillo 437 Genus Oryzomys Baird, 1857: by Alexandre R. Percequillo

439

Genus Pseudoryzomys Hershkovitz, 1962: by Robert S. Voss Genus Scolomys Anthony, 1924: by James L. Patton

443

445

Genus Sigmodontomys J. A. Allen, 1897: by Marcelo Weksler

449

Genus Sooretamys Weksler, Percequillo, and Voss, 2006: by Alexandre R. Percequillo 451 Genus Tanyuromys Pine, Timm, and Weksler, 2012: by Marcelo Weksler 454 Genus Transandinomys Weksler, Percequillo, and Voss 2006: by Michael D. Carleton 456 Genus Zygodontomys J. A. Allen, 1897: by Robert S. Voss Tribe Phyllotini Vorontsov, 1959: by Jorge Salazar-Bravo

460

465

Genus Andalgalomys D. F. Williams and Mares, 1978: by Janet K. Braun 469 Genus Auliscomys Osgood, 1915: by Jorge Salazar-Bravo

472

Genus Calassomys Pardiñas, Lessa, Salazar-Bravo, and Câmara, 2014: by Ulyses F. J. Pardiñas and James L. Patton 479 Genus Calomys Waterhouse, 1837: by Jorge Salazar-Bravo

481

Genus Eligmodontia F. Cuvier, 1837: by Cecilia Lanzone, Janet K. Braun, James L. Patton, and Ulyses F. J. Pardiñas 508 Genus Galenomys Thomas, 1916: by Jorge Salazar-Bravo

522

Genus Graomys Thomas, 1916: by Janet K. Braun and James L. Patton 523 Genus Loxodontomys Osgood, 1947: by Pablo Teta, Ulyses F. J. Pardiñas, Jorge Salazar-Bravo, and Guillermo D’Elía 531 Genus Phyllotis Waterhouse, 1837: by Scott J. Steppan and Oswaldo Ramirez 535 Genus Salinomys Braun and Mares, 1995: by Cecilia Lanzone and Janet K. Braun 555

Sections and Authors xiii

Genus Tapecomys S. Anderson and Yates, 2000: by Jorge Salazar-Bravo 556 Tribe Reithrodontini Vorontsov, 1959: by Ulyses F. J. Pardiñas, Carlos A. Galliari, and Pablo Teta 559 Genus Reithrodon Waterhouse, 1837

559

Tribe Sigmodontini Wagner, 1843: by Robert S. Voss Genus Sigmodon Say and Ord, 1825

566

566

Tribe Thomasomyini Steadman and Ray, 1982: by Víctor Pacheco, James L. Patton, and Guillermo D’Elía 571 Genus Aepeomys Thomas, 1898: by Víctor Pacheco

574

Genus Chilomys Thomas, 1897: by Víctor Pacheco Genus Rhagomys Thomas, 1886: by Lucía Luna

577

580

Genus Rhipidomys Tschudi, 1845: by Christopher J. Tribe Genus Thomasomys Coues, 1884: by Víctor Pacheco

583

617

Tribe Wiedomyini Reig, 1980: by Cibele R. Bonvicino 682 Genus Wiedomys Hershkovitz, 1959

683

Subfamily Tylomyinae Reig, 1984: by Sergio Ticul Álvarez-Castañeda Genus Tylomys Peters, 1866

685

686

Suborder Hystricomorpha Brandt, 1855: by James L. Patton

688

Infraorder Hystricognathi Tullberg, 1899 688 Superfamily Cavioidea G. Fischer, 1817

690

Family Caviidae G. Fischer, 1817: by Jonathan L. Dunnum

690

Subfamily Caviinae G. Fischer, 1817 691 Genus Cavia Pallas, 1766

691

Genus Galea Meyen, 1833

704

Genus Microcavia H. Gervais and Ameghino, 1880 Subfamily Dolichotinae Pocock, 1922

716

Genus Dolichotis Desmarest, 1819 Subfamily Hydrochoerinae Gray, 1825

716 720

Genus Hydrochoerus Brisson, 1762 Genus Kerodon F. Cuvier, 1823

711

720

724

Family Cuniculidae G. S. Miller and Gidley, 1918: by James L. Patton 726 Genus Cuniculus Brisson, 1762

727

Family Dasyproctidae Bonaparte, 1838: by James L. Patton and Louise H. Emmons 733 Genus Dasyprocta Illiger, 1811 Genus Myoprocta Thomas, 1903

735 756

Superfamily Chinchilloidea Bennett, 1833: by Angel E. Spotorno and James L. Patton 762 Family Chinchillidae Bennett, 1833 762 Subfamily Chinchillinae Bennett, 1833 764

xiv Mammals of South America

Genus Chinchilla Bennett, 1829 764 Genus Lagidium Meyen, 1833

770

Subfamily Lagostominae Wiegmann, 1835 779 Genus Lagostomus Brookes, 1829

779

Family Dinomyidae Alston, 1876: by James L. Patton Genus Dinomys Peters, 1873

783

784

Superfamily Erethizontoidea Bonaparte, 1845: by Robert S. Voss Family Erethizontidae Bonaparte, 1845

786

Genus Chaetomys Gray, 1843

789

Genus Coendou Lacépède, 1799

786

791

Superfamily Octodontoidea Waterhouse, 1839: by James L. Patton

805

Family Abrocomidae G. S. Miller and Gidley, 1918: by James L. Patton and Louise H. Emmons 805 Genus Abrocoma Waterhouse, 1837 Genus Cuscomys Emmons, 1999

806

815

Family Ctenomyidae Lesson, 1842: by Claudio J. Bidau

818

Genus Ctenomys Blainville, 1826 819 Family Echimyidae Gray, 1825: by Louise H. Emmons, Yuri L. R. Leite, and James L. Patton 877 Subfamily Dactylomyinae Tate, 1935: by Louise H. Emmons, James L. Patton, and Yuri L. R. Leite 880 Genus Dactylomys I. Geoffroy St.-Hilaire, 1838 881 Genus Kannabateomys Jentink, 1891 Genus Olallamys Emmons, 1988

885

886

Subfamily Echimyinae Gray, 1825: by Louise H. Emmons, Yuri L. R. Leite, and James L. Patton 888 Genus Callistomys Emmons and Vucetich, 1998: by Louise H. Emmons and Yuri L. R. Leite 889 Genus Diplomys Thomas, 1916: by Louise H. Emmons and James L. Patton 890 Genus Echimys F. Cuvier, 1809: by Louise H. Emmons, Yuri L. R. Leite, and James L. Patton 893 Genus Isothrix Wagner, 1845: by Louise H. Emmons and James L. Patton 898 Genus Makalata Husson, 1978: by Louise H. Emmons and James L. Patton 905 Genus Pattonomys Emmons, 2005: by Louise H. Emmons and James L. Patton 910 Genus Phyllomys Lund, 1839: by Yuri L. R. Leite and Ana Carolina Loss 915 Genus Santamartamys Emmons, 2005: by Louise H. Emmons and James L. Patton 928

Sections and Authors xv

Genus Toromys Iack-Ximenes, de Vivo, and Percequillo, 2005: by Louise H. Emmons, Yuri L. R. Leite, and James L. Patton 929 Subfamily Eumysopinae Rusconi, 1935: by James L. Patton and Louise H. Emmons 931 Genus Carterodon Waterhouse, 1848: by Alexandra M. R. Bezerra and Cibele R. Bonvicino 933 Genus Clyomys Thomas, 1916: by Alexandra M. R. Bezerra and Cibele R. Bonvicino 935 Genus Euryzygomatomys Goeldi, 1901: by Cibele R. Bonvicino and Alexandra M. R. Bezerra 937 Genus Hoplomys J. A. Allen, 1908: by James L. Patton and Louise H. Emmons 940 Genus Lonchothrix Thomas, 1920: by James L. Patton

942

Genus Mesomys Wagner, 1845: by James L. Patton and Louise H. Emmons 943 Genus Proechimys J. A. Allen, 1899: by James L. Patton and Rafael N. Leite 950 Genus Thrichomys E.-L. Trouessart, 1880: by Leila M. Pessôa, William C. Tavares, Antonio C. A. Neves, and André L. G. da Silva 989 Genus Trinomys Thomas, 1921: by Leila M. Pessôa, William C. Tavares, João A. de Oliveira, and James L. Patton 999 Subfamily Myocastorinae Ameghino, 1902: by James L. Patton Genus Myocastor Kerr, 1792

1019

1020

Family Octodontidae Waterhouse, 1839: by Diego H. Verzi, M. Mónica Díaz, and Rubén M. Barquez 1023 Genus Aconaemys Ameghino, 1891: by Diego H. Verzi, M. Mónica Díaz, and Rubén M. Barquez 1025 Genus Octodon Bennett, 1832: by M. Mónica Díaz, Rubén M. Barquez, and Diego H. Verzi 1029 Genus Octodontomys Palmer, 1903: by Diego H. Verzi, M. Mónica Díaz, and Rubén M. Barquez 1035 Genus Octomys Thomas, 1920: by Diego H. Verzi, M. Mónica Díaz, and Rubén M. Barquez 1038 Genus Spalacopus Wagler, 1832: by Diego H. Verzi, M. Mónica Díaz, and Rubén M. Barquez 1039 Genus Tympanoctomys Yepes, 1942: by M. Mónica Díaz, Rubén M. Barquez, and Diego H. Verzi 1043

Introduction

The science of Natural History is of so unbounded an extent, that perhaps I may be allowed, comparatively speaking, to say, that scarcely a day passes without an opportunity being afforded to zoologists of bringing to light unknown instances of its latent treasures. joshua brookes (1829:95), British anatomist and naturalist, in reference to his description of the Plains Viscacha, Lagostomus.

I

n his introduction to the first volume in this series, Alfred L. Gardner (2008) detailed the history of the intention that he, Sydney Anderson, and James L. Patton had to produce an updated reference to the mammals of South America, one that would provide a thorough review of knowledge about mammals dating from the mid1700s through today. The goal was to document the rich nomenclatural history for all taxa (families, genera, and species); describe morphological and other traits that aid in identification, both in the field and museum; delimit species’ distributions by listing and mapping marginal records confirmed by voucher specimens and the published literature; and summarize available observations on natural history. Gardner’s volume 1, which covered marsupials, xenarthrans, shrews, and bats, set an exemplary standard of scholarship for this effort. This, the second volume in the series, is restricted to the single order Rodentia, the most diverse of all mammalian groups worldwide, accounting for more than 42% of species and 39% of genera (Wilson and Reeder 2005). All Recent and extant taxa are included; those known only from the fossil record or now extinct are not (e.g., Megaoryzomys from the Galapagos Islands, Ecuador; Noronhomys, from Ilha Fernando de Noronha, Brazil; Dusimys, from Curaçao, Caribbean Netherlands), nor are those introduced to the continent (such as beavers, Castor canadensis, and muskrats, Ondatra zibethicus, from North America, or the Old World rats [Rattus spp.] and mice [Mus spp.], family Muridae). The first substantive review of South American rodents was Angel Cabrera’s seminal Catálogo, the rodent part of which was published in 1961 after his death, thanks to the

efforts of Jorge Crespo. In the intervening 50 years, the recognized diversity of South American rodents at both the genus and species levels has increased by approximately 160%. Perhaps not surprisingly, many of the taxa at all categorical levels treated by Cabrera have also been reordered in fundamentally different ways. To illustrate, we use taxon diversity trends for the largest group of South American mammals: the rats and mice of the cricetid subfamily Sigmodontinae, which encompass some 62% of the generic diversity and 56% of the species diversity of rodents recognized in the accounts presented in this volume. Only about 34% of the genera and 39% of the South American rodent species we recognize today owe their discovery and description to scholars of the nineteenth century. The first two decades of the twentieth century saw an increase of another 25% to the totals of both genus- and speciesgroup taxa, followed by a 50-year rather quiescent period (from 1921 until 1970) which saw only a modest growth in overall diversity at both taxonomic levels of less than 2% per decade. Tracing these trend lines up to the time when our project was initiated (in the 1970s), one might have surmised that most of the known taxonomic diversity of sigmodontines on the continent had already been discovered and described. Such a conclusion, however, could not have been further from reality. Indeed, in the last 30 years, the generic diversity in South American sigmodontines has increased by 27%, with 24 new genera added, and species diversity by 24%, with 56 new species described. And, in the few months since this book went into production, additional species descriptions have appeared in the literature (e.g., Gonçalves and Oliveira 2014). Fully one quarter of

xviii Mammals of South America

all genera and species of this group of rodents that are recognized today have been described in the terminal three of the 25 decades since Linnaeus (1758) established the earliest currently accepted technical names, and the exploration of the biota of South America began (see the historical reviews of Neotropical mammalogy given by Hershkovitz [1987b] and the Introduction in A. L. Gardner [2008]). The remarkable rate of recent discovery and description of South American sigmodontines is mirrored by most other rodent groups (as well as for mammals in general worldwide [e.g., Reeder et al. 2007] or those limited to the Neotropical Realm [e.g., B. D. Patterson 2000, 2001]). This increased rate owes its origin to many factors, perhaps the most important of which has been the establishment of exceptionally strong academic programs in systematic and evolutionary sciences, including mammalogy, in most countries on the continent, a development that has accelerated in the past two decades. Naturally coupled to expansion of academic programs has been the development of professional organizations wherein annual or biannual meetings bring together scholars of all academic stages to share knowledge and inspire further research. These two critical components in the development of the professional field of mammalogy have been directly tied to other factors underlying the increase in our knowledge of South America mammals, including but not limited to (1) substantially increased field research, especially into the remote areas of this ecologically diverse continent; (2) an increase in the diversity of survey methods for securing samples (particularly owl pellet analyses in Argentina and pitfall trapping in Brazil); (3) computer-driven analytical methodologies to evaluate characters, compare morphologies in multivariate space, and construct the trees upon which phylogenetic systematics depend; (4) the explosion of molecular-based methodologies, particularly DNA sequencing, which can be applied to historic specimens in museum collections as well as recently collected materials; (5) the requisite shift in systematic philosophy to one based on phylogenetic principles, with taxon definition appropriately based on relationships determined by shared-derived characters rather than overall similarity, and (6) the recognition, through both policy implementation and financial support, by governmental and nongovernmental agencies of the importance of basic systematic research as a key component of biodiversity assessment, which in turn underlies sound environmental policy and establishes conservation priorities. We intend that this volume and the others in our series will identify gaps in our current knowledge and encourage additional field, museum, and laboratory research to fill those gaps. As noted by A. L. Gardner (2008) in his introduction to volume 1, we selected Cabrera’s (1958–1961) catalog as the primary point of departure because of its strong empha-

sis on taxonomy and nomenclature. Our area of coverage includes nuclear South America as well as the continental islands of Trinidad and Tobago and the Caribbean Netherlands off the Venezuelan coast (Map 1). Along with extensive but not exhaustive synonymies, the accounts in this volume include identification keys and descriptions of each order, family, genus, and species. Each species account also includes comments on distribution; lists of selected localities that are plotted on maps; comments on subspecies and, in a few cases only, lists of subspecies and their synonyms and distributions; summaries of natural history information; and discussions of issues related to type localities, taxonomic interpretations, matters of nomenclatural importance, and karyotype, if known. As with volume 1, this one contains its own Gazetteer and Literature Cited sections, with the latter including all citations in the text as well as those cited in the references relating to dates of publication. Also, as was the case for volume 1, the scope of individual contributions and thus authorship assignments is uneven. The authority and responsibility for a given contribution continue until a new author line is encountered; for example, some authors were responsible for all entries in a single family, while multiple individuals singly or in combination authored the accounts in other families. The Acronyms and Abbreviations, Literature Cited, and Gazetteer sections were compiled from information provided by each account author. With a few exceptions, the taxonomy of higher categories follows McKenna and Bell (1997), and the sequence of family, genus, and species group taxa is based on the third edition of Mammal Species of the World, edited by Wilson and Reeder (2005). Documentation by reference to more recent literature is provided for deviations from either of these two general references, or is noted when based on the personal views of the contributing authors from their own, often unpublished, research. A. L. Gardner (2008:xvi) provided the guidelines followed herein for the synonymies, including citation of the original description and any unique name combination subsequently applied by any author for the first time to that taxon. Interested persons should see his written synopsis for details. We, as did Gardner (see his dedication in volume 1), relied heavily on the “scrapbooks” compiled by Remington Kellogg, the former curator of mammals and director of the U.S. National Museum, in constructing synonymies. Fortunately, much of the early eighteenth and nineteenth century literature is now available in digital form from the Biodiversity Heritage Library (http://www.biodiversitylibrary.org/), a truly remarkable resource. Finally, J. R. Ellerman is credited in this volume with the name combinations cited from his The Families and Genera of Living Rodents; however, if a name came from one of the lists and was available before 1937, in many cases either R. W. Hayman or G. W. C. Holt

Introduction xix

compiled the individual list on which those name combinations are based. This volume deviates from volume 1 in limited but important ways. First, we asked account authors to provide a description of each species beyond those characters that comprise the keys. Most rodents have not been monographed in recent decades or ever, and many species are known only from their initial description. Moreover, an increasing number of species have been defined in the past few decades by karyotypic data (diploid number and arm number of both autosomes and sex chromosomes) and/or DNA sequences. As important as these characters are, neither the karyotype nor sequence are available for the vast majority of specimens in museum collections nor for live animals captured during field studies. As a consequence, reliance on keys alone for identification in the field or museum can be problematic. We thus believe that descriptions of external and/or craniodental characters of each species is an important addition to this volume, one enhanced by multiauthored accounts for large, geographically widespread, and particularly vexing taxa, such as the sigmodontine genus Akodon or the echimyid genus Proechimys. Where possible, the authors have provided the standard external measurements of head and body length, tail length, hindfoot length, ear length, and/or mass, taken either from the literature or from labels of museum vouchers they examined as well as characters of the pelage (color, color pattern, details of hair types), appendages, and both soft and craniodental anatomy. However, these descriptions vary greatly in depth of detail owing to both the level of knowledge of individual and geographic variation available and an author’s direct familiarity with specimens in museum collections. In some cases, our knowledge of a particular species is so poor that little beyond the original description is available. Second, we have allowed authors liberty in delineating locality records beyond just those circumscribing the edge of a species’ range. Many species of rodents are so poorly known that we believed it valuable to list and map virtually all known records in those cases. However, we caution users of metadata, such as marginal locality maps in global analyses of biodiversity, not to confuse a shaded range bounding locality records with actual occurrence throughout. Many species of rodents are habitat specialists and are certainly not evenly spread across the geographic landscape indicated by that shaded range. Shading surrounding the mapped localities is provided primarily to highlight those locality placements and not to identify actual geographic boundaries, although the maps are drawn with as much precision as possible given their scale. The ranges mapped also include locality records assembled over many decades; as a result, they do not accommodate any range shift or fragmentation that may have resulted from anthropogenic

landscape modification or other factors in recent decades. Nor should these range maps be viewed as static into even the near future, as continuing fieldwork in remote areas will invariably expand those ranges now known and global climate change continues to impact both distribution and presence (e.g., Malcolm et al. 2006; Urban et al. 2012). Finally, because the shapes of species’ ranges are diverse, often linear or geographically restricted, we have not followed the uniform clockwise listing of localities, starting with N on a compass, employed in volume 1. Rather than explaining deviations from this scheme in so many individual cases, localities are simply listed alphabetically by country, department/ province/state, and specific locality in all accounts. Virtually all locality records are based on vouchered specimen records where the identification could be verified, either literature records from revisionary accounts or the actual examination of a museum voucher. We note, however, that the advent of widespread camera traps and archives of verifiable digital photos—which have been used so successfully to document new records for large mammals—are beginning to provide insight even into smaller and often very secretive rodents (e.g., Blake et al. 2010). Although photos are unacceptable replacements for vouchered specimens in systematic research, a few accounts have included localities derived from unambiguous recent photographs of rare taxa with few records. Inset maps depicting the range of the genus are also provided in the maps for each species. Third, there is also substantial unevenness in coverage of natural history and other information on population biology, ecology, reproduction, and other attributes across accounts. Some of this simply results from the actual quantity of information available, as so many species of rodents have never been studied in their natural habitats, but some also stems from whether existing or relatively recent synopses have already been published (e.g., the Mammalian Species accounts produced by the American Society of Mammalogists, http://www.mammalsociety.org/publications /mammalian-species). Finally, the construction and use of vernacular names is a vexing problem in mammalogy, as there is no standard set of rules that apply to their formation (but see Duckworth and Pine 2003). This issue is exacerbated by the common application of English names (as given, for example, in Wilson and Cole [2000] for mammal species worldwide) rather than use of the larger number of common terms applied to those species by South American biologists, the lay public in each country, and/or indigenous groups. The common names employed herein are those of the account authors and may reflect either or both English and local terms or equivalents. Many of these follow Wilson and Cole (2000) and/or those of account authors in Wilson and Reeder (2005).

Map 1 Political map of the South American continent including the Caribbean Netherlands, Trinidad and Tobago, and the Galapagos Islands.

Acronyms and Abbreviations

The following acronyms and abbreviations are used in the text to identify collectors and museum collections. AMNH: American Museum of Natural History, New York, New York, United States AL: Alfredo Langguth field numbers AN: Andrea Nunes field numbers APC: Ana Paula Carmignotto field numbers ARG: Field numbers of uncataloged specimens in the Sam Noble Oklahoma Museum of Natural History, Norman, Oklahoma, United States ARP: Alexandre R. Percequillo field numbers BM: The Natural History Museum, London (NHM); formerly the British Museum (Natural History), London, United Kingdom CAS: California Academy of Sciences, San Francisco, California, United States CBF: Colección Boliviana de Fauna, Instituto de Ecología y Museo de Historia Natural, La Paz, Bolivia CEM: Colección Elio Massoia, acquired by the Fundación de Histora Natural Félix de Azara, Buenos Aires, Argentina CIT: Laboratório de Citogenética de Vertebrados, Universidade de São Paulo, São Paulo, Brazil CLH: Christine L. Hice field numbers CM: Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, United States CML: Colección Mamíferos Lillo, Universidad Nacional de Tucumán, Tucumán, Argentina CML-PIDBA: Colección Mamíferos Lillo, Programa de Investigaciones de Biodiversidad Argentina, Universidad Nacional de Tucumán, Tucumán, Argentina CMUFL: Mammal Collection, Universidade Federal de Lavras, Minas Gerais, Brazil CNP: Colección de Mamíferos, Centro Nacional Patagónico, Puerto Madryn, Chubut, Argentina CNP-E: Colección de Material de Egagrópilas y Afines “Elio Massoia,” Centro Nacional Patagónico, Puerto Madryn, Chubut, Argentina CONN: University of Connecticut, Storrs, Connecticut, United States CRB: Cibele R. Bonvicino field numbers CUVLA: Colección de Vertebrados de la Universidad de Los Andes, Mérida, Venezuela EBRG: Museo de la Estación Biológica de Rancho Grande, Maracay, Venezuela EPN: Escuela Politécnica Nacional, Quito, Ecuador FAG: Valéria Fagundes field numbers FLMNH: University of Florida Museum of Natural History, Gainesville, Florida, United States FMNH: Field Museum, Chicago, Illinois, United States GD: Guillermo D’Elía field numbers HGB: Helena de Godoy Bergallo field numbers HTC: Departamento de Microbiología, Universidad del Valle, Cali, Colombia IADIZA: Colección de Mastozoología del Instituto Argentino de Investigaciones de Zonas Áridas, Mendoza, Argentina IAvH: Instituto Alexander von Humboldt, Cartegena, Colombia

xxii Mammals of South America

ICN: Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá, Colombia INDERENA: Instituto Nacional de los Recursos Naturales Renovables y del Ambiente, Bogotá, Colombia INEVH: Instituto Nacional de Enfermedades Virales Humanas, Pergamino, Buenos Aires, Argentina INPA: Instituto Nacional de Pesquisas da Amazônia, Amazonas, Manaus, Brazil JAO: João A. de Oliveira field numbers JPB: Jean-Phillipe Boubi field numbers; voucher specimens in INPA collection. JPJ: Jorge Pablo Jayat field numbers JRM: Jay R. Malcolm field numbers KU: Natural History Museum, University of Kansas, Lawrence, Kansas, United States LACM: Los Angeles County Museum of Natural History, Los Angeles, California, United States LAMAQ: Laboratório de Mamíferos Aquáticos, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil LBCE: Laboratório de Biologia e Controle da Esquistossomose, Fundação Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil LC (and LPC): Leonora Pires Costa field numbers LCM: Laboratorio de Genómica Evolutiva, Facultad de Medicina, Universidad de Chile, Santiago, Chile LF: Luiz Flamarion field numbers LGA: Laboratório de Genética Animal, Departamento de Ciências Biológicas, Universidade Federal do Espírito Santo, Vitória, Espírito Santo, Brazil LHE: Louise H. Emmons field numbers LMT: Liliani Marilia Tiepolo field numbers LPC (and LC): Leonora Pires Costa field numbers LSUMZ: Louisiana State University Museum of Zoology, Baton Rouge, Louisiana, United States LTU: Proyecto Localidades Tipo—CONICET, Argentina (vouchers to be deposited in CNP) LV: Laboratório de Vertebrados, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil MACN: Colección Nacional de Mastozoología, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia,” Buenos Aires, Argentina MAM: Meika A. Mustrangi field numbers MARNR: Ministerio del Ambiente y de los Recursos Naturales Renovables, Maracay, Venezuela MBUCV: Museo de Biología, Universidad Central de Venezuela, Caracas, Venezuela MCZ: Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, United States MECN: Museo Ecuatoriano de Ciencias Naturales, Quito, Ecuador MF: Mônica Fonseca field numbers MFA-ZV-M: Museo Provincial de Ciencias Naturales “Florentino Ameghino,” Santa Fe, Argentina MHNCI: Museu de História Natural Capão de Imbuia, Curitiba, Paraná, Brazil MHNG: Ville de Genève Muséum d’Histoire Naturelle, Genève, Switzerland MHNLS: Museo de Historia Natural La Salle, Caracas, Venezuela MHNSM: Museo de Historia Natural, Universidad de San Marcos (formerly Museo de Historia Natural Javier Prado), Lima, Peru MHNUC: Museo de Historia Natural, Universidad de Caldas, Caldas, Colombia MIC: María Inés Carma field numbers

Acronyms and Abbreviations xxiii

MLP: Museo de La Plata, La Plata, Argentina MLS: Mel L. Schamberger field numbers MMD: M. Mónica Díaz field numbers MNHM: Muséum d’Histoire Naturelle, Neuchâtel, Switzerland MNHNC: Museo Nacional de Historia Natural de Chile, Santiago, Chile MNK: Museo de Historia Natural Noel Kempff Mercado, Santa Cruz de la Sierra, Bolivia MNRJ: Museu Nacional, Rio de Janeiro, Brazil MPEG: Museu Paraense Emilio Goeldi, Belém, Pará, Brazil MSB: Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, United States MSU: Michigan State University, East Lansing, Michigan, United States MUSA: Museo de Historia Natural, Universidad Nacional de San Agustín, Arequipa, Peru MUSM: Museo de Historia Natural, Universidad Mayor de San Marcos, Lima, Peru MV: Michael Valqui field numbers MVZ: Museum of Vertebrate Zoology, University of California, Berkeley, California, United States MW: Marcelo Weksler field numbers MZUFV: Museu de Zoologia João Moojen, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil MZUSP: Museu de Zoologia, Universidade de São Paulo, São Paulo, Brazil NMW: Naturhistorisches Museum Wien, Vienna, Austria NRM: Naturhistoriska Riksmuseet, Stockholm, Sweden NUPEM: Núcleo de Pesquisas Ecológicas de Macaé, Universidade Federal do Rio de Janeiro, Brazil OMNH: Sam Noble Oklahoma Museum of Natural History, University of Oklahoma, Norman, Oklahoma, United States P: Yves Sbalqueiro laboratory numbers, Universidade Federal do Paraná, Curitiba, Paraná, Brazil PEO-e: Pablo E. Ortiz field numbers PMC: field numbers, specimens housed in Museu de História Natural Capão da Imbuia, Curitiba, Paraná, Brazil PPA: Proyecto Patagonia Agencia—Argentina (voucher specimens to be deposited in CNP) PRG: Pablo R. Gonçalves field numbers PVL: Colección de Paleontología de Vertebrados del Instituto Miguel Lillo, Universidad Nacional de Tucumán, Tucumán Province, Argentina QCAZ: Museo de Zoología, Pontifica Universidad Católica del Ecuador, Quito, Ecuador RDS: Richard D. Sage field numbers RMNH: Rijksmuseum van Natuurlijke Historie, Leiden, the Netherlands RNHMS: Royal Natural History Museum, Stockholm, Sweden RNP: Natalie Goodall collection, Estancia Harberton, Museo Acatashún, Tierra del Fuego, Argentina ROM: Royal Ontario Museum, Toronto, Ontario, Canada SDM: Sterling D. Miller field numbers SMF: Naturmuseum Senckenburg, Frankfurt, Germany T: Laboratoire de Paléontologie, Paléobiologie et Phylogénie, Université Montpellier, Montpellier, France TTU: The Museum, Texas Tech University, Lubbock, Texas, United States UACH: (formerly IIEUACH), Facultad de Ciencìas, Universidad Austral de Chile, Valdivia, Chile UFC: Universidade Federal do Ceará, Fortaleza, Ceará, Brazil UFMG: Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil UFPB: Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil

xxiv Mammals of South America

UFPE: Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil UFRGS: Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil UFRJ: Universidade Nacional do Rio de Janeiro, Rio de Janeiro, Brazil UFROM: Fundação Universidade de Rondônia, Porto Velho, Rondônia, Brazil UFSC: Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil UMMZ: University of Michigan Museum of Zoology, Ann Arbor, Michigan, United States UNB: Coleção de Mamíferos, Departamento de Zoologia, Universidade Nacional de Brasília, Brasília, Brazil UNRC: Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina UP: Ulyses F. J. Pardiñas field numbers USNM: National Museum of Natural History (formerly the United States National Museum), Washington, D.C., United States UV: Departamento de Biología, Universidad del Valle, Cali, Colombia UWBM: University of Washington Burke Museum, Seattle, Washington, United States VA: Vale das Antas project field numbers VPF: Valéria Pena-Firme field numbers VPT: Víctor Pacheco field numbers YPM: Yale Peabody Museum, Yale University, New Haven, Connecticut, United States ZINRAS: Zoological Institute, Russian Academy of Sciences, St. Petersburg, Russia ZMB: Museum für Naturkunde der Humboldt-Universität zu Berlin, Berlin, Germany ZMFK: Zoologisches Forschungsinstitut und Museum Alexander Koenig, Bonn, Germany ZMUC (also ZMK): Zoological Museum of the University, Copenhagen, Denmark ZMUM: Zoological Museum, University of Montana, Missoula, Montana, United States The following abbreviations are used to identify statistical or other terms. bp: base pairs (of DNA sequences) FN: fundamental number ft: feet g: grams ha: hectares HPD: highest posterior density IRBP: interphotoreceptor retinoid-binding protein kg: kilograms kya: thousands of years ago m: meters mm: millimeters mtDNA: mitochondrial DNA mya: millions of years ago nucDNA: nuclear DNA pg: picograms s.d.: standard deviation s.s.: sensu stricto ybp: years before present

Acknowledgments

N

o treatise such as this can be completed without the input of many individuals, and not just those who authored the accounts herein. With apologies beforehand for excluding some who deserve mention, we single out several individuals for special recognition for aiding us in so many substantive ways. Specifically, Louise H. Emmons read through most of the completed manuscript in its several iterations, freely offering her vast knowledge, correcting parts, and updating others. Mere mention of her name here does not do justice to her insights and overall contributions. Michael D. Carleton offered expert advice on details of synonymy construction and reviewed large parts of the manuscript with the eye of an editor; his efforts are deeply appreciated. Carola Cañón (Chile), Hugo Mantilla-Meluck and Héctor Ramírez (Colombia), and Julio Torres (Paraguay) reviewed and corrected locality designations in the accounts and gazetteer; we are grateful to each for this very important contribution. Susan Abrams and Christie Henry, both senior editors at the University of Chicago Press over the gestation period of our project, deserve special recognition for their unflagging interest and incredible patience while encouraging us to complete this project, as do Abby Collier, Kyle Adam Wagner, and Amy Krynak, also at the University of Chicago Press, for help with the final stages of manuscript production. Finally, we are especially grateful to Ronald H. Pine and Robert S. Voss for their careful, critical reviews of the entire manuscript; neither should be held responsible for the final product, but their nomenclatural expertise and especially their personal field and museum experience with many taxa have improved virtually every section.

Jim Patton acknowledges Alfred L. Gardner, whose editorship of volume 1 in this series set a standard of scholarship we can only hope to achieve. Gardner not only initiated Patton’s career in mammalogy in the early stages of their respective graduate studies and introduced him to South America and its spectacular mammalian fauna (see Patton 2005c), but he also answered many queries quickly and concisely. Michael Carleton, Judith Chupasco, Robert Fisher, David Flores, Mark Hafner, Yuri Leite, João de Oliveira, Víctor Pacheco, Bruce Patterson, Mario de Vivo, and Robert S. Voss provided Patton with either direct access to the collections under their control, examined critical specimens for him, or sent him crucial specimen records or literature for inclusion in this volume; he thanks each for their professionalism and friendship. James Hanken at the Museum of Comparative Zoology of Harvard University and Mary Sears, librarian of the Mayr Collection of the Museum of Comparative Zoology’s library, kindly provided a digital scan of an important historical document. Ulyses Pardiñas acknowledges the economic support from Agencia Nacional de Promoción Científica y Tecnológica (PICT 2008-547), and Consejo Nacional de Investigaciones Científicas y Técnicas (PIPs 6179 and 2001-164). He is especially grateful to Pablo Teta and Carlos Galliari for many years of collaborative work in the field and museum on sigmodontines, and to Erika Cuéllar, whose love and unconditional support rescued him from unhappiness, and his son Joaquín, a tireless friend in the field, both of whom changed his life. Guillermo D’Elía is grateful to those colleagues, teachers, and students who shared and discussed their views on

xxvi Mammals of South America

the evolutionary history and systematics of South American rodents, and gives special thanks to everyone who made this project possible. Louise Emmons wishes to thank João Oliveira for providing a photograph of Oxymycterus talpinus, essential for her review of Juscelinomys. Claudio Bidau acknowledges Julio R. Contreras, Patricia Mirol, Jeremy B. Searle, Chris G. Faulkes, Enrique Lessa, Andrés Parada, Guillermo D’Elía, Ricardo Ojeda, Thales de Freitas, Yolanda Davies, Alonso Medina, Diego Verzi, Mabel D. Giménez, Claudia Ipucha, Pablo Suárez, Cecilia Lanzone, Joyce Bernardo, Pavel Borodin, Dardo Marti, Juan Luis Santos, and a large number of students during his years at the Universidad Nacional de Misiones, Universidade Estadual de Rio de Janeiro, and Fundação Oswaldo Cruz. He gives his special thanks to Valeria Xinena Rodríguez for her help and endless love. Scott Steppan and Oswaldo Ramirez thank Jim Patton for substantial contributions to their Phyllotis account, and

they acknowledge the financial support of National Science Foundation grants DEB-0841447 and DEB-0108422. Alexandra Bezerra thanks Manoel Santos-Filho and Maria Nazareth F. da Silva for discussions and clarifications regarding the correct identification of a specimen allocated to Euryzygomatomys spinosus in previous studies; Ana Paula Carmignotto and Roberta Paresque for sharing their unpublished karyotypic data for Carterodon sulcidens; Ulyses F. J. Pardiñas for providing key bibliographic references; and the CNPq (150599/2008-0) for postdoctoral support and Conservation International for grants to visit critical museum collections. Mario de Vivo wishes to thank Dr. Robert S. Voss and the Mammal Department of the American Museum of Natural History in New York for postdoctoral advisorship and funding, respectively. He and Ana Paula Carmignotto would also like to extend their heartfelt thanks to Jim Patton “for everything, and more.”

Taxonomic Accounts

Class Mammalia Linnaeus, 1758 Order Rodentia Bowdich, 1821 n e w wo r l d ro d e n t s

3′. Infraorbital foramen positioned on side of rostrum anterior to zygomatic plate; cheek teeth number four, either hypsodont, cylindrical, and planar (Geomyidae) or brachydont, bunodont, and cuspidate (Heteromyidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Castorimorpha

James L. Patton KEY TO THE SUBORDERS OF RECENT SOUTH AMERICAN RODENTS:

1. Well-defined zygomatic plate anterior to zygomatic arch present; infraorbital foramen small and either piercing zygomatic plate or positioned on side of rostrum anterior to zygomatic plate; lower jaw sciurognathous, with origin of angular process directly ventral to sheath of lower incisor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1′. No zygomatic plate; infraorbital foramen greatly enlarged; lower jaw hystricognathous, with the root of the angular process deflected lateral to sheath of lower incisor. . . . . . . . . . . . . . . . . . . . . . . . . Hystricomorpha 2. Zygomatic plate oriented anteriorly; infraorbital foramen small, transmitting only nerves and blood vessels; maxillary teeth number four or five . . . . . . . . . . . . . . 3 2′. Zygomatic plate oriented more laterally; infraorbital foramen enlarged, narrow, but typically expanded dorsally, transmitting medial masseter muscle in addition to nerves and blood vessels; maxillary teeth number three or fewer . . . . . . . . . . . . . . . . . . . . . . . . . . Myomorpha 3. Infraorbital foramen pierces zygomatic plate; cheek teeth number four or five, with molars brachydont, bunodont, with three transversely oriented crests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sciuromorpha

Suborder Sciuromorpha Brandt, 1855 Infraorder Sciurida Carus, 1868 Family Sciuridae G. Fischer, 1817 Mario de Vivo and Ana Paula Carmignotto

Squirrels are ubiquitous inhabitants of all forest biomes throughout South America except the temperate forests, with all species adapted for life in the canopy, even though some forage on the ground. Specialized adaptations for climbing include elongate bodies, forefeet with four long toes with claws, hindfeet with five long toes with claws, large plantar pads on all feet, broad heads, large eyes, short ears, generally soft fur, long bushy tails, and elongated legs. The ankle joint is flexible, allowing the hindfoot to rotate sufficiently for headfirst descent of vertical tree trunks. Most species have enlarged, long incisors accompanied by correspondingly large jaw muscles, which enable them to gnaw through the hardest nuts. Some species specialize on hardshelled seeds of tropical trees such as palms, but most are more omnivorous, feeding on a range of food types such as nuts, fruits, insects, fungi, and sometimes leaves, flowers, and bark (Emmons and Feer 1997). All South American squirrels are diurnal; as such, individuals can be easily

2 Mammals of South America

seen and often readily heard as they move about or gnaw on large nuts. They build round, ball-like nests of leaves and twigs in vine tangles or on tree limbs, or they nest in tree holes. Capuchin monkeys, Cebus [now Sapajus] apella (Galetti 1990), and both medium and large felids (Emmons 1978b) are known predators of South American squirrels. Body size can be arranged into three broadly separable classes, with one pygmy squirrel (maximum head and body length about 115 mm, tail length 120 mm, and mass 45 g), many dwarf squirrels of intermediate size (head and body length 160–300 mm, tail length 150–280 mm, and mass 130–520 g), and a few large squirrels (head and body length 240–300 mm, tail length 240–340 mm, and mass 570– 900 g; Thorington et al. 2012). The skull retains the same generalized shape in all South American species: braincase domed and rounded; interorbital region wide; postorbital processes on both frontals and jugals prominent; rostrum relatively short but broad; zygomatic arches deep and stout; auditory bullae evenly rounded and relatively large but rarely excessively inflated, and divided by several transverse bony septa; incisive foramina short; cheek teeth brachydont and bunodont, with prominent cusps and transverse crests usually on molars; and dental formula I 1/1, C 0/0, PM 2–1/1, and M 3/3 = 20–22, with PM3 reduced or absent. Angular processes of the mandible are slightly inflected. A baculum is present in the phallus of males of all species. Peterka (1937) and Bryant (1945), among others, have provided detailed descriptions of sciurid morphology. Only four taxa have been karyotyped: Guerlinguetus brasiliensis brasiliensis (Lima and Langguth 2002, 2n = 40, FN = 76), G. b. ingrami (Fagundes et al. 2003, 2n = 40, FN = 74), Hadrosciurus spadiceus (Lima and Langguth 2002, 2n = 40, FN = 76), and Notosciurus granatensis (Nadler and Hoffmann 1970, 2n = 42, FN = 78). Despite their broad range throughout much of the continent and local ubiquity in all forest types, South American squirrels remain poorly known in nearly all aspects of their life history and, in particular relevance to this volume, their evolutionary relationships and diversification history. There have been no revisionary studies published in the last half-century or longer. Furthermore, and in contrast to virtually all other South American rodent groups, students of molecular phylogenetics have largely bypassed the Sciuridae, except for the inclusion of a few species in the phyletic delineation of the major lineages in this nearly cosmopolitan family (Mercer and Roth 2003; Steppan, Storz, and Hoffmann 2004; Pecnerová and Martínková 2012). These studies have unambiguously identified two lineages among the South American representatives of the family. One of these contains the monotypic Sciurillus, which forms a

basal offshoot that diverged very early in the history of the family. Although Moore (1959) did recognize the uniqueness of Sciurillus by placing it in its own subtribe Sciurillina in the tribe Sciurini, molecular studies clearly document that Sciurillus has no phylogenetic affinity to other tree squirrels. Consequently, this genus is now uniformly placed in its own subfamily, the Sciurillinae (Steppan, Storz, and Hoffmann 2004; Thorington and Hoffmann 2005; Thorington et al. 2012). The basal position of Sciurillus in the family, moreover, suggests great age for its lineage, which Roth and Mercer (2008) estimated at about 30 mya, a divergence event only slightly younger than the 36-mya age for the family. In contrast, the entire radiation of all remaining tree squirrels in South America, now placed in the subfamily Sciurinae (Thorington and Hoffmann 2005; Thorington et al. 2012), appears to have descended from a single lineage, one that arrived on the continent subsequent to the closure of the Panamanian land bridge (Roth and Mercer 2008; Pecnerová and Martínková 2012). The last revision of South American representatives was J. A. Allen’s classic monograph Review of the South American Sciuridae, published in 1915 and thus now nearly a century old. Allen recognized nine genera, a number reduced to three or four by subsequent reviewers (e.g., Ellerman 1940, three genera [Sciurillus, Microsciurus, and Sciurus, divided into three subgenera]; Moore 1959, four genera [Guerlinguetus, Microsciurus, Sciurillus, and Syntheosciurus]; Cabrera 1961, three genera [Microsciurus, Sciurillus, and Sciurus, divided into two subgenera]; R. S. Hoffmann et al. 1993 and Thorington and Hoffmann 2005, three genera [Microsciurus, Sciurillus, and Sciurus, divided into three subgenera]). The number of species recognized in various treatments over the past 50 years has also differed, sometimes substantially. For example, J. A. Allen (1915a) divided South American squirrels into 25 species, Cabrera (1961) into 13, Emmons and Feer (1997) described and mapped 11, and R. S. Hoffmann et al. (1993) and Thorington and Hoffmann (2005; see also Thorington et al. 2012) listed 15. In part, differences in species boundaries recognized by these and other authors attest to the extreme variability often present geographically in color and color pattern. The concordance of both generic membership and categorical level across these treatments is limited, a fact also attesting to both the extensive variation in coloration that characterizes most of these taxa and the lack of critical reviews. The lack of any comprehensive or even regional analysis of character variation for nearly all species of South American squirrels prompted us to examine most available specimens, including holotypes, to assess both genus- and specieslevel boundaries. As a result, we recognize seven genera and

Suborder Sciuromorpha: Family Sciuridae 3

a total of 19 species. These taxonomic hypotheses differ from previous treatments of South American squirrels, the most recent of which is that of Thorington et al. (2012), and they are ripe for testing by phylogenetic and phylogeographic analyses employing molecular data and methods. KEY TO THE SUBFAMILIES OF SOUTH AMERICAN SCIURIDAE (FROM MOORE 1959:199– 200):

1. Lateral wall of cranium with squamosal extending dorsally to a point less than or equal to halfway from base of zygomatic process of squamosal to base of postorbital process of frontal; typically two transbullar septa; well-developed masseteric tubercle; maxilla contributing much less than half to the lateral side of rostrum; robust zygoma with a well-developed superior process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sciurinae 1′. Lateral wall of cranium with squamosal extending dorsally notably more than halfway between base of zygomatic process of squamosal and base of postorbital process of frontal; one transbullar septum; no masseteric tubercle; maxilla contributing much more than half of the lateral side of rostrum; slender zygoma lacking superior process . . . . . . . . . . . . . . . . . . . . . . . . . Sciurillinae

Subfamily Sciurillinae Moore, 1959 The subfamily Sciurillinae contains only the single genus and species Sciurillus pusillus. This is the smallest of the New World Sciuridae and one of the two most ancient lineages in the family, the other being the Ratufinae, or giant tree squirrels of southern Asia. In erecting this taxon, Moore (1959:180) delineated 12 diagnostic characters of the skull, including those listed in the key. Cladistic analyses of both morphological (Roth 1996) and molecular characters (allozymes: M. S. Hafner et al. 1994; mitochondrial and nuclear DNA sequences: Mercer and Roth 2003; Herron et al. 2004; Roth and Mercer 2008) support the basal position of the Sciurillinae in the Sciuridae and refute the hypothesized phyletic link between Sciurillus and the Asian (Nannosciurus) and African (Myosciurus) pygmy squirrels proposed by G. S. Miller and Gidley (1918). Mercer and Roth (2003) estimated the split between the lineage leading to Sciurillus and all other sciurids (flying, ground, and tree squirrels) at about 36 mya, in the late Eocene. These authors also argued that the deep phylogenetic separation between Sciurillus and other South American sciurids, which formed a monophyletic assemblage, indicated separate invasions of the continent by squirrels. Because Sciurillus has no close relatives in the family, its place of origin and timing of entry to South America remain enigmas.

Genus Sciurillus Thomas, 1914 The genus Sciurillus is a tiny rainforest squirrel with three pairs of mammae, distributed in the Guianas and Amazon Basin. This is the smallest of the New World tree squirrels, with a head and body length averaging 113 mm, tail length 114 mm, hindfoot length 30 mm, and body mass 44 g (N = 5). The ears are small and round, up to 14 mm long. The skull has a strongly convex dorsal profile, with the inflexion point at the middle of the frontals; the rostrum is long, more than one-third the skull length; the frontals are short, as wide or wider than their length; the braincase is relatively large and globose; the temporal part of the orbitotemporal fossa is completely obliterated, with the postorbital process extending posteriorly to almost coincide with a vertical plane at the posteriormost part of the squamosal zygomatic process; the anterior portion of the zygoma is nearly vertical, situated posterior to the first upper molar; a distinct semicircular crest, originating at the infraorbital foramen, runs dorsally along the line of contact between the premaxilla and maxilla on each side; the anterior opening of the infraorbital foramen is positioned midway between the anteriormost part of the zygoma and the incisors, but the infraorbital canal is not conspicuously elongated; the parapterygoid fossa is deep, well delimited, and sometimes perforated by bilateral or unilateral vacuities; the posterior aperture of the alisphenoid canals is small, maximally one-third the width of the foramen ovale; the aperture of the transverse canal is distinctly visible in ventral view, and not covered by the posterior border of the pterygoid encircling the foramen ovale; a sphenopalatine foramen is situated above the third upper molar or, at most, over the region between the second and third molars; and only one bullar septum is present. Very short coronoid processes characterize the mandible. Temporal muscles are correspondingly unusually small for a squirrel, but the anterior deep masseters are enlarged and oriented to assist in retraction of the jaw (Ball and Roth 1995). The dental formula is I 1/1, C 0/0 PM 2/1, M 3/3 = 22. Upper incisors are proodont. PM3 has one root; all remaining permanent cheek teeth have three roots. In occlusal view, the maxillary toothrows form a more or less rounded to slightly oval arrangement. PM3 is small, with a simple, unicuspidate occlusal surface. PM4 is molariform, only slightly smaller than M1; M2 is the largest cheek tooth. PM4 through M2 lack a paraconule, metaconule, and ectostyle; the trigon of all maxillary teeth is shallow. The lower cheek teeth lack a paraconid and ectostylid, and a trigonid is obsolete or absent. sy n o n y m s : [Myoxus]: Shaw, 1801:171; part (included “le petit guerlinguet” of Buffon 1789); not Myoxus Zimmerman, 1780.

4 Mammals of South America

Sciurus: É. Geoffroy St.-Hilaire, 1803:177; part (inclusion of pusillus); not Sciurus Linnaeus, 1758. Sciurus: Desmarest, 1817c:109; part (inclusion of pusillus); not Sciurus Linnaeus, 1758. Macroxus: F. Cuvier, 1823b:119; 1823c:161; part (included “le guerlinguet” of Buffon, 1789). [Funambulus]: Fitzinger, 1867a:487; part (inclusion of pusillus); not Funambulus Lesson, 1835. Sciurus (Macroxus): Liais, 1872:503; part (inclusion of pusillus); not Sciurus Linnaeus, 1758. Sciurus (Microsciurus): E. W. Nelson, 1899b:32; part (inclusion of pusillus and kuhli); not Microsciurus J. A. Allen, 1895. Microsciurus: E.-L. Trouessart, 1904:329; part (inclusion of pusillus and kuhli); not Microsciurus J. A. Allen, 1895. Sciurillus Thomas, 1914f:36 [1914f:415]; type species Sciurus pusillus Desmarest, 1817 (= Sciurus pusillus É. Geoffroy St.-Hilaire, 1803), by original designation. r e m a r k s : Buffon (1789:261, plates 65 and 66, respectively) recognized the existence of two “squirrel-like” animals in the Guiana region, “le grand guerlinguet” (= Sciurus aestuans Linnaeus) and “le petit guerlinguet” (= Sciurillus pusillus É. Geoffroy St.-Hilaire). Buffon used the vernacular French term “guerlinguet” rather than “écureuil” because he was not convinced that the animals were “true” squirrels. When É. Geoffroy St.-Hilaire (1803) named “le petit guerlinguet” as Sciurus pusillus, he implicitly allied the species with other known tree squirrels. Desmarest (1817c:109) redescribed Geoffroy St.-Hilaire’s Sciurus pusillus and, because many subsequent authors regarded the taxa proposed by É. Geoffroy St.-Hilaire (1803) as unavailable manuscript names, much of the nineteenth- and twentieth-century literature credited Sciurus pusillus to Desmarest (J. A. Allen 1915a; Ellerman 1940; Cabrera 1961; R. S. Hoffmannet al. 1993). Desmarest (1822:337) even coined a new common name for the species, calling it “l’Écureuil nain” or “dwarf squirrel,” probably to emphasize its similarity to the European forms and to abolish the distinctiveness suggested by “guerlinguet.” However, some authors continued to distinguish between “guerlinguets” and squirrels. F. Cuvier, in a series of papers dealing with the dentition of mammals, described and figured the dentition of “le petit guerlinguet” (F. Cuvier 1812:277, plate 15, Fig. 1), the distinctive dental characters being the size of the cheek teeth depicted and the presence of a diminutive upper third premolar, a feature present only in Sciurillus pusillus and not in Sciurus aestuans. Indeed, F. Cuvier did not mention “le grand guerlinguet” in his 1812 paper, but in a later publication (F. Cuvier 1819:248), he provided brief descriptions of the “grand” and “petit” guerlinguets, stating that “leurs

molaires [= cheek teeth] sont tout-à-fait semblables à celles des écureuils,” thus making them essentially equal in that respect (although “le grand guerlinguet” [= Sciurus aestuans] actually has a distinctive dentition that lacks third upper premolars). Later, when F. Cuvier published a comprehensive account of mammalian dentition (1823c:161–162), he erected the genus Macroxus, characterized by (among other features) the presence of two upper premolars, and he included as species “le guerlinguet” and “le toupaye” (the latter an oriental squirrel). If his diagnosis is interpreted strictly and if reference is made to his 1812 publication, “le guerlinguet” would mean only the “petit guerlinguet.” However, as he clearly considered (incorrectly) that both “guerlinguets” had similar dentition (F. Cuvier 1819), it can be safely assumed that by “guerlinguet” Cuvier meant both pusillus and aestuans. Husson (1978:382–383) recognized this possible confusion and specifically designated the specimen described and figured by Buffon (1789:261, plate 66: “le petit guerlinguet”) as the lectotype of Sciurus pusillus É. Geoffroy St.-Hilaire. Earlier, Thomas (1898g:933) had designated Sciurus aestuans Linnaeus, 1766 as the type species of Macroxus F. Cuvier, 1823, thus making this name unavailable for Sciurillus. The remaining generic names associated with Sciurillus pusillus (É. Geoffroy St.-Hilaire) clearly belong either to other rodent groups (e.g., Myoxus Zimmermann, Gliridae) or to other groups of sciurids (e.g., Sciurus Linnaeus) and need not be discussed further here.

Sciurillus pusillus (É. Geoffroy St.-Hilaire, 1803) Neotropical Pygmy Squirrel sy n o n y m s : Sciurus pusillus É. Geoffroy St.-Hilaire, 1803:177; type locality “Cayenne,” French Guiana. Sciurus guianensis Goldfuss, 1809:122; based on Buffon’s (1789:261, plate 66) “le petit guerlinguet.” Sciurus olivascens Illiger, 1815:69; nomen nudum. Sciurus pusillus Desmarest, 1817c:109; renaming of Sciurus pusillus É. Geoffroy St.-Hilaire, 1803; based on Buffon’s (1789:261, plate 66) “le petit guerlinguet.” Sciurus olivascens Olfers, 1818:208; part; not olivascens Illiger, 1815, fide Hershkovitz, 1959b:345. Macroxus pusillus: Lesson, 1842:111; name combination. [Funambulus Pucheranii] pusillus: Fitzinger, 1867a:487; part; name combination. Macroxus kuhlii Gray, 1867:433; type locality “Brazil,” restricted by Thomas (1928c) to Pebas, Loreto, Peru. Sciurus leucotis Gray, 1867:433; unavailable name published as a junior synonym and attributed to the French naturalist François de Caumont LaPorte, Comte de Castelnau (see Hershkovitz 1959b:345).

Suborder Sciuromorpha: Family Sciuridae 5

Sciurus (Macroxus) pusillus: Liais, 1872:503; name combination. Sciurus aestuans var. aestuans: J. A. Allen, 1877:756, part; not Guerlinguetus aestuans (Linnaeus, 1766). Macroxus aestuans: E.-L. Trouessart, 1897:428, part (inclusion of pusillus and kuhlii as synonyms); not Guerlinguetus aestuans (Linnaeus, 1766). Sciurus (Microsciurus) pusillus: E. W. Nelson, 1899b:32; name combination. Sciurus (Microsciurus) kuhli: E. W. Nelson, 1899b:32; name combination and incorrect subsequent spelling of Macroxus kuhlii Gray. Microsciurus pusillus: E.-L. Trouessart, 1904:329; name combination. Microsciurus kuhli: E.-L. Trouessart, 1904:329; name combination and incorrect subsequent spelling of Macroxus kuhlii Gray. Microsciurus kuhlii: J. A. Allen, 1914a:162; name combination. [Sciurillus pusillus] kuhli Thomas, 1914b:575; incorrect subsequent spelling or invalid emendation of Macroxus kuhlii Gray. Sciurillus pusillus: Thomas, 1914b:575; first use of current name combination. Sciurillus pusillus glaucinus Thomas, 1914b:575, type locality “Great Falls of Demerara River, British Guiana,” = Ororo Marali, Upper Demerara–Berbice, Guyana. Sciurillus pusillus pusillus: J. A. Allen, 1915a:197; name combination. S[ciurillus]. kuhlii: Thomas, 1928c:291; name combination. Sciurus pusilus Olalla, 1935:426; incorrect subsequent spelling of Sciurus pusillus É. Geoffroy St.-Hilaire. Sciurillus pusillus kuhlii: Cabrera and Yepes, 1940:192; name combination. Sciurillus pusillus hoehnei Miranda-Ribeiro, 1941:10; type locality “Rio Teles Pires (São Manoel), northern Mato Grosso,” Brazil (page number incorrectly given as 139 by Hershkovitz 1959b:346). Sciurus aestuans: Rode, 1943:385; part; not Sciurus aestuans Linnaeus. Microsciurus pusillus hoehnei: C. O. da C. Vieira, 1955: 410; name combination. Sciurillus guajanensis: Hershkovitz, 1959b:345; not gujanensis of Gmelin, 1788, nor guajanensis of Kerr, 1792. Sciurillus pusilus Moore, 1959:204; incorrect subsequent spelling of Sciurus pusillus É. Geoffroy St.-Hilaire. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : Sciurillus pusillus is known from scattered localities in Guyana, Surinam, French Guiana, Amazonian Brazil in Amapá, Amazonas, Pará, and Mato Grosso states, and northeastern Amazonian Peru. Cuervo Díaz et al. (1986) and Rodríguez-Mahecha et al. (1995)

listed this species in their faunal compilations of Colombia but without locality or voucher specimen citations; Alberico et al. (2000) listed S. pusillus from the department of Caquetá in southeastern Colombia without providing an exact locality but referring to specimens in the IAvH and ICN in Bogotá. Jessen, Gwinn, and Koprowski (2013) included southeastern Colombia and Venezuela south of the Río Orinoco in the mapped range, without either literature or specimen documentation. The species has not been recorded from the fauna of either Ecuador (Tirira 2007) or Venezuela (O. J. Linares 1998). s e l e c t e d l o c a l i t i e s (Map 2): BRAZIL: Amapá, Amapá (MPEG 1541), Oiapoque, upper Rio Oiapoque (MZUSP 20353); Amazonas, Andira, near Villa Bella da Imperatriz (AMNH 93154), Estirão do Equador, Rio Javari (MPEG 1557); Mato Grosso, São Manoel, Rio Teles Pires (type locality of Sciurillus pusillus hoehnei MirandaRibeiro); Pará, Boim, Rio Tapajós (MCZ 30216), Igarapé Amorim (AMNH 95727), Igarapé Brabo (= Bravo), left bank Rio Tapajós (AMNH 94743). FRENCH GUIANA: Cayenne (type locality of Sciurus pusillus É. Geoffroy St.Hilaire), Inini, Arataye River (USNM 548447), Paracou (Voss et al. 2001), Tamanoir, Mana River (FMNH 21788). GUYANA: Upper Demerara–Berbice, Great Falls of Demerara River (type locality of Sciurillus pusillus glaucinus Thomas). PERU: Loreto, Estación Biológica Quebrada Blanco (Heymann and Knogge 1997), Pebas (BM 28.7.21.79), Quebrada Orán (M. S. Hafner et al. 1994), Santa Cecília, Río Maniti (FMNH 87182), Sarayacu, Río Ucayali (AMNH 76185). SURINAM: Sipaliwini, Emmaketen [= Emma Keten] (Husson 1978), Frederik Willem IV Falls, Corentyne River (FMNH 48419). s u b s p e c i e s : Two (J. A. Allen 1915a) or three (Anthony and Tate 1935; Cabrera 1961; Thorington and Hoffman 2005) subspecies have generally been recognized. These include the nominotypical form (the Guianas and northeastern Brazil), glaucinus Thomas (the Amazon Basin of central Brazil and interior Guyana), and kuhlii Gray (northeastern Peru and probably western Brazil and southwestern Colombia). Anthony and Tate (1935), who studied specimens from French Guiana, Peru, and the region of the Rio Tapajós, Brazil, believed that three subspecies could be distinguished on the basis of color, having found no significant differences in cranial measurements, specifically: S. p. pusillus— ears black; head decidedly reddish when compared with the grayish dorsum; S. p. glaucinus—ears the same color as the head, which was not very distinct in color from the rest of the grayish dorsum; and S. p. kuhlii—like glaucinus but more “saturated,” with “belly even more cinnamon” (p. 8) than in pusillus and with a darker back. However, our microscopic examination of the pinnae revealed

6 Mammals of South America

that the epithelium is pigmented (thus appearing black on dried skins) in specimens from the entire range of the genus. Moreover, the color of the head is variable in the series from the Rio Tapajós, as is the intensity of the orange mixed with gray in the belly. The number of specimens we have examined from Peru, the putative region of occurrence of kuhlii, is small, but a good series from Estirão do Equador, Rio Javari, Amazonas, which is geographically close to the Peruvian localities, cannot be distinguished from the larger series from the Rio Tapajós, and which has been ascribed to glaucinus. We have not seen the holotype of Sciurillus pusillus hoehnei from northern Mato Grosso, but nothing in the description supports it as a plausible valid taxon. Mercer and Roth (2003) reported substantial sequence divergence in both mitochondrial and nuclear genes between two specimens from opposite ends of the geographic range of this species (USNM 578014 from French Guiana, and LSUMZ 27994 from Loreto department, Peru), positing a late Miocene divergence between these samples. Despite the extensive level of divergence and apparent deep age of the species, we are unable to find significant, geographically partitioned variation among the few samples available from this very large area; we provisionally regard Sciurillus pusillus as a monotypic species. n a t u r a l h i s t o ry: Jessen, Gwinn, and Koprowski (2013) synthesized the few data available on ecology, behavior, and life history. Emmons and Feer (1990, 1997), Ball and Roth (1995), Roth (1996), Heymann and Knogge (1997), Voss et al. (2001:76), and Youlatos (2011) detailed observations of solitary individuals in trees in welldrained primary forest, primarily in Inga (French Guiana) and Parkia (Peru), both in the subfamily Mimosoideae. In both geographic areas, animals were observed gnawing on the bark, probably feeding either on cambium or on exudates (sap or gum), incising pieces of the upper bark layer, and leaving the trunk densely pockmarked. Heymann and Knogge (1997) recorded large amounts of bark chips that accumulated on the ground under one such tree. Emmons and Feer (1990:176) noted that individuals forage on trunks from near the ground to high in the canopy, “hopping and flitting from branch to branch,” and traveling from tree to tree high in the canopy. Their small size makes individuals difficult to spot, but they are not wary of humans and can be easily observed. Youlatos (2011) observed five individuals using wide vertical substrates in the canopy, with locomotion primarily by claw climbing. Velhagen and Roth (1997) suggested that a decrease in bite force with decreasing size might account for a shift in diet of the pygmy squirrels, including Sciurillus, from hard fruits and nuts to gleaning bark. Because most sightings were of solitary individuals, Heymann and

Knogge (1997) also suggested that a solitary lifestyle was the dominant mode of sociospatial organization. Peres et al. (2003) reported four sightings, each averaging 1.5 individuals, in the headwaters of the Rio Arapiuns, Pará state, Brazil, and estimated their density at 0.023 individuals/ha. Dalecky et al. (2002) stated that home range size in French Guiana was small, which facilitated individual persistence in habitat islands created by flooding. Olalla (1935), Heymann and Knogge (1997), and Voss et al. (2001) observed this species only in noninundated or terra firme forest, and Olalla (1935) reported a litter size of two. r e m a r k s : Due to the scarcity of specimens of S. pusillus from the time of its discovery in the late eighteenth century until the 1930s, the taxonomic history of this taxon has presented certain persistent problems. Most of the trouble relates to confusion between Sciurillus pusillus (or some junior synonym) and several other South American squirrels, usually Sciurus aestuans Linnaeus (herein Guerlinguetus aestuans). Because both of these species were first known from Guianan specimens, their respective taxonomic histories are entangled. We comment on all names, available or not, that have been associated with Sciurillus pusillus; however, new combinations and changes in specific versus subspecific status are not discussed because they can be easily followed in the synonymy provided earlier. Sciurillus pusillus was the second squirrel to be known from the Guianan region, the first being Sciurus aestuans, described by Linnaeus in 1766. Ten years later, Buffon (1776:146–147) published his first report on a Guianan squirrel. The essential parts of Buffon’s report are translated as: “M. de la Borde, Physician of the King in Cayenne, said that there is only one species of squirrel in the Guyanne, that it lives in the forests, that its fur is reddish, that it is not larger than the European rat . . . I am not quite certain that this animal from the Guyanne, of which M. de la Borde speaks, is a true squirrel, because the latter are hardly found in excessively hot climates, such as that of the Guyanne” (emphases ours). This is a very uninformative account, but it is clear that Buffon did not have specimens to describe in 1776, only an oral or written account by de la Borde. It is also clear that Buffon believed that there was a single species of “squirrel-like” mammal in the Guiana region, and that it was not larger than the European Rattus. Such reference to size is vague, but it can be interpreted to mean an animal about the size of a Norway or black rat; because Sciurillus is so much smaller, we believe this feature would not go unnoticed even by an amateur such as de la Borde. Also, Sciurillus pusillus can hardly be described as having “reddish” fur, a character that could roughly be applied to Sciurus aestuans. Therefore, it is plausible that the animal reported by de la Borde

Suborder Sciuromorpha: Family Sciuridae 7

was Sciurus aestuans, by far the most common species found in the Guianas. Later, Buffon (1789) was finally provided with specimens from French Guiana, which had been collected by M. Sonini de Manoncourt, and he was able to give firsthand information on the entire squirrel fauna of the region. The essential aspects of this later contribution are, first, that Buffon (1789:261–264, plates 45 and 46) believed the animals were not real squirrels (e.g., the European “écureuil” or Sciurus vulgaris), confirming his earlier prediction, and he called them “guerlinguets”; and, second, that he considered them two species, “le grand” and “le petit guerlinguet.” He then proceeded to reinterpret his own 1776 account of one species to accommodate the two he now had in front of him. Thus, the “petit guerlinguet” became the species “not larger than a rat,” and the “grand” one was compared in size to Sciurus vulgaris. Obviously, anything the size of Sciurillus is “not larger than a rat,” but then neither are its fleas. Buffon’s awkward adaptation of his earlier, vague size reference to the actual specimens collected by Sonini de Manoncourt allowed for some misinterpretation, mainly because other naturalists were also busy reporting and cataloging the Guianan sciurid fauna. It is now important to devote attention to a number of publications dealing with Guianan squirrels, which appeared before É. Geoffroy St.-Hilaire (1803) coined the name Sciurus pusillus for the “petit guerlinguet” of Buffon, because Hershkovitz (1959b) considered some of these names to have priority over pusillus. The first of these is Sciurus gujanensis, coined by Gmelin (1788:152) for two squirrels from different reports concerning the Guianan region. One of these reports is that by de la Borde, which we discussed earlier and associated with Sciurus aestuans Linnaeus. The other report commented on by Gmelin was Bancroft’s (1769:143), taken from his account of the natural history of Guiana, where he states that the animal was close to the common English squirrel in size and morphology, and that it had a pale yellowish brown dorsum, white under parts, small white streaks on the sides of the body, and a tail similar in color to the dorsum but “variegated” with white and black. The presence of lateral white streaks does not fit with the color pattern of any known South American squirrel, and Sciurus aestuans does not have white under parts. Whichever squirrel Bancroft had in mind, however, both his description of the color pattern and size completely eliminate the possibility that his animal was Sciurillus pusillus. Hershkovitz (1959b:345) ignored Gmelin’s name and its complete lack of correspondence with Sciurillus pusillus. He proposed that the valid name for the dwarf squirrel should be Sciurillus guajanensis (Kerr) and then organized a synonymy with that in mind. However, Kerr (1792:265)

both acknowledged that his usage derived from Gmelin and decided to keep the name Sciurus guajanensis (his different spelling of the name either is an unjustified emendation or a lapsus calami) for de la Borde’s animal, while creating the new name Sciurus bancrofti for the other “species.” As documented earlier, these two names have nothing to do with Sciurillus pusillus and do not belong in its synonymy. Hershkovitz (1959b:345) also stated that Turton (1802:94) employed the name Sciurus guajanensis based on the “petit guerlinguet” of Buffon. There is, however, no mention in Turton’s work of the French naturalist or of the “petit guerlinguet.” Indeed, Turton’s General System is only an updating of Kerr’s, which is entirely referable to Gmelin (1788). Finally, Hershkovitz (1959b:345) cited yet another author (Goldfuss 1809:122) who used the name Sciurus guianensis for the “petit guerlinguet,” a publication that can be viewed in the same perspective as those by Kerr and Turton. However, as neither of us has personally seen the work by Goldfuss, we herein treat his Sciurus guianensis as a possible synonym of Sciurillus pusillus. The first scientific name unequivocally associated with “le petit guerlinguet” is Myoxus guerlingus Var. (?), coined by Shaw (1801:171), which actually encompasses both Guianan squirrels, Sciurus aestuans Linnaeus and Sciurillus pusillus Thomas. Because we fix the type specimen of Myoxus guerlingus as the same as that of Sciurus aestuans (guerlingus had no type, being a name for both of Buffon’s guerlinguets; see the account for Guerlinguetus aestuans), Shaw’s name cannot be employed as the valid one for “le petit guerlinguet” and is not listed in the synonymy of S. pusillus as a result. É. Geoffroy St.-Hilaire (1803:177) created the name Sciurus pusillus exclusively for “le petit guerlinguet,” making it the valid one for the species. He stated, however, that de la Borde had collected the specimen he studied. This made Husson (1978:382) question whether Geoffroy St.Hilaire’s specimen was the same as that seen by Buffon, who obtained his material from Sonini de Manoncourt. The holotype of Sciurus pusillus É. Geoffroy St.-Hilaire in the Paris museum (MNHN 312, a mounted skin), however, has an old label bearing de la Borde’s name attached to its support. In our opinion, this is probably the same specimen seen by Buffon (1789), and de la Borde’s name is on the label because Buffon believed it represented the “guerlinguet” he reported. Husson (1978:382) never questioned that the holotype is really what is currently called Sciurillus pusillus, in spite of its somewhat deteriorated condition, but he felt the need to select a lectotype, which he indicated (1978:383) to be the same specimen described and figured by Buffon in 1789 (p. 261, plate 46). Husson’s act, however, was unnecessary, as the specimen (MNHN 312)

8 Mammals of South America

is the holotype of Sciurus pusillus É. Geoffroy St.-Hilaire, as the name is applied today, and is characterized by the small and rounded pinnae and the small size of the feet. It is not the young of a Sciurus aestuans as proposed by Rode (1943:385). Another early name resurrected by Hershkovitz (1959b:345) was Sciurus olivascens, placed in the synonymy of Sciurillus guajanensis (Kerr) [= Sciurillus pusillus], which he attributed to Olfers, 1818. According to Hershkovitz (1959b:345), Olfers erected the name after a manuscript usage by Illiger, purportedly based on “le petit Guerlinguet” of Buffon, but of this Olfers himself was not completely sure because he added a question mark after the French vulgar name. Illiger (1815:69) published the name Sciurus olivascens in a list of mammals from South America without diagnosis or description, and he made no subsequent reference to this name in his brief discussion of South American squirrels (pp. 74–75). It thus seems clear that olivascens is unavailable from Illiger (1815) in the meaning of the International Code of Zoological Nomenclature (ICZN 1999). The same name was again mentioned in yet another list of South American mammals (Minding 1829:89), also unavailable for the same reasons. Given that Olfers (1818:208) only questionably associated “Sc. olivascens Ill.” to Buffon’s “le petit guerlinguet,” and that both Illiger’s (1815) original usage of this name and the subsequent usage by Minding (1829) are nomina nuda, it seems to us that the name continues to be unavailable. But even if Olfers’s usage were judged available, olivascens would remain a junior synonym of Sciurus pusillus, being antedated by E. Geoffroy St.-Hilaire’s name by 15 years. For some decades, no new specimens other than the one(s) in the Paris museum were reported until Gray (1867:433) listed and described Macroxus pusillus and Macroxus kuhlii, the latter a new species said to have been collected by Castelnau in “Brazil.” The name Sciurus leucotis was also given by Gray (1867:433) in the synonymy of kuhlii and attributed to Castelnau (manuscript); leucotis, having never been employed as valid, is not available under the International Code of Zoological Nomenclature (ICZN 1999). Gray’s (1867:433) descriptions are not good, but one of us (MdV) has seen the holotype of Macroxus kuhlii (BM 51.7.3.7, skin and skull); the skin is in bad shape, with extensive loss of hair in the region immediately posterior to the crown, legs, tail, throat, and chest, and with small losses in other scattered areas. Nevertheless, what is left of the animal is very similar to the specimen from Cayenne (BM 45.5.1.3) that probably served as basis for Gray’s account of Macroxus pusillus. Thomas (1920f:276) assigned two specimens from Villa Braga on the Rio Tapajós, Pará, Brazil, to S. pusillus but noted that these were “quite like” the type of Macroxus kuhlii and suggested that the latter likely

came from the same region in Brazil. He later restricted the type locality of kuhlii Gray to Pebas, Loreto, Peru (Thomas 1928c:291). Because we consider Sciurillus pusillus to be a monotypic species, the matter of the correct type locality of Macroxus kuhlii, a junior synonym, is not critical. However, because kuhlii has been considered by Anthony and Tate (1935) to be a valid subspecies (and may even be a species separate from pusillus, as suggested by the deep molecular divergence of western and eastern Amazonian samples; Mercer and Ross 2003), validation of Thomas’s restriction of the type locality to Peru is warranted. J. A. Allen (1877:756–757), without examining specimens of the dwarf squirrel, placed both pusillus and kuhlii as junior synonyms of his excessively broad Sciurus aestuans var. aestuans, believing they could be young specimens of the larger animal. Alston (1878:670) immediately corrected Allen, considering Sciurus pusillus a valid species with Macroxus kuhlii as a junior synonym. Most subsequent authors were convinced of the validity of pusillus but placed the species in the genus or subgenus Microsciurus (e.g., E. W. Nelson 1899b; E.-L. Trouessart 1904; J. A. Allen 1914a). Any remaining doubts regarding the distinctiveness of pusillus were finally dispelled when Thomas (1914b,f) erected the genus Sciurillus, completely divorcing it from the larger squirrels of the genus Microsciurus. Thomas (1914b:575) described Sciurillus pusillus glaucinus from Guyana (former British Guiana), thus adding a third species group taxon to the picture. Anthony and Tate’s (1935) review of Sciurillus took advantage of the first relatively large series of specimens available at any museum; they recognized three subspecies, namely, Sciurillus p. pusillus, S. p. glaucinus, and S. p. kuhlii. They restricted the

Map 2

Selected localities for Sciurillus pusillus (●). Contour line = 2,000 m.

Suborder Sciuromorpha: Family Sciuridae 9

nominotypical subspecies to French Guiana, glaucinus to British Guiana (= Guyana) south to the lower Rio Tapajós, Pará, Brazil, and kuhlii to northeastern Amazonian Peru. Another subspecies, Sciurillus pusillus hoehnei, was posthumously published by Miranda-Ribeiro (1941), from northern Mato Grosso, Brazil. For reasons discussed earlier, we consider Sciurillus pusillus to be a monotypic species, with kuhlii, glaucinus, and hoehnei as junior synonyms.

Subfamily Sciurinae G. Fischer, 1817 Species in the subfamily Sciurinae are the “typical” tree squirrels, with members distributed on all continents save Antarctica and Australia. South American representatives include taxa allocated by Moore (1959) to his subtribes Sciurina and Microsciurina. Both groups are now collectively placed in the Sciurinae (Thorington and Hoffmann 2005). Species in some genera (e.g., Hadrosciurus, Microsciurus, Notosciurus) are characterized by an ear patch colored differently than the top of the head, neck, and shoulders; typically, this patch is continuous from the distal part of the medial surface of the pinna to just behind the ear (herein referred to as a postauricular patch). In a few cases, the colored hairs of the patch protrude above the rim of the ear. In species of Simosciurus, some hairs may extend from the dorsal edge of the pinnae, but none of these resemble a tuft, such as that characterizing the European Sciurus vulgaris (see Thorington et al. 2012). Phylogenetic relationships among the genera and species we recognize are very incompletely known, as few of these taxa have been included in any of the surprisingly small number of molecular phylogenetic studies to date. The most comprehensive analysis of sciurid phylogeny (Mercer and Roth 2003) included only three South American taxa of “Sciurus” and Microsciurus. Assuming an entry into South America at or subsequent to the closure of the Panamanian seaway some 3–4 mya, the net rate of diversification of tree squirrels was exceedingly rapid, more than twice that for any other continental assemblage (Roth and Mercer 2008). KEY TO THE GENERA OF SOUTH AMERICAN SCIURINAE:

1. Mean head and body length of adults 160 mm; orbitotemporal fossa of skull, in dorsal view, evenly divided by the postorbital process of the frontals, resulting in

nearly equal-sized orbital and temporal fossa; always with only one upper premolar . . . . . . . . . . . . . . . . . . 2 2. Mean head and body length of adults between 160 and 180 mm; ears small and rounded . . . . . Syntheosciurus 2′. Mean head and body length of adults >160 mm; ears relatively large and pointed. . . . . . . . . . . . . . . . . . . . . 3 3. Adult females with three pairs of mammae; distinctive postauricular patch of different color than that of top of head usually present . . . . . . . . . . . . . . . . . Notosciurus 3′. Adult females with four pair of mammae; postauricular patch may or may not be present . . . . . . . . . . . . . . . . 4 4. Pelage coarse; distribution west of the Andes in Ecuador and Peru; pinnae hirsute, with somewhat long hairs, but not quite forming a tuft . . . . . . . . . . . . . . .Simosciurus 4′. Pelage normal to soft; distribution east of the Andes; pinnae hirsute, covered with very short hairs . . . . . . . 5 5. Size medium, mean head and body length between 175 and 180 mm . . . . . . . . . . . . . . . . . . . . . . Guerlinguetus 5′. Size large, mean head and body length >215 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hadrosciurus

Genus Guerlinguetus Gray, 1821 Guerlinguetus is a tropical tree squirrel genus occurring from eastern Colombia, Venezuela, and the Guianas, south throughout the lowland Amazonian rainforest, then through the Atlantic Forest of eastern and southern Brazil to northeastern Argentina. It is not known to occur in neighboring Paraguay and Bolivia, where the genus is replaced by the morphologically very similar Notosciurus. Although widespread in Amazonian Brazil, Guerlinguetus is not known from south of the Rio Solimões, between the Rio Javari and Rio Madeira. It is absent from all but the broad gallery forests at the periphery of the Cerrado biome in central Brazil and mesic forest enclaves in the Caatinga of eastern Brazil (Carmignotto et al. 2012). Species of Guerlinguetus, as is true of all other South American squirrels, are exclusive forest dwellers. The genus is mostly parapatric with Notosciurus, except in the general region of the Río Marañón in Peru. Guerlinguetus is easily distinguished from other South American squirrels by its size (larger than Microsciurus, Sciurillus, and Syntheosciurus, but smaller than Hadrosciurus and Simosciurus). In comparison with Notosciurus, which has an approximately similar size range, Guerlinguetus is unique in the possession of four pairs of mammae instead of three and typically by the absence of a differentially colored postauricular patch. Cranially, the genus can be distinguished by an orbitotemporal fossa that is equally divided by a well-developed postorbital process and an upper second molar with two parallel, buccolingual crests perpendicular to the anteroposterior axis of the skull.

10 Mammals of South America

We recognize only two species in Guerlinguetus: G. aestuans, a Guianan and Amazonian species, and G. brasiliensis, from eastern Amazonia to eastern and southern Brazil and northern Argentina. Although there are more publications on aspects of the natural history of these species than for any other South American squirrels, details of ecology, behavior, and other aspects of population biology remain unknown. Guerlinguetus appears to rely heavily on small palm fruits, using several palm genera through its distribution. Several regional Brazilian vernacular names are used for these squirrels, without distinction as to species, including esquilo, serelepe, caxinguelê, and quatipuru, the last used exclusively in the Brazilian Amazon. In Argentina, where only G. brasiliensis occurs, the local name is ardilla gris or ardilla misionera. sy n o n y m s : Sciurus: Brisson, 1762:107; part (inclusion of brasiliensis); not Sciurus Linnaeus, 1758; rejected for nomenclatural purposes (ICZN 1998:Opinion 1894). Myoxus: Shaw, 1801:171; part (included “le grand guerlinguet” of Buffon as species); not Myoxus Zimmermann, 1780. Guerlinguetus Gray, 1821:304; type species Sciurus guerlinguetus, by tautonomy (“le grand guerlinguet” of Buffon, 1789 = Myoxus Guerlingus Shaw, 1801 = Sciurus guerlinguetus Gray, 1821 = Sciurus aestuans Linnaeus, 1766. Gray [1821] writes “Gerlinguet, Guerlinguetus, sciurus guerlinguetus. Lin.”). Macroxus F. Cuvier, 1823c:161; type species Sciurus aestuans Linnaeus designated by Thomas (1898g:933). [Funambulus]: Fitzinger, 1867a:486; part (listing of aestuans); not Funambulus Lesson, 1835. [Sciurus] (Guerlinguetus): Ellerman, 1940:322, 340; as subgenus. r e m a r k s : The first available generic name for this group of medium-sized South American squirrels is Guerlinguetus Gray, 1821, with type species Sciurus guerlinguetus. Gray attributed S. guerlinguetus to Linnaeus, a name that is actually a nomen nudum because Gray’s usage was not followed by any description or plate. However, Gray’s generic name Guerlinguetus is clearly identifiable to the French vernacular “guerlinguet,” which Buffon (1789:261, plates 65, 66) used for the squirrels of the Guianas, for which he recognized two varieties, a larger “le grand guerlinguet” [= Guerlinguetus aestuans (Linnaeus)], and a smaller “le petit guerlinguet” [= Sciurillus pusillus (E. Geoffroy St. Hilaire)]. Since Gray (1821), the name Guerlinguetus has been either ignored or variously employed for a full genus or subgenus, but at either categorical level it broadly encompassed most medium-sized South American squirrels, some now placed in other genera. J. A. Allen (1915a) was the first to restrict the con-

cept of Guerlinguetus, a view that is very close to ours herein. KEY TO THE SPECIES OF GUERLINGUETUS:

1. Ventral coloration orange, or, if mostly orange, only the throat has white or grayish-white hairs; tail color lined with orange . . . . . . . . . . . . . . . Guerlinguetus aestuans 1′. Ventral coloration heavily grizzled with white or grayish-white, either along the entire venter or else only in throat, chest, and inguinal areas; tail color either lined with orange or grayish white . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Guerlinguetus brasiliensis

Guerlinguetus aestuans (Linnaeus, 1766) Guianan Squirrel, Quatipuru sy n o n y m s : [Sciurus] aestuans Linnaeus, 1766:88; type locality “Surinam.” Sciurus bancrofti Kerr, 1792:265; type locality “Guiana.” Sciurus guajanensis Kerr, 1792:265; type locality “Cayenne.” Myoxus Guerlingus Shaw, 1801:171; type locality “Guiana”; based on Buffon’s (1789:261, plate 65) “le grand guerlinguet.” Sciurus brasiliensis: Lichtenstein, 1818:216; part; remainder under Guerlinguetus brasiliensis. Sc[iurus]. guianensis Lichtenstein, 1818:216; type locality not given; name proposed as a synonym of S. brasiliensis and based on Bancroft’s report of a squirrel from (British) Guiana; name became available when Peters (1864) recognized it as a valid taxon. Sciurus guerlinguetus Gray, 1821:304; nomen nudum; name attributed to Linnaeus. aesciurus stuans: F. Cuvier, 1823c:255; typographic error. Macroxus aestuans: Lesson, 1827:238; name combination. Sc[iurus]. gilvigularis Wagner, 1843c:43; nomen nudum. Sciurus gilvigularis Wagner, 1845a:148; type locality “nördlichen Brasilien”; name attributed to Johann Natterer (Wagner 1850:283). S[ciurus]. aestuans: Cabanis, 1848:778; name combination. Sciurus aestuans var. Guianensis Peters, 1864:655; type locality “Guiana” = Guyana. [Funambulus] gilvigularis: Fitzinger, 1867a:486; name combination. Sciurus gilviventris Fitzinger, 1867a:486; incorrect subsequent spelling of Sciurus gilvigularis Wagner; unavailable name cited under [Funambulus] gilvigularis. [Funambulus] aestuans: Fitzinger, 1867a:486; part; name combination. Macroxus aestuans Var. 1: Gray, 1867:432; name combination. [S. aestuans] var. aestuans: J. A. Allen, 1877:672; part; name combination.

Suborder Sciuromorpha: Family Sciuridae 11

Sciurus gilviventris Pelzeln, 1883:59; type locality “Borba,” Amazonas, Brazil (see Goeldi 1893:78). [Macroxus] gilvigularis: E.-L. Trouessart, 1897:429; name combination. Sciurus Quelchii Thomas, 1901e:147; type locality “Kanuku Mountains, British Guiana,” Upper Takutu–Upper Essequibo, Guyana. Sciurus Macconnelli Thomas, 1901e:148; type locality “Mt. Roraima, near its base,” Cuyuni–Mazaruni, Guyana. [Guerlinguetus] gilvigularis: E.-L. Trouessart, 1904:328; name combination. Sciurus aestuans gilvigularis: J. A. Allen, 1910c:146; name combination. Sciurus (Guerlinguetus) aestuans gilvigularis: J. A. Allen, 1911:244; name combination. G[uerlinguetus]. aestuans: Cabrera, 1912:89; part (also included species of Notosciurus); first use of current name combination. Guerlinguetus aestuans aestuans: J. A. Allen, 1915a:256; name combination. Guerlinguetus aestuans gilvigularis: J. A. Allen, 1915a:256; name combination. Guerlinguetus aestuans macconnelli: J. A. Allen, 1915a: 259; name combination. Guerlinguetus aestuans quelchii: J. A. Allen, 1915a:259; name combination. Guerlinguetus aestuans venustus J. A. Allen, 1915a:260; type locality “Boca Sina (altitude 440 ft.), Rio Cunacunumá (southern base of Mount Duida), [Amazonas,] Venezuela.” Guerlinguetus Aestuans Gilvicularis O. M. O. Pinto, 1931:290; incorrect subsequent spelling of Sciurus gilvigularis Wagner. Sciurus [(Guerlinguetus)] aestuans aestuans: Ellerman, 1940:342; name combination. Sciurus [(Guerlinguetus)] aestuans quelchi: Ellerman, 1940:342; name combination, and incorrect subsequent spelling of Sciurus quelchii Thomas. Sciurus [(Guerlinguetus)] aestuans venustus: Ellerman, 1940: 342; name combination. Guerlinguetus gilvigularis gilvigularis: Moojen, 1942:6; name combination. Guerlinguetus poaiae Moojen, 1942:11; type locality “Mata da Poaia, Tapirapoã, Chapada, Mato-Grosso,” Brazil. G[uerlinguetus]. gilvigularis gilvigularis: Melo-Leitão, 1943: 356; name combination. Sciurus (Guerlinguetus) poaiae: W. P. Harris, 1944:11; name combination. Sciurus gilvigularis gilvigularis: Moojen, 1952b:25; name combination. Sciurus poaiae: Moojen, 1952b:26; name combination. Sciurus aestuans quelchii: Moojen, 1952b:27; name combination.

Sciurus (Guerlinguetus) gilvigularis gilvigularis: C. O. da C. Vieira, 1955:407; name combination. Sciurus [(Guerlinguetus)] aestuans poaiae: Cabrera, 1961:361; name combination. Sciurus [(Guerlinguetus)] aestuans quelchii: Cabrera, 1961:361; name combination. Sciurus (Guerlinguetus) aestuans georgihernandezi BarrigaBonilla, 1966:492; type locality “Margen derecha del río Vaupés, cerca de Mitú, Vaupés, Colombia, altura 240 m.s.n.m.” Sciurus (Guerlinguetus) aestuans: Eisenberg, 1989:331; name combination. Sciurus (Guerlinguetus) gilvigularis: Eisenberg, 1989:331; name combination. d e s c r i p t i o n : Adult body weight averages 174 g (N = 28), head and body length 176 mm (N = 235), tail length 177 mm (N = 205), hindfoot length 47 mm (N = 245), and ear length 22 mm (N = 83). Dorsal color uniformly brown to olive brown, heavily streaked with orange throughout, including the upper parts of the legs; ventral color highly variable, with throat orange to grayish white and remaining parts orange, sometimes with dark gray hairs interspersed; inner parts of forelimbs colored similarly to chest and belly; inner parts of hindlimbs darker than belly; area immediately circumscribing mammae not distinct from remainder of venter, and tail color indistinct from dorsum. Postauricular patches absent, except for some specimens from Guianan highlands. d i s t r i b u t i o n : Guerlinguetus aestuans occurs throughout Amazonia, in northeastern Peru, eastern Colombia, Venezuela south of the Río Orinoco, and Brazil north of the Rio Amazonas and west of the Rio Xingu, and throughout the Guianan region. s e l e c t e d l o c a l i t i e s (Map 3): BRAZIL: Amapá, Cachoeira de Santo Antônio, Rio Jari (MPEG 21804), Mazagão, Rio Vila Nova (MPEG 438), Vila Velha do Cassiporé, Oiapoque (MPEG 6742); Amazonas, Igarapé Auará, Rio Madeira (AMNH 91831), Santo Isidoro, Tefé (AMNH 78949); Mato Grosso, Cachoeira Dardanelos, right bank Rio Aripuanã (MPEG 8786), Estação Ecológica Serra das Araras (MPEG 15272); Pará, Aramapucu, Rio Parú do Oeste (MPEG 10019), Cussary (AMNH 37453), Foz do Rio Curuá, right bank Rio Amazonas (MZUSP 4601), Rio Jamanxim, right bank Rio Tapajós (MPEG 453); Rondônia, Cachoeira Nazaré, left bank Rio Ji-Paraná (MPEG 20825), Ouro Preto d’Oeste (MPEG 20529). COLOMBIA: Vaupés, La Providencia, Río Apaporis (Barriga-Bonilla 1966), right bank Río Vaupés, near Mitú (Barriga-Bonilla 1966). FRENCH GUIANA: River Iracoubo (MNHN 1983/350), River Oyapock (MNHN 1983/346). GUYANA: Essequibo Islands–West Demerara, Supinaam River (BM 10.5.4.12); Upper Takutu–Upper Essequibo, Kanuku Mountains

12 Mammals of South America

(type locality of Sciurus Quelchii Thomas). PERU: Loreto, Orosa, Río Amazonas (AMNH 73917), Sarayacu, Río Ucayali (AMNH 75277). SURINAM: Para, Zanderij (BM 52.1102). VENEZUELA: Amazonas, Monduapo, right bank upper Río Orinoco (BM 99.9.11.29–30); Bolívar, Ciudad Bolívar, Suapure, Río Caura valley (AMNH 16128), El Yagual, lower Río Caura (AMNH 16948). s u b s p e c i e s : We recognize two subspecies, namely, G. a. aestuans (Linnaeus, 1766) and G. a. gilvigularis (Wagner, 1845). Distributions and coat color variation of each are discussed in the Remarks section. n a t u r a l h i s t o ry: There are very few published field observations of the ecology or behavior of this species in the wild. It ranges throughout lowland rainforest and, marginally, into the dry forests of Mato Grosso state, Brazil. In French Guiana, and likely throughout this broad range, seed-caching behavior plays an important role in the demography of understory palms such as Astrocaryum sciophilum (see Sist 1989) and other largeseeded plants such as Carapa procera (Forget 1996). Forget (1991) reported that this species did not forage at ground level even when seeds were available. In French Guiana, this squirrel may persist on small and mediumsized islands produced by flooding after dam construction, which suggests that their home range size is relatively small (Dalecky et al. 2002). Peres et al. (2003), from a site in the headwaters of the Rio Arapiuns, Pará state, Brazil, estimated density of 0.444 individuals/ha, with sightings of seven solitary individuals. Voss et al. (2001) observed animals perched in trees at heights of 3–30 m above the ground, with most individuals solitary. Individuals these authors captured came primarily from primary forest at both well-drained and swampy sites as well as from somewhat disturbed habitats. r e m a r k s : Use of the name Sciurus aestuans Linnaeus by almost all authors from the late eighteenth and early nineteenth centuries (e.g., Gmelin 1788:151; Turton 1802:93; Illiger 1815:75; Thunberg 1823:2; Minding 1829:29; Schinz 1840:144; P. Gervais 1841:37, 1854:308; Gray 1843b, 1867; Chenu 1850:34) to the present (e.g., Emmons and Feer 1997; Eisenberg and Redford 1999; Thorington and Hoffmann 2005) includes both G. aestuans, as we restrict this species herein, and G. brasiliensis (next section) or even species we allocate to Notosciurus (e.g., Alston 1878:668). Geographic variation of coat color across the distribution of G. aestuans has led authors to name distinct taxa based on slight variations, all of which names we regard either as applying to subspecies or as synonyms. Here, we summarize the geographic variation of characters to justify our recognition of a single species. There

are no qualitative cranial distinctions along the entire distribution; in fact, the species is cranially indistinct from G. brasiliensis. We recognize two subspecies. The nominotypical form occurs in the Guianas, adjacent Venezuela, Amazonian Brazil, in the states of Roraima, Amazonas (to the north of the Rio Solimões–Amazonas axis), Amapá, Pará (except on the south bank of the Rio Amazonas, to the east of the Rio Xingu, where the other species of Guerlinguetus occurs), in northern Peru from scattered localities along the Río Marañón, and in Colombia near its border with Brazil. By contrast, G. a. gilvigularis (Wagner, 1845) occurs in Brazil, in the Rio Tapajós and Rio Madeira basins, and from there southward to the states of Rondônia and western Mato Grosso. These two taxa can be distinguished by the color of their ventral surfaces, aestuans with a grayish white throat but orange or yellowish chest and belly, and gilvigularis with an entirely orange or yellowish venter. Specimens from the Rio Negro region in Amazonas, Brazil, exhibit a ventral color pattern characteristic of both subspecies, suggesting that this area is a zone of intergradation between aestuans and gilvigularis. Dorsally, all animals are very similarly colored. One important aspect of morphological variation in the distribution of G. a. aestuans is that some animals collected in the highlands of the Guianas and Venezuela possess postauricular patches whereas in the adjacent lowlands such patches are either inconspicuous or absent altogether. The presence of a patch is associated with the names guianensis Peters, 1864, and macconnelli Thomas, 1901, both of which we regard as synonyms to Guerlinguetus aestuans aestuans (Linnaeus, 1766).

Map 3 Selected localities for Guerlinguetus aestuans (●). Contour line = 2,000 m.

Suborder Sciuromorpha: Family Sciuridae 13

Guerlinguetus brasiliensis (Gmelin, 1788) Brazilian Squirrel, Caxinguelê, Serelepe, Esquilo sy n o n y m s : [Sciurus] brasiliensis Gmelin, 1788:151; part; based on “Sciurus brasiliensis” of Marcgraf (1648), cited as synonym; type locality “Brasilia et Guiana,” but restricted herein to Recife, Pernambuco, Brazil (see Remarks). Sc[iurus]. guianensis: Lichtenstein, 1818:216; part; remainder under G. aestuans. Sc[iurus]. brasiliensis Lesson, 1838:468; type locality “Brésil.” Sciurus Ingrami Thomas, 1901d:368; type locality “Tunnel, Southern Minas Gerais: alt. 1200 m,” Brazil. Sciurus Roberti Thomas, 1903d:463; type locality “S. Lourenço [= São Lourenço], near Pernambuco, Alt. 50 m,” Pernumbuco, Brazil. Sciurus aestuans var. paraensis Goeldi and Hagmann, 1904:70; type locality “Mates do Pará,” Pará, Brazil. [Guerlinguetus] ingrami: E.-L. Trouessart, 1904:328; name combination. [Guerlinguetus] roberti: E.-L. Trouessart, 1904:328; name combination. Sciurus Alphonsei Thomas, 1906c:442, replacement name for S. Roberti Thomas, 1903, preoccupied by Sciurus thaiwanensis roberti Bonhote, 1901:166. Guerlinguetus alphonsei alphonsei: J. A. Allen, 1915a:261; name combination. Guerlinguetus alphonsei paraensis: J. A. Allen, 1915a:261; name combination. Guerlinguetus ingrami: J. A. Allen, 1915a:262; name combination. Guerlinguetus Aestuans Paraensis: O. M. O. Pinto, 1931: 291; name combination. Guerlinguetus Aestuans Alphonsei: O. M. O. Pinto, 1931: 292; name combination. Guerlinguetus Aestuans Garbei O. M. O. Pinto, 1931: 294; type locality “Villa Collatino, Espírito Santo,” Brazil. Sciurus [(Guerlinguetus)] ingrami: Ellerman, 1940:343; name combination. Sciurus [(Guerlinguetus)] aestuans garbei: Ellerman, 1940: 343; name combination. Sciurus [(Guerlinguetus)] alphonsei alphonsei: Ellerman, 1940:34; name combination. Sciurus [(Guerlinguetus)] alphonsei paraensis: Ellerman, 1940:34; name combination. Sciurus aestuans henseli Miranda-Ribeiro, 1941:10; type locality “Porto Feliz, Rio Uruguay, Rio Grande do Sul,” Brazil. Guerlinguetus gilvigularis paraensis: Moojen, 1942:9; name combination.

Guerlinguetus ingrami ingrami: Moojen, 1942:14; name combination. Guerlinguetus ingrami henseli: Moojen, 1942:16; name combination. G[uerlinguetus]. g[ilvigularis]. paraensis: Melo-Leitão, 1943: 356; name combination. Sciurus ingrami ingrami: Moojen, 1952b:27; name combination. Sciurus ingrami henseli: Moojen, 1952b:28; name combination. Sciurus garbei: Moojen, 1952b:28; name combination. Sciurus (Guerlinguetus) ingrami ingrami: C. O. da C. Vieira, 1953:131; name combination. Sciurus (Guerlinguetus) ingrami henseli: C. O. da C. Vieira, 1955:407; name combination. Sciurus (Guerlinguetus) garbei: C. O. da C. Vieira, 1955: 407; name combination. Sciurus (Guerlinguetus) alphonsei: C. O. da C. Vieira, 1955: 407; name combination. Sciurus (Guerlinguetus) gilvigularis paraensis: C. O. da C. Vieira, 1955:407; name combination. Sciurus gilvigularis paraensis: C. T. Carvalho, 1959:461; name combination. Sciurus [(Guerlinguetus)] aestuans alphonsei: Cabrera, 1961: 359; name combination. Sciurus [(Guerlinguetus)] aestuans henseli: Cabrera, 1961: 360; name combination. Sciurus [(Guerlinguetus)] aestuans ingrami: Cabrera, 1961: 360; name combination. Sciurus [(Guerlinguetus)] aestuans paraensis: Cabrera, 1961: 361; name combination. Sciurus ingrami sebastiani P. Müller and Vesmanis, 1971: 378; type locality “São Sebastião island [= Ilha de São Sebastião], São Paulo, Brazil.” Sciurus aestuans ingrami: Avila-Pires, 1977:23; name combination and typographical error. Sciurus [(Guerlinguetus)] aestuans: Honacki, Kinman, and Koeppl, 1982:362; name combination; part. Sciurus aestuans ingrami: Vaz, 1983:34; name combination. Guerlinguetus alphonsei: J. A. Oliveira and Bonvicino, 2006:348; name combination. Guerlinguetus henseli: J. A. Oliveira and Bonvicino, 2006:349; name combination. Sciurus aestuans sebastiani: Hutterer and Peters, 2010:14; name combination. d e s c r i p t i o n : Adult mass averages 193 g (N = 33), head and body length 180 mm (N = 175), tail length 183 mm (N = 171), foot length 46 mm (N = 177), and ear length 22 mm (N = 143). Dorsal color uniform brown to olive brown, heavily streaked with orange throughout body, including upper parts of forelegs and hindlegs; ventral color

14 Mammals of South America

highly variable, with throat always white to grayish white, with white hairs sometimes extending to chest and/or belly and/or inner sides of arms and legs; area immediately around mammae lighter than rest of venter; and dorsal color of tail either indistinct from dorsum or, if distinct, grizzled with whitish bands on hairs. Postauricular patches absent. d i s t r i b u t i o n : This species is distributed in Amazonian Brazil east of the Iriri and Xingu rivers and south of the lower Amazon in Pará, Maranhão, Tocantins, and Mato Grosso states, and extends throughout northeastern and southwestern Brazil from the states of Ceará to Rio Grande do Sul and from there to Misiones in Argentina. The species appears to occupy two disjunct areas, one corresponding to the Amazonian subspecies G. b. paraensis and the other to the two subspecies G. b. brasiliensis and G. b. ingrami, which occur continuously from northeastern to southern Brazil and Argentina. s e l e c t e d l o c a l i t i e s (Map 4): ARGENTINA: Misiones, Eldorado (BM 26.2.11.1), Santa Ana (FMNH 49885). BRAZIL: Alagoas, Usina Sinimbú, Mangabeiras (Manimbu) (MZUSP 7532); Bahia, Ilhéus (MZUSP 3501), Macaco Seco, Monte Andaraí, Rio Paraguaçu (FMNH 20424), Senhor do Bonfim [= Villa Nova] (MZUSP 2608); Ceará, Serra do Castelo (BM 20.7.1.7); Espírito Santo, Colatina, right bank Rio Doce (type locality of Guerlinguetus aestuans garbei O. M. O. Pinto), Rio Itaúnas (MZUSP 7071), Rive [= Engenheiro Reeve] (BM 3.9.4.44); Maranhão, Aldeia Gurupiúna, Reserva Indígena Alto Turiaçú (MPEG 21981), Estreito, right bank Rio Tocantins (MPEG 2444), São Bento (BM 25.5.21.6); Mato Grosso, Serra do Roncador, 264 km N of Xavantina (BM 79.203–207); Minas Gerais, Rio das Velhas, near Lagoa Santa (FMNH 20733); Pará, Belém (MPEG 710), Gradaús, right bank Rio Fresco (MZUSP 20399), mouth of Rio Bacajá, right bank Rio Xingú (MZUSP 25455), Portel, Rio Procupi (MPEG 606), Rio Riosinho, left bank Rio Fresco (MPEG 1039), Santa Júlia, Rio Iriri (BM 20.7.1.6), Urumajó, Arabóia, east of Bragança, Estrada de Ferro de Bragança (MZUSP 20398); Paraíba, Mamanguape, Camaratuba (MZUSP 8241); Pernambuco, São Lourenço (type locality of Sciurus Roberti Thomas); Rio de Janeiro, Sepetiba (NMW B1393), Terezópolis (NMW 1693); Rio Grande do Sul, Colônia do Mundo Novo (Ihering 1892:107); Santa Catarina, Joinville (BM 13.7.8.1); São Paulo, Ilha de São Sebastião (type locality of Sciurus ingrami sebastiani P. Müller and Vesmanis), Ilha do Cardoso (MZUSP 3905), Porto Cabral, Rio Paraná (MZUSP 6021), Presidente Epitácio, left bank Rio Paraná (MZUSP 3733), Santos (MZUSP 3699), Serra da Juréia (MZUSP 12835). s u b s p e c i e s : Guerlinguetus brasiliensis is polytypic: G. b. brasiliensis (Gmelin) occurs in northeastern Brazil, in the states of Ceará, Rio Grande do Norte, Paraíba, Per-

nambuco, Alagoas, Sergipe, and Bahia; G. b. paraensis (Goeldi and Hagmann) is distributed in eastern Brazilian Amazonia, in the states of Pará, the south of the Rio Amazonas from the Rio Xingu basin eastward to eastern Maranhão, Tocantins, and eastern Mato Grosso states; and G. b. ingrami (Thomas), which is found in coastal Brazil from Espírito Santo state south to Rio Grande do Sul, and extending to Misiones in Argentina. See Remarks for comments on the geographic variation of these subspecies. n a t u r a l h i s t o ry: Although the distribution suggests that G. brasiliensis inhabits several distinct biomes in eastern South America, from Amazonian rainforest to the central Brazilian savannas (Cerrado), northeastern Brazil dry forests (Caatinga), and Atlantic rainforest, we believe this species is restricted to forest habitats and does not occur in open vegetation communities. In the Amazonian and Atlantic rainforests, this species is common, and specimens are well represented in collections. In contrast, the species appears to be rare in the Cerrado and Caatinga, where it is restricted to marginal gallery forests and isolated pockets of mesic vegetation, respectively. One of us (MdV) has observed solitary individuals or groups of up to four animals in the wild, but there are literature reports of associations of up to eight animals (Solórzano-Filho 2006). As with other tree squirrels, G. brasiliensis is an arboreal specialist, shot, trapped, or observed typically at 5–12 m in the midstratum layer (Grelle 2003) where it builds nests made of moss, twigs, leaves, and plant fibers on the outside and exclusively of fibers internally; nest circumference averages 56 cm, and nests are usually placed at midcanopy (Alvarenga and Talamoni 2005). The diurnal activity pattern was represented by two peaks, one in the morning and other during the afternoon (Bordignon and Monteiro-Filho 2000). Fixed routes between the nests and food resources have been observed, and animals mark territories with urine and head-gland rubbing against the substrate. Foods include lichens, bryophytes, mushrooms, leaves, fruits, insects, and bird eggs (L. F. Ribeiro et al. 2009). At some sites, coconuts may be the most consumed item, comprising up to 70% of the diet; foods also include exotic plant seeds such as Pinus, demonstrating this species’ ability to occupy altered habitats (Bordignon and Monteiro-Filho 1999; Alvarenga and Talamoni 2006). Several studies have discussed the role of G. brasiliensis as either a seed predator and/or disperser, especially of palm species with large seeds and hard endocarps (e.g., Paschoal and Galetti 1995; G. S. Silva and Tabarelli 2001; Pimentel and Tabarelli 2004; Donatti et al. 2009). Alvarenga and Talamoni (2005) and T. G. Oliveira et al. (2007) presented evidence of reproduction associated with the onset of the rainy season, but Bordignon and MonteiroFilho (2000) captured pregnant females during two peaks,

Suborder Sciuromorpha: Family Sciuridae 15

one in the winter and the other during the summer; the latter investigators also estimated a population density of 0.89 squirrels/ha, with males occupying larger areas during the winter mating period. r e m a r k s : The name for the Brazilian Squirrel is Guerlinguetus brasiliensis, and its author is Gmelin (1788). The name was published as a synonym of his Sciurus aestuans and was attributed to G. Marcgraf (1648). Lesson (1838) recognized the species as valid, stating that F. Cuvier in Buffon’s Supplement, Tome I, had provided the name; however, in this work, F. Cuvier (1831) does not employ a binomial designation for Marcgraf’s squirrel. According to the International Code of Zoological Nomenclature (ICZN 1999:Arts. 11.6.1 and 50.7), the authorship of such a name must be attributed to the first publisher of the name, even if it was given as a junior synonym. Gmelin (1788) gave the type locality as “Brasilia et Guiana,” but as other authors have argued for the species first reported by Marcgraf (1648), we restrict it here to Recife, Pernambuco, Brazil. There is considerable geographic variation in the wide distributional range of this species, and some of this variation has been recognized at the species or subspecies level. The material examined does allow us to recognize three valid subspecies in G. brasiliensis. The typical subspecies, G. b. brasiliensis, occurs in northeastern Brazil, from the states of Ceará to Bahia, where the color of the venter is generally white on the throat, chest, belly, and inner parts of forelegs and hindlegs, and the tail is grizzled. To the

Map 4 Selected localities for Guerlinguetus brasiliensis (●). The likely disjunct distributions of Amazonian, Caatinga, and coastal populations are emphasized. Contour line = 2,000 m.

south of this area, intermediate forms between the nominotypical subspecies and G. b. ingrami appear in the state of Espírito Santo (the form to which O. M. O. Pinto [1931] gave the name garbei), with specimens having less white and more yellowish under parts but retaining grizzled tails. Farther to the south as well as west of Espírito Santo, animals show white only at the throat and chest, sometimes also at the posterior and inguinal parts of the venter; the tail is never grizzled and is always punctuated with orange or red. The third subspecies, G. b. paraensis from eastern Brazilian Amazonia, resembles ingrami but has less gray on the belly; individuals also appear to have shorter pelage and are slightly smaller. Current records suggest that G. b. paraensis is not contiguous with the other two subspecies because G. b. brasiliensis is known only from forest pockets in the otherwise open formation of the Caatinga and G. b. ingrami occurs in the Atlantic Forest, which is mostly separated from Amazonia by open savannas of the Cerrado, a biome without any squirrel records (Carmignotto et al. 2012).

Genus Hadrosciurus J. A. Allen, 1915 Hadrosciurus contains the largest of the South American squirrels, distributed in Venezuela south of the Orinoco, Colombia, Ecuador, and Peru east of the Andes, western Brazilian Amazonia, and western central Brazil, Bolivia, and northern Paraguay. This genus can be distinguished from most other South American sciurid genera by their size, except for the similarsized Simosciurus, which differs from Hadrosciurus by its distinctly coarser pelage, ears covered by longer hairs, shorter skull with a broader rostrum, and a trans-Andean distribution. Individuals of some species of Notosciurus reach sizes that overlap the lower size limits of Hadrosciurus, but the two genera can be distinguished because the latter exhibits four pair of mammae instead of three. Hadrosciurus, like other South American squirrels, exhibits considerable variation in external morphology and especially in color. Mass varies from 450 to 750 g, head and body length from 215 to 320 mm, tail length from 220 to 330 mm, hindfoot length from 50 to 75 mm, and ear length from 20 to 40 mm. A well-developed postorbital process equally divides the orbitotemporal fossa of the skull. The genus includes three polytypic species, namely, Hadrosciurus igniventris, with three subspecies, Hadrosciurus pyrrhinus, with two subspecies, and Hadrosciurus spadiceus, with three subspecies. These three species present an interesting pattern of sympatry, with their largescale ranges overlapping along the lower Solimões and lower Purús rivers, the only region where museum specimens document the presence of all three. All remaining

16 Mammals of South America

sympatry records are for pairs of species, with H. igniventris and H. spadiceus broadly sympatric in Ecuador and northern Peru; H. pyrrhinus and H. spadiceus sympatric along the middle and lower Rio Juruá in western Brazil; and H. pyrrhinus and H. igniventris sympatric along the lower Rio Negro, also in Brazil. It is somewhat surprising that so few localities have yielded sympatric species of squirrels, if we consider that, at least potentially, the area of sympatry at map scale covers much of central Peru and a vast area of the Brazilian western Amazonia. Patton et al. (1982) and Lemke et al. (1982) documented sympatry for H. igniventris and H. spadiceus in northern Peru and southern Colombia, respectively. sy n o n y m s : Sciurus: Olfers, 1818:208; part (listing of spadiceus); not Sciurus Linnaeus, 1758. Macroxus: Gray, 1867:428; part (listing of langsdorffii); not Macroxus F. Cuvier, 1823. Guerlinguetus: Miranda-Ribeiro, 1914:36; part (listing of langsdorffii); not Guerlinguetus Gray, 1821. Mesosciurus (Histriosciurus) J. A. Allen, 1915a:213; type species Sciurus gerrardi Gray, by original designation; part; all species-level taxa in this genus belong to Notosciurus J. A. Allen except for J. A. Allen’s Mesosciurus pyrrhinus. Hadrosciurus J. A. Allen, 1915a:265; type species Sciurus flammifer Thomas, by original designation. Urosciurus J. A. Allen, 1915a:267, type species Sciurus tricolor Tschudi, by original designation. Sciurus (Urosciurus): Thomas, 1926f:635; name combination. Sciurus (Hadrosciurus): Thomas, 1928b:259; name combination. [Sciurus] (Guerlinguetus): Ellerman, 1940:340; as subgenus (among the included species is Sciurus pyrrhinus Thomas). Guerlinguetus (Hadrosciurus): Moore, 1959:177; name combination. r e m a r k s : Our concept of Hadrosciurus mirrors that of Thomas (1928b), who suggested that Sciurus (Hadrosciurus) encompassed all the largest squirrels east of the Andes, but this concept requires more detailed clarification. As new species of squirrels were added to the roster of taxa from South America, J. A. Allen (1915a), acting as the first true reviewer of the family for the continent, recognized several distinct genera and subgenera, many of which he described as new. For the largest squirrels, Allen described two new genera: Hadrosciurus, containing only H. flammifer, and Urosciurus, with several species, including U. langsdorffii, U. igniventris, U. pyrrhonotus, and others. He also created the genus Mesosciurus for many species and subspecies in the Sciurus granatensis complex, in which he included Sciurus

pyrrhinus Thomas as a species—Mesosciurus (Histriosciurus) pyrrhinus. However, Thomas (1927a) suggested that Allen’s genera were “very intangible” and decided to change the status of many by placing them as subgenera of Sciurus. In this same work, Thomas allied pyrrhinus with igniventris, thus, for all practical purposes, removing pyrrhinus from Mesosciurus. Shortly thereafter, Thomas (1928b) realized that Sciurus flammifer, the type and only species of Allen’s Hadrosciurus, belonged together with all the other large squirrels in a single taxonomic entity and that, having been described a few pages earlier than Urosciurus, the former would be the proper generic name for these squirrels, with Urosciurus as a junior synonym. Except for a few specific and subspecific taxa not yet known at the time of Thomas’s publication, the content he assigned to Hadrosciurus is the same as ours. Ellerman (1940) did not subscribe to Thomas’s views and rearranged the specific contents of Thomas’s Sciurus (Hadrosciurus), placing pyrrhinus with most other South American squirrels in his Sciurus (Guerlinguetus). Moore (1959) arranged all non-dwarf South American squirrels in the genus Guerlinguetus, with Hadrosciurus as a subgenus. Subsequent authors, for example, Thorington and Hoffmann (2005), believed that Moore (1959) had additionally recognized Urosciurus J. A. Allen as a subgenus of his Guerlinguetus. However, Moore (1959:177, 198) included Sciurus igniventris Wagner, the type species of Urosciurus J. A. Allen, as Guerlinguetus (Hadrosciurus) igniventris, thus treating Urosciurus as a junior synonym. Because Cabrera’s (1961) work was published posthumously, he probably never saw Moore’s (1959) arrangement and so employed Thomas’s scheme for the genus. The current practice of regarding Urosciurus as a valid generic name for the large South American squirrels has resulted from a misreading of Moore’s intentions. Hershkovitz (1959b) expanded the discussion of cranial characters initiated by J. A. Allen (1915a) by recognizing two groups of large South American squirrels, which he treated as distinct species based on a characterization of the skull as either “short and broad” (Sciurus igniventris) or “long and narrow” (Sciurus spadiceus). Patton (1984) performed a morphometric study of Peruvian samples, agreed with Hershkovitz (1959b) that two distinct skull morphotypes could be recognized in the area, and resurrected Urosciurus as a subgenus of Sciurus. At present, we cannot ascertain how the three species and subordinated subspecies that we have recognized in the genus Hadrosciurus can be distinguished by the cranial characters described by Hershkovitz (1959b) and Patton (1984), particularly because the presence of these characters has not been tested throughout the entire distribution of the genus. We employ Hadrosciurus as a full genus to keep

Suborder Sciuromorpha: Family Sciuridae 17

what seems to us a distinct group of species—distinguished mainly by their large size from other South American taxa—and to separate these squirrels from Sciurus, a near cosmopolitan taxon. We wish to emphasize that the differences in skull morphology demonstrated by Patton (1984) are quite substantive, contrary to what some previous authors believed (such as Oldfield Thomas). Indeed, we have not found such trenchant character differences in other South American squirrels, and it seems highly unlikely that strongly bimodal distribution is populational or merely geographical. Hadrosciurus might, with further study, be justifiably split into distinct taxonomic groups based on their skull morphology alone. KEY TO THE SPECIES OF HADROSCIURUS:

1. Dorsum black or dark brown background streaked with red, orange, or yellow (dark hairs with red, orange, or yellow subterminal bands) . . . . . . . . . . . . . . . . . . . . . 2 1′. Dorsum brownish red to reddish orange with little or no streaking; postauricular patch small, but distinct. . . . . . . . . . . . . . . . . . . . . . . . . . . Hadrosciurus pyrrhinus 2. Forelimbs uniformly orange or red, differently colored from dorsum; postauricular patch rarely present . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hadrosciurus igniventris 2′. Forelimbs similar to that of anterior dorsum; postauricular patch always absent. . . .Hadrosciurus spadiceus

Hadrosciurus igniventris (Wagner, 1842) Northern Amazon Red Squirrel, Quatipuru-açú sy n o n y m s : See under subspecies. d e s c r i p t i o n : Large, with head and body length 246–300 mm (N = 117 adults), tail length 236–310 mm (N = 118), hindfoot length 58–75 mm (N = 111), ear length 29–40 mm (N = 73), and mass 453–700 g (N = 12). Dorsum dark, distinctly punctuated by light subapical bands to hairs, with background color from dark brown to black, and light bands from pale yellow to orange and red. Presence of distinct postauricular patches variable geographically; if present, pale orange in color. Forelimbs, and sometimes the hind legs, homogeneously orange to red; ventral color from white to reddish orange or orange yellow; base of tail colored like dorsum, with the terminal portion distinctly orange. Completely or partially melanistic individuals common. d i s t r i b u t i o n : The species occurs in northwestern Amazonia from the right bank of the Río Orinoco in Venezuela southward to the Rio Negro and Rio Solimões in Brazil and westward to Colombia, Ecuador, and northern Peru east of the Andes. The record of two specimens (MPEG 21807, 21808) from the Brazilian state of Amapá (Cachoeira do Santo Antonio, Rio Jari) is likely in error because there are no other records between this locality and the easternmost known distributional limit of the species

in Roraima, Brazil, about 1,000 km to the west. Cláudia Regina da Silva (pers. comm. to MdV) has conducted extensive mammal inventories in Amapá and has never encountered this species in the wild, nor has she ever heard locals refer to such a squirrel. s e l e c t e d l o c a l i t i e s (Map 5): BRAZIL: Amazonas, Canabuoca, Paraná do Jacaré (SMF 6918), Igarapé de Alvarães, right bank Rio Solimões (MZUSP 18921), Paraná do Aiapuá, Rio Purus (MZUSP 20357), Paraná do Manhãna, between Rio Japurá and Rio Solimões (MZUSP 6141); Roraima, BR 174, frontier between Brazil and Venezuela, frontier mark 8 (MZUSP 22347), lower Rio Mucajaí, south of Boa Vista (MZUSP 9779); Roraima, Rio Catrimani (MZUSP 13688). COLOMBIA: Boyacá, Río Lengupa (AMNH 38407); Caquetá, Florencia, Río Bodoquera (AMNH 33691); Cundinamarca, Sabana Grande, lowlands near Bogotá (type locality of Sciurus igniventris taedifer Thomas); Meta, La Macarena, Río Yerli (FMNH 87954). ECUADOR: Loja, El Porotillo San José (MNHN 1934/1207); Morona–Santiago, Chiguaza (FMNH 54287), Mendéz Sur (MNHN 1960/3790); Orellano, Río Cotapino (FMNH 47600); Pichincha, Quito (MNHN 1937/893). PERU: Cajamarca, Chaupe (AMNH 64047); Loreto, Pebas (AMNH 98426), Santa Elena, Río Samiria (FMNH 87158), Santa Rita, Iquitos (FMNH 87148), Yurimaguas, Río Huallaga (FMNH 19674); San Martín, about 35 mi W of Moyobamba, Río Negro (AMNH 73214). VENEZUELA: Amazonas, Nericagua (Caño Usate), Río Orinoco (BM 99.9.11.26), Raya 32 km SSE of Puerto Ayacucho (USNM 409801); Bolívar, Ciudad Bolívar (AMNH 16127), El Yagual, lower Río Caura (AMNH 16940). s u b s p e c i e s : We recognize three subspecies of H. igniventris. See Remarks for a description of the geographic variation.

H. i. cocalis (Thomas, 1900) sy n o n y m s : Sciurus cocalis Thomas, 1900e:138, type locality “Mouth of Coca River, Upper Rio Napo,” Orellana, Ecuador. Urosciurus igniventris cocalis: J. A. Allen, 1915a:273; name combination. Sciurus (Hadrosciurus) igniventris: Thomas, 1928c:289; part. Sciurus [(Hadrosciurus)] igniventris cocalis: Ellerman, 1940: 345; name combination. Sciurus igniventris cocalis: Soukup, 1961:244; name combination. Sciurus [(Urosciurus)] igniventris [cocalis]: Thorington and Hoffmann, 2005:762; name combination. This subspecies occurs in Ecuador east of the Andes, and in Peru in the departments of Loreto, Cajamarca, and San Martín.

18 Mammals of South America

H. i. igniventris (Wagner, 1842) sy n o n y m s : Sciurus igniventris Wagner, 1842c:360; type locality “Rio Negro”; restricted by Wagner (1850:277) to “Marabitanos, überhaupt vom Rio negro” [= Marabitanas], right bank of the upper Rio Negro, Amazonas, Brazil. Sciurus Morio Wagner, 1850:275, type locality “Marabitanos, überhaupt vom Rio negro” [= Marabitanas], right bank of the upper Rio Negro, Amazonas, Brazil. (?) Macroxus fumigatus Gray, 1867:428, type locality “Brazil, Upper Amazons”; identity uncertain as holotype is almost entirely melanistic. (?) Macroxus brunneo-niger Gray, 1867:429, type locality “Brazil”; identity uncertain as holotype is almost entirely melanistic. Sciurus igniventer Gray, 1867:433; incorrect subsequent spelling of Sciurus igniventris Wagner. Sciurus igniventris niger Fitzinger, 1867a:479; type locality “Am. Brasilien, Rio negro, Marabitanas,” Amazonas, Brazil. Sciurus igniventris taedifer Thomas, 1903b:487, type locality “Sabaña Grande, near Bogota,” Cundinamarca, Colombia. Sciurus tricolor morio: E.-L. Trouessart, 1904:328; name combination. Sciurus brunneo-niger: E.-L. Trouessart, 1904:328; name combination. Sciurus duida J. A. Allen, 1914d:594, type locality “Rio Cunucunumá (altitude 700 feet), base of Mount Duida, [Amazonas,] Venezuela.” Sciurus igniventris zamorae J. A. Allen, 1914d:594, type locality “Zamora (altitude 2,000 feet), [Zamora– Chinchipe,] Ecuador.” Urosciurus duida: J. A. Allen, 1915a:270; name combination. Urosciurus igniventris igniventris: J. A. Allen, 1915a:271; name combination. Urosciurus igniventris taedifer: J. A. Allen, 1915a:272; name combination. Urosciurus igniventris zamorae: J. A. Allen, 1915a:274; name combination. S[ciurus]. (Hadrosciurus) igniventris: Thomas, 1928c:290; name combination. Hadrosciurus igniventris igniventris: Tate, 1939:176; name combination. Hadrosciurus igniventris duida: Tate, 1939:176; name combination. Hadrosciurus igniventris: Cabrera and Yepes, 1940:195; name combination. Sciurus [(Hadrosciurus)] duida: Ellerman, 1940:344; name combination.

Sciurus [(Hadrosciurus)] igniventris igniventris: Ellerman, 1940:344; name combination. Sciurus [(Hadrosciurus)] igniventris taedifer: Ellerman, 1940: 344; name combination. Sciurus [(Hadrosciurus)] igniventris zamorae: Ellerman, 1940:345; name combination. Hadrosciurus igniventris manhanensis Moojen, 1942:24, type locality “Paraná do Nanhana [= Manhana; Paynter and Traylor 1991], entre o Rio Japurá e o Amazonas, Amazonas,” Brazil. Hadrosciurus pyrrhonotus purusianus Moojen, 1942:31, type locality “Lago Aiapuá, Baixo Purús, Estado do Amazonas,” Brazil. Sciurus [(Hadrosciurus)] igniventris manhanensis: W. P. Harris, 1944:12; name combination. Sciurus [(Hadrosciurus)] igniventris purusianus: W. P. Harris, 1944:12; name combination. Sciurus igniventris igniventris: Sanborn, 1949b:285; name combination. Sciurus igniventris manhanensis: Moojen, 1952b:30; name combination. Sciurus pyrrhonotus purusianus: Moojen, 1952b:31; name combination. Sciurus (Hadrosciurus) pyrrhonotus purusianus: C. O. da C. Vieira, 1955:408; name combination. Guerlinguetus (Hadrosciurus) igniventris: Moore, 1959:203; name combination. Sciurus [(Urosciurus)] igniventris: Patton, 1984:53; name combination. The nominotypical subspecies occurs in Colombia east of the Andes in Cundinamarca, Meta, and Caquetá departments; along the Río Napo in Loreto, Peru; in Amazonas department of Venezuela; and in Roraima state in Brazil, on the left bank of the Rio Branco, and in Amazonas state, along the Rio Solimões and Rio Negro.

H. i. flammifer (Thomas, 1904) sy n o n y m s : Sciurus flammifer Thomas, 1904d:33, type locality “La Union, Caura district, Lower Orinoco,” Bolívar, Venezuela. Hadrosciurus flammifer: J. A. Allen, 1915a:266; name combination. S[ciurus (Hadrosciurus)]. flammifer: Thomas, 1928c:290; name combination. Guerlinguetus (Hadrosciurus) flammifer: Moore, 1959:203; name combination. This subspecies is distributed from the Venezuelan department of Bolívar, south of the Orinoco and west of Río Caroní, to the Brazilian border at Serra de Pacaraima. n a t u r a l h i s t o ry: Emmons and Feer (1997) noted that individuals are diurnal, arboreal, territorial, and

Suborder Sciuromorpha: Family Sciuridae 19

solitary, although several may feed together in a single fruiting tree. Primary foods include large palm nuts and other tree nuts and fruits. Silvius (2002) reported individuals feeding on beetle larvae as well as the endocarp of the palm Attalea maripa. The species is largely limited to closed-canopy rainforest, either mature or disturbed (Emmons and Feer 1997). Youlatos (1999) reported that individuals used all forest heights, preferring tree crowns and lianas, with an ability to walk, leap, and bound along small horizontal supports. Jessen, Palmer, and Koprowski (2013) reported a nest for an unidentifiable melanistic female of either H. igniventris or H. spadiceus from Loreto, Peru, built at 3.6 m above ground with two offspring. r e m a r k s : Hadrosciurus igniventris cocalis is a large squirrel with orange forelimbs, which differs from the nominotypical subspecies by a dark to almost black dorsal color streaked with orange or dark red, the presence of conspicuous orange postauricular patches, and a yellowish orange venter. Hadrosciurus igniventris igniventris is also a large squirrel with orange to red forelimbs, with hindlimbs colored as the forelimbs or dorsum; head blackish above, with an orange muzzle diluted with black and with no conspicuous eye-ring; ears brown to almost black on both sides; postauricular patches, if present, inconspicuous;

Map 5

Selected localities for Hadrosciurus igniventris (●). Contour line = 2,000 m.

dorsum black to dark brown heavily streaked with orange or red; venter red, with same color extending to undersides of legs; and tail dark, mostly black over the proximal third, with some orange distally. J. A. Allen (1915a:267–268) placed Sciurus igniventris Wagner in his new genus Urosciurus. Hadrosciurus igniventris flammifer is similar to H. i. igniventris, with orange to red limbs and a black dorsum heavily streaked with pale yellow to orange, but the former differs from the latter by having conspicuous pale orange postauricular patches and a white venter. The genus Hadrosciurus was created by J. A. Allen (1915a), with Sciurus flammifer as its type and only species.

Hadrosciurus pyrrhinus (Thomas, 1898) Junín Red Squirrel, Quatipuru-açú sy n o n y m s : See under subspecies. d e s c r i p t i o n : Equivalent in size to H. igniventris, with head and body length 220–290 mm (N = 44 adults), tail length 252–305 mm (N = 42), hindfoot length 60– 70 mm (N = 40), and ear length 31–35 mm (N = 19). Color of dorsum, forelimbs, and hindlegs uniform dark red to brownish red, without streaking by hairs with light apical or subapical bands. Conspicuous postauricular patches present, generally pale yellow or light orange throughout most of range but inconspicuous in specimens from upper Rio Negro area of Brazil at Colombian border. Venter white to pale red, mixture of both colors in some individuals; when white, transition from venter to torso, limbs, and head demarcated by a red strip. d i s t r i b u t i o n : This species occurs from the eastern Andean slopes of central Peru to western Brazilian Amazonia, probably limited by the Purus river basin on the east and Negro basin on the north. s e l e c t e d l o c a l i t i e s (Map 6): BRAZIL: Amazonas, between Cajutuba and Airão, Rio Jaú, Rio Negro (syntype of Sciurus igniventris Wagner), Codajás, left bank Rio Solimões (MZUSP 4202), Dejedá, Rio Juruá (type locality of Urosciurus nigratus O. M. O. Pinto), Estirão do Equador, right bank Rio Javari (MPEG 1807), Manaus (syntype of Sciurus igniventris Wagner), Santo Antônio do Içá, left bank Rio Içá (MZUSP 20384), Tahuapunto (Tauá), Rio Vaupés, left bank (AMNH 78620). PERU: Cusco, San Juan Grande, Quincemil, Quispicanchis (FMNH 75208); Huánuco, Tingo Maria, Río Huallaga (FMNH 24112); Junín, Tarma, 2 mi NW of San Ramón (AMNH 231771); Pasco, Puerto Bermudez (FMNH 24110). s u b s p e c i e s : We tentatively recognize two subspecies of H. pyrrhinus, which we compare in the Remarks section.

20 Mammals of South America

H. p. fulminatus (Thomas, 1926) sy n o n y m s : Sciurus [(Urosciurus)] igniventris fulminatus Thomas, 1926f:637; type locality “Manacapuru,” Rio Solimões, Amazonas, Brazil. S[ciurus. (Urosciurus)] i[gniventris]. fulminatus: Thomas, 1928c:290; name combination. Urosciurus nigratus O. M. O. Pinto, 1931:309; type locality “Rio Juruá (Amazonas),” Brazil. Sciurus [(Hadrosciurus)] nigratus: Ellerman, 1940:344; name combination. Sciurus [(Hadrosciurus)] igniventris fulminatus: Ellerman, 1940:345; name combination. Hadrosciurus igniventris fulminatus: Moojen, 1942:22; name combination. Sciurus igniventris fulminatus: Moojen, 1952b:29; name combination. Sciurus (Hadrosciurus) pyrrhonotus fulminatus: AvilaPires, 1964:15; name combination. This subspecies occurs primarily in Amazonas state, Brazil; it is also known from a single locality in Cusco department, Peru.

H. p. pyrrhinus (Thomas, 1898) sy n o n y m s : Sciurus pyrrhinus Thomas, 1898f:265; type locality “Garital del Sol, Vitoc, [Junín,] Peru.” Mesosciurus [(Histriosciurus)] pyrrhinus: J. A. Allen, 1915a:252; name combination. Sciurus [(Urosciurus)] pyrrhinus: Thomas, 1927a:369; implicit allocation to subgenus due to accepted resemblance to S. igniventris. Sciurus [(Guerlinguetus)] pyrrhinus: Ellerman, 1940:342; name combination. Sciurus (Hadrosciurus) pyrrhinus: Cabrera, 1961:378; name combination. The nominotypical subspecies occurs on the eastern slopes of the Andes in the Peruvian departments of Huánuco, Junín, Pasco, and Ucayali. n a t u r a l h i s t o ry: Emmons and Feer (1997) stated that this species inhabits montane forests across an elevational range from 600 to 2,000 m, but it occurs at less than 300 m elevation at localities in the central Amazon. r e m a r k s : The taxonomic history of Hadrosciurus pyrrhinus (Thomas) is marked by its erroneous allocation to a group of Andean and peri-Andean taxa allied to Notosciurus granatensis by J. A. Allen (1915a). Although it is superficially similar to these squirrels, its distribution on the eastern slopes of the central Peruvian Andes only added to the confusion. The alliance of pyrrhinus to other large South American squirrels we include in Hadrosciurus be-

comes clear when it is considered together with its sister subspecies, as we shall do. Hadrosciurus pyrrhinus fulminatus is similar to H. p. pyrrhinus except that dorsal tones are paler, duller red; pale orange postauricular patches are conspicuous; the venter is uniformly yellow to orange. This taxon occurs sympatrically with two other forms in the genus (namely H. i. igniventris and H. spadiceus pyrrhonotus) in the region of the lower Rio Solimões and Rio Purus in the Brazilian state of Amazonas. In this area of sympatry, H. pyrrhinus can be distinguished from H. i. igniventris by its uniform dull dark red dorsal color with very little streaking (which results from a pale band near the tip of the hairs) and the possession of conspicuous postauricular patches. Hadrosciurus pyrrhinus is distinguished from H. spadiceus pyrrhonotus by presence of distinct postauricular patches, a less vivid red dorsum with less streaking, and yellowish orange as opposed to white venter. Since its description, fulminatus has been allied to Sciurus igniventris, and since Thomas (1927a) transferred pyrrhinus to the igniventris complex, both have been usually treated as distinct subspecies under igniventris. The similarity in coat color between pyrrhinus and fulminatus made us consider a probable affinity, here inferred at the subspecific level.

Map 6

Selected localities for Hadrosciurus pyrrhinus (●). Contour line = 2,000 m.

Suborder Sciuromorpha: Family Sciuridae 21

Hadrosciurus spadiceus (Olfers, 1818) Southern Amazon Red Squirrel, Quatipuru-açú sy n o n y m s : See under subspecies. d e s c r i p t i o n : Slightly larger than other species in the genus, with head and body length 215–316 mm (N = 78 adults), tail length 225–325 mm (N = 78), hindfoot 50– 75 mm (N = 76), ear length 20–35 mm (N = 36), and mass 650–750 g (N = 3). Highly variable species, as apparent from several subspecies we recognize (see Remarks for distinctive characters of each subspecies). Dorsum dark, with black background color, strongly streaked with pale yellow, yellow, orange, or red; specimens from Peru have darker mid-dorsal strip. Alternatively, the dorsum may be mostly or entirely red, or divided into relatively distinct anterior and posterior regions, with posterior part uniformly colored orange but anterior portion dark and streaked. Dorsal sides of forelimbs and hindlimbs colored same as adjacent region of upper body; in southeastern portion of distribution, hindlegs divided into paler anterior and darker posterior regions. Differently colored postauricular patches absent. Ventral color variable: white in specimens from Brazilian Amazon and parts of Bolivia, white to yellow in those from Peru, and red in west-central Brazil, central Bolivia, and northern Paraguay. d i s t r i b u t i o n : The species occurs from southern Colombia, Ecuador, and Peru east of the Andes, eastward into Amazonian Brazil, where it is limited to the region south of the Rio Solimões-Amazonas system, from the Rio Tapajós west to the Peruvian border, and south to west-central Brazil in the states of Mato Grosso and Mato Grosso do Sul as well as across the lowlands of Bolivia to northern Paraguay. selected localities (Map 7): BOLIVIA: La Paz, Chimate (BM 1.2.1.7); Santa Cruz, Santa Cruz de la Sierra (FMNH 21420). BRAZIL: Acre, Oriente (= Seringal Oriente), near Taumaturgo, Rio Juruá (MPEG 725); Amazonas, Eirunepé, left bank Rio Juruá (MZUSP 4634), Lago do Batista, Ilha de Tupinambarama, right bank Rio Amazonas (MZUSP 4567), Lago do Mapixi, east of Rio Purus (FMNH 38881), Manaqueri, Rio Solimões (NMW B 1533), mouth Rio Guariba, left bank Rio Aripuanã (MPEG 8785); Mato Grosso, Mato Grosso (= Vila Bela da Santíssima Trindade) (NMW B 1520), Palmeiras (MZUSP 6338), Villa Maria, NNW of Cáceres (NMW B 1518); Mato Grosso do Sul, Urucum (type locality of Sciurus langsdorffii urucumus J. A. Allen); Pará, Flexal, Itaituba–Jacareacanga road, km 212, left bank Rio Tapajós (MPEG 10165), Rio Arapiuns, left bank Rio Tapajós (MPEG 424), Sumaúma, left bank Rio Tapajós (MZUSP 20365); Rondônia, Ouro Preto d’Oeste, Rio Paraíso (MPEG 12411). COLOMBIA: Meta, Cabaña Duda, junction of Río Duda and Río Guayabero (Lemke et al. 1982), Fundo “Guami,” Piñalto (Lemke et al. 1982).

ECUADOR: Morona–Santiago, Río San José (AMNH 68264); Napo, mouth of Río Coca, upper Río Napo (BM 0.6.3.2), boca del Río Lagarto Cocha (AMNH 72231); Pastaza, Mera (AMNH 67674). PARAGUAY: Alto Paraguay, Estancia Kambá Aka, Parque Nacional Río Negro (D’Elía, Mora et al. 2008). PERU: Cajamarca, Huarandosa (AMNH 67095); Huánuco, Tingo Maria, Río Huallaga (FMNH 24113); Loreto, boca del Río Curaray (AMNH 72177), Río Apayacu (AMNH 74389), San Fernando, Río Yavari (FMNH 88967); Puno, Pauquiplaya, below San Ignacio, Río Tambopata (FMNH 79903). s u b s p e c i e s : We tentatively recognize four subspecies of H. spadiceus, as follows.

H. s. castus (Thomas, 1903) sy n o n y m s : Sciurus castus Thomas, 1903b:488, type locality “Chimate, [La Paz,] Bolivia, . . . on the Upper Rio Beni.” Urosciurus pyrrhonotus castus: J. A. Allen, 1915a:276; name combination. Hadrosciurus pyrrhonotus castus: Cabrera and Yepes, 1940: 195; name combination. Sciurus [(Hadrosciurus)] pyrrhonotus castus: Ellerman, 1940:345; name combination. Hadrosciurus langsdorffii rondoniae Moojen, 1942:39; type locality “Cabeceiras do Rio Aripuanã, Rondonia, Mato-Grosso,” Brazil. Sciurus [(Hadrosciurus)] langsdorffii rondoniae: W. P. Harris, 1944:12; name combination. Sciurus langsdorffii rondoniae: Moojen, 1952b:32; name combination. Sciurus pyrrhonotus castus: Soukup, 1961:244; name combination. This subspecies is known from Rondônia state, Brazil, and an isolated locality in La Paz department, Bolivia. It is quite similar morphologically to the nominotypical form, differing primarily by more extensive white on the venter and the lack of a conspicuous eye-ring. The head is black, mixed with orange on the crown; the rostrum also black and orange; the ears brown on both sides; postauricular patches are absent; the dorsum black, finely streaked with vivid yellow; forefeet and limbs the same color as the dorsum, only slightly lighter distally; hindfeet orange streaked with black; bicolored legs—their anterior portion the same color as the sides but darker orange posteriorly; venter entirely white to white with some yellow from throat to chest, white extending to the undersides of fore and hind limbs almost to the feet, with the color near the feet the same as dorsal parts of the legs; and the proximal quarter to third of the tail is dark, and also turning black with an orange tip. Hadrosciurus langsdorffii rondoniae Moojen,

22 Mammals of South America

from west-central Brazil, is identical to castus and thus is placed as a synonym.

H. s. pyrrhonotus (Wagner, 1842) sy n o n y m s : Sciurus pyrrhonotus Wagner, 1842c:360, type locality “Borba,” Amazonas, Brazil. Urosciurus pyrrhonotus pyrrhonotus: J. A. Allen, 1915a: 275; name combination. Urosciurus pyrrhonotus: O. M. O. Pinto, 1931:303; name combination. Sciurus [(Hadrosciurus)] pyrrhonotus pyrrhonotus: Ellerman, 1940:345; name combination. Hadrosciurus pyrrhonotus pyrrhonotus: Moojen, 1942:26; name combination. Sciurus pyrrhonotus pyrrhonotus: Moojen, 1952b:30; name combination. Sciurus pirrhonotus Alho, 1982:144; incorrect subsequent spelling of Sciurus pyrrhonotus Wagner. The range of H. s. pyrrhonotus is limited to Amazonas state, Brazil, south of the Rio Amazonas–Solimões along the lower and middle courses of the Rio Purus and Rio Madeira. Specimens typically have a black head but orange rostrum, and lack a conspicuous eye-ring. The ears are red on both sides. Postauricular patches are absent. The dorsum is red, slightly darker on the midline. The forelimbs and feet are the same color as the dorsum, only slightly lighter distally. The hindlegs and feet are reddish. The venter is white, with the white extending to the undersides of arms and legs almost to the feet. The color near forefeet and hindfeet is the same as dorsal parts of the legs. The tail is dark over the proximal third of its length, with red predominating in the middle section and black predominating distally. Some specimens of this subspecies have the dorsum partially divided into anterior and posterior sections with slightly distinct hues of red and distinct amounts of banding of the hairs, but the dorsal color is always red, and the venter is white.

H. s. spadiceus (Olfers, 1818) Sc[iurus]. spadiceus Olfers, 1818:208; type locality restricted by Hershkovitz (1959b:346) to Cuiabá, Mato Grosso, Brasil. Sciurus langsdorffii Brandt, 1835:89, type locality “Brazil,” restricted to Cuiabá, Mato Grosso, Brazil by Wagner (1850:275). Sciurus Langsdorfii Gray, 1843b:137; incorrect subsequent spelling of Sciurus langsdorffii Brandt. Sciurus langsdorffii Var. rufa Wagner, 1844:plate CCXV; preoccupied by Sciurus rufus Kerr, 1792. Sciurus Langsdorffi: E.-L. Trouessart, 1897:429; name combination and incorrect subsequent spelling of Sciurus langsdorffii Brandt.

Sciurus Langsdorfi: Thomas, 1900e:137; name combination and incorrect subsequent spelling of Sciurus langsdorffii Brandt. Sciurus langsdorffii urucumus J. A. Allen, 1914d:595; type locality “Urucum, (altitude 400 feet), Rio Paraguay (at mouth of Rio Tacuari), [Mato Grosso do Sul,] Brazil.” Sciurus langsdorffii steinbachi J. A. Allen, 1914d:596; type locality “Santa Cruz de La Sierra, [Santa Cruz,] Bolivia.” Guerlinguetus langsdorffi: Miranda-Ribeiro, 1914:36; name combination and incorrect subsequent spelling of Sciurus langsdorffii Brandt. Urosciurus langsdorffii langsdorffii: J. A. Allen, 1915a:276; name combination. Urosciurus langsdorffii urucumus: J. A. Allen, 1915a:278; name combination. Urosciurus langsdorffii steinbachi: J. A. Allen, 1915a:279; name combination. Urosciurus langsdorffi urucumus: J. A. Allen, 1916d:572; name combination. Hadrosciurus langsdorffii urucumus: Cabrera and Yepes, 1940:196; name combination. Hadrosciurus langsdorffii steinbachi: Cabrera and Yepes, 1940:196; name combination. Sciurus [(Hadrosciurus)] langsdorffi langsdorffi: Ellerman, 1940:345; name combination. Sciurus [(Hadrosciurus)] langsdorffi urucumus: Ellerman, 1940:345; name combination. Sciurus [(Hadrosciurus)] langsdorffi steinbachi: Ellerman, 1940:345; name combination. Hadrosciurus langsdorffii langsdorffii: Moojen, 1942:36; name combination. Sciurus langsdorffii langsdorffii: Moojen, 1952b:32; name combination. Guerlinguetus (Hadrosciurus) urucumus: Moore, 1959: 203; name combination. Guerlinguetus (Hadrosciurus) spadiceus: C. T. Carvalho, 1965:52; name combination. Sciurus [(Urosciurus)] spadiceus: Patton, 1984:53; name combination. Sciurus (Hadrosciurus) spadiceus: Eisenberg, 1989:335; name combination. Sciurus [(Urosciurus)] spadiceus [steinbachi]: Thorington and Hoffmann, 2005:763; name combination. Urosciurus spadiceus: J. A. Oliveira and Bonvicino, 2006: 350; name combination. The nominotypical subspecies occurs in the southern part of Mato Grosso and northwestern Mato Grosso do Sul states, Brazil, and extends west to Santa Cruz department, Bolivia. Specimens are characterized by a black head mixed with orange on the crown, a black and orange muzzle, a conspicuous eye-ring, ears brown on both

Suborder Sciuromorpha: Family Sciuridae 23

sides; no postauricular patches; dorsum black finely lined with yellow and slightly darker on the midline; forefeet and limbs the same color as dorsum, only slightly lighter distally; black hindfeet streaked with orange; bicolored hindlegs, anteriorly the same pale orange as the sides but posteriorly darker reddish; venter yellowish orange, with some white on the throat and with color extending to the undersides of forelegs and hindlegs, almost to the feet; color near feet same as dorsal parts of legs; and proximal quarter of tail dark, becoming black before terminating in an orange tip.

H. s. tricolor (Tschudi, 1845) sy n o n y m s : Sc[iurus]. tricolor Tschudi, 1845:156, plate XI; type locality “Peru”; restricted to “Maynas, in the angle between the lower Huallaga and the Marañon [Loreto]” (Thomas 1900e:137). Urosciurus tricolor: J. A. Allen, 1915a:269; name combination. Sciurus (Urosciurus) pyrrhonotus taparius Thomas, 1926f: 635; type locality “Uricurituba, Santarem [= Santarém],” Pará, Brazil. Sciurus [(Urosciurus)] pyrrhonotus juralis Thomas, 1926f:636, type locality “Juruá River,” Amazonas, Brazil. Sciurus (Urosciurus) tricolor: Thomas, 1927f:599; name combination. Sciurus (Hadrosciurus) tricolor: Thomas, 1927f:599; name combination. Hadrosciurus tricolor: Cabrera and Yepes, 1940:195; name combination. Sciurus [(Hadrosciurus)] pyrrhonotus taparius: Ellerman, 1940:345; name combination. Sciurus [(Hadrosciurus)] pyrrhonotus juralis: Ellerman, 1940:345; name combination. Hadrosciurus pyrrhonotus taparius: Moojen, 1942:30; name combination. Hadrosciurus pyrrhonotus juralis: Moojen, 1942:34; name combination. Sciurus pyrrhonotus taparius: Moojen, 1952b:30; name combination. Sciurus pyrrhonotus juralis: Moojen, 1952b:31; name combination. Sciurus [(Urosciurus)] spadiceus [tricolor]: Thorington and Hoffmann, 2005:763; name combination. This subspecies occurs east of the Andes in Colombia south through Ecuador and Peru to central Bolivia, extending to the east to Acre and Amazonas states in Brazil, and south of the Rio Solimões along the upper course of the Rio Juruá and Rio Purus. There is an apparent gap in the distribution, as the taxon is also known from the Rio Aripuanã,

a tributary on the right bank of the middle Rio Madeira, Amazonas, Brazil, and from there to Pará state west of the Rio Tapajós. Melanistic individuals of H. s. tricolor are common, with some individuals entirely black, others only partially so. The color pattern for non-melanistic specimens includes a black head with orange rostrum, no conspicuous eye-ring, reddish brown to brownish black ears on both sides; no postauricular patches; dorsum generally black, sometimes darker red posteriorly, but heavily streaked with orange; forefeet and limbs same color as the dorsum, only slightly paler distally; hindfeet and limbs reddish orange, with or without black streaking; venter white, extending to undersides of forelegs and hindlegs almost to the paws, color near hands and feet the same as dorsal parts of the legs; proximal third of the tail dark, with red predominating in the middle section and orange and black predominating distally. n a t u r a l h i s t o ry: Gwinn et al. (2012) compiled information on the natural history of this species. Peres, Barlow, and Haugaasen (2003) reported an estimated density of 0.08 individuals/ha at a site in the headwaters of Rio Arapiuns, Pará state, Brazil; they observed solitary individuals twice. H. Gómez et al. (2003) reported a larger average density for a site in the department of La Paz, Bolivia, with 0.122 individuals/ha. Patton et al. (2000) recorded scrotal males in the headwaters of the Rio Juruá, Amazonas state, Brazil, in September and February. They also collected a lactating female with three placental scars in February. Anderson (1997) reported litter sizes ranging from two to four in August from Bolivia. These very limited data suggest breeding in both wet and dry seasons. According to sources cited in Gwinn et al. (2012), the species is mostly seen at ground level, using the canopy when the forest is flooded. Nuts of four genera of trees (the palms Astrocaryum, Attalea, and Scheelea, and the legume Dipteryx) comprise the majority of its diet. Della-Flora et al. (2013) reported the association of this species with mixedspecies bird flocks in western Brazil. r e m a r k s : The distributions of three subspecies (H. s. castus, H. s. tricolor, and H. s. spadiceus) approach one another in Bolivia. Here, those specimens we assign to tricolor differ from both spadiceus and castus in dorsal color, with the dorsum black streaked with red or orange, not the pale yellow characteristic of the latter two subspecies. However, Bolivian tricolor also differ from their counterparts east of the Andes in Ecuador and Peru, where specimens typically exhibit a mid-dorsum darker than the sides, a characteristic not present in Bolivian tricolor. Samples from the western Brazilian Amazon, in the states of Acre and Amazonas, also differ from typical tricolor, with the mid-dorsum not markedly darker than the sides and the venter tending to white, with some orange. The dorsum of

24 Mammals of South America

these Brazilian samples also varies from being uniformly colored from front to back or divided between a more orange posterior section and a black grizzled with orange anterior section; this phenotype has an available name, Sciurus pyrrhonotus juralis Thomas, with type locality on the middle Rio Juruá, Amazonas, Brazil. There are few samples from the east and northeast along the Rio Amazonas, but those from the Rio Aripuanã, in southeastern Amazonas state, as well as those from the left bank of the Rio Tapajós, Pará state, are similar to those from the Juruá region, except that the top of the head is paler. As is usual for most color variants of South American squirrels, there is a name available for these squirrels, namely, Sciurus (Urosciurus) pyrrhonotus taparius Thomas. If taken in isolation, specimens from central Peru and from the Rio Tapajós are quite distinct from each other and could be distinguished as valid taxa. We do not do so, however, because we cannot presently establish clear geographical limits to this variation. We believe that the taxon we are recognizing here is a complex and will probably be split into a number of distinct, valid taxa with a deeper study of geographical variation. Sciurus langsdorffi steinbachi J. A. Allen, described from Santa Cruz de la Sierra, Bolivia, is identical to our concept of H. s. spadiceus, and we treat it as a junior synonym. In the southern portion of the geographical distribution of spadiceus, specimens from the Serra do Urucum and Cáceres, Mato Grosso do Sul, Brazil, are identical to typical spadi-

Map 7 Selected localities for Hadrosciurus spadiceus (●). Contour line = 2,000 m.

ceus in color but average distinctly smaller in size. J. A. Allen (1914d) described these specimens as Sciurus langsdorffii urucumus; we have placed urucumus as a junior synonym of S. spadiceus because there is an overlap in size between the largest specimens of urucumus and the smallest of spadiceus.

Genus Microsciurus J. A. Allen, 1895 Microsciurus is a genus of small tree squirrels distributed in Central and South America. Among neotropical squirrels, Microsciurus species are intermediate in size between the diminutive Sciurillus and the slightly larger Syntheosciurus, with mass ranging from 80–120 g and external measurements of head and body length of 112–170 mm, tail length 82–165 mm, hindfoot length 28–45 mm, and ear length 8–19 mm. The ears are small and rounded. Females possess three pairs of evenly spaced mammae. Except for a few taxa, the color pattern is very conservative, usually some shade of brown finely streaked with orange or red on the dorsum, and with a paler ventrum. Several species have colored postauricular patches. High-elevation populations typically have longer and denser fur than lowland ones, and the tail is never very bushy. The skull has a strongly curved dorsal profile with an inflection point at the middle of the frontals. From the inflection point to the anteriormost portion of skull, the rostrum maintains a straight or even slightly concave profile. The rostrum is short, at most one-third the length of the skull. The frontals are longer than they are wide, and the braincase is globose. The temporal portion of the orbitotemporal fossa is greatly reduced but not obliterated; the postorbital process extends posteriorly almost to a vertical plane passing through the internal (anterior) portion of the squamosal zygomatic process in the fossa. The maxillary process of the zygomatic arch is oblique in lateral view, originating anterior to the cheek teeth and above the infraorbital foramen. The sphenopalatine foramen is situated above the second molar or the contact between the second and third molars. There are two complete bullar septa, and rarely a third incomplete septum. The mandible has a very short coronoid process. The dental formula is I 1/1, C 0/0, PM 2–1/1, M 3/3 = 20– 22; PM3 is absent in some populations, particularly those of M. flaviventer. When present, PM3 is simple, small, unicuspidate, and has one root; all remaining permanent cheek teeth possess three roots. PM4 is molariform but varies in size, from one-third smaller to only slightly smaller than M1. M1 and M2 are subequal, but M3 is distinctly smaller in size. Paraconule, metaconule, and ectostyle are absent or vestigial; the trigon is shallow. Only pm4 has a vestigial paraconid, a structure absent in all remaining lower cheek teeth. The trigonid is vestigial.

Suborder Sciuromorpha: Family Sciuridae 25

sy n o n y m s : Macroxus: Gray, 1867:432; part (description of flaviventer); not Macroxus F. Cuvier. Sciurus: J. A. Allen, 1877:750; part (inclusion of rufoniger); not Sciurus Linnaeus. [Sciurus] (Microsciurus) J. A. Allen, 1895b:332; type species Sciurus (Microsciurus) alfari, by original designation. Microsciurus: E.-L. Trouessart, 1897:429; elevation to generic status. Microsciurus (Microsciurus): Moore, 1959:179; name combination. r e m a r k s : J. A. Allen (1895b) described Microsciurus as a subgenus, designating Sciurus (Microsciurus) alfari J. A. Allen as the type species. Being quite easily diagnosable in terms of size and a number of cranial characters from other squirrels, the taxonomic history of Microsciurus is relatively unproblematic. The only major taxonomic changes subsequent to Allen’s description were E.-L. Trouessart’s (1897) elevation to full genus and Thomas’s (1914b,f) placement of Microsciurus pusillus (sensu J. A. Allen 1914a) in its own genus, Sciurillus. Moore (1959) used the name in a broader sense, including several genera and subgenera in it, but his subgenus Microsciurus is equal to the genus Microsciurus of other authors and ourselves. We recognize 11 species of Microsciurus, three in Central America (M. alfari, M. boquetensis, and M. venustulus) and eight in South America (M. flaviventer, M. isthmius, M. mimulus, M. otinus, M. sabanillae, M. santanderensis, M. similis, and M. simonsi). Only the South American species are detailed herein. Both Hall (1981) and Thorington et al. (2012) extended the range of boquetensis into extreme northwestern Colombia (as a subspecies of M. mimulus). KEY TO THE SOUTH AMERICAN SPECIES OF MICROSCIURUS:

1. Postauricular patch present . . . . . . . . . . . . . . . . . . . . 2 1′. Postauricular patch absent . . . . . . . . . . . . . . . . . . . . . 3 2. Dorsum brown, streaked with red . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Microsciurus flaviventer 2′. Dorsum dark brown, with mid-dorsal dark stripe . . . . . . . . . . . . . . . . . . . . . . . . . Microsciurus santanderensis 3. Dorsum dark brown streaked with red to reddish orange tones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 3′. Dorsum dark brown streaked with yellow to pale yellow tones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 4. Venter orange, mixed with brown on belly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Microsciurus isthmius 4′. Venter washed with red on throat and chest; mixed brown, dark gray, and red on belly . . . . . . . .Microsciurus otinus 5. Basal third of hairs of venter gray. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Microsciurus mimulus 5′. Hairs of ventrum without gray basal third . . . . . . . . . 6

6. Venter with predominantly red tones . . . . . . . . . . . . . 7 6. Ventral color variable, dark gray, pale gray, or pale yellow on throat, and dark gray to dark brown and yellow on chest and belly . . . . . . . . . . . . Microsciurus simonsi 7. Venter red to mixed red and gray on throat and chest, dark gray to dark brown punctuated with red on belly . . . . . . . . . . . . . . . . . . . . . . . . . . . Microsciurus similis 7′. Venter brown washed with red on throat and chest, dark gray and red on belly . . . .Microsciurus sabanillae

Microsciurus flaviventer (Gray, 1867) Amazon Dwarf Squirrel sy n o n y m s : Macroxus flaviventer Gray, 1867:432; type locality “Brazil.” Sciurus aestuans: Alston, 1878:668 part (inclusion of flaviventris [= flaviventer]); not aestuans Linnaeus. Macroxus flaviventris Alston, 1878:668; incorrect subsequent spelling of Macroxus flaviventer Gray. Sciurus chrysurus: Thomas, 1893a:337; part; not chrysurus Pucheran. Sciurus (Microsciurus) peruanus J. A. Allen, 1897c:115; type locality “Guayabamba, alt. 4000 feet,” = Santa Rosa de Huayabamba, Amazonas, Peru. Sciurus (Microsciurus) peruanus napi Thomas, 1900f:295; type locality “Mouth of Coca River, Upper Rio Napo,” Orellana, Ecuador. Sciurus peruanus: Ihering, 1904:420; name combination. Microsciurus peruanus: E.-L. Trouessart, 1904:329; name combination. Microsciurus peruanus napi: E.-L. Trouessart, 1904:329; name combination. Microsciurus brevirostris J. A. Allen, 1914a:147; nomen nudum; indicated as a new species in a list but with no further description or reference to a description or illustration, likely a lapsus calami for M. rubrirostris, described in the same paper. Microsciurus napi: J. A. Allen, 1914a:163; name combination. Microsciurus rubrirostris J. A. Allen, 1914a:163; type locality “Chanchamayo, [Junín,] central Peru; altitude 2000 m.” Microsciurus florenciae J. A. Allen, 1914a:164; type locality “Florencia (altitude 1000 feet), Caquetá district, Colombia.” Microsciurus avunculus Thomas, 1914b:574; type locality “Gualaquiza; alt. 2500′,” Morona–Santiago, Ecuador. Microsciurus rubricollis Thomas, 1914b:574; incorrect subsequent spelling of Microsciurus rubrirostris J. A. Allen. Microsciurus manarius Thomas, 1920f:275; type locality “Acajutuba, Rio Negro, near its mouth,” Amazonas, Brazil.

26 Mammals of South America

Microsciurus flaviventer: Thomas, 1920f:275; first use of current name combination. Microsciurus mannarius: O. M. O. Pinto, 1931:284; inadvertent subsequent spelling of Microsciurus manarius Thomas. Microsciurus [(Microsciurus)] napi: Moore, 1959:203; name combination. Microsciurus flaviventer flaviventer: Cabrera, 1961:355; name combination. Microsciurus flaviventer napi: Cabrera, 1961:356; name combination. Microsciurus flaviventer peruanus: Cabrera, 1961:357; name combination. Microsciurus flaviventer rubrirostris: Cabrera, 1961:357; name combination. d e s c r i p t i o n : Adult mass 80–111 g (N = 16); head and body length 124–170 mm (N = 76), tail length 115– 165 mm (N = 79), hindfoot length 30–44 mm (N = 76), and ear length 13–19 mm (N = 65). Dorsal color brown streaked with red; most samples have yellowish to white postauricular patches; venter of mixed colors, with throat and chest yellowish orange and belly slightly darker. d i s t r i b u t i o n : Microsciurus flaviventer occurs widely in western Amazonia, from southern Colombia through eastern Ecuador, Peru, and northeastern Bolivia, then eastward to the Brazilian states of Amazonas, Acre, and Rondônia. It ranges in elevation from 100 to 1,500 m. s e l e c t e d l o c a l i t i e s (Map 8): BOLIVIA: Pando, left bank Río Madre de Dios near Santa Elena (SalazarBravo, Yensen et al. 2002). BRAZIL: Acre, Oriente (= Seringal Oriente), near Taumaturgo, Rio Juruá (MZUSP 20351); Amazonas, Acajutuba, Rio Negro (type locality of M. manarius Thomas), Codajás, left bank Rio Solimões (MZUSP 4207), Eirunepé, left bank Rio Juruá (MZUSP 4621), Estirão do Equador, right bank Rio Javari (MZUSP 20350), Lago do Mapixi, east of Rio Purus (FMNH 38880), Manacapuru, Rio Solimões (BM 26.5.5.36), Paraná do Aiapuá, Rio Purus (BM 27.8.11.61); Rondônia, Cachoeira Nazaré, left bank Rio Ji-Paraná (MPEG 20826). COLOMBIA: Caquetá, Florencia (type locality of M. florenciae J. A. Allen); Putumayo, La Tagua, Tres Troncos, Río Caquetá (FMNH 71118); Vaupés, Río Vaupés, in front of Tahuapunto (AMNH 78625). ECUADOR: Loja, El Porotillo, San José (MNHN 1934/1210); Morona–Santiago, Mendez Sur, Oriente (MNHN 1987/338); Napo, Archidona (MNHN 1932/2876), San José abajo (AMNH 66792). PERU: Amazonas, Guayabamba (AMNH type locality of Sciurus (Microsciurus) peruanus J. A. Allen), near Huampani, Río Cenepa (MVZ 154929), 12 km E of La Peca Nueva (LSUMZ 21876); Cusco, Quincemil (FMNH 75210); Junin, Chanchamayo (type locality of Microsciurus rubrirostris J. A. Allen); Loreto, boca Río Curaray (AMNH

71606), Hacienda Santa Elena, ca. 35 km NE of Tingo Maria (LSUMZ 17720), left bank at mouth of Río Yaquerana, alto Río Yavarí (FMNH 88991), Pebas. Río Amazonas (BM 28.7.21.74–78), Quebrada Pushaga, left bank Río Morona, alto Río Amazonas (FMNH 88984), San Fernando, left bank Río Yavari (FMNH 88990), Santa Rita, Iquitos (FMNH 87178), Sarayacu, Río Ucayali (AMNH 75279); Madre de Dios, Altamira, Manu (FMNH 98067); Ucayali, Lagarto, upper Río Ucayali (AMNH 76538). s u b s p e c i e s : We regard M. flaviventer as monotypic (but see Remarks). Thorington and Hoffmann (2005) recognized seven subspecies, and Thorington et al. (2012) listed eight, three and four of which, respectively, we regard herein as full species. n a t u r a l h i s t o ry: This species is found only in evergreen rainforest (Emmons and Feer 1997). Surprisingly, few ecological, reproductive, behavioral, or other natural history data are available for this wide-ranging squirrel. Emmons and Feer (1997) stated that individuals search actively over the trunks of large trees, on vines, and in treefalls, apparently searching for insects, but that they also feed on substances scraped from tree bark such as gum (as was suggested by A. C. Smith [1999], who observed two solitary individuals moving through the subcanopy). Youlatos (1999) noted that individuals primarily used the subcanopy or canopy at heights above 5 m. Emmons and Feer (1997) recorded ball nests of leaves lined with fibers in the top of palms. Eisenberg (1989) reported a litter size of two offspring. Buitron-Jurado and Tobar (2007) reported on associations between individuals of this species and bird flocks, with squirrels actively searching for insects at heights of 2– 10 m in the company of birds. r e m a r k s : Microsciurus flaviventer has a wide distribution, from the eastern slopes of the Andes to central Amazonia. In this vast area, authors have distinguished several taxa, all listed in the previous synonymy. Our study of material deposited in many collections revealed that this variation is real, but we have not been able to decide how much of it is of taxonomic value. There are important differences in size (Andean forms such as napi are large, for example). And the upper third premolar may be present or absent in different samples. The fur is also longer and denser in Andean samples, and the color, especially that of ventral surfaces, varies regionally. We believe that recognizing a single species for the whole of the samples examined is, in this case, a decision of convenience. It is quite possible that further study of this material will reveal the existence of additional taxa, either to be recognized as valid subspecies or as full species. Microsciurus flaviventer is one of the two Colombian species of the genus occurring east of the Andes, the other being M. santanderensis. Their known distributions are interrupted

Suborder Sciuromorpha: Family Sciuridae 27

Map 8

Selected localities for Microsciurus flaviventer (●). Contour line = 2,000 m.

by a large gap in the eastern Andes, a region well sampled for other squirrels, and this gap likely represents a true disjunction. Salazar-Bravo, Yensen et al. (2002) extended the range of this species into northern Bolivia, reidentifying a specimen that S. Anderson (1997:397) originally assigned to Sciurus ignitus (= Notosciurus pucheranii herein).

Microsciurus isthmius (E. W. Nelson, 1899) Isthmian Dwarf Squirrel sy n o n y m s : (?) Sciurus aestuans var. rufoniger: J. A. Allen, 1877:757; part. Sciurus (Microsciurus) isthmius E. W. Nelson, 1899a:77; type locality “Truando River [= Río Truandó], [Chocó,] Colombia.” Microsciurus isthmius: E.-L. Trouessart, 1904:329; name combination. Sciurus (Microsciurus) palmeri Thomas, 1909:234; type locality “Sipi, Rio Sipi, Rio San Juan, Chocó, western Colombia.” Microsciurus isthmius vivatus Goldman, 1912b:4; type locality “near Cana, (altitude 3,500 feet), in the Pirri range of mountains, [Darien,] eastern Panama.” Microsciurus isthmius isthmius: J. A. Allen, 1914a:57; name combination. Microsciurus palmeri: J. A. Allen, 1914a:160; name combination.

Microsciurus [(Microsciurus)] isthmius: Moore, 1959:203; name combination. Microsciurus flaviventer isthmius: Cabrera, 1961:355; part; name combination. Microsciurus mimulus isthmius: Handley, 1966:778; part; name combination. d e s c r i p t i o n : Adult mass 120 g (one female); head and body length 120–165 mm (N = 41), tail length 98– 150 mm (N = 36), hindfoot length 32–45 mm (N = 39), and ear length 10–19 mm (N = 20). Dorsum dark brown to black, heavily speckled with yellow; postauricular patches absent; venter not sharply distinct from dorsum, generally orange in color but with mixture of orange and brown on belly. d i s t r i b u t i o n : Microsciurus isthmius occurs in rainforests west of the Andes in northwestern Colombia and adjacent Panama; in Colombia, it ranges in elevation from sea level to 800 m. s e l e c t e d l o c a l i t i e s (Map 9; South America only): COLOMBIA: Antioquia, Alto Bonito, upper Río Sucio (AMNH 37645), Murindó (FMNH 44855); Cauca, Río Saija (FMNH 90210); Chocó, Bagadó (AMNH 34132), Baudó (AMNH 33812), Nóvita, Río Tamaná (BM 9.7.17.26), Río Nuqui, base of Baudó Mts. (USNM 292132), Río Truandó (type locality of Sciurus [Microsciurus] isthmius E. W. Nelson), Sipí, Río Sipí, Río San Juan (type locality of Sciurus [Microsciurus] palmeri Thomas); Nariño, Buenavista (AMNH 34158), La Guayacana (FMNH 89518); Valle Del Cauca, Mechenquito (ROM 63217), Río Mechengue (FMNH 90201), San José (AMNH 31680). s u b s p e c i e s : We treat M. isthmius as monotypic. n a t u r a l h i s t o ry: Goldman (1920: 144) reported specimens from about 1,150 m on Cerro Pirre, Darién, Panama (his M. isthmius vivatus), collected from lower branches or the trunks of trees in cloud forest. r e m a r k s : Variation in the coat color is limited to the amount of black on the crown and rest of dorsum, which is slightly more pronounced in some specimens. J. A. Allen (1877:756–763) recognized five species of squirrels in South America, among which was Sciurus aestuans and in which he listed “aestuans” and “rufoniger” as two “varieties.” These together encompassed all of the thenknown smaller South American squirrels. This was a very broad concept, and even Allen himself (1914a, 1915) did not succeed in settling all the synonymic implications of his earlier lumping effort. E. W. Nelson (1899a:77–78) subsequently described Sciurus (Microsciurus) isthmius based on the material collected at the Río Truandó, Chocó, Colombia. Cabrera (1961) proposed a new arrangement for the species level taxa in the genus Microsciurus, one in which isthmius E. W. Nelson and all other South American taxa

28 Mammals of South America

Map 9 Selected localities for Microsciurus isthmius (●). Range in Panama from Hall (1981). Contour line = 2,000 m.

were placed as subspecies, or synonyms, of a single species, namely, M. flaviventer (Gray). Cabrera’s arrangement, however, was not uniformly followed (e.g., see Handley 1966; Hall 1981; and Honacki et al. 1982). Thorington et al. (2012) retained isthmius as a subspecies in their concept of M. mimulus.

patches absent; venter not sharply distinct from dorsum, with color ranging from orange to pale yellow with basal third of hairs gray, with belly orange to pale yellow with some brown. d i s t r i b u t i o n : Microsciurus mimulus occurs in rainforests west of the Andes in northwestern Ecuador and southwestern Colombia, at elevations from sea level to 1,000 m. s e l e c t e d l o c a l i t i e s (Map 10): COLOMBIA: Nariño, Barbacoas (AMNH 34159), La Guayacana (USNM 309028). ECUADOR: Esmeraldas, Cachabí (type locality of Sciurus [Microsciurus] mimulus Thomas), Carondelet (USNM 113310); Imbabura, Lita (BM 1.1.6.3). s u b s p e c i e s : Microsciurus mimulus is monotypic. n a t u r a l h i s t o ry: We have found no information about the natural history of this species. r e m a r k s : Thomas (1898f:266–267) described Sciurus (Microsciurus) mimulus based on three specimens from northwestern Ecuador. This was the first name applied to dwarf squirrels from South America west of the Andes. Cabrera (1961:356) considered M. flaviventer to be the only South American species in the genus, using all other names either for subspecies (including mimulus Thomas) or as synonyms. As in many occasions throughout his catalog of South American mammals, this decision was based on the literature and on his own (limited, in this case) experience with the group. Handley (1966:777) considered M. mimulus to be a good species, and although he did not provide a reason for this decision, his arrangement

Microsciurus mimulus (Thomas, 1898) Western Dwarf Squirrel sy n o n y m s : Sciurus (Microsciurus) mimulus Thomas, 1898f:266; type locality “Cachavi [= Cachabí], [Esmeraldas,] N. Ecuador, alt. 167 m.” Microsciurus mimulus: E.-L. Trouessart, 1904:329; first use of current name combination. Microsciurus [(Microsciurus)] mimulus: Moore, 1959:203; name combination. Microsciurus flaviventer mimulus: Cabrera, 1961:356; name combination. d e s c r i p t i o n : Head and body length 114–159 mm (N = 17), tail length 90–125 mm (N = 17), hindfoot length 30–38 mm (N = 16), and ear length 13–16 mm (N = 8). Dorsum dark brown to black, speckled with red or orange, sometimes with mid-dorsal dark stripe; postauricular

Map 10

Selected localities for Microsciurus mimulus (●). Contour line = 2,000 m.

Suborder Sciuromorpha: Family Sciuridae 29

met with wide acceptance and has been adopted by most subsequent authors (e.g., Emmons and Feer 1997; Thorington and Hoffmann 2005). Our concept of M. mimulus is more restricted geographically than that espoused by these authors, generally equivalent to that given by Thorington et al (2012:35) for the nominotypical form of their polytypic M. mimulus. Some specimens from Nariño, Colombia, show individual variation in belly color, from almost black punctuated with orange to brown mixed with orange. The type series of M. mimulus and other specimens from northwestern Ecuador have a black mid-dorsal stripe continuing to the crown (Thomas 1898f; J. A. Allen 1914a). This character, however, while present in Ecuadorean material, is variable in specimens from farther to the north in Nariño, Colombia, with only one specimen in five presenting it fully.

Microsciurus otinus (Thomas, 1901) White-eared Dwarf Squirrel sy n o n y m s : Sciurus (Microsciurus) otinus Thomas, 1901c:193; type locality “Medellin, [Antioquia,] Colombia.” Microsciurus otinus: E.-L. Trouessart, 1904:329; first use of current name combination. Microsciurus flaviventer otinus: Cabrera, 1961:357; name combination. d e s c r i p t i o n : Head and body length 120–141 mm (N = 15), tail length 95–132 mm (N = 12), hindfoot length 35–39 mm (N = 13), and ear length 11–16 mm (N = 6). Dorsum dark brown streaked with pale yellow; postauricular patches absent but ears tipped with white; throat and chest washed with reddish orange, belly mixed brown, dark gray, and red; tail frosted whitish. d i s t r i b u t i o n : Microsciurus otinus occurs west of the Andes, in rainforests in the Colombian departments of Antioquia, Bolívar, and Córdoba, at elevations from 200 to 1,500 m. s e l e c t e d l o c a l i t i e s (Map 11): COLOMBIA: Antioquia, La Tirana, 25 km S and 22 km W of Zaragoza (USNM 499515), Medellín (type locality of Sciurus [Microsciurus] otinus Thomas), Purí, above Caceres (FMNH 70046), Valdívia, right bank of lower Río Cauca (AMNH 37640); Bolívar, 15 mi W of Simiti, 6 mi above Santa Rosa (USNM 282755); Córdoba, Socorré, upper Río Sinú (FMNH 69034). s u b s p e c i e s : Microsciurus otinus is monotypic. n a t u r a l h i s t o ry: Rojas-Robles et al. (2008) reported on the importance of a species of Microsciurus in the short-distance dispersal (typically 120% of head and body length, and hairy, but scales visible; nose conspicuously reddish; palate narrow, short; rostral tube absent; sphenopalatine vacuities moderate, elongated; auditory bullae large, inflated; primary cusps opposite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wilfredomys 6. Upper incisors smooth, without groove; carotid circulation pattern 1 (sensu Voss 1988); cheek teeth tetralophodont or pentalophodont . . . . . . . . . . . . . . . . . . . . 7 6′. Upper incisors with longitudinal groove; carotid circulation pattern 1 or 2 (sensu Voss 1988); cheek teeth tetralophodont . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7. Body not uniformly colored, darker on midback, with conspicuous black and white thigh stripes and strongly contrasting whitish venter; body large, very stout, mass

>120 g; pelage long, very thick and soft; tail short (39 mm); in Andean foothills of eastern Ecuador and Peru . . . . . . . . . . . Ichthyomys stolzmanni 1′. Tail unicolored (dark above and below); hindfoot smaller (30%; M1 narrow, width >1.45 mm; 2n = 50 or 54, FN = 62–63 or 66 . . . 5 5. Tail with sparse hairs but large scales (14 per cm at midtail); lacrimals broad and posterolaterally expanded; supraorbital and lambdoidal crests pronounced; 2n = 54, FN = 66. . . . . . . . . . . . . . . . . . . . . Cerradomys goytaca 5′. Tail more hirsute and with small scales (16–18 per cm at midtail); lacrimals diminutive and sometimes absent; supraorbital and lambdoidal crests slender and small; 2n = 50, FN = 62–63 . . . . . . . . . . . . . Cerradomys vivoi 6. Mesolophid reduced or absent and posterolophid absent; 2n = 58, FN = 54 . . . . . . . . .Cerradomys marinhus 6′. Mesolophid and posterolophid well developed; 2n = 58, FN = 58. . . . . . . . . . . . . . . . Cerradomys maracajuensis

302 Mammals of South America

Cerradomys goytaca Tavares, Pessôa, and Gonçalves, 2011 Goytacá Cerradomys sy n o n y m : Cerradomys goytaca: Tavares, Pessôa, and Gonçalves, 2011:647: type locality “Parque Nacional Restinga de Jurubatiba, municipality of Carapebus, Rio de Janeiro, Brazil, 22°15′28′′S, 41°39′49′′W, 1 m altitude.” d e s c r i p t i o n : Small, with head and body length 116–166 mm, tail length 130–181 mm. Dorsal pelage short, overall color orange grizzled with brown; head color grayish, especially around eyes and on cheeks; venter whitish and covered by short and sparse hairs with pale gray to brownish gray bases. Tail markedly bicolored, with completely unpigmented hairs and scales on ventral surface along proximal portion, and uniformly dark above; scales large, with modal number 14 per cm near base. Ungual hair tufts over claws rarely exceed claw length. Skull large and robust; rostrum broad, lacrimals broad; zygomatic arches wide; supraorbital ridges that extend almost to occipital crest along temporal region prominent; palatal fossae deep with complex and broad posteropalatal pits; mesopterygoid roof with wide and large sphenopalatine vacuities extending broadly along presphenoid and alisphenoid (exposing the orbitosphenoid); no alisphenoid strut; small posterior opening of alisphenoid canal; and relatively narrow upper molars. Cerradomys goytaca larger in most craniodental measurements than C. langguthi and C. vivoi, and significantly larger than samples of C. subflavus in length of diastema and breadth of rostrum. d i s t r i b u t i o n : Cerradomys goytaca is known from only five localities in coastal Espírito Santo and Rio de Janeiro states, Brazil. s e l e c t e d l o c a l i t i e s (Map 149): BRAZIL: Espírito Santo, Praia das Neves, Presidente Kennedy (MNRJ 67543); Rio de Janeiro, Parque Nacional da Restinga de Jurubatiba, Carapebus (type locality of Cerradomys goytaca Tavares, Pessôa, and Gonçalves, 2011), Restinga de Iquipari-Grussai, Grussai, São João da Barra (MNRJ 73261), Restinga do Faroizinho, Farol de São Tomé, Campos dos Goytacazes (MNRJ 73276), Sítio Santana, Beira de Lagoa, Quissamã (MNRJ 73198). s u b s p e c i e s : Cerradomys goytaca is monotypic. n a t u r a l h i s t o ry: All known collecting localities are in the narrow sandy plains covered by distinctive shrubby and open vegetation, locally known as restingas, along the Atlantic coast of south-central Brazil (see D. Araújo 1992; Oliveira-Filho and Fontes 2000). Cerradomys goytaca is one of the most abundant small mammals in the Parque Nacional da Restinga de Jurubatiba, occurring in most plant formations but at higher densities

in the open shrublands that are distributed as vegetation islands in sandy plains. It is most common in patches of Clusia hilariana (Clusiaceae), the largest tree in these shrubland patches. Specimens have also been taken in forests that develop in more humid terrain and near lagoons. This species plays an important role as a seed predator of the palm Allagoptera arenaria (Grenha et al. 2010). Specimens were captured in traps placed on limbs up to 2 m above the ground, suggesting some degree of arboreal activity. Nests were found on tree branches and tangled bromeliads (Bergallo et al. 2005). Dense litter is also likely used as shelter. Pregnant females were captured in April and September, each with four embryos. In the laboratory, litters consisted of four to five pups; eyes and external ears opened four to nine days following birth, with different growth rates in the two sexes. Both macronyssid (Ornithonyssus sp.) and laelapid mites (Laelaps manguinhosi, Gigantolaelaps goyanensis, and G. vitzthumi) parasitize this species (Bergallo et al. 2004). One individual was found with a botfly larva (Diptera, Cuterebridae). r e m a r k s : Among the diagnostic features given by Tavares et al. (2011) in their description of C. goytaca is a unique karyotype with 2n = 54 and FN = 66, including a single large acrocentric pair and four small biarmed pairs in the autosomal complement, a large subtelocentric X chromosome, and a medium-sized acrocentric Y chromosome.

Map 149

Selected localities for Cerradomys goytaca (●).

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 303

Cerradomys langguthi Percequillo, Hingst-Zaher, and Bonvicino, 2008 Langguth’s Cerradomys sy n o n y m : Cerradomys langguthi: Percequillo, Hingst-Zaher, and Bonvicino, 2008:13; type locality “Corredor São JoãoFazenda Pacatuba, Sapé, State of Paraíba, Brazil, at ca. 07°02′S, 35°09′W.” d e s c r i p t i o n : Small, with head and body length 119–153 mm, tail length 144–195 mm. Dorsal pelage short and dense; body color orange grizzled with brown; head color contrastingly grayish; ventral body color grayish or slightly yellowish. Skull with short and narrow sphenopalatine vacuities, restricted to presphenoid and thus partially exposing orbitosphenoid; no alisphenoid strut; palatal fossae deep (complex posterolateral palatal pits). d i s t r i b u t i o n : Cerradomys langguthi occurs from the left bank of the Rio São Francisco through the Brazilian states of Pernambuco, Paraíba, Ceará, and Maranhão. In Pernambuco, Paraíba, and Ceará, records extend from the coastal lowlands to the interior highlands and mountain ranges; in Maranhão, the species is associated with lowlands of the central portion of the state. s e l e c t e d l o c a l i t i e s (Map 150): BRAZIL: Ceará, Sítio Friburgo, Serra de Baturité, Pacoti (MZUSP [ARP 11]); Maranhão, Fazenda Lagoa Nova (MPEG 23482); Paraíba, João Pessoa (UFPB 31), Fazenda Pacatuba, Sapé, Corredor São João (type locality of Cerradomys langguthi Percequillo, Hingst-Zaher, and Bonvicino); Pernambuco, Buíque, Sítio Mata Verde (MZUSP 20604), Exu (MZUSP 18900), Fazenda Saco IBA, 6.6 km NNE of Serra Talhada (MZUSP 18905), São Vicente Ferrer (UFPB 19). s u b s p e c i e s : Cerradomys langguthi is monotypic. n a t u r a l h i s t o ry: Cerradomys langguthi inhabits several vegetation types, including the coastal lowland humid Atlantic Forest (locally called zona da mata), the open and relatively dry forests (locally called agreste) in the zone between the more humid and dense coastal forest and the more open and drier Caatinga, the Caatinga, and the forests restricted to humid slopes of mountain ranges in areas of Caatinga (brejos). This species is associated with sugarcane plantations, near humid and mesic areas in Ceará and Pernambuco states (Paiva 1973; Mares, Willig et al. 1981); with natural and cultivated fields, where the rats construct nests in the wetter grass patches (Karimi et al. 1976); and with secondary forests and shade-grown coffee plantations on the slopes of Serra de Baturité (a typical brejo) in Ceará state (Percequillo et al. 2008). r e m a r k s : In the genus, C. langguthi is nested in a monophyletic group along with C. vivoi and C. subflavus

Map 150 vivoi (ᇲ).

Selected localities for Cerradomys langguthi (●) and Cerradomys

(Percequillo et al. 2008), as based on mtDNA cytochromeb sequences. Cranially, C. langguthi exhibits short and narrow sphenopalatine vacuities that barely expose the orbitosphenoids; C. subflavus and C. vivoi, in contrast, have long and narrow or long and wide vacuities, respectively. There are also noticeable quantitative differences among these three species, with C. subflavus being significantly larger and more robust, C. vivoi of intermediate size, and C. langguthi the smallest. The karyotype of C. langguthi is variable in diploid number (2n = 46 or 48–50) but constant in fundamental number (FN = 56), with the variation in diploid number due to multiple centric fusions that are polymorphic in some populations (Maia and Hulak 1981; Bonvicino et al. 1999; Percequillo et al. 2008).

Cerradomys maracajuensis (Langguth and Bonvicino, 2002) Maracaju Cerradomys sy n o n y m s : Oryzomys maracajuensis Langguth and Bonvicino, 2002: 292; type locality “Brazil, Mato Grosso do Sul, Municipality of Maracaju (approx. 21°38′S, 55°09′W) Fazenda da Mata.”

304 Mammals of South America

[Cerradomys] maracajuensis: Weksler, Percequillo, and Voss, 2006:8; first use of current name combination. d e s c r i p t i o n : Large, head and body length 140– 185 mm, and tail length 171–227 mm; hindfeet long and robust, 34–43 mm; dorsal body color coarsely grizzled, buffy brown to orange brown, and ventral body color grayish to buffy to yellow gray. Skull with shallow rostral fossae; roof of mesopterygoid fossa with small and narrow sphenopalatine vacuities or fully ossified; palatal fossae shallow, with large posterolateral palatal pits; palatal excrescences developed; all lower molars with well-developed mesolophids (but narrow and reduced in some individuals from Bolivia). Phallus lacks central cartilaginous digit of distal baculum. d i s t r i b u t i o n : Cerradomys maracajuensis occurs in open vegetation habitats of central South America, including the Cerrado in Brazil, the eastern Chaco and grasslands of Paraguay (see D’Elía, Pardiñas, Jayat, and Salazar-Bravo 2008), the Cerrado and Chaco Boreal of Bolivia, and the islands of open, Cerrado-like vegetation in southern Peru. Elevational range is from 100 m (Tacuatí, Paraguay) to 1,750 m (Pitiguaya, Bolivia), with most records from the lowland. s e l e c t e d l o c a l i t i e s (Map 151): BOLIVIA: Beni, Boca del Río Baures (AMNH 210227), Pampa de Meio, Rio Itenéz (AMNH 210024); La Paz, Pitiguaya, Río Unduavi (AMNH 72641). BRAZIL: Mato Grosso, 264 km N of Xavantina, Serra do Roncador (BM 81.450); Mato Grosso do Sul, Fazenda Primavera, Bataiporã (MZUSP 28766); Minas Gerais, Reserva do Jacob, Nova Ponte (UFMG 1970). PARAGUAY: Paraguarí, Sapucay (BM 3.2.3.9). PERU: Puno, Aguas Claras camp, Río Heath (USNM 579688). s u b s p e c i e s : Cerradomys maracajuensis is monotypic. n a t u r a l h i s t o ry: Cerradomys maracajuensis has been collected in “woods,” “bush and grass,” “brush pile in grass at edge of rice field,” “brush-swampy,” “forest,” and “brush and grass” (R. M. Gilmore, from AMNH and MNRJ museum labels on specimens collected near the type locality), dense shrubby and grassy fields (cleared forest) and adjacent dense forest (G. Schmitt, AMNH labels), gallery forest (Langguth and Bonvicino 2002), and seasonally flooded pampas (Emmons et al. 2006). Pregnant females were caught in Bolivia during June and September, with two and four embryos (S. Anderson 1997). r e m a r k s : A recently described species, C. maracajuensis is readily distinguishable from other members of the genus (with the exception of C. marinhus) by its larger size and long tail, longer and more robust hindfeet, shallower rostral fossae, narrower zygomatic notches, developed palatal excrescences, and fully ossified roof of mesopterygoid fossa (small sphenopalatine vacuities are present in some Bolivian and Paraguayan specimens). Another diagnostic feature of C. maracajuensis is the 2n = 56 and FN = 54 karyotype (Bonvicino et al. 1999). Bonvicino

Map 151 Selected localities for Cerradomys maracajuensis (●). Contour line = 2,000 m.

(2003) hypothesized that C. marinhus and C. maracajuensis form the most basal clade of the genus.

Cerradomys marinhus (Bonvicino, 2003) Marinho’s Cerradomys sy n o n y m s : Oryzomys marinhus Bonvicino, 2003:84; type locality “Fazenda Sertão do Formoso (known formerly as Fazenda Jucurutu, 14°40′20′′S 45°49′71′′ [sic] W, altitude around 775 m), Jaborandi municipality, Goiás, Brazil” (corrected to Bahia state, at coordinates 14°48′S, 45°57′W; see comment under Remarks). [Cerradomys] marinhus: Weksler, Percequillo, and Voss, 2006:8; first use of current name combination. d e s c r i p t i o n : Large, with head and body length 153–179 mm; tail longer than body (length 198–212 mm); hindfeet long and robust (length 38–43 mm). Dorsal body color coarsely grizzled, buffy brown to orange brown; ventral body color grayish to buffy to yellowish gray. Skull with shallow rostral fossae; roof of mesopterygoid fossa either fully ossified or with small and narrow sphenopalatine vacuities; palate with shallow fossae and large posterolateral palatal pits; mesolophid of m3 reduced or absent. d i s t r i b u t i o n : Cerradomys marinhus is known only from two localities, one each in Bahia and Minas Gerais states, Brazil. s e l e c t e d l o c a l i t i e s (Map 152): BRAZIL: Bahia, Fazenda Sertão do Formoso (type locality of Oryzo-

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 305

mys marinhus Bonvicino); Minas Gerais, Parque Nacional Grande Sertão Veredas (MZUSP [APC 764]). s u b s p e c i e s : Cerradomys marinhus is monotypic. n a t u r a l h i s t o ry: Specimens of C. marinhus have been captured in seasonally flooded semideciduous forests (Percequillo et al. 2008) and in vereda, the periodically flooded grasslands with scattered palm trees of the genera Mauritia and Mauritiella and that usually occur along headwater streams in the Cerrado (Bonvicino 2003). Pregnant females were captured in both dry and rainy seasons, suggesting that breeding takes place throughout the year; embryo counts range from two to four, with mode of four (Bonvicino 2003:87). Bonvicino also stated that individuals of C. marinhus were infested with mesostigmatid mites and ticks, Polygenis tripus fleas, and flies of the family Hippoboscidae. r e m a r k s : The type locality specified in the original description is incorrect. As Bonvicino (2003:79) has noted, Fazenda Sertão do Formoso is “located in Jaborandi and Cocos municipalities, Bahia state” and not in Goiás state. Moreover, all specimens were captured in one particular habitat type, the geographical coordinates of which were specified by Bonvicino (2003:79). Thus, the correct type locality for this species is Fazenda Sertão do Formoso (formerly known as Fazenda Jucurutu), 14°48′S, 45°57′W, elevation about 775 m, municipality of Jaborandi, Bahia, Brazil.

Map 152 Selected localities for Cerradomys marinhus (ᇲ) and Cerradomys subflavus (●).

Cerradomys marinhus and C. maracajuensis were recovered as sister taxa in a molecular phylogenetic analysis with high bootstrap support (Bonvicino and Moreira 2001; Bonvicino 2003), and perhaps not surprisingly because the two species are remarkably similar in body and skull size, overall pelage color, and qualitative skull characters (e.g., shallow rostral fossae, ossified mesopterygoid fossa roof, and presence of palatal excrescences; see Percequillo et al. 2008). The karyotype of C. marinhus consists of 2n = 56 and FN = 54, with an entirely uniarmed autosomal set whereas that of C. maracajuensis is 2n = 56 and FN = 58, with two metacentric pairs (Bonvicino 2003). The absence of a mesolophid on m1 is the only diagnostic feature separating C. marinhus from C. maracajuensis.

Cerradomys scotti (Langguth and Bonvicino, 2002) Lindbergh’s Cerradomys sy n o n y m s : Oryzomys scotti Langguth and Bonvicino, 2002:290; type locality “Brazil, Goiás: municipality of Corumbá de Goiás (approx. 15°54′S, 48°48′W), Morro dos Cabeludos [= Morro de Cabeludo].” Oryzomys andersoni Brooks, Baker, Vargas, Tarifa, Aranibar, and Rojas, 2004:3; type locality “Pozo Mario, Estancia Las Conchas, Santa Cruz, Bolivia; 17°35′46.9′′S; 59°30′20.5′′ W.” [Cerradomys] scotti: Weksler, Percequillo, and Voss, 2006:8; first use of current name combination. d e s c r i p t i o n : Medium sized, with head and body length 125–181 mm and tail length 141–198 mm; hindfeet small (length 24–27 mm). Dorsal body color coarsely grizzled buffy brown, ventral color grayish. Tail bicolored and noticeably hirsute. Skull with deep rostral fossae and mesopterygoid fossa roof with large and wide sphenopalatine vacuities that expose the orbitosphenoid; alisphenoid strut present; palatal fossae deep (complex posterolateral palatal pits). M2 with reduced mesoloph, and mesolophid absent or reduced on m1 and m2. Central cartilaginous digit of distal baculum absent. d i s t r i b u t i o n : Cerradomys scotti occurs in the highlands of central South America, with records from the Cerrado of Brazil and eastern Bolivia and the Chaco Oriental of Paraguay. The species ranges in elevation from 250 m to about 1,180 m. s e l e c t e d l o c a l i t i e s (Map 153): BOLIVIA: Santa Cruz, El Refugio Pampa, 3 km NE from camp (USNM 584583), Santa Rosa de la Roca (AMNH 263872). BRAZIL: Bahia, Fazenda Sertão do Formoso (MNRJ 61667); Maranhão, Estiva (MPEG 22670); Mato Grosso, 264 km N of Xavantina, Serra do Roncador (BM 81.439); Minas Gerais, Conquista, Usina Hidroelétrica de Igarapava (UFMG 29), Lagoa Santa (BM 88.1.9.5), Serra Azul

306 Mammals of South America

(COPASA, Mateur Leme) (UFMG 21); Piauí, Estação Ecológica de Uruçuí-Una (MZUSP 137); São Paulo, Estação Ecológica de Santa Bárbara (MZUSP [APC 1157]). PARAGUAY: Paraguarí, Sapucaí (BM 3.4.7.13). s u b s p e c i e s : I treat Cerradomys scotti as monotypic. n a t u r a l h i s t o ry: Cerradomys scotti is most frequently captured in open habitats of the Cerrado and through the ecotone between forested and open areas (voucher data, journal notes, and collector information), in habitats locally referred to as cerrado and pampa arbolada (Emmons et al. 2006), cerrado sensu stricto (grassland densely covered with bushes and small trees), cerrado rupestre (similar to the previous, but with rocky outcrops), campo úmido (seasonally flooded grassland), and campo cerrado (grassland sparsely covered with bushes; Bonvicino, Lemos, and Weksler 2005). This is in contrast to other members of the genus that are associated more with forested habitats, such as gallery forest and woodland savanna, or cerradão (Percequillo et al. 2008). Langguth and Bonvicino (2002) stated that this species is also found in veredas and gallery forests but less frequently than in more open habitats of the Cerrado. Cerradomys scotti is scansorial (Alho and Villela 1984). This species may be sympatric with three other species: C. maracajuensis in the Brazilian states of Minas Gerais, Mato Grosso, and Mato Grosso do Sul, the Paraguayan state of Paraguarí, and in Santa Cruz department, Bolivia; C. marinhus in Bahia state, Brazil; and C. subflavus in Minas Gerais and São Paulo states, Brazil. r e m a r k s : Cerradomys scotti can be easily distinguished from its congeners by the presence of an alisphenoid strut and most notably by reduction to loss of the mesolophid in almost all individuals and of the mesoloph in many (Percequillo et al. 2008). Cerradomys scotti, along with Microakodontomys transitorius, Akodon lindberghi, and Thalpomys cerradensis, belongs to a fringe zone fauna that collectively inhabits transitional communities between open and forested habitats. Each of these species is characterized by reduction or loss of a mesoloph(id) (Hershkovitz 1993). Based on molecular evidence, Emmons et al. (2006) suggested that Cerradomys andersoni and C. scotti are conspecific. Brooks et al. (2004) also highlighted the close relationship between the haplotype of the holotype of C. andersoni and specimens of C. scotti. The only specimen ever assigned to C. andersoni shares some similarities with specimens of C. scotti such as a bicolored tail, presence of the alisphenoid strut, and reduction of the mesoloph on M2. Additionally, this specimen is nearly identical to the holotype of C. scotti as well to some other Bolivian specimens of this latter species from Santa Cruz department and to some Paraguayan specimens from Sapucay, Tobati, Altos, and Concepción departments (Percequillo et al. 2008). Thus, I feel confident in regarding andersoni as a

Map 153

Selected localities for Cerradomys scotti (●). Contour line = 2,000 m.

synonym of C. scotti. The karyotype of C. scotti is 2n = 58 and FN = 70 to 72 (Bonvicino et al. 1999).

Cerradomys subflavus (Wagner, 1842) Flavescent Cerradomys sy n o n y m s : Mus vulpinus Lund, 1839a:233; nomen nudum. Mus vulpinus Lund, 1840b [1841c:279]; type locality “Rio das Velhas’s Floddal” (Lund 1841c:292), Lagoa Santa, Minas Gerais, Brazil; part; preoccupied by Mus vulpinus Brants. Hesperomys subflavus Wagner, 1842c:362; type locality “Brasilia”; restricted to “Lagoa Santa, estado de Minas Gerais,” Brazil by Cabrera (1961:396). Mus subflavus: Schinz, 1845:190; name combination. Mus vulpinoides Schinz, 1845:193; renaming of Mus vulpinus Lund. Hesperomys laticeps: Burmeister, 1854:171; part; not Mus laticeps Lund. Calomys vulpinus: Fitzinger, 1867b:86; part; name combination. Calomys laticeps: Winge, 1887:51; part; not Mus laticeps Lund (see Percequillo 1998 and Musser et al. 1998:263, 298, concerning this usage). Oryzomys subflavus: Thomas, 1901g:528; name combination. [Oryzomys (Oryzomys)] subflavus: E.-L. Trouessart, 1904: 421; name combination.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 307

[Oryzomys] vulpinoides: Tate, 1932e:18; name combination. Holochilus physodes physodes: C. O. da C. Vieira, 1953: 134; part. Oryzomys laticeps intermedius: C. O. da C. Vieira, 1953: 137–138; part. Oryzomys subflavus subflavus: C. O. da C. Vieira, 1955: 411; part; name combination. [Cerradomys] subflavus: Weksler, Percequillo, and Voss, 2006:8; first use of current name combination. d e s c r i p t i o n : Medium sized to large, with head and body length 120–179 mm and tail length 150–210 mm. Hindfeet small (length 31–34 mm). Dorsal body color coarsely grizzled buffy to orange brown, head contrastingly grayish, and ventral color also grayish. Skull with deep rostral fossae; roof of mesopterygoid fossa with large and wide sphenopalatine vacuities exposing orbitosphenoid; palatal fossae long, deep, and narrow, with multiple posterolateral palatal pits; bony tubes of bullae short, with distinct medial lamina dorsal to carotid canal. Central cartilaginous digit of distal baculum present but reduced in size. d i s t r i b u t i o n : Cerradomys subflavus is endemic to central Brazil, in the states of São Paulo, Minas Gerais, Bahia, and Goiás. s e l e c t e d l o c a l i t i e s (Map 152): BRAZIL: Bahia, Nova Viçosa (LV [MW 13]); Goiás, Anápolis (MNRJ 4345); Minas Gerais, Fazenda Triangulo Formoso, Buritizeiros (UFMG 3), Fazenda Esmeralda, 30 km E and 4 km N (by road) from Rio Casca (UFMG 1200), Lagoa Santa (type locality of Hesperomys subflavus Wagner), Parque Estadual do Rio Preto, 15 km S of São Gonçalo do Rio Preto (UFMG 2852), Prados (UFMG 448); São Paulo, Avanhandava, Rio Tieté (MZUSP 2872), Itapetininga (UFMG [MAM 182]), Salto de Pirapora, Bairro da Ilha (MZUSP 24599). s u b s p e c i e s : I treat Cerradomys subflavus as monotypic. n a t u r a l h i s t o ry: Cerradomys subflavus occurs in mesic habitats in the Cerrado, including gallery forest and woodland savanna (cerradão), and in patches of semideciduous forest of the interior Brazilian highlands. It is primarily terrestrial (Stallings 1989), although individuals have been caught in trees (G. A. B. Fonseca and Kierulff 1989). r e m a r k s : The karyotype consists of 2n = 54 and FN = 62 or 64 (E. J. C. Almeida and Yonenaga-Yassuda 1974; Bonvicino and Moreira 2001; J. C. Moreira et al. 2009).

Cerradomys vivoi Percequillo, Hingst-Zaher, and Bonvicino, 2008 Vivo’s Cerradomys sy n o n y m : Cerradomys vivoi Percequillo, Hingst-Zaher, and Bonvicino, 2008:24; type locality “Parque Zoobotânico da

Comissão Executiva do Plano da Lavoura Cacaueira (CEPLAC), situated 6 km E of Itabuna by road, state of Bahia, Brazil, at 14°48′S, 39°16′W, on sea level.” d e s c r i p t i o n : Size intermediate for genus, with head and body length 127–160 mm and tail length 153–200 mm; hindfeet rather small (length 30–36 mm). Dorsal pelage short and dense, colored orange grizzled with brown, head contrastingly grayish, and venter grayish or slightly yellowish. Skull with long and wide sphenopalatine vacuities; alisphenoid strut absent; palatal fossae deep, with multiple posterolateral palatal pits. d i s t r i b u t i o n : Cerradomys vivoi occurs through the Brazilian states of Minas Gerais, Bahia, and Sergipe. In Minas Gerais, most records are restricted to northern basins of the Rio Jequitinhonha and Rio São Francisco, including its right bank tributaries. In Bahia, records of C. vivoi are concentrated in the coastal region on the right (eastern) bank of Rio São Francisco, while in Sergipe, the only record is from the coast, near the mouth of the Rio São Francisco. s e l e c t e d l o c a l i t i e s (Map 150): BRAZIL: Bahia, Parque Zoobotânico CEPLAC, 6 km E of Itabuna (type locality of Cerradomys vivoi Percequillo, Hingst-Zaher, and Bonvicino), Lagoa de Itaparica (MZUSP 28889), Fazenda Bolandeira, 10 km S of Una (UFMG, not cataloged), Valença, Rio Unamirim (UFPB 540); Minas Gerais, Riacho Mocambinho, Jaíba (MNRJ 34433), Fazenda Canoas, 36 km NE and 12 km W of Montes Claros (MNRJ 61662), Jequitinhonha (UFMG 1458); Sergipe, Fazenda Capivara, 7 km SE of Brejo Grande (MNRJ 30587). s u b s p e c i e s : Cerradomys vivoi is monotypic. n a t u r a l h i s t o ry: Cerradomys vivoi is associated with the drier areas of the Cerrado and Caatinga as well as the transition between these biomes and the wetter Atlantic Forest (Percequillo et al. 2008). In the drier biomes, this species inhabits secondary semideciduous and gallery forests as well as arboreal Caatinga. In the Atlantic Forest of southern Bahia (Pardini 2004), C. vivoi was considered absent or very rare in mature forests (including their edges) but occurred in disturbed forests, particularly those in initial stages of regeneration or more commonly in open areas (Percequillo et al. 2008). Diet consists mainly of plant material and arthropods. The only ectoparasite thus far found on C. vivoi is the mite Gigantolaelaps vitzthum: (Hingst et al. 1997). r e m a r k s : See comparisons in the discussion of C. langguthi. There are some karyotypic similarities between C. vivoi (2n = 50, FN = 64; Bonvicino et al. 1999, as “O. subflavus variant 3”) and C. langguthi, which is characterized by population polymorphism of 2n = 48 to 50 and FN = 56 (Percequillo et al. 2008), but the overlap is restricted to the diploid number, not to the fundamental number. Morphological differences in the autosomal complements of these

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two species suggest that hybrids, if possible, would suffer meiotic incompatibilities, thus supporting recognition of both forms as separate species.

Genus Drymoreomys Percequillo, Weksler, and Costa, 2011 Alexandre R. Percequillo and Marcelo Weksler

Drymoreomys is a monotypic genus found in the Atlantic Forest biome of eastern Brazil, known from fewer than 20 specimens from four localities ranging in elevation from 650 m to 1,200 m. Its sole species, D. albimaculatus Percequillo, Weksler, and Costa (2011), first collected in 1992, is the sister group to Eremoryzomys polius, a taxon endemic to the dry forests of the Río Marañón basin in the northern Andes of Peru, according to phylogenetic analyses of molecular and morphological data (Percequillo, Weksler, and Costa 2011; Suárez-Villota et al. 2013). Drymoreomys are medium-sized rodents, with moderate head and body size (length 109–149 mm) and mass (44– 102 g). The tail is longer than combined head and body length (tail length 150–176 mm), the pinnae are small, and the hindfeet are wide and short (hindfoot length 26– 30 mm). The dorsal pelage consists of long and dense underfur and longer and lax overfur (length of aristiforms 14–17 mm). Dorsal color ranges from dull orange to fulvous buffy weakly grizzled with reddish-brown; the ventral pelage is grayish, with distinctive white patches present in gular, thoracic, and inguinal regions (the inguinal patch is sometimes absent), and distinctively paler than the dorsal pelage. The ears are rounded and small, covered internally with short golden hairs and externally densely covered with reddish-brown hairs. The mystacial vibrissae usually extend posteriorly for a few millimeters beyond the caudal margins of the pinnae when laid back. The tail is unicolored, densely covered with short and stiff brown hairs on dorsal and ventral surface and with very reduced scales. Forefeet are small and wide, covered by brown hairs proximally with the digits covered with white/silvery hairs. Hindfeet are short and moderately wide, densely covered above with a patch of brown hairs over the metatarsus surrounded by white/silvery hairs; conspicuous ungual tufts of long white to silvery hairs are present at the base of the claws on digits II to V; the plantar pads are very large and fleshy, and the interdigital pads are set close together. The skull is medium sized and moderately robust, its condyloincisive length ranging from 27.1–32.4 mm. The rostrum is long (nasal length 11.25–13.51 mm) and wide (breadth of rostrum range from 4.82–5.98 mm), tapering distally; nasals and premaxillae are slightly projected anteriorly, forming a short bony rostral tube. Shallow zygo-

matic notches flank the rostrum; the zygomatic plates are not projected forward, their anterior margins are straight or slightly concave, without dorsal free margins and zygomatic spines. The interorbital region is long and narrow (least interorbital breadth ranges from 5.01–5.68 mm), anteriorly convergent, with squared to lightly beaded supraorbital margins. The braincase is oblong, with or without weakly developed temporal crests. The incisive foramina are long (averaging about 71% of the diastema length) and widest posteriorly, sometimes extending to the level of the alveoli or anterocones of M1s; lateral margins are abruptly indented anteriorly near the premaxillomaxillary suture or sharply constricted posteriorly, near the posterior border. The palate is short and wide, without palatal excrescences, and with small to moderately large posterolateral palatal pits, single to multiple and recessed in shallow fossae. The mesopterygoid fossa reaches the level of the posterior borders of M3s (penetrating to the level of the hypocones of M3s in some specimens); the bony roof of the mesopterygoid fossa is completely ossified, or perforated only by small sphenopalatine vacuities restricted to the presphenoid (only marginally in the basisphenoid). The stapedial foramen, squamosoalisphenoid groove, and sphenofrontal foramen are absent; the posterior opening of alisphenoid canal is large and conspicuous but lacks a posterior groove or depression; and the secondary anastomosis of internal carotid artery crosses the dorsal surface of parapterygoid plate, all traits that define carotid circulatory pattern 3 (sensu Voss 1988). An alisphenoid strut is present as a robust bony bar separating the buccinator-masticatory and accessory oval foramina. Auditory bullae are globose, with short bony tubes; the stapedial process is long and narrow, overlapping the lateral margin of the squamosal. The posterior suspensory process of the squamosal is absent; a bony projection dorsolateral to the stapedial process is present, overlapping the squamosal; and the periotic is exposed posteromedially between the ectotympanic and the basioccipital, but does not extend anteriorly to the carotid canal in most specimens. Each mastoid is perforated by a conspicuous posterodorsal fenestra; the postglenoid foramina are large and rounded; and the subsquamosal fenestrae are large and patent. The mandible is long and shallow; the coronoid process is large, falciform or triangular, nearly equal in height to the condyloid process; the angular process is short, not extending past the condyloid process posteriorly. Both superior and inferior notches are shallow. The capsular process is not noticeable. Upper incisors are opisthodont, and molars are pentalophodont and high-crowned. The maxillary toothrows are subparallel or weakly convergent anteriorly; the molar series is robust and long, 4.93–5.43 mm. Labial and lingual flexi of upper molars shallowly penetrate at the

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 309

molar midline; both are arranged in opposite pairs. The labial and lingual cusps are high (molars nearly hypsodont) and compressed anteroposteriorly; labial cusps are quite distinct and project laterally. The occlusal surfaces of the labial cusps of the upper molars are oriented posteriorly; the occlusal surfaces of the lingual cusps are labially oriented. The anterocone of M1 is divided into labial and lingual conules (anteromedian flexus present); the anteroloph is well developed and fused with an anterostyle on the labial cingulum, and separated from the anterocone by a persistent anteroflexus. A protostyle is present (in most specimens) as an isolated accessory cuspule or fused to an anterior mure. An enamel bridge connects the paracone to the middle or the anterior portion of the protocone. The protoflexus of M2 is variably present; the mesoflexus is long and obliquely or transversally oriented, divided into two (labial and lingual) or three (labial, medial, and lingual) fossettes. M3 has a mesoloph, posteroloph, and persistent hypoflexus; the paracone and protocone are distinguishable on the occlusal surface; the hypocone is reduced, and the metacone is greatly reduced and completely fused with the posteroloph. The labial accessory root of M1 is possibly absent (not visible in lateral view). Labial cusps of the lower molars are slightly anterior to the lingual cusps; the occlusal surfaces of the lingual cusps are oriented anteriorly, and those of the labial cusps are lingually oriented. The anteroconid of m1 is divided by an anteromedian flexid; the anterolabial cingulum is developed in m1 and m2, and variably present in m3; the anterolophid is present in all lower molars; the ectolophid is variably present on m1 only; and the posteroflexid on m3 is large and persistent. All lower molars have two roots, one each in anterior and posterior positions. The axial skeleton includes 12 ribs and 19 thoracolumbar, 4 sacral, and 36–38 caudal vertebrae. The hemal arch at the boundary of the second and third caudal vertebrae hasa posterior spinous process. The trochlear process of the calcaneus is long and shelf-like, positioned immediately posterior to the articular facet. The entepicondylar foramen is absent. The supratrochlear is absent in adults but is observable in young individuals. The stomach is unilocular and hemiglandular, with the gastric glandular epithelium restricted to the antrum. The glans penis does not have lateral bacular mounds; the distal cartilaginous apparatus is tridigitate, with the central digit more robust than the lateral ones; the dorsal papilla has one apical spine; and the urethral process has a large lateral lobule. The preputial glands are very large. sy n o n y m : Drymoreomys Percequillo, Weksler, and Costa, 2011:360; type species Drymoreomys albimaculatus by original designation and monotypy.

Drymoreomys albimaculatus Percequillo, Weksler, and Costa, 2011 White-throated Montane Forest Rat sy n o n y m : Drymoreomys albimaculatus Percequillo, Weksler, and Costa, 2011:368; type locality “Brazil, Estado de São Paulo, Município de Ribeirão Grande, Parque Estadual Intervales, Base do Carmo, 700 m; 24°20′S, 48°25′W.” d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : All known specimens referred to Drymoreomys are from the eastern slopes of the Serra do Mar, in the coastal Brazilian Atlantic Forest, from São Paulo to Santa Catarina states, at elevations ranging from 650 m to 1,200 m. s e l e c t e d l o c a l i t i e s (Map 154): BRAZIL: São Paulo, Estação Ecológica do Bananal (MZUSP 33782), Estação Biológica de Boracéia (MZUSP [BO 24]), Parque Estadual Intervales, Base do Carmo (type locality of Drymoreomys albimaculatus); Santa Catarina, Parque Estadual da Serra do Tabuleiro (UFSC 860). s u b s p e c i e s : Drymoreomys albimaculatus is monotypic. n a t u r a l h i s t o ry: Available evidence (see Percequillo, Weksler, and Costa 2011) suggests that D. albimaculatus is an Atlantic Forest endemic, inhabiting dense and humid montane and premontane forests. Apparently, this species does not exhibit preferences for pristine forests, as it has also found in secondary and disturbed forests, and even in areas that were completely deforested a few decades ago. Additional evidence (Pardini and Umetsu 2006; Bueno 2008; R. Pardini, pers. comm.), however, suggests that D. albimaculatus inhabits areas of both pristine and disturbed forest. Females were reproductively active in June and from November to December, and males possessed scrotal testes in December, suggesting that reproduction may take place throughout the year (Percequillo, Weksler, and Costa 2011). r e m a r k s : This recently discovered rat comes from one of the most densely populated areas in South America. Furthermore, the unexpected close phylogenetic relationship between Drymoreomys and Eremoryzomys, as recovered by Percequillo, Weksler, and Costa (2011) and Suárez-Villota et al. (2013), provides one of the most noteworthy sister taxon duos in South America biogeography. Drymoreomys is endemic to lower montane areas in the Atlantic Forest of eastern Brazil, whereas Eremoryzomys is an Andean endemic (760 to 2,100 m) from the valley of the lower Río Marañón in northern Peru. Each taxon is restricted to wellknown Neotropical centers of endemism (P. Müller 1973; Cracraft 1985), with D. albimaculatus part of the Serra do Mar center and E. polius from the Marañón center. A closely parallel case illustrating a biogeographic connection

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Map 154

Selected localities for Drymoreomys albimaculatus (●).

between the Brazilian Atlantic Forest and central Andes is that of Rhagomys. It is likely that additional discoveries of rodents or many other organismal groups will fill the large geographic gap between these two distributional areas. Suárez-Villota et al. (2013) described a karyotype with 2n = 62, FN = 62; the autosomal complement consists of 29 pairs of acrocentrics grading evenly from large to small plus a single pair of small metacentrics; the X chromosome is a large subtelocentric, the Y a slightly small submetacentric.

Genus Eremoryzomys Weksler, Percequillo, and Voss, 2006 Alexandre R. Percequillo

The genus Eremoryzomys is monotypic, with the single species, E. polius, limited to the upper Río Marañón valley in northern Peru. Since it was described, the validity of this species has never been questioned (see Cabrera 1961; Musser and Carleton 1993, 2005), although its phylogenetic relationships to other oryzomyines have remained unclear. Osgood (1913) emphasized the distinctness of E. polius in comparison with Aegialomys xanthaeolus, and Musser and Carleton (2005) declared its affinities to be obscure. The morphology of Eremoryzomys is quite distinctive both in external and cranial traits. This rat is medium sized, with the head and body length 125–161 mm. The

tail is longer than the head and body (135–188 mm). The dorsal pelage is dense and harsh, coarsely grizzled grayish to brownish or yellowish gray; the ventral pelage is noticeable paler, with gray-based hairs tipped very light buff. The tail is distinctly bicolored. Ears are small and rounded, and do not reach the eye when laid forward. The hindfoot has conspicuous and dense tufts of long, white ungual hairs at the base of the claws; the hypothenar pad is large and distinct, as are other plantar pads. The skull is medium-sized, with its condyloincisive length 29.9–36.8 mm. The rostrum is long and stout, flanked by moderately deep zygomatic notches. The interorbital region is divergent posteriorly, with beaded supraorbital margins. The braincase is rounded, with distinct temporal crests. Posterior margins of the zygomatic plates are located above the alveoli of the M1s. The zygomatic arches are strong and flared, widest at the squamosal root; jugals are large (the maxillary and squamosal zygomatic processes are widely separated, not overlapping, in lateral view). The nasals are short and do not extend posterior to the lacrimals, which are equally sutured to the maxillary and frontal bones. The frontosquamosal suture usually is collinear with the frontoparietal suture. Incisive foramina are very long, usually extending posteriorly between the anterocones or even protocones of the M1s; the lateral margins are subparallel and widest medially. The palate is short and wide, with the anterior margin of the mesopterygoid fossa penetrating anteriorly to, or slightly between, the molar rows; the bony roof of mesopterygoid fossa is perforated by large sphenopalatine vacuities. The palate has large and complex posterolateral palatal pits recessed in deep fossae. The alisphenoid strut is usually present so that the buccinator-masticatory foramen and accessory foramen ovale are separate, but the strut is unilaterally absent on some skulls. The stapedial foramen and the posterior opening of alisphenoid canal are small, the squamosal-alisphenoid groove and the sphenofrontal foramen are absent, and the secondary anastomosis of the internal carotid crosses dorsal surface of the pterygoid plate, all features that definecarotid circulatory pattern 3 (sensu Voss 1988). The postglenoid foramen is large and rounded, and the subsquamosal fenestra is large and conspicuous. The periotic bone is exposed posteromedially between the ectotympanic and the basioccipital but does not extend anteriorly to the carotid canal; each mastoid is perforated by a small or large posterodorsal fenestra. The capsular process is indistinct or absent, and both superior and inferior masseteric ridges are usually conjoined anteriorly below m1 as a single crest. Labial and lingual flexi of M1 and M2 do not interpenetrate. The anterocone of M1 is not divided into labial and lingual conules (but a small internal fossette ob-

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 311

viously derived from the anteromedian flexus is present); the anteroloph usually is well developed, fused with an anterostyle on the labial cingulum, and separated from the anterocone by a persistent anteroflexus; a protostyle is absent; the paracone is connected by an enamel bridge to the middle or posterior part of the protocone. The protoflexus of M2 is present but shallow; the mesoflexus is present as one or more internal fossettes (both conditions occurring on opposite sides of some specimens: e.g., AMNH 64054). Both a posteroloph and diminutive hypoflexus are present on M3, the latter tending to disappear with moderate to heavy wear. A labial accessory root of M1 is absent. The anteroconid of m1 lacks an anteromedian flexid; the anterolabial cingulum and anterolophid are present on all lower molars; an ectolophid is absent on m1 and m2; a mesolophid is variably developed on m1 and m2, large and distinct in some specimens but much reduced or absent in others; and the hypoflexid of m2 is short. Accessory roots are absent on m1; m2 and m3 each has one large anterior and posterior root. sy n o n y m s : Oryzomys: Osgood, 1913:97; part (description of polius); not Oryzomys Baird. Eremoryzomys Weksler, Percequillo, and Voss, 2006:10; type species Oryzomys polius Osgood, by original designation. r e m a r k s : According to Weksler (2003, 2006), Eremoryzomys is the most basal lineage of a clade (Clade D) containing Oryzomys, Pseudoryzomys, Lundomys, Holochilus, Sooretamys, Cerradomys, Nesoryzomys, Aegialomys, Amphinectomys, Nectomys, Sigmodontomys, and Melanomys.

s u b s p e c i e s : Eremoryzomys polius is monotypic. n a t u r a l h i s t o ry: Eremoryzomys polius inhabits the upper Marañón Valley westward to the Cordillera Central of northern Peru, in a rain-shadow area characterized by hot and arid climate (Cracraft 1985; Osgood 1914b:145). Nothing is known about the behavior or population biology of this species. What little is known of the habitat was summarized by Osgood (1914b:145), who stated that the type series was obtained at “a dilapidated tambo on the side of the mountains directly east of and overlooking Balsas and the [Río] Marañón. A tiny spring here is surrounded by a clump of trees . . . and the steep slope below has some moderately extensive thickets of low bushes which moisture from the spring permits to flourish. Elsewhere conditions are arid with occasional bunches of grass, cactuses, or small bushes.” Thomas (1926g:157) stated that Condechaca, situated a few kilometers south of Chachapoyas but north of Tambo Carrizal in the Marañón valley, “is surrounded by relatively arid foothills.” r e m a r k s : As with species of Aegialomys, Eremoryzomys polius appears to be an open habitat specialist. As such, members of these two genera share some resemblances

Eremoryzomys polius (Osgood, 1913) Gray Eremoryzomys sy n o n y m s : Oryzomys polius Osgood, 1913:97; type locality “Tambo Carrizal, mountains east of Balsas, [Amazonas], Peru. Altitude about 5000 ft.” Oryzomys [(Oryzomys)] polius: Cabrera, 1961:394; name combination. [Eremoryzomys] polius: Weksler, Percequillo, and Voss, 2006:10; first use of current name combination. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : Known only from seven localities in the upper Río Marañón valley of northern Peru, in Amazonas and Cajamarca departments. s e l e c t e d l o c a l i t i e s (Map 155): PERU: Amazonas, Condechaca, Río Utcubamba (BM 26.5.3.16), Tambo Carrizal, mountains E of Balsas (type locality of Oryzomys polius Osgood), Tingo, 30 km S and 41 km E of Bagua, Río Utcubamba (MVZ 135658); Cajamarca, Chaupe (AMNH 64054), San Ignacio (AMNH 64055).

Map 155 Selected localities for Eremoryzomys polius (●). Contour line = 2,000 m.

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(grayish dorsal coloration, long incisive foramina, mesoloph/ id reduction) that are apparently convergences owing to adaptations to open, dry areas (Weksler 2003, 2006). Weksler et al. (2006:11) noted that “Eremoryzomys differs from Aegialomys by its much grayer dorsal pelage (the dorsal fur is distinctly yellowish or brownish in Aegialomys); larger jugal (the jugal of Aegialomys is much smaller); longer incisive foramina (these openings never extend posteriorly between the M1 protocones in Aegialomys); shorter palate (the mesopterygoid fossa never extends anteriorly to the molar rows in Aegialomys); presence of an alisphenoid strut separating the buccinator-masticatory and accessory oval foramina (the strut is invariably absent and the foramina are confluent in Aegialomys); absence of a distinct capsular process (although well developed in Aegialomys); absence of accessory roots on M1/m1 (accessory roots are normally present on these teeth in Aegialomys); and presence of the anterolophid on m2 and m3 (the anterolophid is absent on these teeth in Aegialomys).”

Genus Euryoryzomys Weksler, Percequillo, and Voss, 2006 Alexandre R. Percequillo

According to recent revisionary work (Weksler 1996, 2006; Musser et al. 1998; Percequillo 1998, 2003), the genus Euryoryzomys includes six valid species: E. emmonsae, E. lamia, E. legatus, E. macconnelli, E. nitidus, and E. russatus. These studies also emphasize that some members of the genus exhibit variation in morphology, karyology, and/ or molecular phylogeography that may merit taxonomic recognition. This is especially so for E. russatus from northeastern Brazil (Weksler 1996; Percequillo 1998; M. J. de J. Silva et al. 2000b), E. macconnelli from western Amazonia (Musser et al. 1998; see also Patton et al. 2000; Voss et al. 2001), and E. emmonsae from south central Amazonia (L. P. Costa 2003). The species of Euryoryzomys are widely distributed throughout South America (hence the name, from the Greek eurus, meaning “far reaching or far-spread”), occurring in lowland and lower montane tropical rainforest of the Amazon Basin; Brazilian and Argentinean Atlantic Forest; Bolivian and Argentinean yungas; the semideciduous forests of Paraguay, Brazil, and Bolivia; isolated patches of rainforest (brejos) in the northeastern Brazilian Caatinga; and gallery forests in the Brazilian Cerrado and Paraguayan Chaco. Species of this genus exhibit a considerable range in size (head and body length 90–96 mm; tail length 100–185 mm). The tail is longer than the head and body, except in E. nitidus and E. lamia, which have a tail as long as head and body (head and body length 113–160 mm versus tail length

108–163 mm, and head and body length 135–165 mm versus tail length 135–165 mm, respectively). The dorsal pelage is soft and dense, varying from long in most species (fur length ranges from 12–16 mm) to very long in E. macconnelli (fur length from 17–20 mm). The dorsal and ventral pelage coloration is variable among species, but always shows strong countershading; the dorsal color ranges from buffy-brown to reddish cinnamon brown, and the ventral color varies from grayish-white to almost pure white. The tail is always bicolored. The hindfoot is long and narrow (length 25–44 mm), and has very dense and long ungual tufts that conceal the claws. The ungual tufts are usually white. The skull ranges from medium sized to large (mean greatest skull length varies among species from 28.8– 39.2 mm), and is of lightly to moderately heavily build. The rostrum is long and narrow, flanked by narrow and shallow to deep (in E. lamia and E. legatus) zygomatic notches. Incisive foramina range from short to long (4.0–7.0 mm) and are variable in shape, with their lateral margins either nearly parallel, convex, or divergent posteriorly (width 1.9–3.2 mm); their posterior margins never reach the level of the alveoli of M1s. The interorbital region is narrow (4.4–6.5 mm in least breadth) with lateral margins divergent posteriorly; the supraorbital margins are weakly to strongly beaded, and form discrete crests that extend posteriorly onto the dorsolateral margins of braincase, which is long and narrow. The zygomatic arches project laterally and are widest at their squamosal roots; jugals are absent in almost all specimens of E. lamia. The zygomatic plates span a considerable range in width, from 2.6–5.2 mm; the free dorsal margins project anteriorly, with their anterior margins sloping backward from top to bottom in E. lamia and E. legatus and either straight to slightly concave. A stapedial foramen, squamosal-alisphenoid groove, and sphenofrontal foramen are present, defined as carotid circulatory pattern 1 (sensu Voss 1988). An alisphenoid strut, present in all specimens of E. legatus, occurs at low to moderate frequencies in E. russatus, E. lamia, and E. nitidus, but is absent in individuals of E. macconnelli and E. emmonsae. The palate is long and narrow, with puntiform to small posterolateral palatal pits placed either at palatal level or in a shallow palatal depression; palatal excrescences are present in most species. The mesopterygoid fossa is narrow with its anterior margin rounded; the roof of the fossa is completely ossified or perforated only by small sphenopalatine vacuities. Parapterygoid fossae are flat or only moderately concave. Auditory bullae are small and rounded, with both the bony tubes and stapedial processes long and narrow. The tegmen tympani is small, rounded, squared, or triangular, and may or may not overlap the squamosal; the suspensory process of the squamosal is absent.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 313

The mandible is deep and robust. The coronoid and condyloid processes are equal in height, and separated by a shallow superior notch. The angular process does not extend posteriorly past the condyloid process. The capsular process is a distinct projection in most species but is absent in E. macconnelli and E. emmonsae. Upper incisors are opisthodont, fronted by distinct orange enamel bands. Toothrows are parallel and of medium length (length 4.3–5.6 mm). Main cusps are arranged in opposite pairs and are low to high crowned. The anterocone of M1 is undivided; M1 and M2 have two distinct enamel islands between the paracone and metacone; and M3 possesses a distinct anterolabial cingulum in some species such as E. lamia. The first lower molar is not divided by an anteromedian flexid; m2 has a distinct ectostylid or even a narrow and delicate ectolophid. M1 has three main roots, anterior and posterior labial and lingual, as well as an accessory rootlet between the two labials and beneath the paracone; M2 and M3 each has three main roots. All lower molars have two roots, one anterior and one posterior. The axial skeleton is composed of 7 cervical, 12–13 thoracic, 6–7 sacral, and 25–33 caudal vertebrae; thoracic vertebrae bear 12–13 ribs, or rarely 11 ribs plus a vestigial one. Hemal arches on caudal elements at the junction of the first and second and/or second and third caudal vertebrae have a distinct medial posterior process. The stomach is unilocular and hemiglandular, with a shallow angular notch. The glans penis is of the complex type (Hooper and Musser 1964), with a well-developed, tridigitate cartilaginous baculum. Both a single dorsal papilla and urethral flap are present, and three bacular mounds are visible at the terminal crater. The basal portion of the bony baculum is wide and spatulate, barely concave. sy n o n y m s : Mus: Brants, 1827:139; part (description of physodes); not Mus Linnaeus. Hesperomys: Wagner, 1848:312; part (description of russatus); not Hesperomys Waterhouse. Calomys: Winge, 1887:51; part (description of coronatus); not Calomys Waterhouse. Oryzomys: E.-L. Trouessart, 1897:525; part (inclusion of intermedius and nitidus as subspecies of laticeps); not Oryzomys Baird. Oryzamys: Avila-Pires, 1968:162; lapsus calami (description of kelloggi and ratticeps moojeni). Euryoryzomys Weksler, Percequillo, and Voss, 2006:8; type species Oryzomys macconnelli Thomas, by original designation. r e m a r k s : In 1960 (and subsequently in 1966a), Hershkovitz committed one of the most controversial and influential nomenclatural acts in the convoluted history of

oryzomyine species-group taxa (see Pine 1973; A. L. Gardner and Patton 1976; Musser et al. 1998; Weksler 2006). In a footnote comment, apparently not based on the examination of voucher specimens (especially type material) and clearly without any extensive discussion of morphological variation, Hershkovitz (1960:544) lumped under Oryzomys laticeps/capito (see Musser et al. 1998:10) the species of the genus Euryoryzomys (boliviae, legatus, and macconnelli) as well as those now belonging to other oryzomyine genera such as Hylaeamys (goeldii, modestus, oniscus, perenensis, saltator, and velutinus), Nephelomys (caracolus), and Transandinomys (casteneus [sic; Hershkovitz attributed the name authorship of castaneus to Oldfield Thomas, but this author never coined either castaneus or casteneus for any sigmodontine rodent genus according to J. E[dwards]. Hill 1990; the name castaneus was proposed by J. A. Allen in 1901; see Cabrera 1961], magdalenae, medius, mollipilosus, rivularis, sylvaticus, and talamancae). Moreover, Hershkovitz also mentioned that “a few other” species were also synonyms of Oryzomys laticeps/capito, but he never clarified the composition of this group in subsequent papers (e.g., Hershkovitz 1966a). Through the following decades, Hershkovitz’s footnote taxonomy was followed, partially or entirely, by other authorities (most notably Cabrera [1961]), until the publication of two important but temporally widely separated contributions. A. L. Gardner and Patton (1976), in their pioneering and influential paper on the cytogenetics of Neotropical Oryzomyini, paved the way for subsequent authors by showing that, under the name capito, Hershkovitz (1960, 1966a) had hidden extensive morphologic, karyologic, and taxonomic diversity. And, 20 years later in their massive revision, Musser et al. (1998) defined the limits of several species historically assigned to Oryzomys “capito” (sensu Hershkovitz 1960), recognizing 11 species grouped into six species groups based on extensive analysis of geographic variation and, critically, on their examination of almost all available type material. Combined, these two efforts plus several subsequent contributions have been responsible for the substantial advances in the classification and nomenclature of the Oryzomyini, as now presented throughout this volume. KEY TO THE SPECIES OF SOUTH AMERICAN EURYORYZOMYS:

1. Lateral face of mandibular ramus without trace of capsular process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1′. Lateral face of mandibular ramus with prominent capsular process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Dorsal pelage very dense, lax, and long (aristiform length 17–20 mm); dorsal pelage cinnamon brown or orange brown grizzled with dark brown or black; inci-

314 Mammals of South America

sive foramina short (length 4.1–6.2 mm, mean 5.4 mm) but widest posteriorly (teardrop in shape; see Musser et al. 1998:196, Fig. 82; palatal excrescences frequently present; upper molars with high cusps; enamel islands (fossettes) on M1 and M2, specially the labial fossette, quickly obliterated by wear; m1 with ectolophid frequently present; diploid number of western Brazilian Amazon and Peruvian populations 2n = 64 and fundamental number FN = 70 and FN = 64, respectively; of Venezuelan populations 2n = 76 and FN = 85, and of Brazilian central Amazon 2n = 58 and NF = 90 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Euryoryzomys macconnelli 2′. Dorsal pelage soft and short (aristiform length 12– 15 mm); dorsal pelage ochraceous brown grizzled with dark brown; incisive foramina short (length 4.0– 6.0 mm, mean 5.2 mm) but widest medially; palatal excrescences absent; upper molars with lower cusps, more flat-crowned; enamel islands more persistent, well resistant to wear; m1 without noticeable ectolophid; 2n = 80 and FN = 86 . . . . . . . . . . . . . Euryoryzomys emmonsae 3. Zygomatic plates very wide (3.7–5.2 mm), defining extremely deep zygomatic notches . . . . . . . . . . . . . . . . . 4 3′. Zygomatic plates narrower (3.2–4.6 mm), defining moderately deep zygomatic notches . . . . . . . . . . . . . . 5 4. Dorsal fur long (aristiform length 15–16 mm) and dense; head and body length (135–165 mm, mean 149.4 mm) equal to tail length (135–165 mm, mean 149.2 mm) in most specimens (few specimens have tail longer or shorter than head and body length); hindfoot more robust and longer (32–37 mm, mean 34 mm); zygomatic plates very wide (4.0–5.2 mm); zygomatic notches narrow and very deep; jugal absent; alisphenoid struts present in few specimens; palate without palatal excrescences . . . . . . . . . . . . . . . . . . . . . . Euryoryzomys lamia 4′. Dorsal fur very long (aristiform length 17–19 mm) and dense; tail length (130–180 mm, mean 146.5 mm) exceeds head and body length (110–159 mm, mean 136.3 mm) in all specimens; hindfoot shorter (30– 36 mm, mean 32.9 mm); zygomatic plates wide (3.7– 4.6 mm); zygomatic notches narrow and deep; jugal present; alisphenoid struts present; palate ornate with small palatal excrescences. . . . . . Euryoryzomys legatus 5. Tail (112–185 mm, mean 151.7 mm) longer than head and body (105–196 mm, mean 143.2 mm); restricted to eastern South America, in Atlantic Forest from Bahia to Rio Grande do Sul states, Brazil, west to Missiones province, Argentina and eastern Paraguay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Euryoryzomys russatus 5′. Tail (108–163 mm, mean 136.1 mm) equals head and body length (113–160 mm, mean 136.2 mm); restricted to western Amazon Basin south to western Mato Grosso state, Brazil. . . . . . . . . . . . . . . . . Euryoryzomys nitidus

Euryoryzomys emmonsae (Musser, Carleton, Brothers, and Gardner, 1998) Emmons’s Euryoryzomys sy n o n y m s : Oryzomys emmonsae Musser, Carleton, Brothers, and Gardner, 1998:233; type locality “east [= right] bank of Rio Xingu, 52 km SSW Altamira (03°39′S/52°22′W), below 100 m in Estado de Pará, Brazil.” [Euryoryzomys] emmonsae: Weksler, Percequillo, and Voss, 2006:11; first use of current name combination. d e s c r i p t i o n : Characterized by long tail relative to head and body length (average about 114%); small and delicate cranium, with long but slender rostrum; narrow zygomatic plates; narrow interorbital region with smooth dorsolateral margins; and narrow occiput. Incisive foramina short and wide; bony palate correspondingly long. d i s t r i b u t i o n : Euryoryzomys emmonsae is currently known from the south bank of the Rio Amazonas, throughout the Amazonian interfluvial forest between the left bank of the Rio Tocantins to the right bank of the Rio Xingu, in Pará state, Brazil. Two records from the Rio Teles Pires (a headwater tributary of the Rio Tapajós) in Mato Grosso state are included here, although these might represent an undescribed species (see below and L. P. Costa 2003). All localities range in elevation from 80 and 200 m. s e l e c t e d l o c a l i t i e s (Map 156): BRAZIL: Mato Grosso, Cláudia (L. P. Costa 2003), Reserve Ecológica Cristalino, 40 km N of Alta Floresta (MVZ 197523), Vila Rica (L. P. Costa 2003), 264 km N of Xavantina, Serra do Roncador (BM 81.436); Pará, 52 km SSW of Altamira, right bank Rio Xingu (type locality of Oryzomys emmonsae Musser, Carleton, Brothers, and Gardner), Floresta Nacional Tapirapé-Aquiri (Patton et al. 2000), Serra Norte (MPEG 8188). s u b s p e c i e s : Euryoryzomys emmonsae is monotypic. n a t u r a l h i s t o ry: Data summarized by Musser et al. (1998:236) suggests that this species is typically captured on the ground and under logs in viney forests and bamboo thickets. Most collecting localities are from nonflooded (terra firme) forest, although some are on riverbanks where the habitat may be influenced by seasonal flooding. r e m a r k s : Euryoryzomys emmonsae is very similar to both E. nitidus and E. russatus in morphological and karyological traits, although the size and proportions of both body and cranial parts distinguish these three species (see Musser et al. 1998). The most important diagnostic feature of this species is the absence of a capsular process on the mandibular ramus. The karyotype of E. emmonsae is very similar to those described for E. nitidus (A. L. Gardner and Patton 1976) and for E. russatus (M. J. de J. Silva et al. 2000b), with 2n = 80 and FN = 86. Specimens from two localities in the drainage of the Rio Teles Pires

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 315

Map 156 Selected localities for Euryoryzomys emmonsae (❍) and Euryoryzomys lamia (●).

in Mato Grosso state share similar morphological traits with E. emmonsae but are divergent from it in mtDNA cytochrome-b sequence (L. P. Costa 2003: localities 20 and 21). These likely represent an undescribed species but are included here under E. emmonsae because they are placed with this species in phylogenetic analyses of sequence data.

Euryoryzomys lamia (Thomas, 1901) Buffy-sided Euryoryzomys sy n o n y m s : Oryzomys lamia Thomas, 1901g:528; type locality “Rio Jordão near Araguary,” Minas Gerais, Brazil. Oryzomys (Oryzomys) lamia: Tate, 1932e:18; name combination. [Euryoryzomys] lamia: Weksler, Percequillo, and Voss, 2006:11; first use of current name combination. d e s c r i p t i o n : Dorsal pelage long and dense, with aristiforms 15–16 mm long and bicolored tail equal to or shorter than head and body length (average about 92%). Skull long and robust; rostrum wide; zygomatic notches deeply excavated; zygomatic plates very wide with straight anterior free margin; incisive foramina medium in length (mean 6.2 mm; range: 5.5–7.0 mm) with parallel lateral margins; palatal excrescences absent; roof of mesopterygoid fossa completely ossified; and M2 with well-developed anterolabial cingulum. d i s t r i b u t i o n : Euryoryzomys lamia is known from three localities in the semideciduous forest of the Brazilian central plateau in western Minas Gerais and southern Goiás states (Percequillo 1998) and in Cerrado habitats of northern Goiás state (Bonvicino et al. 1998).

s e l e c t e d l o c a l i t i e s (Map 156): BRAZIL: Goiás, Anápolis (MNRJ 4352), Fazenda Fiandeira, Parque Nacional da Chapada dos Veadeiros, 65 km SSW of Cavalcante (MNRJ 46826); Minas Gerais, Araguari, Rio Jordão (type locality of Oryzomys lamia Thomas). s u b s p e c i e s : Euryoryzomys lamia is monotypic. n a t u r a l h i s t o ry: Available evidence (Weksler 1996; Percequillo 1998) suggests that E. lamia is a forestdweller, inhabiting gallery forests (along the Rio Jordão) and a luxuriant semideciduous forest locally known as Mato Grosso de Goiás (at Anápolis; Faissol 1952). More recent published data suggest that this species also occurs in Cerrado habitats, such as cerradão (a dry woodland savanna), cerrado sensu stricto, and campo úmido (both open habitats), although, in the last, two specimens were captured in the ecotone with gallery forest (Bonvicino et al. 1998). r e m a r k s : Although regarded as a synonym of Euryoryzomys russatus by Musser et al. (1998), E. lamia is now recognized as a separate species (e.g., Musser and Carleton 2005; Weksler et al. 2006). These two species differ in several morphological attributes (Weksler 1996; Percequillo 1998), notably, the tail length of E. lamia is equal to or shorter than the head and body length while that of E. russatus exceeds the head and body length; E. lamia has much deeper zygomatic notches; and E. lamia has a longer palate (palatal bridge length 7.2–8.2 mm) rarely ornamented by palatal excrescences whereas E. russatus possesses a shorter palate (palatal bridge length 5.6– 7.6 mm). Univariate and multivariate analyses also differentiate the two taxa (Weksler 1996; Percequillo 1998; Musser et al. 1998). The two species also have different karyotypes (2n = 58, FN = 82 for E. lamia [Bonvicino et al. 1998] and 2n = 80, FN = 86 for E. russatus [Musser et al. 1998]) and display divergent mitochondrial and nuclear sequences (Bonvicino and Moreira 2001; Weksler 2003). The assignment of specimens from Cavalcante, Goiás state (reported by Bonvicino et al. 1998), to E. lamia deserves further investigation because there are noticeable morphometric differences between these specimens and series from Anápolis and Rio Jordão (Percequillo 1998).

Euryoryzomys legatus (Thomas, 1925) Tarija Euryoryzomys sy n o n y m s : Oryzomys legatus Thomas, 1925b:577; type locality “Carapari [= Caraparí], 1000 m., about 35 kilometres north of Yacuiba, on the way towards Tarija,” Tarija, Bolivia. Oryzomys (Oryzomys) legatus: Tate, 1932e:18; name combination. Oryzomys laticeps: Hershkovitz, 1960:544, footnote; part; not Mus laticeps Lund (= Hylaeamys laticeps [Lund]).

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Oryzomys capito legatus: Cabrera, 1961:386; name combination. [Euryoryzomys] legatus: Weksler, Percequillo, and Voss, 2006:11; first use of current name combination. d e s c r i p t i o n : Most informative traits include very dense and long dorsal pelage where aristiform hairs reach 17–19 mm in length; distinctly bicolored tail longer than combined head and body length (average about 108%); small skull (greatest length 32.9–36.8 mm), more delicate than E. lamia (length 34.2–38.1 mm) but more robust than other species; zygomatic notches narrow and deep, similar to E. lamia but less excavated; zygomatic plates wide; incisive foramina short (length 4.9–6.6 mm, mean 5.5 mm) and narrow, with parallel lateral margins; bony palate with small palatine excrescences; roof of mesopterygoid fossa completely ossified; and alisphenoid strut universally present. d i s t r i b u t i o n : The collecting localities of E. legatus are in premontane and montane forests along the eastern Andean slope in extreme southern Bolivia and northernmost Argentina, at elevations from 500 to 2,100 m; there are no records of this species in the Bolivian or Argentinean lowlands. s e l e c t e d l o c a l i t i e s (Map 157): ARGENTINA: Jujuy, 8.4 km E of El Palmar, Sierra Santa Bárbara (Musser et al. 1998); Salta, Santa Victoria, Parque Nacional Baritú, Arroyo Santa Rosa (MACN 20708), Piquirenda (Musser et al. 1998). BOLIVIA: Chuquisaca, 2 km E of Chuhuayaco (AMNH 263886), Tola Orco, 40 km from Padilla (USNM 271584); Santa Cruz, 1 km NE of Estancia Las Cuevas (AMNH 264182), Mataracú (FMNH 129267); Tarija, 1 km S of Camatindi (AMNH 264186), 3 km SE of Cuyambuyo (AMNH 264280). s u b s p e c i e s : Euryoryzomys legatus is monotypic. n a t u r a l h i s t o ry: This species is found in mesic and transitional forests of Salta province, Argentina (Mares, Ojeda, and Kosco 1981:174), where specimens were commonly acquired in “littered forested areas supporting little undergrowth,” but also caught in “dense second growth vegetation along streams and roads, and along the rocky banks of water courses.” Mares, Ojeda, and Kosco (1981) also stated that this species inhabited burrows in the forest floor, but the notes on specimen tags (MACNBR) also indicate that it frequents the canopy (habita la selva sobre los arboles). Euryoryzomys legatus feeds on vegetation and insects. S. Anderson (1997:401) summarized available information on the ectoparasites found on Bolivian specimens, including the ticks Eulaelaps halleri and Schistolaelaps mazzaias well as the flea Polygenis (Polygenis) typus. r e m a r k s : Musser et al. (1998) treated E. legatus as a synonym of E. russatus, but it is currently recognized as a

Map 157 Selected localities for Euryoryzomys legatus (ᇲ) and Euryoryzomys nitidus (●). Contour line = 2,000 m.

separate species (Musser and Carleton 2005; Weksler et al. 2006). The two are demonstrably different by morphologic and morphometric comparisons (Weksler 1996; Percequillo 1998), with the most distinctive morphological traits of E. legatus being the presence of a deep and narrow zygomatic notch and an alisphenoid strut present in all specimens. Limited mtDNA sequence analyses, however, suggest that E. legatus is nested within samples of E. nitidus (Patton et al. 2000). While not refuting the species distinctness of E. legatus, these data do suggest that the origin of this species has been relatively recent, possibly as a peripheral isolate of a more widespread E. nitidus. These data also strongly support phylogenetic separation from E. russatus.

Euryoryzomys macconnelli (Thomas, 1910) McConnell’s Euryoryzomys sy n o n y m s : Oryzomys macconnelli Thomas, 1910b:186; type locality “River Supinaam [= Supenaam], a tributary of the lower Essequibo, Demerara, British Guiana,” PomeroonSupenaam, Guyana (see Musser et al. 1998:278). Oryzomys incertus J. A. Allen, 1913c:598; type locality “La Murelia (altitude 600 feet), Rio Bodoquera, Caquetá, Colombia.” Oryzomys mureliae J. A. Allen, 1915b:630; replacement name for Oryzomys incertus J. A. Allen, preoccupied by Oryzomys alfaroi incertus J. A. Allen. Oryzomys (Oryzomys) macconnelli: Tate, 1932e:17; name combination.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 317

Oryzomys (Oryzomys) mureliae: Tate, 1932e:17; name combination. Oryzomys macconnelli macconnelli: Cabrera, 1961:392; name combination. Oryzomys macconnelli mureliae: Cabrera, 1961:392; name combination. [Euryoryzomys] macconnelli: Weksler, Percequillo, and Voss, 2006:11; first use of current name combination. d e s c r i p t i o n : Medium sized, with average head and body length 143 mm; tail equal to or longer than head and body (average 104%); closely resembles E. nitidus but differs in very dense, lax, long (aristiforms 17–20 mm), and orange to reddish brown fur in most samples. Skull with narrower zygomatic plates with correspondingly shallower zygomatic notches; wider interorbital region; shorter and wider incisive foramina (teardrop in shape); longer bony palate; alisphenoid struts absent in majority of specimens; m1 with ectolophid frequently present; capsular process not evident. d i s t r i b u t i o n : Euryoryzomys macconnelli is distributed throughout the Amazon Basin, from eastern Ecuador to eastern Pará state, Brazil, and from northern Guyana to southern Peru (Musser et al. 1998:176, Fig. 78). Over this extensive area, elevational records range from near sea level in the eastern Amazonian lowlands and Guianan region to about 1,500 m in the tepuis of Venezuela and Andean foothills of Peru. s e l e c t e d l o c a l i t i e s (Map 158): BRAZIL: Amapá, Serra do Navio (MZUSP 20521); Amazonas, Barro Vermelho, left bank Rio Juruá (Patton et al. 2000), Macaco, left bank Rio Jaú (Patton et al. 2000), PDBFF, 82 km N of Manaus (Patton et al. 2000), alto Rio Urucu (Patton et al. 2000); Mato Grosso, Aripuanã (L. P. Costa 2003), Juruena (L. P. Costa 2003); Pará, 54 km S and 150 km W of Altamira (Musser et al. 1998), Flexal, Itaituba-Jacareacanga, km 212 (USNM 545293), Floresta Nacional Tapirapé-Aquiri (INPA 2796), Igarapé-Assu (BM 4.7.4.65), 19 km S of Itaituba (Musser et al. 1998), Serra Norte (MPEG 15101). COLOMBIA: Caquetá, La Morelia [= La Murelia], Río Bodoquera (AMNH 33756). ECUADOR: Orellana, San José Abajo (Musser et al. 1998). FRENCH GUIANA: Cayenne, Arataye (USNM 548449). GUYANA: Pomeroon-Supenaam, Supenaam River (type locality of Oryzomys macconnelli Thomas). PERU: Amazonas, headwaters Río Kagka (MVZ 154972); Cusco, Río San Miguel (USNM 194564); Huánuco, Hacienda Éxito, Río Cayumba (Musser et al. 1998); Junín, Perené (BM 0.7.7.31); Puno, Pampa Grande, below San Ignacio on the Río Tambopata (FMNH 79900). SURINAM: Para, Finisanti, Saramacca River (FMNH 95595). VENEZUELA: Amazonas, Cerro Duida, Cabecera del Caño Culebra, 40 km NW of Esmeralda (USNM 406044); Bolívar, Auyán-tepuí (AMNH 131119).

s u b s p e c i e s : As currently understood, E. macconnelli is monotypic, but the considerable geographic variation in karyotype and mtDNA diversity (as described here) could signal greater specific and/or subspecific diversity than currently recognized. n a t u r a l h i s t o ry: This uncommon terrestrial species is found exclusively in primary tropical evergreen rainforest (Musser et al. 1998) and is considered a good indicator of pristine forests (Patton et al. 2000), being negatively affected by forest fragmentation (Malcolm 1991). Malcolm (1990) reported trapping density of 0.387 individuals/ ha and nocturnal census density of 0.095 individuals/ha in the central Brazilian Amazon, near Manaus; these values are smaller than those reported for other sympatric oryzomyines, especially Hylaeamys megacephalus. Individuals of both sexes with limited to moderate wear on the upper molars were sexually mature, with pregnant or lactating females found in both the rainy and dry seasons. Embryo counts ranged from two to four (modal number three) in the western Brazilian Amazon (Patton et al. 2000). r e m a r k s : Euryoryzomys macconnelli has been consistently considered a valid species by most authors (Gyldenstolpe 1932; Tate 1932e; Ellerman 1941; Cabrera 1961; Pine 1973; A. L. Gardner and Patton 1976; Husson 1978; Musser and Carleton 1993; Musser et al. 1998), except for Hershkovitz (1960), who incorrectly included this species in the synonymy of Hylaeamys megacephalus (then Oryzomys capito; see Musser et al. 1998). Analyses of geographic variation in external and cranial traits exhibited no significant differences among samples (Musser et al, 1998), but karyological data (summarized by Musser et al. 1998 and Patton et al. 2000) and molecular evidence (Patton et al. 2000) suggest that E. macconnelli is

Map 158 Selected localities for Euryoryzomys macconnelli (●). Contour line = 2,000 m.

318 Mammals of South America

composite. Populations north of the Amazon River are quite distinct, with the Rio Negro isolating two groups, one on the eastern and northeastern (left) bank with 2n = 76, FN = 85 and another on the west (right) bank with 2n = 58, FN = 90. Samples from Para state, Brazil, south of the Amazon River, and those from the western reaches of Amazonia in Ecuador, Peru, and western Brazil have a similar karyotype with 2n = 64, FN = 70. The very limited mitochondrial sequence data suggest that each karyotype, and thus geographic region, represents reciprocally monophyletic lineages. The status of Oryzomys mureliae J. A. Allen as a synonym of E. macconnelli was pointed out early by Tate (1932e) and confirmed by Musser et al. (1998). If, however, the geographic variants in this species merit taxonomic recognition, this is an available name (Voss et al. 2001).

Euryoryzomys nitidus (Thomas, 1884) Elegant Euryoryzomys sy n o n y m s : Hesperomys (Calomys) laticeps: Thomas, 1882:102; part (assignment of specimens from Peru); not Mus laticeps Lund. Hesperomys (Oryzomys) laticeps: Thomas, 1884:452; part (assignment of specimens from Peru); not Mus laticeps Lund. Hesperomys laticeps, var. nitidus Thomas, 1884:452; type locality “situated between the streams of Chanchamayo and Anamayo, at a little distance from the river Tutamayo [sic]” (Thomas 1884:447), and designated as “Amable Maria” based on the selection of a lectotype (Thomas 1927b:549); type locality further refined to “Amable María, valley of Río Tulumayo, 10 km south of San Ramón, Departamento de Junín, Peru, 2000 ft” (A. L. Gardner and Patton 1976:42). [Oryzomys] laticeps nitidus: E.-L. Trouessart, 1897:525; name combination. Oryzomys boliviae Thomas, 1901h:536; type locality: “Mapiri, Upper Beni River, (about 68°W. and 15°S.). Alt. 800 m,” La Paz, Bolivia. Oryzomys nitidus: Thomas, 1920h:228; name combination. Oryzomys (Oryzomys) nitidus nitidus: Tate, 1932e:17; name combination. Oryzomys capito nitidus: Cabrera, 1961:386; name combination. [Euryoryzomys] nitidus: Weksler, Percequillo, and Voss, 2006:11; first use of current name combination. d e s c r i p t i o n : Medium sized, with mean head and body length 136.1 mm (range: 108–163 mm) and tail nearly as long (mean length 136.2 mm; range: 113–160); short and close dorsal pelage; upper parts bright tawny or tawny brown with ochraceous highlights along sides of head and body; venter whitish gray; unicolored tail,

mottled on ventral surface near tip; dorsal surfaces of forefeet and hindfeet covered with dense white hairs, claws nearly hidden by long and dense ungual tufts; all plantar pads present; superciliary, genal, and mystacial vibrissae moderately long, not reaching past ear. Skull elongate (mean skull greatest length 33.3 mm; range: 25.5–36.3 mm) with narrow interorbital region (compared with E. macconnelli) bounded by dorsolateral ridges; alisphenoid struts present in about half of specimens examined; incisive foramina long (mean 5.7 mm; range: 4.6–6.8 mm) and narrow; bony palate short; zygomatic plates wide, zygomatic notches correspondingly moderately deep. M2 with short paraflexus and labial as well as medial fossettes; m2 with moderately deep entoflexid and short hypoflexid extending only halfway across tooth, with fossetid present. d i s t r i b u t i o n : Euryoryzomys nitidus is restricted to the western Amazon Basin, east of Andes in Peru and Bolivia and extending into adjacent western Brazil, as far east as the left bank of the Rio Teles Pires. It ranges in elevation from about 200 m in Brazil to 1,500 m on the eastern Andean slopes of Peru. s e l e c t e d l o c a l i t i e s (Map 157): BOLIVIA: Beni, Guayaramerín, Rio Mamoré (S. Anderson 1997), Lago Victoria (S. Anderson 1997); Cochabamba, 2 km E of Villa Tunari (AMNH 247779); La Paz, La Reserva (AMNH 264722), Mapirí (S. Anderson 1997); Pando, Río Nareuda (S. Anderson 1997); Santa Cruz, Parque Noel Kempff Mercado, 17 km S of Los Fierros (S. Anderson 1997), San Ignacio de Velasco (Musser et al. 1998), San Rafael de Amboró (Musser et al. 1998), 4 km N and 1 km W of Santiago de Chiquitos (S. Anderson 1997), 8 km SE of Tita (AMNH 260377). BRAZIL: Acre, Igarapé Porongaba, right bank Rio Juruá (Patton et al. 2000), Manuel Urbano, Sena Madureira, BR 364 km 8 (MPEG 10609); Mato Grosso, Apiacás (L. P. Costa 2003), Juruena (L. P. Costa 2003); Mato Grosso do Sul, Urucum, 22 km S of Corumbá (USNM 390109). PERU: Ayacucho, San José, Río Santa Rosa above Hacienda Luisiana (LSUMZ 16693); Huánuco, Chinchavito, at the mouth of the Río Chiraco (Musser et al. 1998); Junín, Amable Maria (type locality of Hesperomys laticeps var. nitidus Thomas); Madre de Dios, Reserva Cusco Amazónico (Woodman et al. 1991); San Martín, Moyobamba (USNM 259606); Ucayali, Balta, Río Curanja (A. L. Gardner and Patton 1976). s u b s p e c i e s : I treat Euryoryzomys nitidus as monotypic. n a t u r a l h i s t o ry: Based on information compiled by Musser et al. (1998:188–189; see also Patton et al. 2000), E. nitidus is a terrestrial inhabitant of humid tropical evergreen forests, largely restricted to Amazonian uplands on the western and southwestern border of the Amazon Basin.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 319

The species also occurs in mature and secondary deciduous forests and gallery forests through palm savannas and Cerrado, floodplain forest (including that adjacent to seasonally inundated swamp forest), and near anthropogenic areas (such as soccer fields, old vegetable gardens, and pastures). Emmons and Patton (2005) stated that E. nitidus was also captured in dry forests and grassland habitats in the Parque Nacional Noel Kempff Mercado of eastern Bolivia. The outlier locality of Urucum in Mato Grosso do Sul (also called Serra do Urucum) is an isolated massif on the western border of the Brazilian Pantanal covered with deciduous forest. This area is characterized by the presence of various Amazonian mammalian taxa, such as the marmoset Callithrix melanura (Vivo 1991), the titi monkey Callicebus donacophilus, and the tree squirrel Hadrosciurus spadiceus (see that account). r e m a r k s : My concept of E. nitidus is more restricted than that of Musser et al. (1998), because I believe that samples west of the Rio Teles Pires to the west bank of Rio Xingu belong to an undescribed species (see L. P. Costa 2003), but specimens from localities on the east bank of the Rio Xingu are E. emmonsae (see above). Therefore, it is likely that samples from the Serra do Roncador, assigned by Musser et al. (1998) to E. nitidus, belong to this undescribed form. Furthermore, specimens from Paraguayan and Argentinean localities, as reported by Musser et al. (1998), are not E. nitidus but rather E. russatus. A. L. Gardner and Patton (1976) suggested that Oryzomys boliviae was a synonym of E. nitidus, based on their examination of the holotype, a hypothesis subsequently confirmed by the morphological and morphometric analyses of Musser et al. (1998). The karyotype of E. nitidus consists of a 2n = 80 and FN = 86 (A. L. Gardner and Patton 1976; Patton et al. 2000).

Euryoryzomys russatus (Wagner, 1848) Russet Euryoryzomys sy n o n y m s : Mus physodes Brants, 1827:139; type locality “Provinz San Paulo,” São Paulo, Brazil; preoccupied by Mus physodes Olfers, a species of Reithrodon (see Musser et al. 1998:284). Hesperomys russatus Wagner, 1848:312; no type locality given in original description, but the selection by Musser et al. (1998) of a lectotype for E. russatus, from among specimens collected by J. Natterer, unequivocally established the type locality as Ipanema, São Paulo, Brazil (= Floresta Nacional de Ipanema, 20 km NW Sorocaba, São Paulo, Brazil, 23°26′7′′S, 47°37′41′′W, 701 m; L. P. Costa et al. 2003). Hesperomys physodes: Burmeister, 1854:167; name combination. Holochilus physodes: Fitzinger, 1867b:90; name combination.

Hesperomys Darwinii?: Hensel, 1872b:48; part; not Mus darwini Waterhouse. Hesperomys laticeps var. intermedia Leche, 1886:693; type locality “Rio dos Linos [= Rio dos Sinos], Taquara do Mundo Novo [= Taquara],” Rio Grande do Sul, Brazil. Calomys coronatus Winge, 1887:51; type locality “Lapa da Serra das Abelhas,” Lagoa Santa, Minas Gerais, Brazil. Hesperomys (Oryzomys) laticeps var. intermedia: Ihering, 1893:15; name combination. Hesperomys leucogaster: Ihering, 1897:150; not Hesperomys leucogaster Wagner [= Sooretamys angouya]. [Oryzomys] laticeps intermedia: E.-L. Trouessart, 1897: 525; name combination. Oryzomys intermedius: Thomas, 1901g:528; name combination. Oryzomys physodes: Thomas, 1904b:142; name combination. Oryzomys kelloggi Avila-Pires, 1959a:2; type locality “Brasil, Minas Gerais, Além Paraíba, Fazenda São Geraldo.” Oryzomys ratticeps moojeni Avila-Pires, 1959b:3; type locality “Brasil, São Paulo, Cananéia, Morro de São João.” Oryzomys capito intermedius: Cabrera, 1961:385; name combination. [Euryoryzomys] russatus: Weksler, Percequillo, and Voss, 2006:11; first use of current name combination. d e s c r i p t i o n : Closely similar to E. nitidus but with differences that allow specific recognition based on greater average external, cranial, and dental dimensions. Large (mean head and body length 151.7 mm; range: 112–185 mm) with tail equal to or longer (mean length 143.2 mm; range: 105–196). Skull robust and large (mean greatest length 34.6 mm; range: 28.3–39.2 mm); molar toothrow long (mean length 5.1 mm; range: 4.5–5.5 mm; in E. nitidus, average length 4.8; range: 3.9–5.6 mm). Other differences between two species include moderately long and generally brighter dorsal pelage in E. russatus; usually shorter incisive foramina relative to occipitonasal length in most specimens (Musser et al. 1998); presence of alisphenoid strut in less than half of examined specimens; and presence of small sphenopalatine vacuities in several specimens. d i s t r i b u t i o n : Euryoryzomys russatus is distributed along the eastern Brazilian coastal region from Bahia (lowland) to Rio Grande do Sul (montane areas), including coastal islands in São Paulo and Rio de Janeiro states, and from there to the western highlands of São Paulo state, reaching Paraguay (Caaguazú) and Argentina (Misiones), and limited to the west by the Rio Paraná in São Paulo and by the Río Paraguay in Paraguay. Euryoryzomys russatus is also a part of the fossil fauna of Lagoa Santa (see Remarks). Specimens from Ceará and Paraíba states are provisionally assigned to this species (see Remarks).

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s e l e c t e d l o c a l i t i e s (Map 159): ARGENTINA: Misiones, Puerto Gisela, San Ignacio (Musser et al. 1998). BRAZIL: Bahia, Ilhéus, Almada, Rio do Braço (MNRJ 9032); Ceará, São Benedito (MNRJ 37049), Sitio Friburgo, Serra de Batuité, Pacoti (MZUSP [ARP 15]); Espírito Santo, Castelo, 3 km NE Forno Grande (MNRJ 32813), Fazenda Santa Terezinha, 33 km NE of Linhares (UFMG [LPC 27]); Minas Gerais, Lagoa Santa (ZMUC uncatalogued specimen); Paraíba, Mata do Pau Ferro, 6 km from Areia (UFPB 2046); Rio de Janeiro, Centro de Primatologia, Magé (L. P. Costa 2003); Rio Grande do Sul, Fazenda Aldo Pinto, São Nicolau (MPEG 22249), Morro do Osório (UFRGS 1080); Santa Catarina, Florianópolis, Rio Tavares, CASAN, Rodovia Estadual SC 405 (LAMAQ 168); São Paulo, Ariri (MZUSP [ARP 5]), Estação Biológica de Boracéia (MVZ 183114), Lins, Campestre (MZUSP 6160), Teodoro Sampaio (MZUSP 8859). PARAGUAY: Caaguazú, Sommerfeld Colony #11 (MNRJ 32764). s u b s p e c i e s : I treat Euryoryzomys russatus as monotypic. n a t u r a l h i s t o ry: Euryoryzomys russatus is predominantly associated with forested coastal plains and with the evergreen and semideciduous forests of the coastal highlands. This species apparently avoids open vegetation types, such as the Cerrado and Chaco, preferring primary forests (Bonvicino et al. 1997; R. Pardini, pers. comm.). In northeastern Brazil, this species is found in montane enclaves covered by moist semideciduous forest in the Caatinga (locally called brejos). The abundance of this species in the Brazilian Atlantic Forest varies at both large and small geographical scales. In some areas of southeastern Brazil, E. russatus is the most common terrestrial species (Bergallo 1994) while in others it is less common (Olmos 1992). In northeastern Brazil where the small mammal community is dominated by Hylaeamys laticeps, this species is uncommon (Laemmert et al. 1946; Pardini 2004). Bergallo (1994) reported population and reproductive data for the species in southern Brazil. The home range varied from 0.16 to 1.12 ha, with a mean size of 0.46 ± 0.31 ha; population density, averaging 5.26 ± 1.02 individuals/ha, was stable throughout the year, with no correlation between rainfall and birth frequencies. Apparently this species breeds year-round, because juveniles were captured in every month except July, November, and January, and pregnant females were recorded from March to July, August, and November. Females attained reproductive maturity by day 115 following birth and could produce more than six litters in a single year (Bergallo 1995). Püttker, Bueno et al. (2013) described survival rates, population change rates, and capture probability for populations in different forest cover landscapes.

Euryoryzomys russatus builds egg-shaped nests (15 cm long and 10 cm wide), with dry leaves and grass, under or inside fallen logs, and among the aerial roots of various species of palms (Briani et al. 2001). r e m a r k s : The record of E. russatus from Lagoa Santa (as Calomys coronatus Winge; see synonymy above) is based on specimens obtained from cave deposits. Several other species described from the cave material of Lagoa Santa (e.g., Protopithecus brasiliensis, Caipora bambuirorum, Blarinomys breviceps, Delomys sp., Sooretamys angouya; see Harttwig and Cartelle 1996; Voss and Myers 1991; C. R. Silva et al. 2003) are members of a wet forest community that is no longer found in the region. Although the vegetation of the Lagoa Santa region today is a mosaic of Cerrado and semideciduous forest habitats, no recent specimens of any of these species have been found at or in the vicinity of Lagoa Santa. Therefore, it is reasonable to assume that E. russatus is now presently extinct in this part of interior Brazil. In the early nineteenth to middle twentieth centuries, several specific names were coined for this species. Each of these is available, but russatus Wagner has priority (see Musser et al. 1998). Throughout history, this species was considered to be a subspecies of Hylaeamys laticeps (Leche 1886; E.-L. Trouessart 1897), Hylaeamys megacephalus (Cabrera 1961), or even a synonym of E. nitidus (A. L. Gardner and Patton 1976). However, the validity of Euryoryzomys russatus as a full species is supported by morphological (Weksler

Map 159 Selected localities for Euryoryzomys russatus (●). Contour line = 2,000 m.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 321

1996; Musser et al. 1998; Percequillo 1998) and molecular (Patton et al. 2000; L. P. Costa 2003) analyses. Euryoryzomys russatus is the only species in its distributional range to have an orange to orange-rufous dorsal pelage sharply contrasting with a grayish-white to almost pure white ventral coloration; a white foot with very long and dense ungual tufts; an M2 with two enamel islands; and a distinct capsular process on the mandibular ramus. While I assign samples of genus Euryoryzomys from brejos in northeastern Brazil (Paraíba and Ceará states; see Weksler 1996; Percequillo 1998; M. J. de J. Silva et al. 2000b) to E. russatus, these are likely to represent an undescribed species, based on morphological and karyological data. These samples have smaller and more delicate skulls, with shorter and narrower incisive foramina, an anterolingual cingulum on M2, and a karyotype with 2n = 76 rather than the 2n = 80, FN = 86 that characterizes E. russatus throughout the majority of its range (E. J. C. Almeida and Yonenaga-Yassuda 1974, as “Oryzomys capito”; Musser et al. 1988).

Genus Handleyomys Voss, Gómez-Laverde, and Pacheco, 2002 Marcela Gómez-Laverde, Robert S. Voss, and Víctor Pacheco

The genus Handleyomys includes two species: H. fuscatus, endemic to the western Andes of Colombia, and H. intectus, endemic to the central Andes of Colombia; the elevational range of the genus is from about 1,700 to 2,800 m. No fossil material is known. The following account is abstracted from Voss et al. (2002), with additional information based on newly examined specimens. Handleyomys fuscatus and H. intectus are both small (17–34 g) mice with tails that are about as long as the combined length of the head and body (length of head and body 80–130 mm; length of tail 75–110 mm). The adult body pelage is fine and soft, uniformly dull brownish gray dorsally, but usually darker (sometimes almost blackish) middorsally than on the flanks; the ventral pelage is dark gray frosted with paler gray or buff and is not sharply countershaded. The tail appears naked to the eye (a sparse caudal pelage is visible under magnification) and unicolored (dark above and below). Mystacial, superciliary, genal, submental, interramal, and carpal vibrissae are present; mystacial vibrissae are neither very short nor very long, extending posteriorly to (but not beyond) the caudal margins of the pinnae when laid back against cheeks. The pinnae are not large, but they are clearly visible above the fur of the head and are sparsely covered with short dark hairs. The manus is sparsely covered dorsally with short

pale hairs; the plantar surface is unpigmented, with two carpal and three interdigital pads; and the claws are short, neither conspicuously elongated nor unusually curved. The pes is long (21–26 mm) and narrow, with the outer digits much shorter than the middle three (the claw of digit I extends to the middle of the first phalanx of digit II, and the claw of digit V extends just beyond the first interphalangeal joint of digit IV); conspicuous ungual tufts of long silvery hairs are rooted at the bases of the claws on digits II to V, but the pedal dorsum otherwise is only sparsely covered with short pale (whitish or silvery) or dark-banded hairs; the plantar surface (including the heel) is naked, weakly pigmented (grayish in life), with two metatarsal and four interdigital pads; indistinct squamae (scale-like tubercles) are sparsely distributed along the outer distal plantar surfaces, but not in the center of the sole. Unusually for an oryzomyine, there are only six mammae (in inguinal, abdominal, and postaxial pairs). The skull has a long, tapering rostrum flanked by shallow but distinct zygomatic notches; the interorbital region is hourglass shaped, neither greatly inflated nor unusually constricted, with rounded supraorbital margins; the braincase is moderately inflated and rounded, without prominent temporal crests, ridges, or beads. The zygomatic plates are moderately broad, with their anterior edged vertical or nearly so, with a rounded (never angular or spinous) anterodorsal contour. Premaxillae are short (not produced anteriorly beyond the incisors to form a rostral tube with the nasals). Incisive foramina are neither very short nor greatly elongated, averaging about 60% of the diastemal length (not extending posteriorly between the molar rows) and are widest near the premaxillary-maxillary suture. The palatal bridge is long and wide, without a median ridge or deep lateral gutters; the posterolateral pits are usually large and often complex. The mesopterygoid fossa does not penetrate anteriorly between the molar rows, and the bony roof of the fossa is complete or perforated only by narrow slits (it is never conspicuously fenestrated). The alisphenoid strut is absent, and the buccinator-masticatory foramen and the foramen ovale are therefore confluent. The carotid arterial morphology is primitive, with the orbitofacial circulation supplied by separate supraorbital and infraorbital branches of a large stapedial artery (= pattern 1 of Voss, 1988); the course of the supraorbital stapedial ramus is marked by a prominent squamosalisphenoid groove and a sphenofrontal foramen. The postglenoid foramen is separated from the large subsquamosal fenestra by a slender hamular process of the squamosal. The tegmen tympani either does not overlap the squamosal at all, or the tegmen tympani-squamosal overlap is shallow (not involving a distinct posterior suspensory process of the latter bone). The bullae are small, the pars flaccida of the tympanic mem-

322 Mammals of South America

brane is present and large, and the orbicular apophysis of the malleus is well developed. The mandible has a well-developed, falciform coronoid process, and a distinct capsular process on the lateral mandibular surface is absent. The basihyal bone (known only in H. fuscatus) is not strongly arched and lacks an entoglossal process; the thyrohyals are shorter than the basihyal. The incisors are ungrooved and opisthodont. The maxillary molar rows are parallel. The principal molar cusps, arranged in opposite labial/lingual pairs, are bunodont when unworn but are quickly eroded with age to the same level as other enamelled occlusal structures (the occlusal surfaces of most adult teeth are more or less planar); the labial and lingual re-entrant folds are interpenetrating (incipiently lophodont sensu Voss 1993); the anterocone of M1 is not divided into labial and lingual conules (an anteromedian flexus is absent); the anteroflexus is very deep, extending lingually beyond the dental midline on M1 and M2; anterolophs and mesolophs are large, fused with corresponding (antero- and meso-) styles on the labial margins of M1 and M2; posterolophs are distinct on M1 and M2, persisting with moderate to heavy wear; M3 is subtriangular in occlusal view, smaller than more anterior teeth, with most of the same occlusal elements but usually without a distinct hypocone or posteroloph. M1 has one accessory labial root (four roots total), but M2 and M3 are each three-rooted. The anteroconid of m1 is undivided by a median flexid and is fused with the protolophid and/or the anterolophid to enclose a persistent internal fold of uncertain homology (anteroflexid and/or protoflexid); the anterolophid is absent on m2 and m3; the anterolabial cingulum is absent or indistinct on m2, and consistently absent on m3; the mesolophids and posterolophids are large and well developed on all mandibular teeth; the ectolophids are consistently absent. The m1 has an accessory labial root and occasionally also an accessory lingual root (three to four roots total); m2 and m3 each have two small anterior roots and one large posterior root (three roots total). Axial skeletal elements include 12 ribs, 19 thoracolumbar vertebrae, 4 sacral vertebrae, and 28–30 caudal vertebrae; hemal arches appear to be present on the caudal vertebrae of H. fuscatus, but not on those of H. intectus. The tuberculum of the first rib articulates with the transverse processes of the seventh cervical and first thoracic vertebrae, and the second thoracic vertebra has a greatly elongated neural spine. The entepicondylar foramen of the humerus is absent. The stomach in both species is unilocular and hemiglandular, without any extension of glandular epithelium into the corpus; the bordering fold crosses the lesser curvature slightly to the right of the incisura angularis (between that

flexure and the pylorus), and it crosses the greater curvature opposite the incisura angularis. The gall bladder is absent. The morphology of the glans penis and other male reproductive structures is unknown. sy n o n y m s : Aepeomys: J. A. Allen, 1912:89; part (description of fuscatus); not Aeepomys Thomas. Oryzomys: Thomas, 1921j:356 (description of intectus); part; not Oryzomys Baird. Thomasomys: Ellerman, 1941:369; part (listing of fuscatus); not Thomasomys Coues. ?Nectomys: Ellerman, 1941:351 (provisional listing of intectus); part; not Nectomys Peters. Handleyomys Voss, Gómez-Laverde, and Pacheco, 2002:5; type species Aepeomys fuscatus J. A. Allen, by original designation. KEY TO THE SOUTH AMERICAN SPECIES OF HANDLEYOMYS:

1. Hindfeet covered dorsally with dark-banded hairs (the melanic bands distinctly visible under low magnification); nasals short, truncated posteriorly at or near the premaxillomaxillary suture; incisive foramina anteriorly constricted, with lateral margins abruptly narrowed at or near the premaxillomaxillary suture; interparietal broad (transverse dimension) relative to its depth (anteroposterior dimension). . . . . . Handleyomys fuscatus 1′. Hindfeet covered dorsally with pure white or indistinctly pigmented hairs; nasals long, extending posteriorly well beyond the premaxillomaxillary suture; incisive foramina smoothly tapering, with evenly rounded lateral margins; interparietal narrow (transverse dimension) relative to its depth (anteroposterior dimension) . . . . . . . . . . . . . . . . . . . . . . . . . . Handleyomys intectus

Handleyomys fuscatus (J. A. Allen, 1912) Colombian Western Andes Cloud Forest Mouse sy n o n y m s : Aepeomys fuscatus J. A. Allen, 1912:89; type locality “San Antonio (near Cali, alt. 7000 ft), Cauca [= Valle del Cauca], Colombia.” Thomasomys fuscatus: Ellerman, 1941:369; name combination. Thomasomys lugens fuscatus: Cabrera, 1961:431; name combination. Handleyomys fuscatus: Voss, Gómez-Laverde, and Pacheco, 2002:23; first use of current name combination. d e s c r i p t i o n : See the Key. d i s t r i b u t i o n : Handleyomys fuscatus is known only from the western Andes (Cordillera Occidental) of Colombia between 1,800 and 2,530 m in the departments of Antioquia and Valle del Cauca.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 323

s e l e c t e d l o c a l i t i e s (Map 160): COLOMBIA: Antioquia, Vereda La Soledad, Finca La Reina (ICN 16510– 16523); Valle del Cauca, Finca La Playa (Voss et al. 2002), San Antonio (type locality of Aepeomys fuscatus J. A. Allen). s u b s p e c i e s : Handleyomys fuscatus is monotypic. n a t u r a l h i s t o ry: This apparently terrestrial and nocturnal species inhabits both primary cloud forest and adjacent secondary growth, usually in cool and very humid environments (12–18°C mean ambient temperature; >2,000 mm annual precipitation) corresponding to the vegetation zone that Espinal and Montenegro (1963) called Bosque muy húmedo montano bajo. Four of six known pregnant females (each with two to three embryos) were collected during the rainy season (April or June), but another was taken during the late dry/early rainy season (September), and the fourth in the dry season (February); one pregnant female was also lactating in June. The only additional recorded lactating female was captured during the rainy season (September). Juveniles have been caught during the rainy season and the late dry/early rainy seasons. r e m a r k s : The karyotype is 2n = 54, FN = 62; the X and Y chromosomes are both submetacentrics (A. L. Gardner and Patton 1976).

Handleyomys intectus (Thomas, 1921) Colombian Central Andes Cloud Forest Mouse sy n o n y m s : Oryzomys intectus Thomas, 1921j:356; type locality “Medellin. Santa Elena,” Antioquia, Colombia. ?Nectomys intectus: Ellerman, 1941:351; suggested name combination. Oryzomys (Oryzomys) intectus: Tate, 1932e:16; name combination. Handleyomys intectus Voss, Gómez-Laverde, and Pacheco, 2002:24; first use of current name combination. d e s c r i p t i o n : See the Key. d i s t r i b u t i o n : Handleyomys intectus is known only from the central Andes (Cordillera Central) of Colombia between 1,700 and 2,800 m, in the departments of Antioquia, Quindío, and Risaralda. s e l e c t e d l o c a l i t i e s (Map 159): COLOMBIA: Antioquia, Santa Elena (type locality of Oryzomys intectus Thomas), Ventanas (Voss et al. 2002); Quindío, Salento (Voss et al. 2002). s u b s p e c i e s : Handleyomys intectus is monotypic. n a t u r a l h i s t o ry: This apparently terrestrial and nocturnal species occurs in the same types of cloud forest and secondary habitats as those inhabited by H. fuscatus. The only recorded pregnant female was caught during the rainy season (April) and gave birth to two young in the trap; one lactating female was captured during the dry season (January). Juveniles have been caught during both rainy and dry seasons. r e m a r k s : The karyotype is 2n = 54, FN = 68–70; the morphology of the X and Y chromosomes is undetermined (M. L. Bueno, M. Gómez-Laverde and C. A. Delgado-V., unpubl. data).

Genus “Handleyomys” “Handleyomys” alfaroi (J. A. Allen, 1891) Alfaro’s Rice Rat Marcelo Weksler

Map 160 Selected localities for Handleyomys fuscatus (●) and Handleyomys intectus (ᇲ). Contour line = 2,000 m.

This species is treated here independently because of its provisional position as a member of Handleyomys. The ex“Oryzomys alfaroi” group was included in Handleyomys by Weksler et al. (2006); as they explained (Weksler et al. 2006:2), however, “[pending] the description of other new genera (by M. D. Carleton and G. G. Musser, pers. com.), we provisionally transfer members of the ‘alfaroi group’ (herein understood to include alfaroi, chapmani, melanotis, rhabdops, rostratus, and saturatior) to Handleyomys, a suboptimal but phylogenetically defensible nomenclatural option previously discussed by Weksler (2006).” Unfortunately, no new genus to encompass these taxa has yet been

324 Mammals of South America

described. The taxon is included in the Key to genera of the Oryzomyini, but not in the Key to species of Handleyomys. sy n o n y m s : Hesperomys (Oryzomys) alfaroi J. A. Allen, 1891b:214; type locality “San Carlos,” Alajuela Province, Costa Rica. Oryzomys alfaroi: J. A. Allen, 1894b:36; name combination. Oryzomys gracilis Thomas, 1894b:358; type locality “Concordia, Medellin, Colombia.” Oryzomys palatinus Merriam, 1901:290; type locality “Teapa, Tabasco, Mexico.” Oryzomys alfaroi incertus J. A. Allen, 1908:655; type locality “Rio Grande,” Río Grande de Matagalpa, south of Tuma, Nicaragua. Oryzomys palmirae J. A. Allen, 1912:83; type locality “a few miles east of Palmira, eastern slope of Central Andes,” Valle del Cauca, Colombia. Oryzomys alfaroi dariensis Goldman, 1915:128; type locality “Cana, eastern Panama (altitude 2,000 feet).” Oryzomys alfaroi alfaroi: Goldman, 1918:59; name combination. Oryzomys alfaroi palatinus: Goldman, 1918:65; name combination. Oryzomys (Oryzomys) alfaroi intagensis Hershkovitz, 1940a:78; type locality “Hacienda Chinipamba near Peñaherrera, Intag, in the subtropical forest of the western slope of the western cordillera of the Andes, Imbabura Province, northwestern Ecuador. Altitude, about 1500 meters.” Oryzomys alfaroi gloriaensis Goodwin, 1956:8; type locality “La Gloria, rain forest, about 2500 feet elevation, 10 kilometers south of Santa Maria Chimalapa, District of Juchitan, Oaxaca, Mexico.” Oryzomys alfaroi agrestis Goodwin, 1959:7; type locality “12 miles southeast of Tapachula, Chiapas, Mexico; altitude 1000 feet.” Oryzomys alfaroi gracilis: Cabrera, 1961:383; name combination. Oryzomys alfaroi palmirae: Cabrera, 1961:383; name combination. [Handleyomys] alfaroi: Weksler, Percequillo, and Voss, 2006: 2; name combination. d e s c r i p t i o n : Small sized; adult head and body length 90–106 mm, tail length 89–101 mm, hindfoot length 25–28 mm, ear length 14–17, mass 20–32 g; dorsal pelage color dull yellow-brown to dark reddish-brown; sides ochraceous to orangish; venter grayish white. Fur short (27% of females were reproductively active (Twigg 1962). Litter size was affected by environmental variables and increased with the size and age of the females (Twigg 1965). In captivity, gestation lasted about 28–30 days, and the mean number of embryos was 3.1 (range: 1–6); males reached maturity at the age of 2–3 months and females within 2–5 months (Mello 1986). This species is a reservoir of Leishmania (Viannia) brasiliensis at Amajari, Pernambuco state, Brazil (Brandão-Filho et al. 2003). r e m a r k s : Massoia (1981b) raised sciureus Wagner to species rank, distinguishing between this taxon

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 333

and members of the brasiliensis group of species. Our deductions about the concept of this species stem from the analysis of samples from northeastern Brazil (Bahia, Alagoas, Pernambuco, and Ceará states) and Amazonia, which appear to form a morphologically cohesive entity lacking mesoloph-like structures on M1–M2 and with upper and lower mandibular masseteric ridges fused at the level of the anterior portion of m1 in most specimens. In addition, Pardiñas and Galliari (1998c) and Pardiñas and Teta (2011b) found morphological differences between H. sciureus and H. chacarius, particularly in their respective lower dentitions, including the form of the lophids (compressed with acute outer margins in H. chacarius versus compressed with strongly acute outer margins and more prismatic in H. sciureus); form and size of the anteromedian fossetid (subcircular and large in H. chacarius versus transversally elongated and small in H. sciureus); and occlusal development of the metaflexid (scarcely developed, not reaching the midline of the tooth in H. chacarius versus well developed, freely connected with the protoflexid in subadults of H. sciureus; see also Percequillo 2006). Petter and Tostain (1981) described morphological variation in M3 for French Guiana specimens. This species is characterized by 2n = 55–56 and FN = 56, with a marked predominance of acrocentrics in the autosomal complement, as based on specimens from Argentina (Vidal-Rioja et al. 1976), Brazil (T. R. O. Freitas, Mattevi, Oliveira et al. 1983), Peru (A. L. Gardner and Patton 1976; Aniskin 1994), and Surinam (R. J. Baker et al. 1983). Karyotypes from specimens identified as H. balnearum

Map 165 Selected localities for Holochilus sciureus (●). Contour line = 2,000 m.

(= H. chacarius herein) from northwestern Argentina are nearly identical to those of H. sciureus (Vidal-Rioja et al. 1976; but see Remarks under H. chacarius), leaving some question as to whether H. sciureus may extend south of 20°S latitude.

Holochilus venezuelae J. A. Allen, 1904 Venezuelan Marsh Rat sy n o n y m s : Holochilus venezuelae: J. A. Allen, 1904b:330; type locality “El Llagual [= El Yaguel], [Bolívar,] Venezuela.” Holochilus brasiliensis venezuelae: Hershkovitz, 1955b: 670; name combination. Holochilus sciureus: Voss and Carleton, 1993:12; part (venezuelae listed as synonym); not Holochilus sciureus Wagner. d e s c r i p t i o n : Second largest species, with head and body length 130–226 mm, tail length 124–194 mm, and hindfoot 36–48 mm (O. J. Linares 1998). General color reddish brown above, strongly streaked with black middorsally, lighter and more fulvous on sides; and reddish fulvous on lower back and rump; venter buffy gray, hairs gray basally with yellowish white to deep buff tips; feet thinly haired, grayish flesh-colored; claws whitish with subapical dusky ring, and fringed with whitish hairs at base; tail dark brown, not appreciably bicolored, with short black bristles increasing in length and abundance apically; terminal fifth of tail well clothed with blackish bristly hairs that conceal underlying scales (J. A. Allen 1904b). d i s t r i b u t i o n : Holochilus venezuelae occurs in Venezuela, from the lower Orinoco Basin to Lago Maracaibo (Fuentes and Poleo 2005). The distributional limits of H. venezuelae in comparison with those of H. sciureus need clarification. s e l e c t e d l o c a l i t i e s (Map 166): VENEZUELA: Bolívar, El Yagual (type locality of Holochilus venezuelae J. A. Allen); Guárico, Calabozo (Eiris and Barreto 2009); Portuguesa, Piritu (FLMNH 13323); Zulia, Misión Tokuko (USNM 448570). s u b s p e c i e s : Holochilus venezuelae is monotypic. n a t u r a l h i s t o ry: Holochilus venezuelae is considered an important agricultural pest in Venezuelan rice plantations, with densities measured between 5 and 713 rats/ ha (Cartaya and Aguilera 1985). Its diet is mostly grasses, especially Leptochloa scabra and Oryza sativa, with small amounts of Cyperaceae, dicots, and invertebrates (A. M. G. Martino and Aguilera 1993). The mean home range size for 11 individuals inhabiting one rice field was 0.278 ha (Cartaya and Aguilera 1984). Eiris and Barreto (2009) examined home range, territoriality, individual movement, and dispersal. Gestation lasts about 29 days, and the mean number of embryos ranged between 5.8 (Venezuelan Lla-

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nos) and 7.4 (Acarigua, Venezuela) (Agüero 1978; Cartaya 1983; Poleo and Mendoza 2001). The mass of pregnant females increased about 48% (Aguilera 1987). In Venezuelan savannas dominated by Paspalum fasciculatum, marsh rats account for 0.2–1.3% of all rodents captured. Ectoparasites found on H. venezuelae include mites and ticks (Amblyomma ovale, Androlaelaps fahrenholzi, Eutrombicula alfreddugesi, E. batatas, Gigantolaelaps canestrinii, G. mattogrossensis, and Ornithonyssus bacoti), lice (Hoplopleura contigua and H. quadridentata), and a flea (Polygenis dunni). Known endoparasites include the nematodes Physaloptera sp., Stilestrongylus sp., and Strongyloides sp. (Guerrero 1985). r e m a r k s : Holochilus venezuelae has been considered a full species (Aguilera et al. 1993), a subspecies of H. sciureus (O. J. Linares 1998), or a junior synonym of H. s. sciureus (Barreto and García-Rangel 2005). This taxon, however, is characterized by a karyotype with 2n = 44, FN = 56 (Aguilera and Pérez-Zapata 1989), and thus with a relatively higher FN/2n ratio than H. sciureus. A. L. Gardner and Patton (1976) described a karyotype from Villavicencio, Colombia, with 2n = 50, FN = 58, one outside the known karyotypic variation for H. venezuelae and H. sciureus and which may represent an undescribed form. Further morphological and molecular comparisons are needed to test the affinities between the Colombian form and H. venezuelae. If these two forms prove to be conspecific, the range of H. venezuelae will extend west-

Map 166 Selected localities for Holochilus venezuelae (●). Contour line = 2,000 m.

ward into the headwaters of the Meta-Orinoco fluvial system in Colombia.

Holochilus vulpinus (Brants, 1827) Crafty Marsh Rat sy n o m y n s : Mus vulpinus Brants, 1827:137; type locality “Brasil”; regarded as Rio Uruguay, southeastern Brazil, by Lichtenstein (1830; see Hershkovitz 1955b:660); restricted to Maldonado, Uruguay, by Cabrera (1961), but Cerqueira (1975) convincingly placed the type locality in Brazil, on the banks of Rio Uruguay, between Itaqui and Uruguay, Rio Grande do Sul. Mus Braziliensis Waterhouse, 1839:58; type locality “Bahia Blanca,” Buenos Aires, Argentina; not Mus brasiliensis Desmarest (see Remarks). Holochilus brasiliensis: Gray, 1843b:114; part (listing of brasiliensis Waterhouse); not Mus brasiliensis Desmarest. H[olochilus]. vulpinus: Wagner, 1843a:554; first use of current name combination. Hesperomys vulpinus: Burmeister, 1854:163; name combination. Hesperomys [(Holochilus)] vulpinus: Burmeister, 1879: 210; name combination. Holochilus multannus Ameghino, 1889:117; type locality “río Luján cerca de la estación Olivera en la provincia de Buenos Aires,” Argentina. Holochilus Darwini Thomas, 1897c:496; replacement name for Mus braziliensis Waterhouse, which is preoccupied by Mus brasiliensis Desmarest. Holochilus chrysogaster Cabrera, 1912:102; nomen nudum, erroneously attributed to Waterhouse. Holochilus brasiliensis vulpinus: Hershkovitz, 1955b:662; name combination. d e s c r i p t i o n : Largest species in genus, with range in head and body length 141–238 mm, tail length 160– 238 mm, and hindfoot 41–55 mm (Massoia 1976b; Bonvicino, Oliveira, and D’Andrea 2008). General coloration above deep orangish to reddish brown strongly intermixed with long, glistening blackish brown hairs; sides bright ochraceous buff; ventral surface entirely white (northern populations), with narrow band of grayish to orangish hairs, or golden yellowish with throat and chest covered by patches of entirely white hairs (Massoia 1976b). d i s t r i b u t i o n : Holochilus vulpinus ranges from Paraguay and east-central Argentina throughout Uruguay to Rio Grande do Sul state in Brazil (Massoia 1976b, 1981b; Marques 1988). Extralimital fossils, referred to H. brasiliensis by Pardiñas and Teta (2011b), suggest that this species had a wider distribution during the Late Holocene,

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 335

reaching the northern border of Patagonia and the hill systems of central Argentina. s e l e c t e d l o c a l i t i e s (Map 164): ARGENTINA: Buenos Aires, Arroyo Brusquitas (Massoia 1976b), Arroyo Chasicó (Massoia 1976), Bahía Blanca (type locality of Holochilus brasiliensis Waterhouse), Estancia La Providencia (Teta, González-Fischer et al. 2010), Mar del Tuyú (Massoia 1976b), Marucha (Teta, González-Fischer et al. 2010), 20 km S of Pedro Luro on Hwy 3 (Formoso et al. 2010), Punta Lara (Massoia 1976); Chaco, Parque Nacional Chaco (Teta, González-Fischer et al. 2010); Córdoba, Marull (Jayat et al. 2006 [erroneously cited as for H. chacarius]); Misiones, Oberá, Escuela Provincial 639 “Rosario Vera Peñaloza,” Lote 92, Sección II de Campo Ramón (Massoia 1993); Santa Fe, Jacinto L. Aráuz (Teta and Pardiñas 2010). BRAZIL: Rio Grande do Sul, Itaqui (Tiepolo 2007). PARAGUAY: Estancia Yacaré (GD 071). URUGUAY: Montevideo, Parque Lecocq (E. M. González 1996). s u b s p e c i e s : We regard Holochilus vulpinus as monotypic, but Massoia (1976b), based on morphometrics, treated darwini Thomas as a subspecies separate from a more northern nominal form. n a t u r a l h i s t o ry: Holochilus vulpinus constructs spherical and unlined nests of leaves, sticks, and grasses that average 22–27 mm in diameter or excavates galleries at the water level. Nests are often in tangles of vines and terminal forks of tree branches, up to 2–3 m above the ground (Barlow 1969) or in hygrophilous vegetation such as the bulrushes Schoenoplectus californicus or Scirpus giganteus (Cyperaceae) as high as 40–50 cm above the water level (Massoia 1976b). In Buenos Aires province, Argentina, up to seven young individuals were found in each nest (Massoia 1976b). In Uruguay, males and females found in reproduction condition were caught in May and April; pregnant females had two to four embryos (Barlow 1969). Population densities in southeastern Buenos Aires reached 4.3 individuals/ha (range 0–12.5; Dalby 1975). In Uruguay, Barlow (1969) found 45 nests in an area of 50 ha. Plants, including aquatic, riparian, and cultivated species, comprise the diet. Barlow (1969) described the molt cycle in Uruguayan specimens. This species is infested by the mites Laelops manguinhosi, Androlaelaps fahrenholzi, and Gigantolaelaps wolffsohni, and the fleas Craneopsylla minerva, Polygenis (N.) atopus, P. (N.) frustratus, P. (P.) acodontis, P. (P.) platensis (Nava et al. 2003; Navone et al. 2010), the mite Notoedres muris (Klompen and Nachman 1990), the digenean Urotrema scabridum, Cladorchis pyriformis, and the nematode Tapironema coronatum (DuretteDesset et al. 1997). r e m a r k s : Waterhouse (1839) described Mus brasiliensis based on a specimen collected by Charles Darwin

at Bahía Blanca, on the coast of Buenos Aires province, Argentina. Although Waterhouse equated his animal to A. Saint-Hilaire’s “le rat du Brézil,” which formed the basis for Desmarest’s earlier description of Mus brasiliensis, Waterhouse’s taxon is not the same species although his Mus brasiliensis is pre-occupied by Desmarest’s name. Thomas (1897c) recognized this problem and proposed Holochilus darwini as a replacement for Waterhouse’s brasiliensis. Massoia (1971a, 1976b) and Pardiñas and Galliari (1998c) described external, cranial, and dental morphology of H. vulpinus but under the name of H. brasiliensis. Specimens from owl pellets in central and eastern Argentina and previously identified as H. brasiliensis (e.g., Formoso et al. 2010) probably represent H. vulpinus. Specimens of H. vulpinus exhibit larger dimensions than H. brasiliensis, especially in its cranial measurements, such as the condyloincisive length (36.3–45.9 mm in H. vulpinus and 34.6– 36.9 mm in H. brasiliensis) and length of the upper molar series (7.3–8.1 mm in H. vulpinus and 6.3–7.5 mm in H. brasiliensis). This species is characterized by 2n = 35–39 and FN = 57– 61 in Argentina and Paraguay (Nachman 1992a, b), with a higher proportion of biarmed autosomes than in H. brasiliensis from coastal Rio Grande do Sul (Riva et al. 1977; T. R. O. Freitas, Mattevi, Oliveira et al. 1983; Nachman 1992a,b). Better documentation of the morphological distinction between H. brasiliensis and H. vulpinus is needed to clarify the geographic distribution of both taxa in Uruguay, Paraguay, and Argentina. Holochilus vulpinus differs from H. chacarius by a genetic distance of 18.9% in sequence comparisons of the mtDNA ND3 gene (Kennedy and Nachman 1998).

Genus Hylaeamys Weksler, Percequillo, and Voss, 2006 Alexandre R. Percequillo

Species of Hylaeamys, previously known as the capito complex or megacephalus group of the genus Oryzomys (sensu lato), are widely distributed throughout cis-Andean South America, from Colombia south to Paraguay and east to coastal Brazil. In this large area, they inhabit lower slopes of the Andes, extending to an elevation of 1,000 m, Amazonian lowlands and floodplains, lowlands and highlands of the Atlantic Forest, and forested habitats in Cerrado and Chaco, among the drier biomes of the continent. There are no known records from the Caatinga or the central portion of the Brazilian Pantanal. I recognize seven species of Hylaeamys: H. acritus Emmons and Patton, H. laticeps (Lund), H. megacephalus

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(G. Fischer), H. oniscus (Thomas), H. perenensis (J. A. Allen), H. tatei (Musser, Carleton, Brothers, and Gardner), and H. yunganus (Thomas). I include seuanezi Weksler, Geise, and Cerqueira as a synonym of H. laticeps, but see Brennard et al. (2013) who characterized this taxon morphologically and chromosomally, and mapped its range, as a species distinct from other coastal Brazilian Hylaeamys (laticeps, megacephalus, and oniscus). Morphological characters that diagnose the genus include a tail length equal or subequal to head and body length; short, teardrop-shaped incisive foramina; and carotid circulatory pattern 2 (sensu Voss 1988), a trait that is shared only with the genus Oligoryzomys among members of the Oryzomyini. The pelage is usually short and harsh, with viliform, setiform, and aristiform hairs homogeneous in texture and similar in length (aristiforms 9– 14 mm). The dorsal color ranges from a dark grayish to a rich buffy brown; ventral color is uniformly gray. The tail is shorter than the head and body; its surface is usually darker than the ventral one, but the tail is not conspicuously bicolored. Hindfeet are long and narrow, with ungual tufts just reaching the tips of the claws; and with four interdigital pads and two plantar pads, the thenar and hypothenar (with polymorphism in the presence of the hypothenarin some samples of H. yunganus; see Musser et al. 1998:59, Table 7). The skull is moderately to heavy built, 27.5–37.9 mm in greatest length. The rostrum has weakly projected nasolacrimal capsules; zygomatic notches are narrow and either shallow to moderately deep; the free dorsal margins of the zygomatic plates are reduced, with their anterior margins either straight or weakly concave. The zygomatic arches are slender and nearly parallel; the jugal is small. The interorbital region is slightly divergent posteriorly; supraorbital margins are squared or possess small dorsolateral projections, rarely strongly beaded. The braincase is elongate with a discrete temporal crest. Incisive foramina are short (3.5–5.8 mm long), and their lateral margins diverge posteriorly, making them teardrop in shape. The palate is long and wide, with small to large posterolateral palatal pits in shallow to deep palatine depressions; palatal excrescences are present in most specimens (Musser et al. 1998:74, Table 12). The anterior margin of the mesopterygoid fossa does not reach the level of the alveoli of the M3s; the roof of the fossa is either completely ossified or perforated only by small and narrow sphenopalatine vacuities on the presphenoid or at the presphenoid-basisphenoid suture. A modified cephalic arterial circulation is present (pattern 2 of Voss 1988), as indicated by absence of sphenofrontal foramina and squamosoalisphenoid grooves and presence of large stapedial foramina and a deep furrow in the posterolateral portion on the ventral surface of each

pterygoid plate. The buccinator-masticatory and accessory oval foramina are confluent, so an alisphenoid strut is absent in all specimens. Auditory bullae are small, stapedial processes are long and narrow, and bony tubes are short. The suspensory process of the squamosal is absent, and the tegmen tympani varies from small and triangular to large and squared, and does not extend anteriorly to overlap the squamosal; the postglenoid foramen is long and wide, and the subsquamosal fenestra is absent. The mandible is shallow; the posterior margin of the angular process is at the same vertical plane as that of the condyloid process; the coronoid process reaches the same height as the condyle; inferior and superior notches are shallow; and a capsular projection is absent. Upper incisors are opisthodont. Molars are pentalophodont and moderately high-crowned; labial and lingual cusps are arranged in opposite pairs. Both labial and lingual flexi are moderately deep and narrow, overlapping on each molar at midplane. Musser et al. (1998) described and figured occlusal surfaces of H. laticeps, H. megacephalus, H. oniscus, H. perenensis, H. tatei, and H. yunganus. Young and a few adult specimens of H. megacephalus have m2s bisected by a long hypoflexid (Musser et al. 1998:79, Figs. 31 and 32). M1 has three main roots, anterior and posterior labial and lingual; M2 and M3 also have three main roots. Each lower molar has two roots, one each in anterior and posterior positions. The axial skeleton is composed of 7 cervical, 12–13 thoracic, 6–7 lumbar, 4 sacral, and 27–30 caudal vertebrae; there is some variation in the number of ribs, but the modal count is 12. Hemal processes and hemal arches (rarely observed in H. megacephalus) are present at the junctions of the first and second and/or second and third caudal vertebrae. The stomach is unilocular and hemiglandular, with a shallow angular notch. The glans penis is of the complex type (Hooper and Musser 1964), with a tridigitate and well-developed cartilaginous baculum. The three bacular mounds are visible in the terminal crater, and the basal portion of the bony baculum is wide and spatulate, barely concave. A single dorsal papilla and one urethral flap are present. All species are very similar in external and cranial morphology, more easily differentiated by morphometric and karyological criteria and geographic ranges (see Percequillo 1998; Musser et al. 1998; Emmons and Patton 2005). Consequently, my Key employs all useful characters in the recognition of these species. Brennand et al. (2013) provided details of locality distribution and morphological comparisons among four species (H. laticeps, H. megacepahlus, and H. oniscus, including the recognition of H. seuanezi) that occur in coastal Brazil.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 337

sy n o n y m s : Mus: G. Fischer, 1814:71; part (description of megacephalus); not Mus Linnaeus. H[esperomys].: Wagner, 1843a:542; part (listing of cephalotes); not Hesperomys Waterhouse. Calomys: Fitzinger, 1867b:87; part (listing of cephalotes); not Calomys Waterhouse. Oryzomys: Thomas, 1894b:354; part (listing of laticeps); not Oryzomys Baird. Hylaeamys Weksler, Percequillo, and Voss, 2006:8; type species Mus megacephalus G. Fischer, by original designation. r e m a r k s : The species-group taxa assigned to the genus Hylaeamys were profoundly affected by Hershkovitz’s (1960, 1966a) revisionary acts in footnotes. I discussed the consequences of these acts in the Remarks section for the genus Euryoryzomys. KEY TO THE SOUTH AMERICAN SPECIES OF HYLAEAMYS:

1. Second upper molar with distinct medial mesofossette and short paraflexus . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1′. Second upper molar without mesofossette and with long paraflexus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Pelage long (fur length 9–12 mm; Musser et al. 1998:101) and dense, uniformly dark brown; upper molar toothrow long (5.5–5.7 mm) and wide (1.7–1.9 mm); incisive foramina short relative to greatest skull length (4.2–4.9 mm and 30.9–33.9 mm, respectively) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hylaeamys tatei 2′. Pelage short (fur length 6–10 mm) and less dense, from grayish brown to buffy brown; upper molar toothrow short (3.9–5.5 mm); incisive foramina long relative to greatest skull length (3.9–5.8 mm and 27.5–35.3 mm, respectively); 2n = 58–60 and FN = 62–66 in western populations (Brazil and Peru), and 2n = 52–59 and FN = 66–67 in eastern samples (Surinam; see Musser et al. 1998:80–81, Table 13 for further details) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hylaeamys yunganus 3. Head and body (80–158 mm) and tail (90–138 mm) long; hypothenar pad large or very small; skull smaller and delicate (greatest length 27.2–34.9 mm); molar toothrow shorter (3.7–5.2 mm) and molars narrower; sphenopalatine vacuities variably present; lower second molar without distinct entoflexid or entofossetid and with long hypoflexid nearly bisecting the molar in most specimens; 2n = 54 . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3′. Head and body (81–174 mm) and tail (94–162 mm) long; hypothenar pad medium sized; skull large and robust (greatest length 29.5–37.9 mm); molar toothrow longer (4.5–5.6 mm) and molars robust; roof of mesopterygoid fossa completely ossified in most specimens (>90% of

specimens from Rio Juruá, Amazonas and Acre states, and eastern Atlantic Forest, Brazil); lower second molar with distinct entoflexid or entofossetid and short hypoflexid in most specimens; 2n = 48 and 52 . . . . . . . . . . . 5 4. Head and body (80–158 mm) and tail (90–138 mm) shorter; hypothenar pads small; skull smaller (greatest length 27.2–34.9 mm) and delicate; molar toothrow shorter (3.7–5.2 mm) and molars delicate; sphenopalatine vacuities small and narrow (vacuities present in 50– 59% of Paraguayan specimens); multiple posterolateral palatal pits set in shallow to deep palatal notches; palatal excrescences present, from small projections to large bone struts fused to maxilla; 2n = 54 and FN = 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . Hylaeamys megacephalus 4′. Head and body (131–152 mm) and tail shorter (110– 130 mm); hypothenar pads large; skull smaller (greatest length 33.9–34.6 mm) and delicate; molar toothrow shorter (4.7–5.2 mm) and molars delicate; roof of mesopterygoid fossa infrequently perforated by sphenopalatine vacuities (when present, very small and narrow); multiple posterolateral palatal pits set in shallow to deep palatal notches; palatal excrescences present as large bone struts fused to maxilla . . .Hylaeamys acritus 5. Head and body 81–169 mm and tail 94–162 mm; 2n = 52, FN = 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5′. Head and body 122–174 mm and tail 100–157 mm; 2n = 48, FN = 60; pelage sparser and coarser; dorsal color dark, grayish or blackish brown; skull larger (greatest length 31.8–37.6 mm); molars more robust (toothrow length 4.6–5.5 mm) . . . . Hylaeamys laticeps 6. Head and body (131–162 mm), tail (135–162 mm), and skull (33.7–37.6 mm slightly larger; occurs in northeastern Brazil, north of Rio São Francisco . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hylaeamys oniscus 6′. Head and body (81–169 mm), tail (94–154 mm), and skull (29.5–37.9 mm smaller; occurs in Amazon Basin of Colombia, Ecuador, Peru, Bolivia, and western Brazil . . . . . . . . . . . . . . . . . . . . . Hylaeamys perenensis

Hylaeamys acritus (Emmons and Patton, 2005) Bolivian Hylaeamys sy n o n y m s : Oryzomys capito: S. Anderson, 1997:399; part (listing of specimens from MNK); not Mus capito Olfers (= Hylaeamys megacephalus [G. Fischer]). Oryzomys megacephalus: Musser, Carleton, Brothers, and Gardner, 1998:32; part; not Mus capito Olfers (= Hylaeamys megacephalus [G. Fischer]). Oryzomys acritus Emmons and Patton, 2005:14; type locality “Bolivia: Departamento de Santa Cruz, Provincia Velasco, Parque Nacional Noel Kempff Mercado, El Refugio Huanchaca, an outpost with a few buildings

338 Mammals of South America

and an airstrip on private property, but within the park (14°42.553′S, 061°2.034′W [WGS 84]; elev. 170 m).” [Hylaeamys] acritus: Weksler, Percequillo, and Voss, 2006: 14; first use of current name combination. d e s c r i p t i o n : Characterized externally by tail much shorter than head and body length (average about 81%); long dorsal (9–10 mm) and ventral hairs (3–4 mm); whitish venter; large and fleshy hypothenar pad; one ring of squamae on digit I of pes. Skull robust and with strongly developed palatal excrescences; very large foramen ovale; M2 with short paraflexus and single labial fossette (mesoflexus); m2 with short hypoflexid. d i s t r i b u t i o n : Hylaeamys acritus is an endemic species of northeastern Bolivia, limited to the west bank tributaries of the Río Iténez (= Rio Guaporé in Brazil), in the departments of Santa Cruz and Beni. s e l e c t e d l o c a l i t i e s (Map 167): BOLIVIA: Beni, Curicha (USNM 551653), San Joaquín, Monto Río Machupo (Emmons and Patton 2005); Santa Cruz, El Refugio Huanchaca, Parque Nacional Noel Kempff Mercado (type locality of Oryzomys acritus Emmons and Patton), Lago Caiman, Parque Nacional Noel Kempff Mercado (MNK 1949), Urubicha, Río Negro (MNK [NR 10]). s u b s p e c i e s : Hylaeamys acritus is monotypic. n a t u r a l h i s t o ry: All natural history data are from populations in Parque Nacional Noel Kempff Mer-

Hylaeamys laticeps (Lund, 1840)

Map 167 Selected localities for Hylaeamys acritus (ᇲ) and Hylaeamys perenensis (●). Contour line = 2,000 m.

Atlantic Forest Hylaeamys sy n o n y m s : Mus laticeps Lund, 1839a:233; nomen nudum. Mus laticeps Lund, 1840b [1841c:279]; type locality “Rio das Velhas’s Floddal” (Lund 1841c:292, 294), Lagoa Santa, Minas Gerais (see also Musser et al. 1998). Hesperomys laticeps: Burmeister, 1854:171; part (excluding Hesperomys subflavus Wagner [= Cerradomys subflavus]); name combination. Calomys saltator Winge, 1887:48, plate I, Figs. 16 and 17; plate III, Fig. 7; renaming of Mus laticeps Lund. Oryzomys laticeps: Thomas, 1894b:354; name combination. [Oryzomys (Oryzomys)] laticeps laticeps: Tate, 1932e:18; part; name combination. [Oryzomys (Oryzomys)] saltator: Tate, 1932e:18; name combination. Oryzomys laticeps laticeps: Gyldenstolpe, 1932a:17; name combination. Oryzomys oniscus: Moojen, 1952b:47; part; not Oryzomys oniscus Thomas (= Hylaeamys oniscus). Oryzomys [(Oryzomys)] capito laticeps: Cabrera, 1961: 386; name combination. Oryzomys capito: Hershkovitz, 1966a:137, footnote; part; not Mus capito Olfers (= Hylaeamys megacephalus [Fischer]).

cado (Emmons and Patton 2005). There, individuals were captured on the ground in evergreen riverine (gallery) forests, deciduous and semideciduous terra firme forests, and seasonally flooded forests on the edge of seasonally flooded pampa. These forests are characterized by two physiognomies: a “seasonally deciduous emergent canopy, sparse understory and midstory varying in deciduousness depending both on the location and on the dryness of the particular year,” or liana forests, exhibiting “low canopies and dense lianas at all levels” (Emmons and Patton 2005:15). Elevational range is 170–700 m. r e m a r k s : This recently recognized species is thoroughly diagnosed and described by Emmons and Patton 2005), who provided molecular and both metric and qualitative morphological characters in support of species status. Phenotypically, the most similar species is H. megacephalus, with which H. acritus shares similarities in body color, body and skull size, and molar topography. Despite these common features, H. acritus is the sister of H. perenensis, a western Amazonian Hylaeamys that is more closely related to the Atlantic Forest H. laticeps than to the eastern Amazonian-Cerrado H. megacephalus. Hylaeamys acritus is sympatric with H. yunganus (Emmons and Patton 2005).

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 339

Oryzomys seuanezi Weksler, Geise, and Cerqueira, 1999: 454; type locality “Fazenda União, Casimiro de Abreu municipality, Rio de Janeiro state (22°25′S, 42°02′W; 50 m.” [Hylaeamys] laticeps: Weksler, Percequillo, and Voss, 2006: 14; first use of current name combination. d e s c r i p t i o n : Large, with head and body length 122–174 mm; tail short (100–157 mm); hindfeet robust, with fleshy hypothenar pads and sparse ungual tufts shorter than claws. Dorsal fur very short and harsh, colored buffy, yellowish, or grayish brown densely grizzled with dark brown; ventral fur shorter and predominantly grayish in color; tail bicolored, basally and uniformly colored distally; ears sparsely covered with reddish-brown hairs. Skull robust and large (greatest skull length 31.8–37.6 mm), with short, narrow, and teardrop-shaped incisive foramina (length 4.3– 5.9 mm; width 2.1–2.9 mm); interorbital region diverges slightly posteriorly, with squared or weakly to moderately beaded supraorbital margins; palate with complex, multiple posterolateral palatal pits recessed in shallow palatine depressions and developed palatal excrescences. Toothrows robust (length 4.6–5.5 mm; M1 width 1.4–1.8 mm). d i s t r i b u t i o n : Hylaeamys laticeps is endemic to the eastern Brazilian Atlantic Forest. Known collecting localities are distributed along coastal lowland forests and eastern forested foothills of the Serra do Mar, from southern Bahia to northern Rio de Janeiro states. Consequently, the elevational range of this species is limited, extending from near sea level (Casimiro de Abreu, Rio de Janeiro, at 17 m) to approximately 100 m at Buerarema, Bahia, and about 300 m in Parque Estadual do Rio Doce, Minas Gerais. s e l e c t e d l o c a l i t i e s (Map 168): BRAZIL: Bahia, Almada, Rio do Braço (MNRJ 9314); Espírito Santo, Linhares, Fazenda Santa Terezinha, 33 km NE of Linhares (UFMG MAS 4); Minas Gerais, Lagoa Santa (type locality of Mus laticeps Lund), Parque Estadual do Rio Doce (UFMG JRS 382); Rio de Janeiro, Casimiro de Abreu, Reserva Biológica de Poço das Antas (MNRJ 29406). s u b s p e c i e s : I treat Hylaeamys laticeps as monotypic. n a t u r a l h i s t o ry: This terrestrial species inhabits lowland evergreen forest and subtropical deciduous forest along the Atlantic coast, where it may be found in swampy, disturbed, and primary forests (G. A. B. Fonseca and Kierulff 1989; Stallings 1989), but most frequently in pristine habitats (Laemmert et al. 1946). In one southern Bahia community, H. laticeps was the most common small mammal, where it was encountered in forest fragments of all sizes as well as in the surrounding matrix, although it was more abundant in mature forests (Pardini 2004).

r e m a r k s : The southeastern Atlantic Forest populations of genus Hylaeamys, called H. laticeps by Musser et al. (1998), were only recently recognized as specifically distinct from other populations of this group, particularly those from the Cerrado (allocated to H. megacephalus) and northeastern Atlantic Forest in Brazil (H. oniscus; see Percequillo 1998; Musser et al. 1998; Weksler et al. 1999; Andrades-Miranda, Zanchin et al. 2002). Throughout much of its recent history, the specific epithet laticeps Lund was not applied to any species, regarded only as a synonym of H. megacephalus (Musser and Carleton 1993; but see Hershkovitz 1960:544, footnote, who recognized laticeps but included in his concept a large number of names now allocated to species in five different genera). Musser et al. (1998), however, stated that laticeps Lund was the valid and available name that should be applied to the large Atlantic Forest Hylaeamys and regarded oniscus Thomas to be a junior synonym. Almost simultaneously, Weksler et al. (1999) proposed Oryzomys seuanezi for the morphologically and karyologically divergent populations from the southeastern Atlantic Forest (Weksler et al. 1999), regarding Oryzomys oniscus Thomas as a species restricted to northeastern Atlantic Forest. Here, I treat seuanezi Weksler, Geise, and Cerqueira as a junior synonym of H. laticeps, but I also regard H. oniscus as a valid species (see that account). Brennard et al. (2013)

Map 168 Selected localities for Hylaeamys laticeps (ᇲ) and Hylaeamys oniscus (●).

340 Mammals of South America

regarded seuanezi as a species distinct from other Atlantic Forest Hylaeamys, including H. laticeps, H. megacephalus, and H. oniscus. Although most recent records would suggest that H. laticeps is a coastal Atlantic Forest dweller, the type locality at Lagoa Santa, Minas Gerais (where this species occurs in sympatry with H. megacephalus) is situated on the western slope of Serra do Espinhaço in a region mostly dominated by open vegetation of the Cerrado, although in a mosaic with patches of semideciduous forest. Lagoa Santa contrasts elevationally with most locality records for this species, because it is about 760 m above sea level. Hylaeamys laticeps can be differentiated from H. megacephalus by its sparser and coarser pelage; dark, grayish or blackish brown dorsal body coloration; larger skull; more robust molars; larger and wider palatal excrescences; diploid number 2n = 48 and FN = 60 (in contrast to 2n = 54 and FN = 62 in H. megacephalus), and geographical distribution (while the former is restricted to eastern Brazilian Atlantic Forest, the latter has a more widespread range that extends from the Cerrado throughout eastern Amazonia).

Hylaeamys megacephalus (G. Fischer, 1814) Azara’s Hylaeamys sy n o n y m s : Mus megacephalus G. Fischer, 1814:71; based on Azara’s (1801, 1802) “rat second ou rat a grosse téte” and “del cola igual al cuerpo”; type locality “Paraguay east of the Río Paraguay, Departamento de Canendiyu [= Canindeyú], 13.3 km (by road) N Curuguaty (24°31′S/55°42′W, 255 m,” based on neotype designation (Musser et al. 1998:251–2). Mus ? Capito Illiger, 1815:70; nomen nudum. ? Mus capito: Olfers, 1818:209; redescription of Mus Capito Illiger; based on Azara’s (1801, 1802) “rat second ou rat a grosse téte” and “del cola igual al cuerpo.” Mus cephalotes Desmarest, 1819d:63; based on Azara’s (1801, 1802) “rat second ou rat a grosse téte” and “del cola igual al cuerpo.” H[esperomys]. cephalotes: Wagner, 1843a:542; name combination. Calomys cephalotes: Fitzinger, 1867b:87; part; name combination. Oryzomys velutinus J. A. Allen and Chapman, 1893:214; type locality “Princestown [= Princes Town], Trinidad,” Trinidad and Tobago. Oryzomys Goeldi Thomas, 1897c:494; type locality “Itaituba, Rio Tapajós,” Pará, Brazil. [Oryzomys] cephalotes: E.-L. Trouessart, 1897:526; name combination.

Oryzomys modestus J. A. Allen, 1899b:212; type locality “Campo Alegre, Sucre, Venezuela.” [Oryzomys (Oryzomys)] goeldi: Tate, 1932e: 7; part; name combination. [Oryzomys (Oryzomys)] cephalotes: Tate, 1932e:18; part; name combination. [Oryzomys (Oryzomys)] saltator: Tate, 1932e:18; part; name combination. Oryzomys angouya: C. O. da C. Vieira, 1953:137; part; not Mus angouya G. Fischer (= Sooretamys angouya [G. Fischer]). Oryzomys capito: Hershkovitz, 1959b:339; part; name combination. Oryzomys [(Oryzomys)] capito capito: Cabrera, 1961:385; name combination. Oryzomys [(Oryzomys)] capito goeldii: Cabrera, 1961: 385; name combination and incorrect subsequent spelling of Oryzomys goeldi Thomas. Oryzomys (Oryzomys) laticeps cf. modestus: C. T. Carvalho, 1962:290; part; name combination. Oryzomys capito goeldi: C. T. Carvalho and Toccheton, 1969:290; name combination. [Oryzomys] megacephalus: Langguth, 1966b:287; name combination. Oryzomys oniscus: Alho, 1981:225; part; not Oryzomys oniscus Thomas (= Hylaeamys oniscus [Thomas]). [Hylaeamys] megacephalus: Weksler, Percequillo, and Voss, 2006:14: first use of current name combination. d e s c r i p t i o n : Small to medium sized (head and body length 80–158 mm; mean 121.9 mm, N = 151); tail shorter than head and body (range: 90–138 mm; mean 115.4 mm, N = 145); hindfeet short with small plantar pads (especially hypothenar), and sparse ungual tufts shorter than claws. Dorsal fur short, dense, and slightly harsh, colored overall with ochraceous, yellowish, or orangish weakly to moderately ticked with dark brown; ventral fur shorter and predominantly gray, often with small white gular and inguinal patches; tail uniform in color or weakly to completely bicolored; ears sparsely covered with either entirely brown or banded hairs, brown basally but white or golden distally. Skull small and delicate (greatest length 27.2–34.8 mm); incisive foramina very short and broad, teardrop in shape (length 3.5–5.4 mm; width 1.9–3.1 mm); interorbital region diverges slightly posteriorly, with supraorbital margins rounded to weakly beaded; palate with complex and multiple posterolateral palatal pits recessed in shallow palatine depressions and with palatal excrescences varying from small projections to large struts fused to maxilla; short and narrow toothrows (length 3.7–5.2 mm; M1 width 1.1–1.6 mm). d i s t r i b u t i o n : Hylaeamys megacephalus has the largest known distribution of all congeners, occurring

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 341

throughout forested areas of the Cerrado and Chaco in central Paraguay, Cerrado and semideciduous forests in southeastern and central Brazil, and Amazonian forests of eastern Brazil, the Guianan region, and southern Venezuela, as well as forested areas in the Venezuelan Llanos; and on the coastal island of Trinidad. Hylaeamys megacephalus ranges in elevation from the Amazonian lowlands, such as Itaituba, Pará state, at 15 m, to the central Brazilian highlands, such as at Brasília, Distrito Federal, at 1,100 m. s e l e c t e d l o c a l i t i e s (Map 169): BRAZIL: Amapá, Terezinha, Rio Amapari, Serra do Navio (MPEG 15024); Amazonas, Tambor, left bank Rio Jaú (INPA 2014); Ceará, Serra de Maranguape (UFC 74); Maranhão, Alto Parnahyba [= Alto Parnaíba] (FMNH 26447); Mato Grosso, Cidade Laboratório de Humboldt, Aripuanã (MPEG 12647), Juruena (MZUSP M 97.179); Mato Grosso do Sul, Fazenda Califórnia, Morraria do Sul, Bodoquena (MZUSP [APC 731]), Porto Faya (MZUSP 1700); Minas Gerais, Formoso, Parque Nacional Grande Sertão Veredas (MZUSP M 97.140); Pará, Bragança, Santa Maria, Tracuateua [= Tracuatena] (USNM 394180), Itaituba, Rio Tapajós (type locality of Oryzomys Goeldi Thomas); São Paulo, Fazenda Sete Lagoas, Mogi Guaçu (MZUSP 25759). FRENCH GUIANA: Cayenne, Paracou (Voss et al. 2001). GUYANA: Barima-Waini, Santa Cruz (ROM 98827). PARAGUAY: Caaguazú, 22.5 km N of Coronel Oviedo by road (UMMZ 124499); Canindeyú, 13.3 km by road N of Curuguaty (type locality of Mus megacephalus G. Fischer); San Pedro, Tacuati, Aca-Poi (USNM 293148). SURINAM: Saramacca, La Poule (FMNH 95623). TRINIDAD AND TOBAGO: Trinidad, Princestown (type locality of Oryzomys velutinus J. A. Allen and Chapman). VENEZUELA: Amazonas, Cerro Neblina Base Camp, left (west) bank Río Baria [= Río Mawarinuma] (USNM 559193), Tamatama, Río Orinoco (USNM 409873); Sucre, Campo Alegre (type locality of Oryzomys modestus J. A. Allen). s u b s p e c i e s : As currently understood, Hylaeamys megacephalus is monotypic, although molecularly divergent samples from south of the Amazon River (from eastern Pará state, Brazil, to Paraguay), and those from north of the Amazon in central Brazil and the Guianan region (Patton et al. 2000; L. P. Costa 2003) may represent either valid infraspecific groups or require specific recognition. n a t u r a l h i s t o ry: This species inhabits a range of biomes across its distribution but is always restricted to forested habitats (Mares et al. 1986; Ochoa et al. 1993). Specimens have been obtained in well-drained, swampy, or creekside primary forest as well as secondary forest. This species can also be common near human dwellings and rock outcrops (Handley 1976) and in overgrown orchards (Barnett and Cunha 1994). Sites of trap captures include

under fallen logs, under roots and buttresses of fallen trees, in tangled branches of fallen trees, at the base of buttressed trees, and in hollow logs (Voss et al. 2001). Hylaeamys megacephalus is a predominantly terrestrial species (Nitikman and Mares 1987; Voss et al. 2001) but can be scansorial (Marinho-Filho et al. 1998; Voss et al. 2001), with arboreal captures always in the lower forest strata (300g) with long, dense, soft, yellowish-brown dorsal pelage and buffy under parts. The ears are small and well provided with short brownish or yellowish fur (not contrasting in color with the fur of the head). Mystacial, superciliary, genal, submental, interramal, and carpal vibrissae are present; the mystacial hairs are short and do not extend posteriorly behind the pinnae when laid back against the head. The manus is unremarkable, but the huge (58–68 mm) hindfoot has naked claws (not concealed by long tufts of ungual hairs), conspicuous interdigital webbing, and dense fringes of long silvery hairs along the plantar margins; the plantar surface is hairless and densely squamate, with one metatarsal and four very small interdigital pads (the hypothenar pad is absent); the claw of pedal digit V extends to the end of phalanx 1 of digit IV. There are eight mammae in inguinal, abdominal,

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postaxial, and pectoral pairs. The sparsely haired tail (with clearly visible epidermal scales) is unicolored and much longer than the combined length of head and body. The skull in dorsal view has a blunt, massive rostrum flanked by deep zygomatic notches; the interorbital region is narrow with sharp (but not beaded) supraorbital margins; and the braincase lacks well-developed temporal crests. The zygomatic plates are very broad, with concave anterior margins and spinous anterodorsal processes; the jugals are present and consistently separate the maxillary and squamosal zygomatic processes; and there is a welldeveloped vertical ridge along the frontosquamosal suture in the back of the orbit. Incisive foramina are long, extending posteriorly to or between the first molar alveoli; the palatal bridge is long and narrow, with prominent posterolateral pits; the parapterygoid fossae are about as wide as the mesopterygoid fossa; and the roof of the mesopterygoid fossa is completely ossified (or perforated by very small sphenopalatine vacuities). Diagnostic features of the basicranium and ear region include the absence of an alisphenoid strut (the buccinator-masticatory foramen and the foramen ovale are confluent); a derived carotid arterial circulation (pattern 3 of Voss 1988); and a tegmen tympani that is not connected to a posterior suspensory process of the squamosal. The auditory bullae are globular, with short and narrow bony tubes, and although the petrosal is broadly exposed posteromedially between the ectotympanic and the basioccipital, it does not extend anteriorly to the carotid canal; above each auditory bulla, the lateral surface of the braincase is perforated by a large postglenoid foramen and a subequally sized subsquamosal fenestra. The coronoid process of the mandible is about level with the condyle; the tip of the angular process does not extend posteriorly much behind the condylar process; the superior and inferior masseteric crests converge anteriorly as an open chevron (not tightly compressed to form a single anterior ridge); and the capsular process is indistinct. The upper incisors are opisthodont, with smoothly rounded (not faceted) yellow-orange enamel bands. The upper molars are bunodont (not planar), with rounded (rather than angular) labial and lingual cusp margins. The anterocone of M1 is weakly divided (when unworn) into subequal labial and lingual lobes by a shallow anteromedian flexus; an anteroloph is present but small on unworn M1 and well developed on M2 and M3; a shallow protoflexus is present on unworn M2. A small mesoloph is always present on M1 and M2, but it is never fused with a mesostyle on the labial cingulum; no mesoloph is present on M3. All upper molars have three roots. The anteroconid of m1 is entire (not divided by an anteromedian flexid), but it encloses a large enamel pit; minute anterolophids are present on all unworn lower molars; small mesolophs are present on m1 and m2

but not on m3; and discrete posterolophids are present and persistent on m1 and m2. The lower first molar has three or four roots, but m2 and m3 have two roots each. The axial skeleton includes 12 ribs, 19 thoracolumbar vertebrae, 4 sacral vertebrae, and 35–36 caudal vertebrae. The tuberculum of the first rib articulates with the transverse processes of the seventh cervical and first thoracic vertebrae, and the second thoracic vertebra has a greatly elongated neural spine. The entepicondylar foramen of the humerus is absent. The stomach is unilocular and hemiglandular, and the gall bladder is absent. Other visceral and genital characters are unknown. sy n o n y m s : Hesperomys: Winge, 1887:14; part (description of molitor); not Hesperomys Waterhouse. Holochilus: Hershkovitz, 1955b:657; part (description of magnus); not Holochilus Brandt. Lundomys Voss and Carleton, 1993:5; type species Hesperomys molitor Winge, by original designation.

Lundomys molitor (Winge, 1887) Lund’s Water Rat sy n o n y m s : Hesperomys molitor Winge, 1887:14; type locality given originally as “Lapa do Capão Secco [= Lapa do Capão Seco], da Escrivania [= Escrivânia] Nr. 5 og da Serra das Abelhas”; fixed by lectotype designation (Voss and Myers 1993) to “Lapa da Escrivania [= Escrivânia] Nr. 5, “a cave excavated by P. W. Lund near Lagoa Santa, Minas Gerais, Brazil. Oryzomys molitor: E.-L. Trouessart, 1897:528; name combination. Holochilus magnus Hershkovitz, 1955b:657; type locality “Paso de Averías, Río Cebollati, about 40 km south of Trienta y Tres [Lavalleja], eastern Uruguay.” [Calomys] molitor: Hershkovitz, 1962:123; name combination. Holochilus molitor: Massoia, 1980c:282; name combination. Lundomys molitor: Voss and Carleton, 1993:5; first use of current name combination. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : All known Recent specimens of Lundomys molitor have been collected in Uruguay and in the adjacent Brazilian state of Rio Grande do Sul. s e l e c t e d l o c a l i t i e s (Map 172): BRAZIL: Rio Grande do Sul, Tupanciretã (T. R. O. Freitas, Mattevi, Oliveira et al. 1983). URUGUAY: Canelones, Bañado de Tropa Vieja (AMNH 206363); Lavalleja, Paso Averías, Río Cebollatí (type locality of Holochilus magnus Hershkovitz); Soriano, 3 km E of Cardona (AMNH 206368); Treinta y Tres, 8 km E of Treinta y Tres (FMNH 29260).

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Map 172

Selected localities for Lundomys molitor (●).

s u b s p e c i e s : I treat Lundomys molitor as monotypic. n a t u r a l h i s t o ry: Lundomys molitor has been collected in freshwater marshes and along streams bordered by grass and brush. Throughout its range, L. molitor is sympatric (and perhaps syntopic) with Holochilus brasiliensis, an externally similar semiaquatic species with which it was formerly confused (Hershkovitz 1955b). Scant information from several sources suggests that L. molitor is nocturnal, herbivorous, and builds spherical elevated nests supported by and constructed from reeds (Barlow 1969; Sierra de Soriano 1969; Voss and Carleton 1993). r e m a r k s : Extralimital fossil remains of Lundomys molitor (from Argentina and central Brazil) have been interpreted as evidence for geographic range shifts correlated with Quaternary climatic fluctuations—northward into the tropics during cool episodes (Voss and Carleton 1993) and southward into temperate regions during warmer periods (Teta and Pardiñas 2006; Pardiñas and Teta 2011b).

Genus Melanomys Thomas, 1902 Marelo Weksler and Simone Lóss

Members of the genus Melanomys, generally known as dusky rice rats, are found in lowland or lower montane forested habitats in Central America from Honduras to Panama (Hall 1981; F. A. Reid 1997), and south to north-

western South America, in Colombia, Ecuador, Peru, and westernmost Venezuela. We recognize six species in the genus: M. caliginosus, M. columbianus, M. robustulus, M. zunigae, M. chrysomelas, and M. idoneus. The last two species are currently found only in Central America and not included in this account. The genus is poorly known, as the last review was that of J. A. Allen (1913b). The following morphological description is based on the analyses of specimens deposited in the AMNH and USNM collections, including most holotypes, but also includes information from J. A. Allen (1913b), Goldman (1918), Hooper and Musser (1964; glans penis), Carleton (1973; stomach), Voss and Linzey (1981; male accessory glands), Voss (1991a; gall bladder), Weksler (2006), and Lóss and Weksler (unpubl. data). Melanomys are medium-sized (head and body length, 100–150 mm), vole-like rodents with dorsal pelage dark brown, and ventral pelage grayish or yellowish brown; the limits of dorsal and ventral colors are subtle or indistinct. The body pelage is short and close in coastal (lowland) populations, or long, dense, and soft in interior (mountain) forms. Pinnae are small and slightly hairy, not contrasting in color with the dorsal fur. The mystacial vibrissae are short and sparse, extending only to base of pinnae when laid back against cheek. The manus and pes are covered dorsally with short and dark hairs, and the manual claws are long and keeled. The hindfeet do not have natatory fringes or interdigital webs, and have short and sparse tufts of ungual hairs at bases of claws on digit II through digit V; the plantar surface is densely covered with distinct squamae distal to the thenar pad; the hypothenar pad is absent or vestigial, and the interdigital pads are small and fleshy, with pads 1 and 4 displaced proximally relative to 2 and 3. The claw of digit I extends to the middle of phalanx 1 of digit II, and claw of digit V extends to the middle of phalanx 1 of digit IV. The tail is unicolored and dark, sparsely haired, and covered with more or less conspicuous epidermal scales; it is much shorter than the combined length of head and body and does not have a tuft of terminal long hairs. The mammary complement consists of eight teats in inguinal, abdominal, postaxial, and pectoral pairs. The skull has a robust rostrum flanked by moderate to deep zygomatic notches. The interorbital region is convergent anteriorly, with weakly beaded supraorbital margins. The braincase is rounded, without well-developed temporal crests; the lambdoidal and nuchal crests are weakly developed in older adults. The posterior margins of the zygomatic plates are situated anterior to the M1 alveoli in most specimens, but approximately even with M1 in others. The zygomatic plates lack anterodorsal spinous processes. Jugals are present, but they are very small (maxillary and

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 349

squamosal zygomatic processes often overlap in lateral view but rarely are in contact). Lacrimals have a longer maxillary than frontal suture. The frontosquamosal suture is placed either anterior to or continuous with the frontoparietal suture. Parietals have broad lateral expansions. The incisive foramina are short, not extending beyond the M1 alveoli, either with slightly posteriorly divergent or parallel margins. The bony palate between the molar rows is smooth and long; the mesopterygoid fossa penetrates anteriorly between maxillae but not between molar rows. Posterolateral palatal pits are variable in size, number, and morphology but are usually contained within deeply recessed fossae. The bony roof of mesopterygoid fossa is completely ossified or perforated by extremely reduced (slit-like) sphenopalatine vacuities. An alisphenoid strut is absent (buccinator-masticatory foramen and accessory foramen ovale are confluent). The alisphenoid canal has a large anterior opening. The stapedial foramen and posterior opening of the alisphenoid canal are small; a squamosoalisphenoid groove and sphenofrontal foramen are absent; and a secondary anastomosis crosses the dorsal surface of pterygoid plate (characters of carotid circulatory pattern 3 of Voss 1988). A posterior suspensory process of the squamosal is absent. The postglenoid foramen is large and rounded, and the subsquamosal fenestra is absent or vestigial. The periotic is exposed posteromedially between the ectotympanic and basioccipital, usually not extending anteriorly to the carotid canal; the mastoid usually is completely ossified, not fenestrated. A capsular process is present but not well developed in most fully adult specimens. The basihyal is without entoglossal process. Upper incisors have smoothly rounded enamel bands. The maxillary toothrows are parallel; the molars are bunolophodont and with labial flexi enclosed by a cingulum. Labial and lingual flexi of M1 and M2 meet at the midline, with overlapping enamel. The anterocone of M1 is not divided into labial and lingual conules (anteromedian flexus absent), the anteroloph is fused with the anterocone labially, and an anteroflexus is present as a small fossette. M1 lacks a protostyle. Mesolophs are present on all upper molars, the paracone is connected by an enamel bridge to an anterior moiety of the protocone, and the median mure is not connected to the protocone. The protoflexus is absent from M2, but a mesoflexus is present, either as a single internal fossette or divided into labial and medial fossettes. The paracone of M2 lacks an accessory loph. M3 also lacks a posteroloph, but it possesses a diminutive hypoflexus (which tends to disappear with moderate to heavy wear). An accessory labial root of M1 is present. The anteroconid of m1 is usually without an anteromedian flexid. An anterolabial cingulum is present on all lower molars.

An anterolophid is present on m1 but absent on m2 and m3, an ectolophid is absent on m1 and m2, the mesolophid is distinct on unworn m1 and m2, and a posteroflexid is present on m3. Accessory lingual and labial roots are present on m1; m2 and m3 each have one large anterior root and one large posterior root. The first rib has a double articulation. The humerus lacks an entepicondylar foramen, but has a supratrochlear foramen. There are 12 ribs. The fifth lumbar (17th thoracolumbar) vertebra has a vestigial anapophysis. A posterior spinous process is present on the hemal arch at the junction of the second and third caudal vertebrae. The stomach is unilocular-hemiglandular, without extension of glandular epithelium into the corpus. The gall bladder is absent. One pair of preputial glands is present. The distal bacular cartilage of the glans penis is small and trifid (with a short and slender central digit); the nonspinous tissue on the rim of the terminal crater does not conceal the bacular mounds; the dorsal papillae are spineless; and the urethral processes are without subapical lobules. sy n o n y m s : Hesperomys: Tomes, 1860b:263; part (description of caliginosus); not Hesperomys Waterhouse. Hesperomys (Habrothrix): J. A. Allen, 1891b:210; part (listing of caliginosus); not Hesperomys Waterhouse nor Habrothrix Waterhouse. Oryzomys: Thomas, 1894b:355; part (description of phaeopus); not Oryzomys Baird. Akodon: E.-L. Trouessart, 1897:537; part (listing of caliginosus); not Akodon Meyen. Oryzomys (Zygodontomys): Bangs, 1900a:95; part (listing of obscurior as subspecies of phaeopus); not Oryzomys Baird nor Zygodontomys J. A. Allen. Oryzomys (Melanomys) Thomas, 1902f:248; type species of new subgenus Oryzomys phaeopus Thomas (= Hesperomys caliginosus Tomes). Melanomys: J. A. Allen, 1913b:537; first use as generic designation. r e m a r k s : The genus has no fossil record. Melanomys can be distinguished from other oryzomyine genera by the following combination of characters: dark dorsal coloration with minimal ventral countershading, tail shorter than head and body, reduction of ungual tufts, robust rostrum, lacrimals with longer maxillary than frontal sutures, long palate, carotid circulatory pattern 3 (Voss, 1988), and bunolophodont molars. Monophyly of Melanomys is corroborated by cladistic analysis of morphological characters (Pine et al. 2012), an unsurprising result given the morphological distinctiveness of Melanomys within the Oryzomyini, but recent molecular phylogenetic analyses (Hanson and

350 Mammals of South America

Bradley 2008; Pine et al. 2012) recovered Sigmodontomys alfari within Melanomys, rendering the genus polyphyletic. Pine et al. (2012) proposed that incomplete lineage sorting of sequence haplotypes could be causing the nonmonophyly of Melanomys. Herein, both Melanomys and Sigmodontomys are retained as separate genera, but additional analyses are required to confirm or reject this arrangement. KEY TO THE SOUTH AMERICAN SPECIES OF MELANOMYS:

1. Dorsal pelage dark brown, with tips slightly reddish or dark brown; nasals long (mean 12 mm) . . . . . . . . . . . 2 1′. Dorsal pelage streaked with ochraceous and black, paler than in other species; nasals short (mean 11 mm); known only from the region of Sierra Nevada de Santa Marta in Colombia and westernmost Venezuela . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Melanomys columbianus 2. Incisive foramina short (3.7–5.6 mm) . . . . . . . . . . . . . 3 2′. Incisive foramina long (5.6–6.6 mm); known only from the Lomas de Atocongo, Peru . . . . .Melanomys zunigae 3. Dorsal color coppery brown; interorbital region and rostrum wide; size large . . . . . . Melanomys robustulus 3′. Dorsal color olivaceous; interorbital region and rostrum narrow; size smaller . . . . . Melanomys caliginosus

Melanomys caliginosus (Tomes, 1860) Dusky Melanomys sy n o n y m s : Hesperomys caliginosus Tomes, 1860b: 263; type locality “Ecuador” (stated by J. A. Allen [1913b:537] to be “doubtless Esmeraldas [Esmeraldas] (near sea level), Ecuador”). Hesperomys (Habrothrix) caliginosus: J. A. Allen, 1891b: 210; name combination. Oryzomys phaeopus Thomas, 1894b:355; type locality “Pallatanga [Chimborazo], Ecuador.” Oryzomys phaeopus obscurior Thomas, 1894b:356; type locality “Concordia, Medellin, [Antioquia,] Colombia.” Akodon caliginosus: E.-L. Trouessart, 1897:537; name combination. Oryzomys (Zygodontomys) phaeopus obscurior: Bangs, 1900a:95; part; name combination. Oryzomys phaeopus olivinus Thomas, 1902f:247; type locality “Zaruma, Southern [El Oro] Ecuador.” Oryzomys (Melanomys) phaeopus: J. A. Allen, 1912:87; name combination. Oryzomys (Melanomys) obscurior affinis J. A. Allen, 1912:88; type locality “San José, (altitude 200 ft), Cauca [= Valle del Cauca], Colombia.” Melanomys caliginosus caliginosus: J. A. Allen, 1913b:537; name combination.

Melanomys caliginosus oroensis J. A. Allen, 1913b:538; type locality “Rio de Oro (altitude about 1500 feet), Manavi [Manabí] Province, Ecuador.” Melanomys affinis affinis: J. A. Allen, 1913b:539; name combination. Melanomys affinis monticola J. A. Allen, 1913b:540; type locality “Gallera [= La Gallera] (altitude 5700 ft), west slope of Western Andes,” Cauca, Colombia. Melanomys phaeopus phaeopus: J. A. Allen, 1913b:541; name combination. Melanomys phaeopus olivinus: J. A. Allen, 1913b:543; name combination. Melanomys phaeopus vallicola J. A. Allen, 1913b:544; type locality “Rio Frío (altitude 3500 feet), Cauca Valley, [Valle del Cauca,] Colombia.” Melanomys phaeopus tolimensis J. A. Allen, 1913b:545; type locality “Rio Toche (altitude 6800 feet), Tolima Province, Colombia.” Melanomys lomitensis J. A. Allen, 1913b:545; type locality “Las Lomitas [= Lomitas] (altitude 5000 feet), Western Andes, [Valle del Cauca,] Colombia.” Melanomys obscurior: J. A. Allen, 1913b:546; name combination. Melanomys buenavistae J. A. Allen, 1913b:547; type locality “Buenavista (altitude 4500 feet), Eastern Andes, about 50 miles, in a straight line, southeast of Bogota, [Meta,] Colombia.” Melanomys affinis monticolor J. A. Allen, 1916b:214; incorrect subsequent spelling of Melanomys affinis monticola J. A. Allen. Oryzomys (Melanomys) caliginosus caliginosus: Tate, 1932f: 11; name combination. Oryzomys (Melanomys) phaeopus phaeopus: Tate, 1932f: 11; name combination. Oryzomys (Melanomys) phaeopus obscurior: Tate, 1932f: 11; name combination. Oryzomys (Melanomys) affinis affinis; Tate, 1932f:11; name combination. Oryzomys (Melanomys) caliginosus oroensis: Tate, 1932f: 11; name combination. Oryzomys (Melanomys) affinis monticola: Tate, 1932f:11; name combination. Oryzomys (Melanomys) phaeopus vallicola: Tate, 1932f: 11; name combination. Oryzomys (Melanomys) phaeopus tolimensis: Tate, 1932f: 11; name combination. Oryzomys (Melanomys) lomitensis: Tate, 1932f:11; name combination. Oryzomys (Melanomys) buenavistae: Tate, 1932f:11; name combination. Oryzomys (Melanomys) caliginosus phaeopus: Cabrera, 1961:401; name combination.

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Oryzomys (Melanomys) caliginosus obscurior: Cabrera, 1961:401; name combination. Oryzomys (Melanomys) caliginosus olivinus: Cabrera, 1961: 401; name combination. Oryzomys (Melanomys) caliginosus monticola: Cabrera, 1961:401; name combination. Oryzomys (Melanomys) caliginosus buenavistae: Cabrera, 1961:401; name combination. d e s c r i p t i o n : Geographically variable species, but overall very dark dorsally, almost black flecked with ochraceous or reddish, with dark reddish-brown sides, and orange-brown under parts. Nominotypical form more brownish washed with pale yellow and finely lined with black, especially along midback; other geographic populations range from much darker with hairs tipped ochraceous brown to heavily washed with chestnut red. Most similar to M. columbianus, distinguished from it primarily by darker overall color and longer nasals. d i s t r i b u t i o n : Melanomys caliginosus ranges from west-central Colombia to southwestern Ecuador, from sea level to 2,300 m. It is distributed mostly along the Andean Cordillera, but also in the lowland rainforest of the Pacific versant, including the Chocó (see Cadena et al. 1998), and in the Cauca Valley. Hanson and Bradley (2008) assigned Central American records ascribed to this species by previous workers (e.g., Hall 1981; Musser and Carleton 2005) to either M. chrysomelas or M. idoneus. s e l e c t e d l o c a l i t i e s (Map 173): COLOMBIA: Antioquia, Bellavista (FMNH 70356), Concordia (type locality of Oryzomys phaeopus obscurior Thomas), Santa Bárbara, Río Urrao (FMNH 71836); Boyacá, Muzo (FMNH 71838); Caldas, Samana, Río Hondo (FMNH 71816); Cauca, Munchique (AMNH 32406); Huila, Andalucía (AMNH 33783), San Adolfo (FMNH 71823); Meta, Buenavista (type locality of Melanomys buenavistae J. A. Allen); Nariño, Candelilla (FMNH 89550); Tolima, Río Toche (type locality of tolimensis; AMNH 32976); Valle del Cauca, Río Frio (type locality of Melanomys phaeopus vallicola J. A. Allen), Zabaletas (USNM 507245). ECUADOR: Chimborazo, Pallatanga (type locality of Oryzomys phaeopus Thomas); El Oro, Salvias (AMNH 47766), Santa Rosa (AMNH 61296); Esmeraldas, Esmeraldas (type locality of Hesperomys caliginosus Tomes); Loja, Celica (USNM 461644), Guayas, Los Pozos (AMNH 67470); Manabí, Cuaque (AMNH 66338); Pichincha, Las Máquinas (AMNH 66326), San Tadeo (FMNH 53249); Santa Elena, Cerro Manglar Alto (AMNH 66352). s u b s p e c i e s : Melanomys caliginosus is clearly polytypic, displaying extensive variation over its known range. The 10 names we currently treat as synonyms of M. caliginosus may represent either valid subspecies or even species,

but to date we have been unable to detect external or cranial features that consistently separate any into diagnosable units (Weksler and Lóss, unpubl. data). Thus, for the moment we see no value in trying to delineate infraspecific units. n a t u r a l h i s t o ry: Cadena et al. (1998) trapped this species in virtually intact forest with many palms and epiphytes. They found a male with scrotal testes and a lactating and pregnant female during March. The pregnant female gave birth to two young a few hours after capture and proceeded to eat them over the following days. Previous studies describing the natural history of M. caliginosus actually refer to populations from Costa Rica and Panama that we recognize as M. chrysomelas and M. idoneus, respectively. We include this information here because the genus seems to be ecologically conservative. T. H. Fleming (1970) reported pregnant or lactating females in May, July, August, and November in Panama (= M. idoneus). A. L. Gardner (1983b) found pregnant or lactating females in February, March, and August in Costa Rica (= M. chrysomelas); 11 pregnant females from Costa Rica averaged 3.5 embryos (range: 1– 6); one female had postpartum estrus. Laboratory specimens were eager to eat insects, and some specimens were captured

Map 173 Selected localities for Melanomys caliginosus (●); range in Panama from Hall (1981). Contour line = 2,000 m.

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during the day in Costa Rica, around leaves and other debris associated with logs, buttress of large trees, and bases of banana foliage (A. L. Gardner 1983b). r e m a r k s : Hanson and Bradley (2008) described extensive mitochondrial variation in what had been treated as M. caliginosus, which led them to recognize M. chrysomelas, M. idoneus, and M. columbianus as distinct species. We follow their arrangement based on our analyses of morphological and morphometric characters of specimens housed in the AMNH and USNM (Weksler and Lóss, unpubl. data). This complex of species is in need of revision. Specimens from eastern Colombia (Norte de Santander and Arauca) in the Field Museum that are listed as Melanomys caliginosus in the FMNH database (http:// http:// emuweb.fieldmuseum.org/mammals/Query.php) are not included in our analysis. These localities are outliers to the defined range of the species, and we have not been able to examine them to verify this identification. A. L. Gardner and Patton (1976) described the chromosomal complement if M. caliginosus (now M. chrysomelas) from Costa Rica as 2n = 56 and FN = 58. The karyotype of M. caliginosus, as we restrict this species herein, is unknown.

Melanomys columbianus (J. A. Allen, 1899)

s e l e c t e d l o c a l i t i e s (Map 174): COLOMBIA: La Guajira, Chirua (AMNH 36825); Magdalena, Don Diego (AMNH 23291), Manzanares (AMNH 15336). VENEZUELA: Mérida, La Azulita (FMNH 22159); Zulia, Misión Tukuko (USNM 448569). s u b s p e c i e s : Melanomys columbianus is monotypic. n a t u r a l h i s t o ry: There is no published information on any aspect of the ecology or behavior of this species. r e m a r k s : In his original description, J. A. Allen (1912) regarded M. columbianus as a member of the genus Akodon, comparing it only to Akodon venezuelensis (now Necromys venezuelensis; see Musser and Carleton 2005) and Akodon bogotensis. A year later, in his revision of Melanomys, J. A. Allen (1913b) treated columbianus as a species of Melanomys. Cabrera (1961), however, placed it as a subspecies of M. caliginosus without comment. Hanson and Bradley (2008), based on sequences from the mtDNA cytochrome-b gene, recommended that M. columbianus be recognized as a distinct species, pending further morphological review. We regard this species as distinct from M. caliginosus based on as yet unpublished morphometric analyses (Weksler and Lóss, unpubl. data), geographic isolation from the other species, and a few qualitative characters (see above). The karyotype is unknown.

Colombian Melanomys sy n o n y m s : Akodon columbianus J. A. Allen, 1899b:203; type locality “Manzanares (alt. 3000 ft), Santa Marta District, [Magdalena,] Colombia.” Oryzomys (Zygodontomys) phaeopus obscurior: Bangs, 1900a:95; part (listing of specimens from Chirua, La Guajira); not phaeopus obscurior Thomas. Melanomys columbianus: J. A. Allen, 1913b:550; first use of current name combination. Oryzomys (Melanomys) caliginosus columbianus: Cabrera, 1961:400; name combination. d e s c r i p t i o n : Distinguished of M. caliginosus and M. robustulus by paler dorsal pelage, dark brown grizzled with strong yellowish brown varied with black, with tendency for black dorsal stripe. Venter uniform rusty brown, with rusty tips concealing grayish undertones; tail dusky, unicolored, nearly naked, with scanty short hairs not concealing scale annuli. Rostrum broader than in M. caliginosus; otherwise, cranial measurements similar for two species. d i s t r i b u t i o n : Known only from the region of Sierra Nevada de Santa Marta, northern Colombia, and adjacent northwestern Venezuela, at elevations between 1,000 m and 2,500 m. Extensive collecting below 1,000 m in the Sierra Nevada de Santa Marta yielded no specimens (J. A. Allen 1913b).

Map 174 Selected localities for Melanomys columbianus (●). Contour line = 2,000 m.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 353

Melanomys robustulus Thomas, 1914 Robust Dark Rice Rat sy n o n y m s : Melanomys robustulus Thomas, 1914d:243; type locality “Gualaquiza, Oriente of Ecuador [Morona-Santiago]. Alt. 250′.” Oryzomys (Melanomys) robustulus: Tate, 1932f:12; name combination. d e s c r i p t i o n : Largest species in genus, with head and body length of holotype = 122 mm. Skull large, heavily built, with large and convex braincase, broad interorbital region (6.8 mm for holotype), and overhanging supraorbital ledges. Distinguished from both M. caliginosus and M. columbianus by coppery brown rather than olivaceous dorsal color. Forefeet and hindfeet and tail uniformly black. d i s t r i b u t i o n : Southeastern Ecuador and northwestern Peru, in tropical lowland rainforest between elevations of 400 to 1,200 m. s e l e c t e d l o c a l i t i e s (Map 175): ECUADOR: Morona-Santiago, Gualaquiza (type locality of Melanomys robustulus Thomas); Napo, San Javier (FMNH 29454); Pastaza, Montalvo (FMNH 41475), Río Pindo Yacu (FMNH 43228); PERU: Loreto, Boca del Río Curaray (AMNH 71555; see LeCroy and Sloss 2000:43 for position of this locality). s u b s p e c i e s : Melanomys robustulus is monotypic. n a t u r a l h i s t o ry: Little is known of this species. It has been reported as nocturnal and terrestrial (Tirira and Boada 2008).

Map 175 Selected localities for Melanomys robustulus (●). Contour line = 2,000 m.

r e m a r k s : Thomas (1914d:243) regarded this species as more similar to M. chrysomelas from Central America than to the neighboring M. caliginosus. The karyotype is unknown.

Melanomys zunigae Sanborn, 1949 Zuniga’s Dark Rice Rat sy n o n y m s : Oryzomys (Melanomys) zunigae Sanborn, 1949d:2; type locality “Lomas de Atocongo, Department of Lima, Perú.” Melanomys zunigae Musser and Carleton, 1993:708; first use of current name combination. d e s c r i p t i o n : Palest species in genus, with general dorsal color dark brown becoming paler on the sides; under parts paler brown mixed with grayish black but with pale tips; both forefeet and hindfeet brown rather than black; tail blackish brown above and slightly paler below. Skull distinguished from congeneric species by long incisive foramina that extend posteriorly to between first molars.

Map 176 Selected localities for Melanomys zunigae (●). Contour line = 2,000 m.

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d i s t r i b u t i o n : This species is known only from the western coast of central Peru, between 600 and 800 m. s e l e c t e d l o c a l i t i e s (Map 176): PERU: Lima, Cerro San Jerónimo (FMNH 65578), Lomas de Atocongo (type locality of Oryzomys [Melanomys] zunigae Sanborn). s u b s p e c i e s : Melanomys zunigae is monotypic. n a t u r a l h i s t o ry: This species is known only from the Lomas de Atocongo, a group of low lying hills close to Lima in west central Peru (Musser and Carleton 2005). This area is characterized by desert or dryland habitat, with mesic vegetation along streams and on hilltops as a product of sporadic precipitation from fog during the winter season (Mena et al. 2007). The species is terrestrial and probably nocturnal (Zeballos and Vivar 2008). Melanomys zunigae is listed as Critically Endangered (Possibly Extinct) by the IUCN (2011) because it has not been seen despite extensive searching over the past 50 years, and because there is a continuing, severe decline in the extent and quality of any remaining habitat (Zeballos and Vivar 2008). r e m a r k s : Sanborn (1949d) regarded M. zunigae as most closely related to populations of M. caliginosus phaeopus from western Ecuador. No phylogenetic analyses of any character set, however, are available comparing this species to any other in the genus. The karyotype is unknown.

Genus Microakodontomys Hershkovitz, 1993 Roberta Paresque and J. Delton Hanson

Microakodontomys is a monotypic genus (Hershkovitz 1993) with a restricted distribution in the Brazilian Cerrado biome. The single species is one of the smallest sigmodontines (mean head and body length = 35.3 ± 7.7 mm), with a long, conspicuously scaled tail that is much longer than head and body (mean 93 ± 6.1 mm). It has a relatively long and narrow hindfoot (mean 24 ± 0.8 mm) with small interdigital and hypothenar plantar tubercles and an elongate thenar tubercle. Digit I is much shorter than digits II–IV, which are about the same length, and digit V extends just to the base of the third phalanx of digit IV. Claws are thin, and moderately long with sparse pale ungual hairs. Dorsally Microakodontomys is buffy-ochraceous tinged blackish in color; the venter is creamy. Tricolored hairs, dark brown at the base and black at the tip, with an intermediate and broad buffy band, define the dorsal coloration. Guard hairs on the dorsum are black, forming a dark dorsal strip compared with the fewer, shorter guard hairs on the flanks, which appear more ochraceous. The snout has a black band reaching from the tip to the corner of the eye where it becomes a black eye-ring. The mystacial vibrissae are relatively short, with the longest only extend-

ing to the ears. The proximal half of the tail is bicolored, and on the bicolored half of the tail the hair on the dorsal surface is black, whereas on the ventral surface the hair grades from completely ochraceous (proximal portion), to basally black with ochraceous tips (distal portion). The tip of the tail has a slight tuft. The skull is small (greatest length 19.3–22.8 mm) with a moderately long, slender rostrum (the nasals are about 35% of the skull length). The lacrimals are slightly inflated, leading into a narrow interorbital region with a slight medial constriction and comparatively little posterior divergence. The zygomatic plates project slightly and partially overlap the capsule of the incisor root. The braincase is flat above and moderately curved behind, with the inflated portion of the supraoccipital bone dorsally visible and the interparietal long and wide. The incisive foramina are narrow and extend to the anterior margins of the M1s, whereas the large posterolateral pits border the palatal bridge, which extends beyond the posterior plane of the M3s. Microakodontomys lacks stapedial or sphenofrontal foramina and a squamosal-alisphenoid groove (i.e., it conforms to carotid circulatory pattern 3 of Voss 1988). Microakodontomys is tetralophodont, with mesolophs and mesolophids absent in all molars. The brachydont upper molar row is short (3.1–3.4 mm) and tuberculate. The paraflexus in all upper molars is isolated from the margin, as is the metaflexus in the first and third upper molars. In M1, the anterocone has well-defined anterolabial and anterolingual conules; an anterior fossette is absent, as are the posterostyle and posteroloph. M3 is less than half the size of M2, but has an enlarged median fossette and is subtriangular in occlusal outline. The lower molars are subhypsodont; m1 and m2 has isolated mesoflexids and postereoflexids and lacks ectolophids; m1 is also missing an anterolophid and stylid; and m3 is subtrapezoidal in occlusal outline and has isolated lingual flexids. Upper incisors are opisthodont. Nearly all cranial and dental information for this species was gleaned from Hershkovitz’s (1993) description of the type specimen. Recent material has been collected from the Cerrado of Brazil and is discussed here. sy n o n y m : Microakodontomys Hershkovitz, 1993:2; type species Microakodontomys transitorius, by original designation. r e m a r k s : In his description, Hershkovitz (1993) discussed affinities of the genus based on size as well as on cranial measurements. He viewed this taxon as a derived member of the Sigmodontinae, suggesting it was intermediate between akodontines and oryzomyines: resembling Akodon in its molar pattern and certain cranial characteristics and Oligoryzomys or Microryzomys in overall cranial similarity. Although Hershkovitz (1993:4) ac-

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 355

knowledged the possibility that his new taxon was only a “well-differentiated species of Oligoryzomys,” he believed that based on dental characteristics, facial coloration, and tail length Microakodontomys was easily distinguishable from any other sigmodontine rodent. However, the lack of mesolophs and mesolophids in some specimens of Oligoryzomys rupestris as well as in O. fornesi and the general characteristics of small body, long tail, and long hindfeet have called into question the status of the Microakodontomys. Musser and Carleton (2005) recognized Microakodontomys but recommended additional studies to determine its relationships with Oligoryzomys. In contrast, Weksler et al. (2006) considered M. transitorius an aberrant form of Oligoryzomys and subsumed Microakodontomys within that genus. During a recent collecting effort at the type locality of M. transitorius, R. Paresque and colleagues (unpubl. data) trapped four additional specimens and compared them with sympatric individuals of two Oligoryzomys species (O. nigripes and O. fornesi) to test whether Microakodontomys was a valid genus. Their parsimony analyses of DNA sequence data from Microakodontomys (including from the holotype) and other sigmodontine genera supported Microakodontomys as a valid genus within the Oryzomyini, and one with a closer relationship to Sigmodontomys alfari, Melanomys caliginosus, and Oryzomys couesi than to Oligoryzomys.

Microakodontomys transitorius Hershkovitz, 1993 Transitional Colilargo sy n o n y m s : Microakodontomys transitorius Hershkovitz, 1993:2; type locality “Parque Nacional de Brasília [Distrito Federal], about 20 km NW of Brasília, D. F., [Brazil] about 1100 m.” Oligoryzomys transitorius: Weksler, Percequillo, and Voss, 2006:4; name combination. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : This species has an extremely restricted distribution, known only from two sites in the Parque Nacional de Brasília in central Brazil. s e l e c t e d l o c a l i t i e s (Map 177): BRAZIL: Distrito Federal, Parque Nacional de Brasília (type locality of Microakodontomys transitorius Hershkovitz). s u b s p e c i e s : Microakodontomys transitorius is monotypic. n a t u r a l h i s t o ry: Microakodontomys transitorius is found in edge habitat in the Cerrado biome of Brazil that is transitional between campo limpo (wet grassland) and campo sujo (grass and shrub assemblage). With its long tail and moderately long feet, this mouse is presumably adapted to both sylvan environs as well as more pastoral habitats

Map 177

Selected locality for Microakodontomys transitorius (●).

(Hershkovitz 1993). Additionally, its external morphology is similar to that of Oligoryzomys fornesi and O. nigripes, both of which are also found syntopically in edge habitats. The restricted distribution, combined with the low incidence of capture despite frequent collection efforts over the years, suggests that M. transitorius is a rare species. r e m a r k s : The karyotype has 2n = 38, FN = 46 (R. Paresque et al., unpubl. data). The autosomal complement includes 13 acrocentric pairs, gradually decreasing in size, and five pairs of small, biarmed chromosomes. The X chromosome is large submetacentric, and the Y chromosome is a small submetacentric.

Genus Microryzomys Thomas, 1917 Michael D. Carleton

Species of Microryzomys are small oryzomyines (10– 15 g) that are externally recognizable by their soft, luxuriant fur and a tail notably longer than head and body. The hindfeet are short and slender, the plantar surface bears six fleshy pads (thenar and hypothenar pads are large), and the fifth digit (V) is nearly as long as the central three (II–IV). Females possess eight mammae, arranged in four pairs and anatomically positioned as in

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other Oryzomyini (Carleton and Musser 1989; Voss and Carleton 1993). The skull is delicately constructed, characterized by a short, attenuate rostrum, hourglass-shaped interorbit, and smooth, rounded braincase devoid of ridges. The zygomatic plate is conspicuously narrow and the dorsal notch rudimentary. The cranial wall above the otic capsule is perforated by a spacious subsquamosal fenestra and postglenoid foramen, which together delineate a narrow hamular process. For an oryzomyine, the bony palate is short, extending only slightly beyond the end of the third molars, and the posterolateral palatal pits are correspondingly small and simple; parapterygoid fossae are shallow and narrow. An alisphenoid strut is uniformly absent, the masticatory-buccinator foramen and foramen ovale accessorius being broadly confluent. The cooccurrence of certain cranial foramina and osseus grooves indicates a primitive cephalic arterial supply (Carleton and Musser 1989; pattern 1 of Voss 1988): large stapedial foramen, large posterior opening of the alisphenoid canal, and presence of an squamosoalisphenoid groove leading to the sphenofrontal foramen. The ectotympanic bulla is small, exposing a broad wedge of the periotic in ventral view, and the tegmen tympani does not overlap the squamosal (Voss 1993). Species of Microryzomys possess diminutive, cuspidate molars with brachydont crowns and a pentalophodont occlusal pattern. The upper and lower third molars are noticeably smaller than the second molars. The anterocone(-id) is deeply bifurcated and wide, imparting a rectangular shape to the first molars; the well-developed mesoloph(id) reaches the buccal margin of the tooth; and an anteroloph(id) is usually present and distinct. Three roots anchor each upper molar; each lower molar has two. The upper incisors are narrow, asulcate, and typically orthodont. See Carleton and Musser (1989) and accounts herein for additional external, cranial, and dental descriptions and comparisons with Oligoryzomys and Oryzomys sensu stricto; see Musser and Carleton (2005) and Weksler et al. (2006) for contrasts with the externally similar Andean species Oryzomys balneator Thomas (1900), now placed in the newly described genus Oreoryzomys Weksler, Percequillo, and Voss (2006). Stomach morphology conforms to the unilocularhemiglandular plan, but glandular epithelium is more extensive over the lesser curvature than in Oryzomys sensu stricto (Carleton and Musser 1989). No gall bladder is present (Voss 1991a). A full complement of male accessory reproductive glands, including preputials, has been reported based on single examples of each species (Voss and Linzey 1981; Carleton and Musser 1989). sy n o n y m s : Hesperomys: Tomes, 1860a:215; part (description of minutus); not Hesperomys Waterhouse.

Oryzomys: E.-L. Trouessart, 1897:527; part (listing of minutus); not Oryzomys Baird. Oryzomys (Microryzomys) Thomas, 1917g:1; type species Oryzomys minutus (Tomes), by original designation. Microryzomys: Thomas, 1926b:314; first usage as genus. Oryzomys (Oligoryzomys): Thomas, 1926e:613: part (allocation of Microryzomys as full synonym, invalid as subgenus); not Oligoryzomys Bangs. Oligoryzomys: Gyldenstolpe, 1932a:26; part (listing of Microryzomys as full synonym); not Oligoryzomys Bangs. Thallomyscus Thomas, 1926e:612; type species Oryzomys dryas Thomas, by original designation. Oryzomys (Thallomyscus): Tate, 1932f:5; name combination. Oryzomys (Microryzomys): Osgood, 1933c:1; name combination (Thallomyscus allocated as full synonym, invalid as subgenus). r e m a r k s : Microryzomys was originally designated as a subgenus of Oryzomys and subsequently retained as such (Osgood 1933c; Ellerman 1941; Cabrera 1961) or placed in synonymy with Oligoryzomys (Thomas 1926e; Gyldenstolpe 1932; Tate 1932f). The junior synonym Thallomyscus has been formally retained as a subgenus (Tate 1932f) or allocated as a full synonym (Osgood 1933c; Carleton and Musser 1989). Microryzomys, along with Oligoryzomys, was once considered to be a taxonomic grade that artificially united merely small-bodied species of Oryzomys (Goldman 1918; Tate 1932f; Hershkovitz 1944); however, Carleton and Musser (1989) consolidated discrete morphological traits that differentiate species of Microryzomys from both Oligoryzomys and typical Oryzomys and recast its diagnosis as genus. Microryzomys is a member of Oryzomyini (sensu Voss and Carleton 1993; Musser and Carleton 2005; Weksler 2003, 2006) and shares certain morphological traits with Neacomys, Oligoryzomys, and Oreoryzomys (Carleton and Musser 1989; Weksler 2006; Weksler et al. 2006). In phylogenetic interpretations using allozymic or mitochondrial sequence data, Microryzomys variously falls in a clade that includes Neacomys and Oligoryzomys (Dickerman and Yates 1995; Myers et al. 1995; Patton and da Silva 1995; M. F. Smith and Patton 1999). In taxonomically broad studies of oryzomyines (Weksler 2003, 2006; Weksler et al. 2006; Percequillo, Costa, and Weksler 2011; Pine et al. 2012), using morphology in combination with nuclear and/or mitochondrial genes, the genus emerges as sister to Oreoryzomys, usually in the cladistic hierarchy (Neacomys (Oligoryzomys (Microryzomys + Oreoryzomys))). Both forms of Microryzomys may prove to be species composites. Carleton and Musser (1989) drew attention to the strong morphometric differentiation of their isolated samples of M. altissimus in central Colombia and questioned

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 357

the apparent morphological homogeneity of both M. altissimus and M. minutus across the Huancabamba Depression in northwestern Peru. The high-elevation occurrence of the genus in different Andean cordilleras elegantly lends itself to a phylogeographic study using molecular data. KEY TO THE SPECIES OF MICRORYZOMYS:

1. Pelage principally ochraceous-tawny; dorsal and ventral body fur faintly contrasted; tail basically unicolored and longer (usually >110 mm); dusky markings present on tops of forefeet and hindfeet; skull with shorter, ovate incisive foramina (usually terminating short of or even with the level of the M1s) and shorter toothrow (usually 75% of specimens; interorbital region hourglass in shape, with rounded or weakly beaded supraorbital margins; ventral pelage grayish to grayish yellow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2′. Alisphenoid strut present in 50%) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6′. Ventral white patches present in low frequencies (ca. 12%); posterolateral palatal pits small and numerous, situated in shallow or moderately deep palatal fossae. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nephelomys childi 7. Ventral white patches large and wide, occupying a large area on gular and pectoral regions . . . . . . . . . . . . . . . 8

7′. Ventral white patches small and narrow, restricted to the gular and pectoral regions in about 60% of specimens; incisive foramina long (mean length 6.1 mm; range: 5.3–6.9 mm) and narrow, with nearly parallel lateral margins; interorbital region divergent posteriorly, with supraorbital margins beaded to strongly beaded; posterolateral palatal pits small, varying in depth from palatal level or in shallow palatal fossae; 2n = 66, FN = 90 . . . . . . . . . . . . . . . . . . . . . . . . . Nephelomys caracolus 8. Ventral white patches large, present in more than 90% of specimens; alisphenoid strut absent . . . . . . . . . . . . 9 8′. Ventral white patches present in about 50% of specimens; delicate alisphenoid strut present in >60% of specimens; interorbital region convergent posteriorly, with rounded supraorbital margins in its anterior portion and squared margins in posterior portion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Nephelomys albigularis 9. Posterolateral palatal pits vary from few to many, deep, and situated in shallow to moderately deep palatal fossae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 9′. Posterolateral palatal pits numerous and deep, situated in sharply delimitated, very deep and complex palatal fossae; white ventral patches very large, occupying gular and pectoral regions, rarely inguinal region; 2n = 66, FN = 94. . . . . . . . . . . . . . . . . . . Nephelomys pectoralis 10. White ventral patches extremely long and wide, occupying gular and pectoral regions, reaching middle of abdomen or, more frequently, inguinal region (very few specimens have venter entirely white); few posterolateral pits, placed at palatal level or in shallow palatal fossae; shorter rostrum (mean nasal length 12.1 mm; range 10.85–13.65 mm); 2n = 66, FN = 112 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nephelomys maculiventer 10′. White ventral patches very large, occupying gular and pectoral regions; numerous posterolateral palatal pits, situated in shallow to deep palatal fossae; longer rostrum (mean nasal length 13.01 mm; range: 11.78–14.3 mm); 2n = 66, FN = 104 . . . . . . . . . . .Nephelomys meridensis

Nephelomys albigularis (Tomes, 1860) White-throated Nephelomys sy n o n y m s : Hesperomys albigularis Tomes, 1860b:264; type locality: “taken en camino [sic] on my return from Pallatanga”; restricted to “Pallatanga, [Chimborazo,] Ecuador” (Tate 1939:189). Hesperomys (Calomys) albigularis: Thomas, 1882:103; name combination. [Hesperomys (Oryzomys)] albigularis: Thomas, 1884:448; name combination. [Oryzomys] albigularis: E.-L. Trouessart, 1897:524; name combination.

380 Mammals of South America

[Oryzomys (Oryzomys)] albigularis: E.-L. Trouessart, 1904: 417; name combination. [Oryzomys (Oryzomys)] albigularis albigularis: Tate, 1932e: 16; name combination. Oryzomys albigularis albigularis: Gyldenstolpe, 1932a:14; name combination. [Nephelomys] albigularis: Weksler, Percequillo, and Voss, 2006:18; first use of current name combination. d e s c r i p t i o n : Recognized by combination of following traits: medium body size (head and body length 102–162 mm) with tail longer than head and body (138– 184 mm); tail bicolored or weakly bicolored (few specimens with unicolored tails); long, dense and soft dorsal fur, ranging from buffy orange grizzled with dark brown to ochraceous intensely grizzled with dark brown; whitish or yellowish ventral pelage, with or without small patches of self-colored hairs in gular region (rarely in pectoral region); skull with long incisive foramina, nearly parallel lateral margins widening posteriorly; posterolateral palatal pits small and numerous, on level of palate or situated in moderately deep palatal fossae; alisphenoid strut variably present; interorbital region hourglass in shape or convergent posteriorly, with supraorbital margins rounded or slightly squared; sphenopalatine vacuities small and variably present. d i s t r i b u t i o n : Nephelomys albigularis occurs on the eastern and western slopes of the Andean Cordillera Oriental, from northwestern Peru to central Ecuador. The species is present on both sides of the arid Huancabamba Depression, and in isolated forested patches in this area. The elevational range is from 900 m (Hacienda Éxito, Huánaco, Peru) to 3,100 m (Taraguacocha, Cordillera de Chilla, El Oro, Ecuador). The southernmost record of this species is Hacienda Éxito, in Huánuco department, Peru, at about 900 m. This site is located at the left margin of Río Cayumba, a left margin tributary of the Río Huallaga, which drains the upper elevations of the Cordillera Oriental. Farther to the north in Peru, most samples are distributed along the eastern slope of the Cordillera Oriental (in the upper Río Huallaga drainage) or on both banks of rivers (e.g., Río Cutervo, Río Utcubamba, and Río Huancabamba, all tributaries of the Río Marañón) between the central and eastern Andean cordilleras. Only specimens from Taulis (Cajamarca) and Seques (Lambayeque) represent unequivocal records of this species on the western slope in northern Peru. All remaining localities in the Cordillera Occidental, such as Cutervo (on the Río Chatano) and Tambo (on the Río Huancabamba), are in drainages of the Amazon Basin. North of the Huancabamba Depression, in Ecuador, records of N. albigularis are predominantly from the western slopes of Cordillera Occidental. The species is known

from only two localities on the eastern slopes that drain to the Amazon Basin, near Loja in the headwaters of the Río Zamora (a Río Marañón tributary) and Mazán (in the inter-Andean Cuenca basin). The northernmost record of this species is Carmen, in Bolívar province, central Ecuador. s e l e c t e d l o c a l i t i e s (Map 193): ECUADOR: Azuay, Mazán (BM 84.306), Molleturo (AMNH 61898); Bolívar, Carmen, near Sinchic (AMNH 66944); Cañar, Chical (AMNH 63333); Chimborazo, Pallatanga (type locality of Hesperomys albigularis Tomes); El Oro, El Chiral (AMNH 46481); Loja, Celica (AMNH 47813), 8 km W of Loja (UMMZ 164889). PERU: Amazonas, Uscho, about 50 km E Chachapoyas (FMNH 19698); Cajamarca, Taulis (AMNH 73135); Huánuco, Hacienda Éxito, Río Cayumba (FMNH 24771); La Libertad, Utcubamba, on trail to Ongón (LSUMZ 24790); Piura, Cerro Chinguela, ca. 5 km NE of Zapalache (LSUMZ 26992). s u b s p e c i e s : Nephelomys albigularis is monotypic. n a t u r a l h i s t o ry: Throughout its latitudinal and elevational range, N. albigularis inhabits the humid slopes of the Peruvian and Ecuadorean Andes (Chapman 1926), generally in montane and cloud/elfin forests. Barnett (1999) trapped N. albigularis in both primary and secondary cloud forests between 2,400 m and 2,700 m in Ecuador. Over a five-year period from June to October, he observed no pregnant females and captured one lactating female; of 16 males trapped, only four were in breeding condition (Barnett 1999). In northern Peru, N. albigularis inhabits very humid forests from 1,525 to 2,440 m, dwelling under logs, roots, and debris. Females captured in Amazonas, Peru, during August showed no evidence of embryos, although one lactating female was collected (data from museum tags). r e m a r k s : Nephelomys albigularis was previously considered to be widely distributed, occurring from northwestern Peru to northern Colombia, northwestern Venezuela, and eastern Panama (Eisenberg 1989; Corbet and Hill 1991; Musser and Carleton 1993; Eisenberg and Redford 1999). This concept included populations that exhibit substantial karyological variation and morphological differences in external features such as the presence and extension of ventral white patches and also in several skull characters. Herein, I recognize these morphologically and chromosomally distinct geographic units as separate species (see following accounts). My more restricted concept of N. albigularis includes samples that share the following morphological traits: medium frequency (50%) of gular and/or pectoral white patches; bicolored tail present in >70% of specimens; interorbital region hourglass in shape, with dorsolateral margins converging posteriorly; supraorbital margins rounded or only slightly beaded; incisive foramina long,

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 381

Map 193 Selected localities for Nephelomys albigularis (●). Contour line = 2,000 m.

wide, and teardrop in shape; palate long and ornate, with shallow to deep posterolateral palatal pits at the palatal level or in deep palatal notches; and alisphenoid strut present in >60% of examined specimens.

Nephelomys auriventer (Thomas, 1899) Greater Golden-bellied Nephelomys sy n o n y m s : Oryzomys auriventer Thomas, 1899d:379; type locality “Mirador, below Baños, on the Upper River Pastasa [= Río Pastaza], E Equador [= Tunguruhua, Ecuador]. Altitude 1500 m.” Oryzomys (Oryzomys) auriventer auriventer: Tate, 1932e: 16; name combination. [Oryzomys] albigularis: Hershkovitz, 1944:72, footnote; name combination; part; not Hesperomys albigularis Tomes, 1860 (= Nephelomys albigularis [Tomes]). Oryzomys albigularis auriventer: Cabrera, 1961:381; name combination. [Nephelomys] auriventer: Weksler, Percequillo, and Voss, 2006:18; first use of current name combination.

d e s c r i p t i o n : Body long and robust (head and body length 140–173 mm), tail very long (range: 160–191 mm). Dorsal pelage short and harsh, colored orange yellow to orange golden densely grizzled with brown; ventral pelage light yellowish to intensely golden; white gular patches absent (except for one specimen from Peru with a small patch); tail uniformly colored or weakly bicolored. Skull long and robust (greatest length 36.2–39.9 mm); incisive foramina long and wide posteriorly (teardrop in shape); interorbital region slightly to strongly convergent anteriorly, with sharply angled supraorbital margins; palate long, with large and complex posterolateral palatal pits recessed in shallow fossae; alisphenoid strut rarely present; medial lacerate foramen narrow, and postglenoid foramen small and narrow. d i s t r i b u t i o n : Nephelomys auriventer is known from three closely adjacent localities in the upper Río Pastaza drainage of the Cordillera Oriental of Ecuador and from one locality in the Apurímac drainage in the Cordillera Oriental of Peru, at elevations between 1,140 m (Mera) to 1,660 m (Huanhuachayo). s e l e c t e d l o c a l i t i e s (Map 194): ECUADOR: Pastaza, Mera (AMNH 67351), Tunguruhua: Mirador (type locality of Oryzomys auriventer Thomas). PERU: Ayacucho, Huanhuachayo (LSUMZ 16667). s u b s p e c i e s : Nephelomys auriventer is monotypic. n a t u r a l h i s t o ry: The few collecting localities for N. auriventer are characterized by “paramo or temperate plants” and “subtropical vegetation” (G. H. H. Tate notes cited in Musser et al. 1998:103), cultivated lands, secondgrowth forest, and primary forest (Rageot and Albuja 1994). r e m a r k s : Known from fewer than 20 specimens, N. auriventer is readily distinguished from congeners by the following combination of characters: ochraceous yellow to nearly golden ventral pelage color; large size (mean skull length 37.9 mm; range: 36.2–39.8 mm); robust molar series (mean length 6.22 mm; range: 6.03–6.5 mm); strongly beaded supraorbital ridges; and extremely narrow lacerate foramen and medium foramen postglenoid. A. L. Gardner and Patton (1976) reported karyotypic data from a Peruvian specimen with 2n = 70 and FN = 84; although there is no karyological information available for Ecuadorean specimens, these share the same unique combination of morphological traits as the Peruvian specimen. The considerable distributional hiatus (about 1,300 km) between Ecuadorean and Peruvian localities may be due to a truly disjunct range or to a sampling artifact. Few recent collecting efforts have been made across the wide region between these distributional end points since the Godman-Thomas expeditions of 1926 and 1927 (see, for example, Thomas 1926b,e,g, 1927a,f; Thomas and Leger 1926a).

382 Mammals of South America

Map 194 Selected localities for Nephelomys auriventer (●). Contour line = 2,000 m.

Nephelomys caracolus (Thomas, 1914) Coastal Cordilleran Nephelomys sy n o n y m s : Oryzomys caracolus Thomas, 1914d:242; type locality “Galiparé [= Galipán or Pichacho de Galipán], Cerro del Avila, near Caracas. Alt. 6000′,” Vargas, Venezuela. Oryzomys (Oecomys) caracolus: Tate, 1939:190; name combination. Oryzomys laticeps: Hershkovitz, 1960:544, footnote; part; not Mus laticeps Lund (= Hylaeamys laticeps [Lund]). Oryzomys capito velutinus: Cabrera, 1961: 387; part; not Oryzomys velutinus J. A. Allen and Chapman (= Hylaeamys megacephalus [G. Fischer]) Oryzomys albigularis caracolus: Hershkovitz, 1966a:137, footnote; name combination. [Nephelomys] caracolus: Weksler, Percequillo, and Voss, 2006:8; first use of current name combination. d e s c r i p t i o n : Medium body size (head and body length 120–165 mm) and tail longer than head and body combined (tail length 144–176 mm). Dorsal pelage long and dense, yellowish intensely grizzled with brown in color; ventral pelage grayish to whitish, with narrow white pectoral patches variably present (in some specimens patches especially long, extending to gular region). Skull of medium size (greatest length 31.1–38.4 mm); incisive foramina long and

narrow, with acutely pointed anterior and posterior margins; palate with few, small posterolateral palatal pits at palate level or recessed in very shallow fossae, lacking palatine crests or excrescences; interorbital region divergent posteriorly, with supraorbital margins strongly angled and beaded. d i s t r i b u t i o n : Nephelomys caracolus is distributed throughout the Venezuelan Cordillera de la Costa, in Aragua, Carabobo, and Miranda states as well as in the Distrito Federal. Most records are associated with the Caribbean (or northern) slope; only a few samples are from the southern slope. Elevation ranges from 1,050 to 2,300 m. See R. P. Anderson and Raza (2010), who modeled the climatic niche and potential distribution of the species. s e l e c t e d l o c a l i t i e s (Map 195): VENEZUELA: Aragua, Rancho Grande, Estación Biologica de Rancho Grande, 13 km NW of Maracay (USNM 405988); Carabobo, La Cumbre de Valencia (AMNH 31541); Miranda, Curupao, 19 km E of Caracas (AMNH 135170), Hacienda Las Planadas (R. P. Anderson and Raza 2010); Vargas, Galiparé [= Galipán], Cerro de Ávila (type locality of Oryzomys caracolus Thomas). s u b s p e c i e s : Nephelomys caracolus is monotypic. n a t u r a l h i s t o ry: This species has been captured in mature and disturbed humid evergreen and cloud forests with a rich subcanopy of ferns and vines and covered with abundant moss and epiphytes (Handley 1976). Specimens have also been taken in drier evergreen and cloud forests, with limited epiphytic cover, on the inland slopes of the Cordillera de la Costa (Handley 1976). O. J. Linares (1998) summarized the natural history of “Oryzomys albigularis” in Venezuela, but his concept included specimens and localities now assigned to both N. caracolus and N. meridensis. r e m a r k s : Nephelomys caracolus has been listed as a species of the genus Oecomys (Tate 1939), as a synonym of Hylaeamys megacephalus (= Oryzomys capito, sensu Hershkovitz 1960; or Oryzomys capito velutinus, see Cabrera 1961), and as a synonym or subspecies of Oryzomys (= Nephelomys) albigularis (Hooper and Musser 1964; Musser and Carleton 1993; Handley 1976; Hershkovitz 1966a). Tate (1947:66) included some specimens of this species in his concept of Oryzomys [= Nephelomys] meridensis. More recently, Aguilera, Pérez-Zapata, and Martino (1995) and Márquez et al. (2000) established the species validity of N. caracolus based on karyological (2n = 66, FN = 90) and morphometric data, respectively. This species is morphologically distinct from other Venezuelan populations, treated here as N. meridensis, by the following combination of characters: lower frequency of ventral patches of self-colored white hairs, which are smaller and restricted to the gular region; interorbital region divergent posteriorly, with supraorbital margins beaded; incisive foramina longer with lateral margins wider medially (convex); and postero-

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 383

Map 195 Selected localities for Nephelomys caracolus (●) and Nephelomys meridensis (ᇲ). Contour line = 2,000 m.

lateral palatal pits smaller and placed at the palatal level or in shallow palatal notches.

Nephelomys childi (Thomas, 1895) Child’s Nephelomys sy n o n y m s : Oryzomys childi Thomas, 1895b:59; type locality “Bogota,” Cundinamarca, Colombia.” Oryzomys meridensis: Bangs, 1900a:93; part; childi Thomas given as a synonym of Oryzomys meridensis Thomas. O[ryzomys]. Childi: Thomas, 1901b:188; name combination. [Oryzomys (Oryzomys)] childi: E.-L. Trouessart, 1904: 419; name combination. Oryzomys o’connelli J. A. Allen, 1913c:597; type locality “Buenavista (altitude 4500 feet), about 50 miles southeast of Bogota,” Meta, Colombia. [Oryzomys (Oryzomys)] o’connelli: Tate, 1932e:17; name combination. [Oryzomys] albigularis: Hershkovitz, 1944:72 footnote; part; not Hesperomys albigularis Tomes, 1860 (= Nephelomys albigularis [Tomes]). Oryzomys albigularis childi: Cabrera, 1961:381; name combination. Oryzomys albigularis o’connelli: Cabrera, 1961:82; name combination. [Oryzomys] oconnelli: Márquez, Aguilera, and Corti, 2000:85; corrected spelling of species epithet (ICZN 1999:Art.32.5.2.3). [Nephelomys] childi: Weksler, Percequillo, and Voss, 2006: 18; first use of current name combination. d e s c r i p t i o n : Distinguished from congeners by following traits: medium body size (head and body length

120–184 mm); tail longer than head and body (tail length 110–194 mm); dorsal pelage varying in length and texture geographically, with some samples presenting dense and shorter fur and other exhibiting very dense and longer hairs; ventral pelage of few individuals with small white patches in gular region. Skull with interorbital region hourglass in shape or convergent posteriorly, with supraorbital margins rounded; rounded braincase, with discrete temporal border; long incisive foramina, with lateral margins wider posteriorly (teardrop in shape); palate with numerous posterolateral palatal pits recessed in shallow to moderately deep fossae; and developed palatal excrescences situated on palatine level or on palatine crests. d i s t r i b u t i o n : Nephelomys childi is endemic to Colombia, occurring in all three cordilleras of the northern Andes. In the Cordillera Oriental, this species is distributed on both the eastern and western forested slopes from the headwaters of Río Magdalena (Huila department), in the Sierra de Macarena (Meta department), and in the plains of Bogotá (Cundinamarca department). In the Cordillera Central, isolated populations occur in upper Cauca and Magdalena drainages (Huila and Cauca departments, respectively) and on the eastern slope in the departments of Antioquia, Caldas, Quíndio, and Tolima. The only known populations of N. childi in the Cordillera Occidental are isolated on the extreme northwestern slope at Santa Barbara and Guapantal (Antioquia department). Elevational range is 1,140 to 3,400 m. s e l e c t e d l o c a l i t i e s (Map 196): COLOMBIA: Antioquia, San Pedro (FMNH 72101), Santa Barbara, RíoUrrao (FMNH 71882); Cauca, Almaguer (BM 13.5.27.42); Cundinamarca, Anolaima (BM 99.10.3.23), Guasca, Río Balcones (FMNH 71896), Paime (AMNH 71340); Huila, Andalucía, eastern Andes (AMNH 33755); Meta, Buenavista (type locality of Oryzomys oconnelli J. A. Allen), Macarena Mt. (AMNH 142160); Tolima, El Éden, E Quindio Andes (AMNH 32983). s u b s p e c i e s : Nephelomys childi is monotypic. n a t u r a l h i s t o ry: Data on ecology or other aspects of the natural history of N. childi are lacking. r e m a r k s : The holotypes and topotypes of N. childi and N. oconnelli are extremely similar in external and cranial traits, and, as a result, I regard these taxa as conspecific. Previous authors have considered N. childi a synonym of Nephelomys meridensis based on the presence and size of ventral white patches (Bangs 1900a; Thomas 1901b; Osgood 1914b) or as a synonym (Hershkovitz 1944) or subspecies (Cabrera 1961) of N. albigularis. Furthermore, many specimens referrable to N. childi have been erroneously identified as N. auriventer (J. A. Allen 1916b; Cuervo Díaz et al. 1986) or N. pectoralis (J. A. Allen 1916b; Anthony 1923a).

384 Mammals of South America

Map 196

Selected localities for Nephelomys childi (●). Contour line = 2,000 m.

This species can be readily recognized from its Colombian congeners N. pectoralis and N. maculiventer by the combination of a low frequency of small ventral white patches (about 12%) and shallow and small posterolateral palatal pits placed in shallow to moderately deep palatal fossae.

Nephelomys keaysi (J. A. Allen, 1900) Keays’s Nephelomys sy n o n y m s : Oryzomys keaysi J. A. Allen, 1900a:225; type locality “Juliaca, Peru, altitude 6000 ft,” corrected to “Inca Mines [= Santo Domingo Mine], about 200 miles northeast of Juliaca, on the east side of the Andes, on the Inambary River [= Río Inambarí],” Puno, Peru, by J. A. Allen (1901b:41). Oryzomys obtusirostris J. A. Allen, 1900a:225; type locality “Juliaca, Peru, altitude 6000 ft”; corrected to “Inca Mines [= Santo Domingo Mine], about 200 miles northeast of Juliaca, on the east side of the Andes, on the Inambary River [= Río Inambarí],” Puno, Peru, by J. A. Allen (1901b:41). Oryzomys (Oligoryzomys) obtusirostris: Thomas, 1901b: 188; name combination. [Oryzomys (Oryzomys)] keaysi: E.-L. Trouessart, 1904:419; name combination. [Oryzomys (Oryzomys)] obtusirostris: E.-L. Trouessart, 1904: 419; name combination.

Zygodontomys obtusirostris: Gyldenstolpe, 1932a:114; name combination. [Oryzomys] albigularis: Hershkovitz, 1944:72, footnote; part; not Hesperomys albigularis Tomes (= Nephelomys albigularis [Tomes]). Oryzomys albigularis keaysi: Cabrera, 1961:381; name combination. [Nephelomys] keaysi: Weksler, Percequillo, and Voss, 2006: 18; first use of current name combination. d e s c r i p t i o n : Medium sized (head and body length 125–165 mm); tail much longer than head and body (length 146–207), not bicolored in most specimens; dorsal pelage dense, long, and lax, colored ochraceous to buffy ochraceous intensely grizzled with brown; ventral pelage grayish, whitish, or rarely yellowish, without white pectoral or gular patches; interorbital region of skull slightly to strongly divergent posteriorly, with supraorbital margins squared to strongly beaded; incisive foramina long, with lateral margins wider posteriorly and posterior margins not reaching M1s; palate long, with large posterolateral pits at palate level or recessed in shallow and narrow fossae; palatal excrescences small and delicate; alisphenoid strut present in most specimens. d i s t r i b u t i o n : Nephelomys keaysi occurs on the forested eastern slopes of the Andes in central Peru (Santa Cruz, Pasco) south to central Bolivia (Chaparé, Cochabamba), at elevations between 1,000–2,600 m; most records are from 1,200–1,500 m). s e l e c t e d l o c a l i t i e s (Map 197): BOLIVIA: Cochabamba, Chaparé (BM 34.9.2.128); Yungas (AMNH 38557); La Paz, Pitiguaya, Río Unduavi (AMNH 72647). PERU: Ayacucho, Yuraccyacu (LSUMZ 15693); Cusco, Machu Picchu, San Miguel Bridge (BM 22.1.1.28), Marcapata, Camante (FMNH 68628), 72 km NE of Paucartambo (MVZ 166682); Junín, Acobamba, 45 mi NE of Cerro de Pasco (BM 27.11.1.91), Satipo, Cordillera de Vilcabamba (USNM 582120); Pasco, Santa Cruz, ca. 9 km SSE of Oxapampa (LSUMZ 25894); Puno, Sagrario (FMNH 52705), Inca Mines (type locality of Oryzomys keaysi J. A. Allen and Oryzomys obtusirostris J. A. Allen). s u b s p e c i e s : Nephelomys keaysi is monotypic. n a t u r a l h i s t o ry: Nephelomys keaysi inhabits montane and cloud forests (Patton et al. 1990). Pregnant females were captured in November, with three embryos, at Santa Cruz, Peru, and females with uterine scars (four to five) were observed in July, east of Paucartambo, Peru. Stomachs of specimens from Bosque Aputinye, Cusco, Peru contained arthropods and vegetable matter (diet and reproductive data from museum tags and field notes). r e m a r k s : Nephelomys keaysi was resurrected from the synonymy of N. albigularis on the basis of karyo-

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 385

logical (A. L. Gardner and Patton 1976) and molecular studies (Patton et al. 1990; see also Musser and Carleton 1993). The karyotype of N. keaysi is 2n = 80, FN = 92–94, based on specimens from localities in Junín, Ayacucho, and Cusco departments, Peru (A. L. Gardner and Patton 1976, “Oryzomys albigularis variant 3”; J. L. Patton, pers. comm.). The separate specific status of N. keaysi and N. levipes, which replace one another on the elevational gradient in southeastern Peru, was demonstrated by karyological (J. L. Patton, pers. comm.) and allozyme analyses (Patton 1986; Patton et al. 1990). Morphologically, N. keaysi differs from N. albigularis by absence of self-colored ventral patches, divergent interorbital margins with sharp or beaded supraorbital margins, and higher frequency of an alisphenoid strut. For comparisons with N. levipes, see Remarks under that species. Nephelomys obtusirostris, here recognized as a synonym of N. keaysi, has been previously assigned to the longicaudatus-stolzmanni group of Oryzomys (= genus Oligoryzomys; Thomas 1901b) or to Zygodontomys (Gyldenstolpe 1932; Ellerman 1941). However, Tate (1939) correctly noted that the holotype of Oryzomys obtusirostris J. A. Allen was a young specimen of Nephelomys keaysi, with immature pelage and unerupted third upper molars. Nephelomys keaysi is parapatric to N. levipes throughout much of its distribution (see account) and with N. auriventer at Huanhuachayo, Ayacucho, Peru (see account).

Map 197 Selected localities for Nephelomys keaysi (●). Contour line = 2,000 m.

Nephelomys levipes (Thomas, 1902) Nimble-footed Nephelomys sy n o n y m s : Oryzomys levipes Thomas, 1902b:129; type locality “Limbane [= Limbani], 2,000 m,” Puno, Peru. [Oryzomys (Oryzomys)] levipes: E.-L. Trouessart, 1904:419; name combination. [Oryzomys] albigularis: Hershkovitz, 1944:72 footnote; part; not Hesperomys albigularis Tomes (= Nephelomys albigularis [Tomes]). Oryzomys [(Oryzomys)] albigularis keaysi: Cabrera, 1961: 381; part; not Oryzomys keaysi J. A. Allen (= Nephelomys keaysi [J. A. Allen]); name combination. [Nephelomys] levipes: Weksler, Percequillo, and Voss, 2006: 18; first use of current name combination. d e s c r i p t i o n : Medium sized (head and body length 113–161 mm); tail longer than head and body (length 143– 185 mm). Dorsal pelage very dense, very long, and lax, colored from yellowish to ochraceous grizzled with brown; ventral pelage shorter and predominantly yellowish, without patches of self-colored hairs; tail frequently weakly to strongly bicolored, rarely unicolored. Skull length 33.5– 39.8 mm; interorbital region slightly to strongly divergent posteriorly, with squared to beaded supraorbital margins; incisive foramina long, wider in middle, with posterior margins almost reaching M1 alveoli; palate short, with anterior border of mesopterygoid fossa reaching alveoli or even M3 hypocones; posterolateral palatal pits deep, recessed at moderately deep to deep oblique and lateral fossa positioned at maxillopalatine suture; palate with small excrescences; sphenopalatine vacuities long and wide; alisphenoid strut present in all examined specimens. d i s t r i b u t i o n : Nephelomys levipes inhabits cloud and elfin forests on the eastern slopes of the Andes in northwestern Bolivia and southwestern Peru, at elevations from 1,800 to 3,200 m. This species replaces N. keaysi at higher elevations on the eastern Andean slope. s e l e c t e d l o c a l i t i e s (Map 198): BOLIVIA: La Paz, Cocopunco (AMNH 72118); 15 km (by road) NE of Unduavi (UMMZ 156180); Santa Cruz, Serranía Siberia, 11 km NW by road of Torrecillas (AMNH 264192). PERU: Cusco, 32 km NE of Paucartambo (MVZ 166679); Puno, Limbani (type locality of Oryzomys levipes Thomas), 11 km NNE of Ollachea (MVZ 172637), 14 km W of Yanahuaya (MVZ 172639). s u b s p e c i e s : Nephelomys levipes is monotypic. n a t u r a l h i s t o ry: Nephelomys levipes is predominantly terrestrial but has also been captured in trees. Notes on specimen tags state that the species dwells in “humid, dark, mossy forest,” “high forest,” on “steep slopes,” and in “gorges near streams.” Pregnant females with one or three embryos were collected in July and with two, four, or

386 Mammals of South America

Map 198 Selected localities for Nephelomys levipes (●). Contour line = 2,000 m.

five embryos during June–August at localities in Puno and Cusco departments, Peru, respectively (specimen labels and field notes). r e m a r k s : Nephelomys levipes has been considered a junior synonym of either N. keaysi (Gyldenstolpe 1932; Cabrera 1961) or N. albigularis (Hershkovitz 1944, 1966a; Corbet and Hill 1991). The molecular data of Patton et al. (1990), however, support N. levipes as specifically distinct from both N. keaysi and N. albigularis, an arrangement followed by subsequent authors (Musser and Carleton 1993, 2005; Eisenberg and Redford 1999). Nephelomys levipes can be differentiated from N. keaysi by a denser and longer dorsal pelage; longer incisive foramen, with lateral margins wider medially; posterolateral palatal pits situated in deeper and narrower palatal slits; and a higher frequency in the presence of an ectolophid on m1. The two species also differ in karyotype, with a 2n = 76 and FN = 88 for N. levipes and 2n = 80, FN = 92 to 94 in N. keaysi (“Oryzomys albigularis variant 3” of A. L. Gardner and Patton 1976; J. L. Patton, pers. comm.).

Nephelomys maculiventer (J. A. Allen, 1899) Santa Marta Nephelomys sy n o n y m s : Oryzomys maculiventer J. A. Allen, 1899b:204; type locality: “Sierra El Libano (alt. 6000 ft.), Santa Marta District,” Magdalena, Colombia. Oryzomys meridensis: Bangs, 1900a:92; part; maculiventer listed as a synonym of Oryzomys meridensis Thomas.

[Oryzomys (Oryzomys)] maculiventer: E.-L. Trouessart, 1904:418; name combination. Oryzomys meridensis maculiventer: Osgood, 1912:49; name combination. Oryzomys albigularis maculiventer: Osgood, 1914b:159; name combination. [Oryzomys] albigularis: Hershkovitz, 1944:72 footnote; part; not Hesperomys albigularis Tomes (= Nephelomys albigularis [Tomes]). [Nephelomys] maculiventer: Weksler, Percequillo, and Voss, 2006:18; first use of current name combination. d e s c r i p t i o n : Medium to large body size (head and body length 127–180 mm); tail longer than head and body (length 148–194); long, dense, and lax dorsal pelage; ventral pelage with patches of self-colored hairs present in almost all examined specimens, with large patches in gular, pectoral (including ventral surface of forelimbs), abdominal, and inguinal areas; tail usually unicolored, rarely weakly bicolored; small and delicate skull (greatest skull length 32.7– 35.9 mm); interorbital region hourglass in shape or slightly convergent posteriorly, with rounded supraorbital margins; short incisive foramina, wider posteriorly (teardrop in shape); long palate, with few but deep posterolateral pits either recessed in shallow fossae or at palate level. d i s t r i b u t i o n : All known localities of N. maculiventer are from the slopes of Sierra Nevada de Santa Marta and Serranía de Perijá, in northern Colombia, where this species ranges from 900–2,600 m in montane and cloud forests. s e l e c t e d l o c a l i t i e s (Map 199): COLUMBIA: Cesar, Villenueva, Sierra Negra (USNM 280641); La Guajira, San Miguel (AMNH 3894); Magdalena, Sierra El Libano (type locality of Oryzomys maculiventer J. A. Allen). s u b s p e c i e s : Nephelomys maculiventer is monotypic. n a t u r a l h i s t o ry: Nothing is known about the ecology, population biology, or other aspects of the natural history of this species. r e m a r k s : A. L. Gardner and Patton (1976) regarded the population of Nephelomys from the Sierra Nevada de Santa Marta as a subspecies of N. albigularis based on karyological and morphological evidence. Subsequent authors (Musser and Williams 1985; Musser and Carleton 1993, 2005) treated maculiventer simply as a synonym of N. albigularis. The specimens from Santa Marta, however, are sharply differentiated morphologically from other species in the genus and have a different karyotype (2n = 66, FN = 112; “Oryzomys albigularis variant 1” of A. L. Gardner and Patton 1976). As a result, I recognize N. maculiventer as a valid species. Among the morphological features that diagnose this species are large ventral patches of selfcolored hairs in most specimens and a skull with simple and few posterolateral palatal pits situated at the palatal level or in shallow palatal fossae.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 387

Map 199 Selected localities for Nephelomys maculiventer (ᇲ) and Nephelomys pectoralis (●). Contour line = 2,000 m.

Nephelomys meridensis (Thomas, 1894) Mérida Nephelomys sy n o n y m s : Oryzomys meridensis Thomas, 1894b:351; type locality “Merida, Venezuela,” Mérida, Venezuela. [Oryzomys (Oryzomys)] meridensis: E.-L. Trouessart, 1904: 418; name combination. [Oryzomys (albigularis)] meridensis: Osgood, 1914b:159; name combination. [Oryzomys] albigularis: Hershkovitz, 1944:72 footnote; part; not Hesperomys albigularis Tomes (= Nephelomys albigularis [Tomes]). O[ryzomys]. albigularis meridensis: Hershkovitz, 1966a:137, footnote; part; not Hesperomys albigularis Tomes (= Nephelomys albigularis [Tomes]); name combination. Oryzomys [(Oryzomys)] albigularis: Eisenberg, 1989:351; part. [Nephelomys] meridensis: Weksler, Percequillo, and Voss, 2006:18; first use of current name combination. d e s c r i p t i o n : Medium body size (head and body length 135–160 mm); long tail that exceeds head and body (length 170–172 mm), typically unicolored but rarely weakly bicolored; dorsal pelage dense, lax, and very long; ventral pelage with large pectoral patches of self-colored hairs (gular, axillary, and inguinal patches rarely pres-

ent). Skull of medium size (greatest length 32.4–37 mm); interorbital region slightly convergent posteriorly or symmetrically constricted (hourglass in shape), with rounded or slightly beaded supraorbital margins posteriorly; palate with multiple and deep posterolateral palatal pits recessed in shallow depressions; palatine crest present, with small to very large palatal excrescences (if large, may be fused to maxilla). d i s t r i b u t i o n : This species occurs on forested slopes from the northeastern Cordillera Oriental of Colombia in Boyacá department, through the Páramo de Tamá on the Colombian-Venezuelan border, to the northern portion of the Sierra de Mérida, in Trujillo state, Venezuela, at elevations from 1,100 to 4,000 m. See R. P. Anderson and Raza (2010), who modeled the climatic niche and potential distribution of the species. s e l e c t e d l o c a l i t i e s (Map 195): COLUMBIA: Boyacá, La Primavera (FMNH 92408); Norte de Santander, Páramo de Tamá (FMNH 18648). VENEZUELA: Mérida, Montes de Los Nevados (AMNH 33163), Páramo Tambor (BM 29.3.17.55); Táchira, Táchira (FMNH 7044); Trujillo, Hacienda Misisí, 14 km E of Trujillo (USNM 374310). s u b s p e c i e s : Nephelomys meridensis is monotypic. n a t u r a l h i s t o ry: Osgood (1912) secured specimens in ground litter and under logs and roots in the dense, cold, forested areas of the Páramo de Tamá, on the Venezuelan/Colombian border. r e m a r k s : Nephelomys meridensis was recognized as a valid taxon throughout much of its history, either as a species (E.-L. Trouessart 1904; Goldman 1918; Gyldenstolpe 1932; Tate 1939; Ellerman 1941; Aguilera, PérezZapata, and Martino 1995; Soriano and Ochoa 1997; Márquez et al. 2000; Musser and Carleton 2005) or subspecies (Osgood 1914b; Cabrera 1961; Hershkovitz 1966a; O. J. Linares 1998; Rivas and Péfaur 1999a). Other authorities simply included this name in the synonymy of N. albigularis (Hershkovitz 1944; Handley 1976; Péfaur and Díaz de Pascual 1985; Eisenberg 1989; Corbet and Hill 1991; Musser and Carleton 1993; Rivas and Péfaur 1999b). Aguilera, Pérez-Zapata, and Martino (1995) and Márquez et al. (2000) separated populations from the Mérida Andes (= N. meridensis; 2n = 66, FN = 104) from those from the Cordillera de la Costa (= N. caracolus; 2n = 66, FN = 90) of Venezuela on karyological and morphometric grounds, respectively. These authors, as well as Percequillo (2003), also distinguished samples from the Páramo de Tamá on the Colombian/Venezuelan border (2n = 66, FN = 92) from those of the Mérida Andes. Morphologically, specimens from Mérida and the Páramo de Tamá are quite similar in the extent of their ventral white patches and in cranial traits, differing only slightly in the morphology of posterolateral palatal pits, which are

388 Mammals of South America

deeper on N. meridensis. The specimens from the Páramo de Tamá are included in my concept of N. meridensis until the validity of this decision is rejected by subsequent analyses. If differences between specimens from the Páramo de Tamá and the Mérida Andes prove to warrant taxonomic recognition, a new name will have to be erected for the former because none is currently available.

Nephelomys moerex (Thomas, 1914) Gray-bellied Nephelomys sy n o n y m s : Oryzomys albigularis moerex Thomas, 1914d:241; type locality “Mindo, N. W. of Quito. Alt. 4200′,” Pichincha, Ecuador. [Oryzomys] albigularis maerex Anthony, 1926a:4; incorrect subsequent spelling of moerex Thomas. [Oryzomys] moerex: Tate, 1939:189; name combination. Oryzomys albigularis: Boyce et al., 1982:435; part; not Hesperomys albigularis Tomes (= Nephelomys albigularis [Tomes]). [Nephelomys] moerex: Weksler, Percequillo, and Voss, 2006: 18; first use of current name combination. d e s c r i p t i o n : Small to medium body (head and body length 114–160); tail longer than head and body (length 139–169 mm) and usually bicolored; dorsal pelage dense, lax, and short, overall colored ochraceous brown finely grizzled with dark brown; ventral pelage grayish, without patches of self-colored hairs. Skull with slightly convergent posteriorly or symmetrically constricted (hourglass in shape) interorbital region, with rounded or squared supraorbital margins; incisive foramina very short (length 4.1–5.1 mm; mean 4.6 mm), with sides widest medially; alisphenoid strut present in high frequency but ranges from narrow strut oriented parallel to lateral border of parapterygoid plate to wide bone covering almost completely ovale accessorius and buccinator-masticatory foramina. d i s t r i b u t i o n : Nephelomys moerex is endemic to Ecuador, with all known localities from a small area on the northwestern and southwestern faces of Volcán Pichincha and the Mindo river drainage, at elevations from 1,200 to 2,800 m. s e l e c t e d l o c a l i t i e s (Map 200): ECUADOR: Pichincha, Las Máquinas, San [= Santo] Domingo trail (AMNH 64702), Río Tulipe, Gualea (FMNH 94979). s u b s p e c i e s : Nephelomys moerex is monotypic. n a t u r a l h i s t o ry: No data on natural history are available. r e m a r k s : Thomas (1914d) originally described moerex as a subspecies of N. albigularis, a treatment followed by many subsequent authors (Anthony 1926a; Gyldenstolpe 1932; Ellerman 1941; Cabrera 1961). Others, however, regarded moerex as a full species (e.g., Tate 1939). Nevertheless, the name moerex was, until recently (Percequillo

Map 200 Selected localities for Nephelomys moerex (●) and Nephelomys nimbosus (ᇲ). Contour line = 2,000 m.

2003), lost in the synonymy of N. albigularis (Hershkovitz 1966a; Boyce et al. 1982; Corbett and Hill 1991; Musser and Carleton 1993, 2005). Known from only a few specimens (about three dozen deposited in the BM, AMNH, MCZ, and UMMZ collections), N. moerex is considerably different from typical N. albigularis or any other nominal form of the genus, and thus I recognize it here as a valid species (see also Percequillo 2003). This species is diagnosed by the combination of absence of white ventral patches (in all but one specimen), very short and oval incisive foramina, and, most conspicuously, presence of a robust and obliquely oriented alisphenoid strut in all specimens (in some specimens the strut almost obliterates the alisphenoid wall, leaving only small foramina for the passage of nerves and vessels).

Nephelomys nimbosus (Anthony, 1926) Lesser Golden-bellied Nephelomys sy n o n y m s : Oryzomys auriventer nimbosus Anthony, 1926a:4; type locality “San Antonio, on Rio Ulva, northeastern slope of Tunguragua, [Tunguruhua,] Ecuador, altitude 6700 feet.” [Oryzomys (Oryzomys)] auriventer nimbosus: Tate, 1932e: 16; name combination. [Oryzomys] nimbosus: Tate, 1939:189; name combination. Oryzomys [(Oryzomys)] albigularis nimbosus: Cabrera, 1961:382; part; name combination. O[ryzomys]. albigularis: Corbet and Hill, 1991:151; part; not Hesperomys albigularis Tomes (= Nephelomys albigularis [Tomes]); name combination.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 389

Oryzomys auriventer: Musser and Carleton, 1993:720; part; not Oryzomys auriventer Thomas (= Nephelomys auriventer [Thomas]); name combination. [Nephelomys] nimbosus: Weksler, Percequillo, and Voss, 2006:18; first use of current name combination. d e s c r i p t i o n : Small species, with head and body length 122–144 mm, and tail length 147–170 mm. Dorsal pelage very dense and very long, colored yellow orange to golden orange densely grizzled with brown; ventral pelage pale ochraceous yellow to intensely golden, with small white gular patches in most specimens. Skull small and delicate, length 31.5–35.4 mm; interorbital region narrow and either convergent posteriorly or amphoral in shape, with rounded or slightly squared supraorbital margins; incisive foramina short and widest posteriorly (teardrop in shape; mean length 4.98 mm; range: 4.6–5.1 mm); palate with small and simple posterolateral palatal pits located at palatal level or recessed in shallow depressions; alisphenoid strut found in about 30% of specimens. d i s t r i b u t i o n : Nephelomys nimbosus is endemic to Ecuador, with the four known collecting localities on the eastern Andean slope in Napo and Tunguruhua provinces, at elevations from 2,000–2,440 m. Along the Río Pastaza drainage, this species is parapatric to N. auriventer, replacing it at higher elevations. s e l e c t e d l o c a l i t i e s (Map 200): ECUADOR: Napo, Baeza (AMNH 63840), Chaco, Rio Oyacachi (AMNH 66807); Tunguruhua, San Antonio (type locality of Oryzomys auriventer nimbosus Anthony), San Francisco, E of Ambato (AMNH 67354). s u b s p e c i e s : Nephelomys nimbosus is monotypic. n a t u r a l h i s t o ry: There is no published information on the natural history of N. nimbosus. r e m a r k s : Anthony’s nimbosus was considered either a subspecies of N. auriventer or of N. albigularis, or a synonym of the latter, since its description until Weksler et al. (2006) treated it as a species. Specimens of N. nimbosus are rare in museum collections, with fewer than 15 known, and few specialists have examined them. Based on my examination of the available material, I recognize N. nimbosus as a valid species because it can be distinguished from N. auriventer and other species of the genus by the combination of the characters mentioned above.

Nephelomys pectoralis (J. A. Allen, 1912) Western Colombian Nephelomys sy n o n y m s : Oryzomys pectoralis J. A. Allen, 1912:83; type locality “crest of Western Andes (alt. 10, 340 ft.), 40 miles west of Popayán, Cauca, Colombia.” [Oryzomys albigularis] meridensis: Osgood, 1914b:159; part; not meridensis Thomas.

[Oryzomys (Oryzomys)] pectoralis: Tate, 1932e:17; name combination. [Oryzomys] albigularis: Hershkovitz, 1944:72 footnote; part; not albigularis Tomes. Oryzomys [(Oryzomys)] albigularis pectoralis: Cabrera, 1961:382; part; name combination. [Nephelomys] pectoralis: Weksler, Percequillo, and Voss, 2006:18; first use of current name combination. d e s c r i p t i o n : Differentiated from congeners from Colombia or generally northern Andes by medium head and body (length 124–180 mm); tail longer than head and body (length 110–196); long, dense, and lax dorsal pelage, colored yellowish to ochraceous grizzled with brown; ventral pelage grayish, with large and conspicuous white gular and pectoral patches that rarely reach abdominal region; and usually unicolored tail. Distinguishing cranial characteristics include medium-sized skull (greatest length 32.0– 37.5 mm); robust and long rostrum; interorbital region hourglass in shape or posteriorly convergent, with slightly squared posteriorly supraorbital margins; incisive foramina short, with lateral margins widest posteriorly (teardrop in shape); numerous and complex posterolateral palatal pits recessed in very deep and well-defined depressions; roof of mesopterygoid fossa frequently ossified so that sphenopalatine vacuities, when present, small and narrow. d i s t r i b u t i o n : Nephelomys pectoralis is endemic to Colombia, occurring in all three Andean cordilleras. It is restricted to the western slope of the Cordillera Oriental, occurs along the length of the Cordillera Central, and is present on the forested western slope and upper regions of the eastern slope of the Cordillera Occidental. s e l e c t e d l o c a l i t i e s (Map 199): COLUMBIA: Antioquia, La Bodega, N side Río Negrito (USNM 293778), Ventanas, Valdívia (FMNH 70417); Cauca, Cocal (AMNH 32539), Río Mechengue (FMNH 90217); Cundinamarca, Cuchillas del Carnicero, near Bogotá (BM 99.10.3.16); Quindío, El Roble (AMNH 32985); Valle del Cauca, Las Lomitas (AMNH 32200), Miraflores, near Palmira (AMNH 32185). s u b s p e c i e s : Nephelomys pectoralis is monotypic. n a t u r a l h i s t o ry: No details have been published. r e m a r k s : The validity of the name pectoralis has been questioned throughout its history (Osgood 1914b; Hershkovitz 1944; Musser and Carleton 1993), although Cabrera (1961) listed it as a subspecies of N. albigularis. Specimens from Valle del Cauca (Peñas Blancas, Río Pichindé) have a 2n = 66, FN = 94 karyotype (A. L. Gardner and Patton 1976, as “Oryzomys albigularis variant 2”), which differs from those of all other forms of Nephelomys. The limited geographic reprsentation by specimens and lack of karyotypic data from topotypes, however, precluded these authors from associating this karyotype with the name pectoralis.

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Nevertheless, my examination of these specimens and others from the Andes of Colombia supports the hypothesis that N. pectoralis should be distinguished from other members of the genus, and I recognize it as a valid species. Among its distinctive features are large and wide white ventral patches, numerous and deep posterolateral pits placed in deep palatal fossae, the low frequency of small sphenopalatine vacuities, and a karyotype of 2n = 66 and FN = 94 (A. L. Gardner and Patton 1976).

Genus Nesoryzomys Heller, 1904 Robert C. Dowler

Members of the genus Nesoryzomys are restricted to the Galápagos Islands, Ecuador, with Recent species known from only four of the major islands in the archipelago: Isla Baltra, Isla Fernandina, Isla Santa Cruz, and Isla Santiago. Undescribed species, known from fragmentary subfossil remains, have been reported from Isla Isabela and Isla Rábida (Steadman and Zousmer 1988). Of the five described species, two are now considered extinct. Much of the following account is based on Weksler’s (2006) morphological analysis. The five species of Nesoryzomys fall in two size classes. The smaller species (N. darwini and N. fernandinae) have total lengths of about 200 mm and masses about 32 g, whereas the larger (N. indefessus, N. narboroughi, and N. swarthi) are all greater than 250 mm in total length and have masses around 100 g. The ears are medium-sized, well haired proximally and less so distally. Mystacial vibrissae are long, with the longest projecting posterior to the ears. The tail is shorter than the head and body and well haired, with scales rarely visible. Fur is medium-length and color varies among species, usually medium brown or dark brown approaching black. The ventral pelage is paler than that of the dorsum. A white subauricular patch is usually present. Both manus and pes have ungual tufts. The plantar surfaces of the hindfeet are naked with thenar, hypothenar, and four interdigital pads present. There are eight mammae. The skull is elongate with a long rostrum and a very narrow, symmetrical interorbital region that has little, if any, supraorbital bead. The nasals are short, terminating bluntly even with the maxillary-frontal-lacrimal junction. The zygomatic plates are broad with distinct zygomatic notches. The zygomatic arches converge slightly anteriorly with the widest portion at the squamosal root. The lacrimal is primarily in contact with the maxillary and has relatively little contact with the frontal. The incisive foramina are long, with the posterior margins at same level as or posterior to the anterior margins of the M1s. The palate is flat with posterolateral palatal pits. There are large sphenopalatine vacuities that reach the basisphenoid. The

anterior alisphenoid canal is large, and an alisphenoid strut is absent. The carotid circulation is the derived pattern 3 (sensu Voss 1988), with a small stapedial foramen and both squamosoalisphenoid groove and sphenofrontal foramen absent. The ectotympanic bullae are large, covering most of the periotic bone viewed ventrally. The mandible has a sharply curved coronoid process equal in height to the condyle. The posterior border of the angular process lies directly below the tip of the condyle. The mandible has an obvious capsular process. The molars are brachydont and bunodont, with lateral elements higher than central ones. The anterocone of M1 is divided into labial and lingual conules. All upper molars have mesolophs, and a mesoloph is present on m1 and m2. The M2 lacks a protoflexus. A posteroloph is present on M3. Both M1 and m1 have four roots. The axial skeleton has 12 ribs. The first rib has a dual articulation with the seventh cervical and first thoracic vertebrae. A supratrochlear foramen is present in the humerus. The stomach is unilocular and hemiglandular (Patton and Hafner 1983), and a gall bladder is absent. Male accessory reproductive glands include a single pair of preputial glands, a pair of bulbourethral glands, and one pair of ampullary and vesicular glands. There is a single pair of dorsal prostate glands (Patton and Hafner 1983). The glans penis is elongate with a very shallow terminal crater. The osseous baculum is long and slender with a very small tridigitate cartilaginous apparatus (Patton and Hafner 1983). sy n o n y m s : Oryzomys: Thomas, 1899c:280; part (description of indefessus); not Oryzomys Baird. Nesoryzomys Heller, 1904:241; type species Oryzomys indefessus Thomas, by original designation. [Oryzomys] (Nesoryzomys): Ellerman, 1941:343; usage as subgenus. r e m a r k s : Patton and Hafner (1983) reviewed soft and craniodental characters in Nesoryzomys relative to those of other subgenera (now genera) of “Oryzomys” (sensu lato) and supported the generic status originally proposed by Heller. This opinion has been followed in recent reviews (e.g., Musser and Carleton 1993, 2005). The genus Aegialomys is considered sister to Nesoryzomys based on both molecular and morphological phylogenetic analyses (Patton and Hafner 1983; Weksler 2003, 2006; Pine et al. 2012). Patton and Hafner (1983) also suggested that all large forms of Nesoryzomys (indefessus, narboroughi, and swarthi) could be considered subspecies of one species, with N. indefessus having priority. Musser and Carleton (2005) concurred for N. narboroughi and N. indefessus, but retained N. swarthi as a distinct species based on craniodental features presented in the original description of N. swarthi (Orr 1938). Recent molecular studies (Weksler

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 391

2003) verified the divergence of N. swarthi and N. narboroughi. Additional molecular and chromosomal studies under way by the author further support the recognition of different species on separate islands and argue for a conservative retention of the original names for all Nesoryzomys. KEY TO THE SPECIES OF NESORYZOMYS:

1. Hindfeet dark; adult skull length usually less than 36 mm; premaxillae short, terminating anterior to posterior margins of nasals . . . . . . . . . . . . . . . . . . . . . . . 2 1′. Hindfeet white, adult skull length usually greater than 36 mm; premaxillae longer, terminating at the level of posterior margins of nasals . . . . . . . . . . . . . . . . . . . . . 3 2. Pelage dark brown with few yellow-tipped hairs; dorsal hairs of hindfoot brown; interparietal about half as wide as posterior margin of squamosal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nesoryzomys darwini 2′. Pelage brown suffused with yellow-tipped hairs; dorsal hairs of hindfoot silver; interparietal wider than half the width of the posterior margin of squamosal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nesoryzomys fernandinae 3. Pelage dark brown to black; subsquamosal fenestra absent. . . . . . . . . . . . . . . . . . . Nesoryzomys narboroughi 3′. Pelage cinnamon brown; subsquamosal fenestra present . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Posterior margins of the incisive foramina in adults projecting well between M1s; mastoid usually completely ossified; palate long with mesopterygoid fossa extending to posterior margin of maxillae; length of tail 122 mm . . . . . . . . . . . . . Nesoryzomys swarthi

Nesoryzomys darwini Osgood, 1929 Darwin’s Nesoryzomys sy n o n y m s : Nesoryzomys darwini Osgood, 1929: 23; type locality “Academy Bay, Indefatigable Island [= Isla Santa Cruz], Galapagos Islands,” Ecuador. Oryzomys [(Nesoryzomys)] darwini: Ellerman, 1941:359; name combination. d e s c r i p t i o n : One of two small species in genus, total length 204–222 mm; tail shorter than head and body (70–80%); dorsal color reddish brown streaked with black but providing overall bright fulvous tone; sides slightly paler than back; and under parts rufous with gray-based hairs. Skull slender and without sharp ridges or angles. Distinguished from sympatric N. indefessus by much smaller size and cinnamon-brown overall color.

Map 201 Selected localities for Nesoryzomys darwini (●) and Nesoryzomys fernandinae (ᇲ).

d i s t r i b u t i o n : Nesoryzomys darwini was known only from the island of Santa Cruz, Galápagos Islands, Ecuador; it is now considered extinct (Clark 1984; Dexter et al. 2004). s e l e c t e d l o c a l i t i e s (Map 201): ECUADOR: Galápagos, Isla Santa Cruz (= Indefatigable Island), Academy Bay (type locality of Nesoryzomys darwini Osgood), Conway Bay (Osgood 1929), Fortuna, near Bellavista (AMNH 99922). s u b s p e c i e s : Nesoryzomys darwini is monotypic. n a t u r a l h i s t o ry: This species is presumed extinct, with the last specimens known collected in April 1930 (Patton and Hafner 1983). The species likely occurred across most of the island of Santa Cruz as the few specimens are from two coastal sites and two upland sites at 800 and 1,200 feet elevation, respectively. Nothing has been reported on the natural history of this species, although Osgood (1929) commented that it was much less numerous than sympatric N. indefessus based on trapping records of the specimens in the type series.

Nesoryzomys fernandinae Hutterer and Hirsch, 1979 Small Fernandina Nesoryzomys sy n o n y m : Nesoryzomys fernandinae Hutterer and Hirsch, 1979:278; type locality “Insel [= Isla] Fernandina, 300 m, Galápagos, Ecuador.” d e s c r i p t i o n : Second small species, with alveolar length in type series 4.9–5.6 mm, overlapping only minimally with that of N. darwini at lower end of distribution and N. narboroughi at the upper end (see Hutterer and Hirsch 1979). Distinguished from its sympatric congener N. narboroughi by

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smaller size (mass averaging 32.3 g versus 77.5 g, respectively) and darker brown dorsal pelage with dark feet, rather than paler grayish black and white feet (Dowler et al. 2000). d i s t r i b u t i o n : Nesoryzomys fernandinae is known only from the island of Fernandina, Galápagos Islands, Ecuador. All specimen records are from the western half of the island. s e l e c t e d l o c a l i t i e s (Map 201): ECUADOR: Galápagos, Isla Fernandina (type locality of Nesoryzomys fernandinae Hutterer and Hirsch), Cabo Douglas (Dowler et al. 2000), caldera rim (Dowler et al. 2000). s u b s p e c i e s : Nesoryzomys fernandinae is monotypic. n a t u r a l h i s t o ry: Nesoryzomys fernandinae has been collected at coastal sites with saltbush (Cryptocarpus pyriformis [Nyctaquinaceae] up to the highest elevation on Fernandina at approximately 1,360 m. At the higher areas, habitat is dominated by large Scalesia microcephala (Asteraceae), Darwiniothamnus tenuifolius (Asteraceae), and mixed grasses. This species occurs sympatrically with N. narboroughi, but it is rare at coastal sites and much more common at high elevations where vegetation is dense (Dowler and Carroll 1996). This species has not been collected in areas dominated by mangroves, where N. narboroughi may be abundant. Specimens taken in July and August were not in reproductive condition.

Nesoryzomys indefessus (Thomas, 1899) Santa Cruz Nesoryzomys sy n o n y m s : Oryzomys indefessus Thomas, 1899c:280; type locality “Indefatigable Island [= Isla Santa Cruz],” Galápagos Islands, Ecuador. Nesoryzomys indefessus: Heller, 1904:241; name combination. Oryzomys [(Nesoryzomys)] indefessus: Ellerman, 1941:359; name combination. d e s c r i p t i o n : Large bodied, with total length 260– 297 mm; tail length 108–117 mm; Orr 1938); palest species in genus in dorsal color tones (Patton and Hafner 1983). Orr (1938) noted that the skull was virtually indistinguishable from that of N. narboroughi, although the two are slightly separable in multivariate discriminate space based on craniodental measurements (Patton and Hafner 1983). d i s t r i b u t i o n : Nesoryzomys indefessus was known only from the islands of Santa Cruz and Baltra, Galápagos Islands, Ecuador, but is now considered extinct (Clark 1984; Dexter et al. 2004). s e l e c t e d l o c a l i t i e s (Map 202): ECUADOR: Galápagos, Isla Santa Cruz (= Indefatigable Island), Academy Bay (Patton and Hafner 1983), Conway Bay (Patton and Hafner 1983), Isla Baltra (= South Seymour Island; Patton and Hafner 1983).

Map 202 Selected localities for Nesoryzomys indefessus (●), Nesoryzomys narboroughi (▲), and Nesoryzomys swarthi (ᇲ).

s u b s p e c i e s : Nesoryzomys indefessus is monotypic. n a t u r a l h i s t o ry: This species is presumed extinct, with the last specimens collected in 1941 on the island of Baltra. On Santa Cruz, A. Rambech, an early settler, reported native rats to be abundant from the coast to the wet summit in the late 1920s before the introduction of Rattus rattus. Collections by J. P. Chapin in March of 1935 at Conway Bay revealed only Rattus rattus (Clark 1984). Feral cats also may have played a role in the extinction of this species (Dexter et al. 2004). The species likely was common on both Santa Cruz and Baltra based on the number of specimens in collections. Recent surveys on both islands have failed to document an extant population (Patton and Hafner 1983; Dowler et al. 2000; Dexter et al. 2004). Heller (1904) reported that individuals inhabited burrows or rock crevices beneath bushes and was nocturnal.

Nesoryzomys narboroughi Heller, 1904 Large Fernandina Nesoryzomys sy n o n y m s : Nesoryzomys narboroughi Heller, 1904:242; type locality “Mangrove Point, Narborough Island [= Isla Fernandina],” Galápagos Islands, Ecuador. Oryzomys [(Nesoryzomys)] narboroughi: Ellerman, 1941: 359; name combination. Nesoryzomys indefessus: Patton and Hafner, 1983:562; part (narboroughi assigned as synonym); name combination. d e s c r i p t i o n : Large, with total length 264–300 mm; tail length 127–140 mm; Orr 1938); darkest color tones of

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 393

any species in genus (Patton and Hafner 1983). Readily separable from sympatric N. fernandinae by both size and overall color, as noted in that account. d i s t r i b u t i o n : Nesoryzomys narboroughi is known only from the island of Fernandina, Galápagos Islands, Ecuador. It occurs at every locality that has been sampled on the island, from the coast to the summit of the caldera. s e l e c t e d l o c a l i t i e s (Map 202): ECUADOR: Galápagos, Isla Fernandina (= Narborough Island), Cabo Douglas (Dowler et al. 2000), caldera rim (Dowler et al. 2000), Mangrove Point (type locality of Nesoryzomys narboroughi Heller), Punta Espinosa (Patton and Hafner 1983). s u b s p e c i e s : Nesoryzomys narboroughi is monotypic. n a t u r a l h i s t o ry: Nesoryzomys narboroughi is common in all vegetated habitats on the island of Fernandina, including coastal sites with saltbush (Cryptocarpus pyriformis [Nyctaginaceae]) and mangrove up to high elevations where Scalesia microcephala (Asteraceae), Darwiniothamnus tenuifolius (Asteraceae), and mixed grasses dominate. Nesoryzomys narboroughi occurs sympatrically with the smaller species N. fernandinae, but it is far more common at coastal sites and less common at high elevations. Population density in a saltbush community at Cabo Douglas was estimated at 100 per hectare, though the actual population at this site was restricted to relatively small habitat patches (Dowler and Carroll 1996). This species is nocturnal, though occasionally individuals may be active during daylight hours. These rodents show little fear of humans and may damage tents of researchers by gnawing. They probably have a catholic diet composed of both vegetation and invertebrates. Heller (1904) reported red material in the stomach that likely represented remains of crabs (Grapsus grapsus). Both the Galápagos Hawk (Buteo galapagoensis) and the Barn Owl (Tyto alba) prey on N. narboroughi. r e m a r k s : I consider Nesoryzomys narboroughi to be a species separate from N. indefessus, contra Patton and Hafner (1983). The karyotype is 2n = 32, FN = 50, with acrocentric X and Y chromosomes (A. L. Gardner and Patton 1976).

Nesoryzomys swarthi Orr, 1938 Santiago Nesoryzomys, Swarth’s Nesoryzomys sy n o n y m s : Nesoryzomys swarthi Orr, 1938:304; type locality “Sulivan [= Sullivan] Bay, James Island [= Isla Santiago]”, Galápagos Islands, Ecuador. O[ryzomys].(Nesoryzomys) swarthi: Corbet and Hill, 1980: 144; name combination. Nesoryzomys indefessus: Patton and Hafner, 1983:562; part (swarthi assigned as subspecies); name combination. d e s c r i p t i o n : Largest species (total length 310– 317 mm; tail length 124–140 mm; Orr 1938), but only slightly more so than N. narboroughi. Most similar in body

size, length of tail, and hindfoot to N. narboroughi but indistinguishable from N. indefessus in color tones. Patton and Hafner (1983), using colorimetry, verified the similarity in color tones between N. swarthi and N. indefessus and also demonstrated complete cranial separation between it and other large species. d i s t r i b u t i o n : Nesoryzomys swarthi is known only from the island of Santiago, Galápagos Islands, Ecuador. Specimens exist from only James Bay, Sullivan Bay, and La Bomba on the north coast (Dowler et al. 2000). Recent surveys revealed a population restricted to a 14-km stretch of north-central coastline centered on La Bomba (D. B. Harris et al. 2006); these surveys have failed to record the species at the other two historical localities. s e l e c t e d l o c a l i t i e s (Map 202): ECUADOR: Galápagos, Isla Santiago (= James Island), La Bomba (Dowler et al. 2000; D. B. Harris et al. 2006), Sullivan Bay (type locality of Nesoryzomys swarthi Orr), James Bay (Peterson 1966). s u b s p e c i e s : Nesoryzomys swarthi is monotypic. n a t u r a l h i s t o ry: Nesoryzomys swarthi is currently restricted to mature cactus thorn-scrub dominated by the cactus Opuntia galapageia and tree species Bursera graveolens (Burseraceae) and Croton scouleri (Euphorbiaceae). The abundance of this species at La Bomba was positively correlated with cactus density, the proportion of mature cacti, and the presence of the shrub species Lantana peduncularis (Verbenaceae) (D. B. Harris et al. 2006). D. B. Harris and Macdonald (2007) reported median home ranges (minimum convex polygon) to be 1.76 ha for males and 0.68 for females. This Nesoryzomys is the only one to be found sympatrically with the invasive rodent species Rattus rattus and Mus musculus. Nesoryzomys swarthi is usually nocturnal with peak activities between 20:00 and 03:00 hours; however, in areas where high populations of R. rattus occur, activity may extend to crepuscular periods (D. B. Harris et al. 2006). Reproduction coincides with the rainy season from December through May and two litters of two to four young may be produced annually. Annual survival rates for N. swarthi are high (23.2%) relative to most continental oryzomyine species (D. B. Harris and Macdonald 2007). r e m a r k s : As noted previously, this species was regarded as an insular race of Nesoryzomys narboroughi by Patton and Hafner (1983) but as a valid species by Musser and Carleton (1993, 2005), a decision with which I concur.

Genus Oecomys Thomas, 1906 Michael D. Carleton and Guy G. Musser

Oecomys is a moderately speciose genus of Sigmodontinae, containing at least 16 valid species according to current understanding (Musser and Carleton 2005; Carleton et al.

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2009). The generic distribution generally adheres to tropical lowland rainforest, where the greatest species diversity is concentrated in the broad reaches of the Amazon Basin, including lower Atlantic-facing slopes of the Andean cordilleras. Marginal occurrences are found to the north of Amazonia, in coastal forests of northern Venezuela and trans-Andean forest of southernmost Central America, and to the south, in the Atlantic Forest of southeastern Brazil. The genus has been recorded from the Chaco in northern Argentina, but the species allocation of these records remains uncertain (see account for O. mamorae). Species of Oecomys are small to medium-sized oryzomyines (average weights from 15–20 g in O. rutilus to 80– 90 g in O. superans), externally characterized by soft fur, short and broad hindfeet with relatively long toes, and a tail moderately longer than the head and body (tail length about 110–120% of head and body length). The short, wide hindfoot bears thick, bright-white ungual tufts on digits II– V; pedal digit V is nearly as long as digits II–IV; and the plantar surface is smooth with six large, closely positioned pads, including a well-defined hypothenar pad. The tail in most species is basically unicolored, medium to dark brown above and below, or slightly paler underneath in some but never distinctly bicolored; caudal hairs are short, scarcely visible to the unaided eye and not obscuring the fine scale pattern; a rudimentary pencil or tuft of hairs is expressed at the tail tip in several species. The fur is soft, never spinose, and short to moderately long in length. Dorsal coloration varies from grayish brown to tawny to reddish brown, dull to bright in tone; ventral pelage color ranges from pure white to dark gray. Females possess eight mammae, including the pectoral pair, anatomically positioned as in most oryzomyines (Voss and Carleton 1993; Weksler 2006). The skull is moderately robust and features a short and broad rostrum, a broad interorbital region, and slender zygomatic plate with a shallow or indistinct dorsal notch. The supraorbital edges are ridged or beaded, convergent anteriorly and notably divergent posteriorly (interorbital constriction cuneate), and extend across the parietals as temporal ridges in older individuals. A posteroventral flange of the parietal extends onto the lateral wall of the braincase; the interparietal is large, nearly as wide as the posterior border of the frontals. The incisive foramina are moderately long and generally wide, and in most species posteriorly terminate in front of the first molars or even with them. The bony palate is flat, long, and wide in conformation (sensu Hershkovitz 1962), and projects slightly or distinctly beyond the end of the third molars; posterolateral palatal pits are uniformly present but vary in development; parapterygoid fossae are moderately excavated above the plane of the bony palate; the roof of the mesopterygoid fossa is solid (sphenopalatine vacuities absent) or weakly perforated (va-

cuities present as narrow slits). The ectotympanic bullae are small and expose a broad wedge of the periotic in all species except O. mamorae, in which the broader ectotympanic capsule conceals more of the periotic; the tegmen tympani is reduced (see Voss 1993:18), occasionally touching but not overlapping the squamosal in all species except O. rex. Members of Oecomys possess different carotid circulatory patterns: complete in most species (stapedial foramen present, and large, posterior opening of alisphenoid canal large, and squamosal-alisphenoid groove leading to sphenofrontal foramen present; character state 0 of Carleton [1980] or pattern 1 per Voss [1988]); or derived in a few (stapedial foramen absent, or minute, squamosal-alisphenoid groove and sphenofrontal foramen absent; character state 3 of Carleton [1980] or pattern 3 per Voss [1988]; also see those different patterns as illustrated for oryzomyines by Carleton and Musser 1989). The occurrence of alisphenoid struts is variable in the genus, but they tend to be consistently present or absent (buccinator-masticatory and accessory oval foramina confluent) in a particular species. The hamular process of the squamosal is generally short and wide, the subsquamosal fenestra small or absent; a postglenoid foramen is uniformly present and moderately developed in most species. No significant sexual dimorphism is evident in craniodental measurements of those species that have been analyzed (O. bicolor, O. catherinae, O. roberti, O. sydandersoni—Patton et al. 2000; Carleton et al. 2009; Asfora et al. 2011). Explanation and/or illustration of the above characters and additional morphological description of Oecomys are provided by Hershkovitz (1960), Carleton and Musser (1989), Patton et al. (2000), Voss et al. (2001), Weksler (2006), and Carleton et al. (2009). Most members of Oecomys possess opisthodont upper incisors, nearly orthodont in some species, and their maxillary toothrows are parallel. Molars are brachydont and cuspidate, the major lingual and labial cusps positioned oppositely; three roots anchor the upper molars and two roots the lowers. Labial and lingual flexi are broadly open and meet approximately at the tooth’s midline, not interpenetrating. The M1 bears a broad anterocone with anterolingual and anterolabial conules joined medially, not cleft by an anteromedian fold; the conules are distinct in juveniles and young adults but lose definition with wear. A discrete anteroloph is present on M1 and a well-formed mesoloph on M1–2; the M3 retains an irregularly formed mesoloph and weak posteroloph. A mesolophid is consistently present on m1–2, but an ectolophid is variably developed, absent in most species. Hershkovitz (1960) and Weksler (2006) provide additional dental descriptions and character state definitions of Oecomys. Few species of Oecomys have been surveyed for soft anatomical traits of the alimentary canal and reproductive

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 395

tract. Those that have been studied exhibit a complex glans penis, with a large medial bacular mound and smaller lateral bacular mounds; have a complete assortment of male accessory reproductive glands, including one pair of preputial glands; possess a unilocular-hemiglandular gastric morphology; and lack the gall bladder (Hooper and Musser 1964; Carleton 1973; Voss and Linzey 1981; Voss and Carleton 1993; Weksler 2006). No long-term, autecological study is available for any species of Oecomys. Furthermore, correspondence of past natural history and ecological reports on O. “bicolor” or O. “concolor,” sensu Hershkovitz (1960), to a currently recognized species must be cautiously interpreted. In general, species are nocturnal, and individuals are typically associated with tropical lowland rainforest and numerous microhabitats in that broad classification, whether primary or secondary. Hershkovitz (1960) viewed Oecomys as the oryzomyine most specialized for arboreal life, a characterization sustained by collecting surveys, canopy-trapping, and nocturnal head-lamp observations, all of which attest to the superior scansorial abilities of its members (Handley 1976; Malcolm 1991; Patton et al. 2000; Voss et al. 2001). Linares (1998) characterized all species of Venezuelan Oecomys as frugivorous and granivorous; Voss et al. (2001) provisionally assigned Oecomys to the arboreal granivore/frugivore guild, but admitted that no detailed dietary investigations have been published to support their conjecture. Species of Oecomys and the thomasomyine Rhipidomys superficially resemble one another and may be difficult to distinguish in the field where similar-sized members of the two genera co-occur. Several external differences serve to separate adults of the two genera in most instances, notably coloration of the dorsal surface of the hindfeet (darker over the metatarsum in Rhipidomys), length of the tail pencil (caudal pilosity and terminal pencil more strongly expressed in Rhipidomys), and number of mammae (three pairs in Rhipidomys, which lacks the pectoral pair found in Oecomys) (Thomas 1917d; Voss 1993; Patton et al. 2000; Voss et al. 2001). sy n o n y m s : Mus: Pictet and Pictet, 1844:64; part (description of cinnamomeus); not Mus Linnaeus. Hesperomys: Wagner 1845a:147; part (description of concolor); not Hesperomys Waterhouse. Oryzomys: J. A. Allen and Chapman, 1893:212; part (descriptions of speciosus and trinitatis); not Oryzomys Baird. Rhipidomys: E.-L. Trouessart, 1897:520; part (listing of bicolor); not Rhipidomys Tschudi. Oryzomys (Oecomys) Thomas, 1906c:444; type species Rhipidomys benevolens Thomas, 1901 [= Hesperomys bicolor Tomes, 1860], by original designation. Oecomys: Thomas, 1909:379; first usage as genus.

r e m a r k s : Thomas (1906c) erected Oecomys, as a subgenus, to segregate arboreal, pencil-tailed oryzomyines with a long palate from species of Rhipidomys, the externally similar genus under which many Oecomys taxa were first described. Oecomys was afterward treated as a valid genus by some systematists (Thomas 1909, 1917d; Gyldenstolpe 1932), but most regarded it as a subgenus of Oryzomys (Goldman 1918; Ellerman 1941; Hershkovitz 1960; Cabrera 1961; Hall 1981; Honacki et al. 1982; Corbet and Hill 1986). The karyotypic study of A. L. Gardner and Patton (1976) was pivotal in establishing the modern usage of Oecomys as a monophyletic genus (Carleton and Musser 1984; Reig 1984; Voss and Carleton 1993; Musser and Carleton 1993, 2005), a rank vindicated by broad phylogenetic evaluations of Sigmodontinae or Oryzomyini (M. F. Smith and Patton 1999; A. F. B. Andrade and Bonvicino 2003; D’Elía 2003a; Weksler 2003, 2006; Percequillo, Weksler, and Costa 2011; Pine et al. 2012). Within Oryzomyini, Oecomys belongs to a large clade that includes other genera that co-occur with it in lowland rainforest (Euryoryzomys, Hylaeamys, Transandinomys) and some that inhabit Andean montane forest (Handleyomys, Nephelomys). Hershkovitz’s (1960) revision consolidated the taxonomic contents of Oecomys but swept some 25 species and immense morphological variety into just two polytypic species, O. bicolor and O. concolor. His gross underestimation of specific diversity has been exposed by regional field studies in which three to five species of Oecomys have been documented in sympatry (Carleton et al. 1986, 2009; Woodman et al. 1991; Patton et al. 2000; Voss et al. 2001). Morphological definitions and distributional limits of the species recognized herein conform to the taxonomy presented in Musser and Carleton (1993, 2005), as based on the authors’ personal examination of some 1,600 museum specimens and of all type specimens except that of O. cleberi Locks (1981). Identification of valid species and refinement of their distributions still require much systematic research and basic biological inventory. The treatment of all species as monotypic is a pro forma concession to this imperfect understanding of Oecomys systematics. Species of Oecomys may be distinguished based on unique combinations of morphological traits, the most important of which include size; pelage color, especially distinctiveness of the dorsal-ventral contrast; fur texture and length; relative length of tail and development of a modest caudal pencil or tuft; pronouncement of supraorbital and temporal ridging; relative width of the zygomatic plate and expression of the dorsal notch; length and shape of the incisive foramina; presence and size of the subsquamosal and postglenoid foramina; condition of

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the tegmen tympani; presence or absence of alisphenoid struts; and the carotid arterial pattern. Chromosomal differences promise to be a useful tool for discriminating species, but many more forms need to be surveyed (A. L. Gardner and Patton 1976; Patton et al. 2000; AndradesMiranda, Oliveira, Zanchin et al. 2001; A. F. B. Andrade and Bonvicino 2003; Langguth et al. 2005; C. C. Rosa et al. 2012). Descriptions in the species accounts do not repeat traits that are generally characteristic of the genus, as reviewed earlier. “Smaller than” and “larger than” comparative statements in the following descriptions reflect the ordering of select external and cranial dimensions (Table 1). KEY TO THE SPECIES OF OECOMYS (VARIABLE ABBREVIATIONS: CLM, CORONAL LENGTH OF MAXILLARY TOOTHROW, M1– M3; HBL, LENGTH OF HEAD AND BODY; HFL, LENGTH OF HIND FOOT INCLUDING CLAW; IOB, LEAST INTERORBITAL BREADTH; ONL, OCCIPITONASAL LENGTH; TL, LENGTH OF TAIL; ALSO SEE TABLE 1):

1. Carotid circulatory pattern derived (sphenofrontal foramen and squamosoalisphenoid groove absent, stapedial foramen minute or absent) . . . . . . . . . . . . . . . . . . . . . 2 1′. Carotid circulatory pattern complete (sphenofrontal foramen and squamosoalisphenoid groove present, stapedial foramen small but present) . . . . . . . . . . . . . . . . . 4 2. Dorsal pelage predominantly gray to grayish buff, with a buffy to ochraceous lateral stripe; pelage moderately long for the genus (≈7–9 mm over middle rump); alisphenoid struts typically absent; interorbit narrower (IOB ≤5.1 mm), supraorbital shelves weakly defined for the genus; palatal bridge short, terminating about the level of the posterior M3s, posterolateral palatal pits simple . . . . . . . . . . . . . . . . . . . . . . . Oecomys mamorae 2′. Dorsal pelage ochraceous brown to rufous brown, without distinct lateral stripe; pelage shorter (≤5–7 mm over middle rump); alisphenoid struts typically present; interorbit broader (IOB ≥5.1 mm), supraorbital shelves moderately developed as per genus; palatal bridge long, projecting notably beyond M3s, posterolateral palatal pits pronounced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Size larger (HFL ≈ 26–30 mm, ONL ≈ 31–34 mm, CLM ≈ 4.8–5.2 mm); tail notably longer than head and body; dorsal pelage more uniformly rufous brown and darker in tone, shorter in length (4–5 mm over middle rump); ventral pelage usually dull white, dorsal-ventral contrast more apparent; incisive foramina evenly curving, widest near their middle with the anterior and posterior ends acutely pointed . . . . . . . . . . . . Oecomys concolor 3′. Size smaller (HFL ≈ 22–26 mm, ONL ≈ 28–31 mm, CLM ≈ 4.4–4.8 mm); tail slightly longer than head and

body; dorsal pelage ochraceous brown to pale tawny generally bright in tone and showing more grayish over forequarters, slightly longer (5–7 mm over middle rump); ventral pelage grayish; incisive foramina noticeably widest toward the rear, the posterior ends blunt and anterior ends sharp. . . . . . Oecomys sydandersoni 4. Size large (HFL ≈ 27–29 mm, ONL ≈ 33–35 mm, CLM ≈ 5.1–5.5 mm); pelage thick, long, and richly luxuriant; interorbital region wide (IOB ≥ 6 mm), with conspicuous supraorbital shelves and distinct postorbital processes; tegmen tympani well developed, securely overlapping squamosal . . . . . . . . . . . . . . . . . .Oecomys rex 4′. Size small to large; pelage short to long, coarse to soft in texture; interorbital region narrower (IOB usually ≤ 6 mm), supraorbital shelves moderate to strongly developed, without postorbital processes; tegmen tympani reduced, sometimes contacting but not overlapping squamosal, postglenoid foramen medium to large . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5. Size small (HFL ≈ 18–23 mm, ONL ≈ 23–28 mm , CLM ≈ 3.2–4.0); underparts typically all white, bright in tone, dorsal-ventral pelage contrast well defined; tail relatively short (TL ≈ 105–110% of HBL), caudal hairs long, obscuring distal scale rows and forming a penicillate or tufted tip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5′. Size medium to large (HFL usually ≥ 23 mm, ONL usually ≥ 27 mm, CLM ≥ 4.0); under parts variable, dull white to some shade of grayish white, dorsal-ventral contrast variably delineated . . . . . . . . . . . . . . . . . . . . 7 6. Cranium and toothrow diminutive (ONL ≤ 25.0 mm, CLM ≈ 3.2–3.4 mm); dorsal pelage moderately long for body size (6–8 mm over the middle rump); terminal tail tuft longer, better developed; alisphenoid struts usually present . . . . . . . . . . . . . . . . . . . . . . . . Oecomys rutilus 6′. Cranium and toothrow more robust (ONL ≥ 25.0 mm, CLM ≈ 3.6–4.0 mm); dorsal pelage short for body size (3–6 mm over the middle rump); terminal tail tuft shorter, less conspicuous; alisphenoid struts usually absent. . . . . . . . . . . . . Oecomys bicolor/Oecomys cleberi 7. Size medium (HFL ≈ 22–26 mm, ONL ≈ 27–31 mm, CLM ≈ 4.0–4.6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 7′. Size medium large to large (HFL ≈ 26–31 mm, ONL ≈ 30–37 mm, CLM ≈ 4.6–5.6) . . . . . . . . . . . . . . . . . . . 11 8. Dorsal pelage soft, dense, and long (9–12 mm over middle rump), caudal hairs long, obscuring scale pattern and forming a conspicuous terminal tuft . . . . . . . . . . 9 8′. Dorsal pelage shorter (5–8 mm over the middle rump), texture coarser; under parts typically pure white, sharply contrasting with bright orange-brown dorsum and ochraceous flanks; tail absolutely and relatively long (TL ≈ 118% of HBL), with short caudal hairs and indistinct terminal pencil . . . . . . . . Oecomys speciosus

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 397

9. Tail relatively short (TL ≈ 107% of HBL); alisphenoid struts typically present; subsquamosal fenestra occluded. . . . . . . . . . . . . . . . . . . . . .Oecomys auyantepui 9′. Alisphenoid struts typically absent; subsquamosal fenestra open . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 10. Under parts typically grayish white; tail absolutely and relatively long (TL ≈ 117% of HBL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oecomys paricola 10′. Under parts typically dull white; tail relatively short (TL ≈ 105% of HBL) . . . . . . . . . . . .Oecomys phaeotis 11. Dorsal pelage shorter (5–10 mm over middle rump) and moderately soft . . . . . . . . . . . . . . . . . . . . . . . . . 12 11′. Dorsal pelage longer (10–14 mm over middle rump), very dense and palpably soft to touch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oecomys trinitatis complex 12. Size large (HFL ≥ 28 mm, ONL ≥ 34 mm, CLM ≥ 5.2 mm), dorsal pelage medium in length (8–10 mm over middle rump), pelage somber in tone with dark grayish venter, tail moderately longer than head and body (TL ≈ 118% of HBL) . . . . . . . Oecomys superans 12′ Size medium large (HFL ≤ 28 mm, ONL ≤ 34 mm, CLM ≤ 5.1 mm), dorsal pelage short (5–7 mm over middle rump), pelage brighter in tone with white to grayish white venter, tail notably longer than head and body (TL ≈ 123% of HBL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oecomys roberti 13. Size medium large (HFL ≈ 25–27 mm, ONL ≈ 30– 32 mm, CLM ≈ 4.6–4.8 mm), confined to lower elevations in mountains of northeastern Colombia and northern Venezuela . . . . . . . . . . . . . . . . . Oecomys flavicans 13′. Size medium large (HFL ≈ 26–29 mm, ONL ≈ 31– 33 mm, CLM ≈ 4.8–5.2 mm), distribution in greater Amazonia and trans-Andean forests of lower Central America and northwestern South America . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Oecomys trinitatis 13′′. Size large (HFL ≈ 28–30 mm, ONL ≈ 32–34 mm, CLM ≈ 5.0–5.2 mm), confined to Atlantic Forest region of southeastern Brazil . . . . . . . . . . Oecomys catherinae

Oecomys auyantepui Tate, 1939 Guianan Oecomys sy n o n y m s : Oecomys auyantepui Tate, 1939:193; type locality “south slopes of Mt. Auyan-tepui, Caroni River, [Bolívar,] Venezuela, 3500 feet.” Oryzomys auyantepui: Goodwin, 1953:302; name combination. Oryzomys concolor speciosus: Hershkovitz, 1960:553; part (auyantepui allocated as full synonym, invalid as subspecies). Oryzomys trinitatis auyantepui: Cabrera, 1961:407; name combination.

Oecomys paricola: Musser and Carleton, 1993:716; part (auyantepui allocated as synonym without indication of rank). d e s c r i p t i o n : Similar in body size to O. paricola and O. phaeotis (Table 1), larger than O. rutilus and O. bicolor, the two smallest-bodied species in genus, and appreciably smaller than all other congeners. Luxuriant pelage soft, dense, and long (10–12 mm over middle rump), with demarcation between dorsal and ventral pelage sharp. Dorsal fur rich ochraceous tawny (nearly orange brown) in most specimens, but darker—brownish tawny—in others; tops of hind feet dark brown to tip of digits. Ventral pelage typically grayish white (hairs with gray bases and white tips), or uncommonly with rich ochraceous overwash of gray bases; in some specimens, chin and throat pure white, in others white strip extends along midline from throat to groin. Tail only slightly longer than combined head and body (TL ≈ 106% of HBL) and dark brown on all surfaces; caudal hairs long, typically obscuring distal scale rows and forming conspicuous tuft at tip (6–10 mm long per Voss et al. 2001). Skull small and compact, with relatively short rostrum and narrow interorbit. Conspicuous supraorbital ridges outline interorbital and postorbital regions and sweep caudad to join distinct temporal beading. Zygomatic arches narrower rostrally and wider toward braincase; zygomatic plates relatively narrow and dorsal notches shallow. Incisive foramina moderately long and broad, their posterior margins situated about even with anterior rim of first molars. Pair of prominent posterolateral palatal pits and smaller foramina adorn bony palate behind molars. Mesopterygoid fossa wide and U-shaped at anterior margin, its roof entirely osseous. Strong alisphenoid struts present (Voss et al. 2001), and carotid circulatory plan primitive (pattern 1 of Voss 1988). Posterolateral wall of braincase bears postglenoid foramen but no subsquamosal fenestra. Ectotympanic bullae small, in ventral view exposing much of medial periotic. d i s t r i b u t i o n : Southeastern Venezuela (Bolívar), the Guianas, and north-central Brazil (Amazonas, Amapá)— the Guiana subregion of Amazonia; known elevational range from sea level to about 1,100 m. s e l e c t e d l o c a l i t i e s (Map 203; from Voss et al. 2001, except as noted): BRAZIL: Amapá, Serra do Navio; Amazonas, 80 km N of Manaus. FRENCH GUIANA: Paracou; Trois Sauts. GUYANA: Cuyuni-Mazaruni, Kartabo, Cuyuni River; Upper Takutu–Upper Essequibo, 5 km SE of Surama. SURINAM: Sipaliwini, Avanavero Falls, Kabalebo River (RMNH 21733); Brokopondo, Brownsberg Nature Park, 7 km S and 18.5 km W of Afobakka (CM 54055). VENEZUELA: Bolívar, Auyan-tepuí, south slope, Río Caroni (type locality of Oecomys auyantepui Tate).

398 Mammals of South America

Map 203 Selected localities for Oecomys auyantepui (●). Contour line = 2,000 m.

s u b s p e c i e s : In resurrecting O. auyantepui to species, Voss et al. (2001) provided no evidence for definable subspecies; we provisionally regard the species as monotypic. n a t u r a l h i s t o ry: At the type locality in Venezuela (Auyantepui, 3500 ft), Tate (1939) merely noted the habitat as humid forest. In French Guiana, specimens were obtained in primary lowland forest, both in well-drained sites and in creekside or swampy settings, mostly in arboreal trap-sets (lianas, canopy platforms) but rarely on the ground (Voss et al. 2001). r e m a r k s : Populations of auyantepui are clearly distinct from those of O. concolor or O. trinitatis, the species under which it was earlier synonymized (Cabrera 1961; Hershkovitz 1960), and the taxon was returned to specific status by Voss et al. (2001). However, its level of relationship and nomenclatural status with regard to O. paricola (a synonym per Musser and Carleton 1993) and to O. phaeotis require further investigation. The geographic range of O. auyantepui, as so far known, is limited to the Guiana subregion of Amazonia, its distribution congruent with the ranges of O. rex and O. rutilus.

Oecomys bicolor (Tomes, 1860) White-bellied Oecomys sy n o n y m s : Hesperomys bicolor Tomes, 1860a:217; type locality “Gualaquiza,” Rio Gualaquiza, 885 m, Morona-Santiago, Ecuador.

Hesperomys (Rhipidomys) bicolor: Thomas, 1884:448; name combination (tentative subgeneric referral of species). Rhipidomys bicolor: E.-L. Trouessart, 1897:520; name combination. Rhipidomys dryas Thomas, 1900c:271; type locality “Paramba, [Imbabura,] N. Ecuador. Alt. 1100 m.” Rhipidomys benevolens Thomas, 1901d:369; type locality “Chimate, Upper Beni River, [La Paz,] Bolivia, 68° W., 15° S.; alt. 700 m.” Rhipidomys rosilla Thomas, 1904d:35; type locality “La Union, Lower Orinoco,” Bolívar, Venezuela. [Oryzomys (Oecomys)] bicolor: Thomas, 1906c:445; name combination. Oryzomys (Oecomys) benevolens: Thomas, 1906c:445; name combination. Oryzomys (Oecomys) dryas: Thomas, 1906c:445; name combination. [Oryzomys (Oecomys)] rosilla: Thomas, 1906c:445; name combination. Oecomys nitedulus Thomas, 1910d:505; type locality “Lower Essequibo, 13 miles from mouth,” Essequibo Islands-West Demerara, Guyana. Oecomys bicolor: Osgood, 1914b:161; first use of current name combination. Oecomys milleri J. A. Allen, 1916c:523; type locality “Barão Malgaço [Barão de Malgaço], Matto Grosso [now Rondônia], Brazil.” Oecomys florenciae J. A. Allen, 1916c:524; type locality “Florencia (altitude 675 feet), Rio Caquetá drainage, [Caquetá,] southwestern Colombia.” Oecomys trabeatus G. M. Allen and Barbour, 1923:262; type locality “Rio Jesusito, [Darién,] eastern Panama.” Oecomys bicolor: Gyldenstolpe, 1932a:39; name combination (dryas allocated as full synonym without indication of rank). Oecomys rosilla: Gyldenstolpe, 1932a:39; name combination. Oecomys benevolens: Gyldenstolpe, 1932a:40; name combination. Oecomys endersi Goldman, 1933:525; type locality “Barro Colorado Island, Canal Zone [now Panamá province], Panama.” Oecomys phelpsi Tate, 1939:194; type locality “south slope Mt. Auyan-tepui, 3500 feet,” Bolívar, Venezuela. Oryzomys [(Oecomys)] benevolens: Ellerman, 1941:357; name combination. Oryzomys [(Oecomys)] florenciae: Ellerman, 1941:358; name combination. Oryzomys [(Oecomys)] milleri: Ellerman, 1941:358; name combination. Oryzomys [(Oecomys)] nitedulus: Ellerman, 1941:358; name combination.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 399

Oryzomys [(Oecomys)] rosilla: Ellerman, 1941:359; name combination. Akodon (Chalcomys) aerosus: Tate, 1945:316; part (restriction of type specimen, phelpsi allocated as synonym). Oryzomys (Oecomys) bicolor trabeatus: Hershkovitz, 1960: 533; name combination (endersi allocated as full synonym, invalid as subspecies). Oryzomys (Oecomys) bicolor occidentalis Hershkovitz, 1960: 533; replacement name for Rhipidomys dryas Thomas, 1900, preoccupied by Oryzomys dryas Thomas (now = Microryzomys minutus). Oryzomys bicolor bicolor: Hershkovitz, 1960:535 name combination (florenciae, milleri, nitedulus, and rosilla allocated as full synonyms, invalid as subspecies). Oryzomys bicolor phaeotis: Hershkovitz, 1960:540; part (benevolens allocated as full synonym, invalid as subspecies). Oryzomys bicolor bicolor: Cabrera, 1961:403; name combination (dryas allocated as full synonym, invalid as subspecies). Oryzomys bicolor benevolens: Cabrera, 1961:403; name combination. Oryzomys bicolor florenciae: Cabrera, 1961:403; name combination. Oryzomys bicolor milleri: Cabrera, 1961:403; name combination. Oryzomys bicolor nitedulus: Cabrera, 1961:404; name combination. Oryzomys bicolor rosilla: Cabrera, 1961:404; name combination. Oryzomys marmosurus guianae: Cabrera, 1961:405; part (phelpsi questionably listed as synonym). Oecomys bicolor: Musser and Patton, 1989:6; name combination (restriction of type specimen, provisional allocation of phelpsi as synonym without indication of rank). Oecomys bicolor: Musser and Carleton, 1993:716; name combination (benevolens, dryas [of Thomas, 1900], endersi, florenciae, milleri, nitedulus, occidentalis, rosilla, and trabeatus listed as synonyms without indication of rank). d e s c r i p t i o n : Recognizable chiefly by small size (averaging only larger than O. rutilus), combined with white under parts and relatively short tail (TL ≈ 105–110% of HBL) that bears moderate terminal tuft. Pelage dense and felt-like, somewhat crisp to touch, and short compared with body size (3–6 mm over middle rump); demarcation between dorsal and ventral pelage sharp. Dorsal fur ranges from rich ochraceous tawny (nearly orange brown) to rufous brown, finely mixed with dark brown over middle dorsum and becoming slightly paler along lower sides of head and body, a bright buffy gray. Darker dorsum sharply set off from bright ventral pelage, which is uniformly white

(hairs self-colored) in the majority of specimens examined; variations include ventral hairs with white bases and buff to ochraceous tips, imparting pale wash to white ground color, or white over belly and chest with varying suffusion of gray-based hairs toward sides. Short tail all brown, and caudal hairs notably long for small size of species, typically obscuring scale rows and forming short but discrete tuft at tip (hairs extend 5–7 mm beyond tip). Skull stoutly built for its compact size, with short rostrum, narrow interorbit with finely beaded supraorbital ledges, and relatively inflated braincase. Temporal ridges weakly defined and become obsolete over posterior braincase. The zygomatic arches slightly narrower rostrally and slightly wider toward braincase; zygomatic plates narrow and dorsal notches shallow. Incisive foramina relatively long and narrow, their posterior margins situated about even with anterior margin of first molars. Pair of prominent posterolateral palatal pits adorns bony palate; mesopterygoid fossa wide and U-shaped at anterior margin; roof entirely osseous. Postglenoid foramen and subsquamosal fenestra present and spacious. Alisphenoid struts commonly absent, but occurrence highly variable within species as currently defined; carotid circulatory plan complete (pattern 1 of Voss 1988). Ectotympanic bullae small, exposing much of medial periotic. d i s t r i b u t i o n : Lowlands of trans-Andean rainforests (eastern Panama to western Ecuador) and greater Amazonia (eastern Colombia and central Venezuela, through the Guianas, eastern Peru and Ecuador, to eastern Bolivia and south-central Brazil); known elevational range from sea level to 1,537 m, most locality records falling between sea level and 800 m. s e l e c t e d l o c a l i t i e s (Map 204): BOLIVIA: Beni, Las Peñas (Anderson 1997); La Paz, Chimate (type locality of Rhipidomys benevolens Thomas); Santa Cruz, Ayacucho (Anderson 1997), 2.5 km NE of El Refugio, Parque Nacional Noel Kempff Mercado (Carleton et al. 2009). BRAZIL: Acre, Nova Vida, right bank Rio Juruá (Patton et al. 2000); Amapá, Serra do Navio (Voss et al. 2001); Amazonas, Colocação Vira-Volta, left bank Rio Juruá (Patton et al. 2000); Distrito Federal, 20 km S of Brasília (OMNH 17482, 17483); Mato Grosso, 264 km N of Xavantina, Serra do Roncador Base Camp (BM 81.385–81.388); Mato Grosso do Sul, Urucum de Corumbá (FMNH 26806); Pará, Capim (AMNH 188963), Gonotire, Rio Fresco at confluence with Rio Xingu (MZUSP 1298, 1301); Rondônia, Barão de Malgaço (type locality of Oecomys milleri J. A. Allen). COLOMBIA: Amazonas, Río Apaporis, Ina Gaje, Río Pacoa (FMNH 57237, 57239); Boyacá, Arauca, Río Covaria (FMNH 92524); Caquetá, Florencia, Río Bodoquera (type locality of Oecomys florenciae J. A. Allen). ECUADOR: Imbabura, Paramba, Río Mira (type locality of Oryzomys (Oecomys) bicolor occidentalis Hershkovitz, replacement

400 Mammals of South America

name for Rhipidomys dryas Thomas); Morona-Santiago, Gualaquiza (type locality of Hesperomys bicolor Tomes); Sucumbios, Santa Cecilia (KU 135116, 135153). FRENCH GUIANA: Nouragues (Voss et al. 2001). GUYANA: Essequibo Islands-West Demerara, 13 mi from mouth of Lower Essequibo (type locality of Oecomys nitedulus Thomas); Upper Takutu–Upper Essequibo, 5 km SE of Surama (Voss et al. 2001). PERU: Junín, Chanchamayo (BM 5.11.2.16, FMNH 29453); Loreto, San Jacinto (KU 158191), Boca Río Peruate, Río Amazonas (FMNH 88940–88943); Madre de Dios, Reserva Cuzco Amazonico, 14 km E of Puerto Maldonado (KU 144302–144304); San Martín, Yurac Yacu (BM 27.1.1.122–27.1.1.124). SURINAM: Sipaliwini, Oelemarie (CM 76862–76866); Paramaribo, Paramaribo (USNM 319963–319967). VENEZUELA: Amazonas, Tamatama, Río Orinoco (Handley 1976); Aragua, Estación Biológica Rancho Grande (AMNH 144851, KU 135127); Bolívar, La Unión (type locality of Rhipidomys rosilla Thomas), south slope Auyán-tepuí (type locality of Oecomys phelpsi Tate). s u b s p e c i e s : As here defined, O. bicolor encompasses many junior synonyms and appreciable size and color variation. Whether such variation represents definable geographic races or the presence of additional valid species requires further investigation. In lieu of such studies, we provisionally treat O. bicolor as monotypic. Linares (1998) retained four subspecies for Venezuelan populations (O. b. bicolor, O. b. nitedulus, O. b. phelpsi, O. b. rosilla). n a t u r a l h i s t o ry: Oecomys bicolor inhabits tropical evergreen forest, both primary and secondary and in seasonally inundated vegetation (várzea) and unflooded, upland forest (terra firme) (Handley 1966; Carleton et al. 1986; Patton et al. 2000). Along the Rio Juruá, western Brazil, Patton et al. (2000) collected most specimens of O. bicolor in undisturbed várzea forest but some in terra firme; a majority were captured in canopy traps (74%), some in traps placed in viny tangles about 2 m above ground and very few in ground sets. Pregnant females (litter size mode = 2, range: 1–4) have been recorded throughout the dry season and beginning of the rainy season (August–February; Patton et al. 2000). Perhaps more than any other Oecomys, individuals of O. bicolor have been documented from commensal settings, such as orchards, overgrown fields, and rustic dwellings (Hershkovitz 1960; Hutterer et al. 1995; Emmons et al. 2006). r e m a r k s : Of the species-group taxa that Hershkovitz (1960) associated under his polytypic view of O. bicolor, three have been resurrected to species (O. paricola, O. phaeotis, O. rutilus—see Musser and Carleton 1993, 2005; Voss et al. 2001). The contents presented here also may be a complex of species. The status of taxa described from the Trans-Andean region (trabeatus, endersi, and

Map 204

Selected localities for Oecomys bicolor (●). Contour line = 2,000 m.

occidentalis) in particular warrant attention. As recorded by Hershkovitz (1960) and affirmed by our own museum research, a wide geographic hiatus separates these trans-Andean forms, described from Panama and northwestern Ecuador, from the core distribution of O. bicolor in Amazonia (Map 204), in spite of ample inventory in northern Colombia and northwestern Venezuela where other Oecomys have been recovered (e.g., O. flavicans, O. speciosus). In addition, Patton et al. (2000) identified a small, white-bellied form in sympatry with O. bicolor in western Brazil; the status of this indeterminate form invites resolution. The karyotype has a diploid number of 80, with a high proportion of biarmed chromosomes (FN = 140; A. L. Gardner and Patton 1976; Patton et al. 2000).

Oecomys catherinae Thomas, 1909 Atlantic Forest Oecomys sy n o n y m s : Mus cinnamomeus Pictet and Pictet, 1844:64; type locality, Brazil, Bahia (name preoccupied by Mus cinnamomeus Lichtenstein, 1830, a Trinomys [Echimyidae]). Oecomys catherinae Thomas, 1909:234; type locality “Joinville, Santa Catherina [Santa Catarina], S. Brazil.” Oryzomys [(Oecomys)] catherinae: Ellerman, 1941:357; name combination. Oecomys cinnamomeus: Moojen, 1952b:53; name combination. Oryzomys subflavus: Hershkovitz, 1960:543; part (catherinae allocated as full synonym); not subflavus Wagner. Oryzomys concolor bahiensis Hershkovitz, 1960:561; type locality “Fazenda Almada, Ilhéus, Bahía, Brazil.” Oryzomys catherinae catherinae: Cabrera, 1961:404; name combination.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 401

Oecomys trinitatis: Musser and Carleton, 1993:717; part (bahiensis, catherinae, and cinnamomeus listed as synonyms without indication of rank); not trinitatis J. A. Allen and Chapman. Oecomys catherinae: Musser and Carleton, 2005:1137 (bahiensis and cinnamomeus listed as synonyms without indication of rank). d e s c r i p t i o n : Specimens suggest slightly larger version of O. trinitatis. Dorsal pelage lush and thick (12– 14 mm), sleek in texture, brownish-orange to tawny chestnut in color, and bright in tone. General impression of under parts dark grayish-white, ventral hairs with dark to slate gray bases, usually tipped with white; variations include streaks or patches of buffy-tipped hairs on chest and/or abdomen and creamy hairs confined to throat. Demarcation between dorsum and ventrum weakly defined. Tail dusky brown all around for most of length, paler beneath toward base; caudal hairs short, revealing the fine scale rows and not forming discrete tuft. Robust skull features relatively long and narrow rostrum, pronounced supraorbital shelves with free edge reflected dorsally, and conspicuous temporal ridges that extend across braincase to occiput. Postglenoid foramen small, and subsquamosal fenestra tiny or absent. Incisive foramina relatively narrow and long, reaching level of anterior roots of upper first molars. Roof of mesopterygoid fossa usually fully ossified, sphenopalatine vacuities absent or minute. Alisphenoid struts commonly absent; carotid circulatory plan complete (pattern 1 of Voss 1988). Ectotympanic bullae small, exposing much of medial periotic. d i s t r i b u t i o n : Atlantic coast forests in southeastern Brazil (Paraíba southward to northern Santa Catarina) and along riverine forest into south-central Brazil (Goiás, Federal District, Mato Grosso do Sul) (see Fig. 3 in Asfora et al. 2011); known elevational range sea level to 700 m. s e l e c t e d l o c a l i t i e s (Map 205; from Asfora et al. 2011, except as noted): BRAZIL: Paraíba, Mamanguape; Alagoas, Ibateguara; Bahía, Fazenda Almada, Ilhéus (type locality of Oryzomys concolor bahiensis Hershkovitz); Goiás, Barra do Rio São Domingos (MZUSP 4012, 4020), Minaçu; Distríto Federal, 20 km S of Brasília (OMNH 17487, 17488); Goiás, Caldas Nova; Espírito Santo, Águia Branca; Minas Gerais, Pirapitanga; Espírito Santo, Viana; Mato Grosso do Sul, Brasilândia; Rio de Janeiro, Cambuci, Mangaratiba; São Paulo, Parque Estadual Intervales; Santa Catarina, Joinville (type locality of Oecomys catherinae Thomas). s u b s p e c i e s : Although bahiensis Hershkovitz has been recognized as a subspecies, knowledge of intraspecific variation is too poor to defend usage of subspecies at this stage of understanding; O. catherinae is provisionally regarded as monotypic (also see Asfora et al. 2011).

Map 205

Selected localities for Oecomys catherinae (●).

n a t u r a l h i s t o ry: Asfora et al. (2011) recorded the species as occurring in dense rainforest, open rainforest, and semideciduous forest in a savanna-forest mosaic (i.e., gallery forest settings in the Cerrado biome). r e m a r k s : Hershkovitz (1960) erected his new subspecies Oryzomys concolor bahiensis because he viewed Oecomys catherinae Thomas (1909) as well as Oecomys rex Thomas (1910) as a synonym of Oryzomys subflavus (now Cerradomys subflavus sensu Weksler et al. 2006). With correction of this misidentification (Musser and Carleton 2005) and because Mus cinnamomeus Pictet and Pictet is a junior homonym, O. catherinae assumes priority for Atlantic Forest populations. Samples of O. catherinae from the Atlantic Forest and Cerrado riparian formations are closely related to, but genetically well differentiated from, samples of O. trinitatis in the Amazon Basin (L. P. Costa 2003). The karyotype uniformly consists of 2n = 60 and displays minor variation in the number of autosomal arms (FN = 62/64) as based on broad geographic survey of chromosomal numbers (Asfora et al. 2011).

Oecomys cleberi Locks, 1981 Cleber’s Oecomys sy n o n y m : Oecomys cleberi Locks, 1981:1; type locality “Fazenda Agua Limpa, da Universidade de Brasília, Distrito Federal, Brasil. Longitude: 45°54′W. Latitude: 15°57′S.”

402 Mammals of South America

d e s c r i p t i o n : Small species, slightly larger than examples of O. bicolor and slightly smaller than those of O. paricola (Table 1). In general appearance, it recalls O. bicolor, having pure white to pale cream under parts sharply contrasted to orange-brown upper parts and relatively short tail with modest terminal tuft. Cranial architecture also resembles O. bicolor, including possession of primitive carotid circulatory plan (pattern 1 of Voss 1988); alisphenoid struts usually absent. R. G. Rocha et al. (2012) provide additional description and comparisons with O. paricola and O. roberti, other species that cohabit Cerrado of south-central Brazil. d i s t r i b u t i o n : Known from the southern Cerrado biome of Brazil based on four localities documented to date. s e l e c t e d l o c a l i t i e s (Map 206; from R. G. Rocha et al. 2012, except as noted): BRAZIL: Mato Grosso, Fazenda São Luís, 30 km N of Barra do Garças; Distrito Federal, Fazenda Água Limpa, Universidade Federal de Brasília (type locality of Oecomys cleberi Locks); Minas Gerais, Fazenda Cafundó, 13 km NE of Nova Ponte; Mato Grosso do Sul, Fazenda Maringá, 54 km of Dourados. s u b s p e c i e s : Based on the few specimens (15) and few localities (4) so far known, O. cleberi is regarded as monotypic (R. G. Rocha et al. 2012). n a t u r a l h i s t o ry: Locks (1981) reported the habitat as riparian forest.

Map 206

Selected localities for Oecomys cleberi (●).

r e m a r k s : Locks (1981) critically contrasted her new form to O. bicolor and O. milleri (here considered another synonym of O. bicolor). Morphological evidence and analysis of mtDNA cytochrome-b sequences affiliate O. cleberi and O. bicolor as cognate species, the former apparently endemic to the Cerrado and a vicariant relative to the latter distributed across greater Amazonia (R. G. Rocha et al. 2012). R. G. Rocha et al. (2012) cautioned that past reports of O. bicolor from Cerrado localities might instead represent O. cleberi. Morphological discrimination of the two species and the distributional extent of O. cleberi require further study.

Oecomys concolor (Wagner, 1845) Natterer’s Oecomys sy n o n y m s : Hesperomys concolor Wagner, 1845a:147; type locality “Flusse Curicuriari im nordwestlichen Brasilien” [= Brazil, Amazonas, Rio Curicuriari, a tributary of the upper Rio Negro, below São Gabriel (da Cachoeira), fide Hershkovitz 1960; also see Carleton et al. 2009:24]. Rhipidomys marmosurus Thomas, 1899d:378; type locality “Maipures, Upper Orinoco,” Vichada, Colombia. [Oryzomys (Oecomys)] marmosurus: Thomas, 1906c:445; name combination. O[ecomys]. marmosurus: Thomas, 1910b:187; name combination. [Oryzomys (Orzyomys)] concolor: Tate, 1932e:3; name combination, taxonomic history. Oryzomys [(Oecomys)] marmosurus: Ellerman, 1941:358; name combination. Oryzomys (Oecomys) concolor concolor: Hershkovitz, 1960: 545–546; name combination (marmosurus allocated as full synonym, invalid as subspecies). Oecomys concolor: A. L. Gardner and Patton, 1976:13; first use of current name combination. Oecomys concolor: Musser and Carleton, 1993:716; name combination (marmosurus listed as synonym without indication of rank). d e s c r i p t i o n : Characterized by combination of medium-large size, relatively long tail (TL ≈ 118% of HBL), and short pelage (5–7 mm over middle rump). Dorsal pelage varies from dull fulvous brown to brighter ochraceoustawny, especially over shoulders and cheeks. Venter also varies, wholly dull white in most specimens, or some with strong overwash of buff-tipped to ochraceous-tipped hairs, or some with small to broad expanses of gray over middle abdomen; dorsal-ventral pelage contrast weakly defined in the last two conditions. Pinnae dark brown, usually contrasting with adjacent upper parts. Tail brown to dark brown all around for most of length, mottled beneath near base; short caudal hairs expose scale rows for most of tail length, without formation of terminal pencil.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 403

Skull with moderately prominent supraorbital ridges, with distinct interorbital constriction and posteriorly diverging supraorbital shelves (cuneate shape). Incisive foramina relatively narrow, their anterior and posterior ends acute, gently curving along lateral edges and widest near middle. Bony palate noticeably projecting beyond posterior margins of M3s, as in most oryzomyines; posterolateral palatal pits well developed, typically consisting of one large pit with interior perforations plus one or two supernumerary foramina. Alisphenoid struts typically present (Carleton et al. 2009), and carotid circulatory plan derived (pattern 3 of Voss 1988). d i s t r i b u t i o n : Lowland rainforest to the north of the Rios Amazonas-Solimões in northwestern Brazil and to the south of the Río Orinoco in eastern Colombia and southern Venezuela; known elevational range sea level to 400 m. s e l e c t e d l o c a l i t i e s (Map 207; from Carleton et al. 2009, except as noted): BRAZIL: Amazonas, Ilha das Onças, left bank Rio Negro, Macaco, left bank Rio Jaú, Rio Curicuriari below São Gabriel da Cachoeira (type locality of Hesperomys concolor Wagner), Rio Uaupés, opposite Tahuapunta, Yavanari, right bank Rio Negro; Roraima, Rio Uraricoera. COLOMBIA: Meta, Los Micos, 18 km SW of San Juan de Arama; Vichada, Maipures, middle Río Orinoco (type locality of Rhipidomys marmosurus Thomas). VENEZUELA: Amazonas, Belén, Río Cunucunuma, Boca Mavaca, 68 km SE of Esmeralda, 12 mi W of Río Jawasu, left bank Río Casiquiare, San Juan, Río Manapiare, Tamatama, Río Orinoco; Apure, Hato Caribén, 60 km NE of Puerto Páez, Río Cinaruco. s u b s p e c i e s : Carleton et al. (2009) provided no evidence for subspecific divisions within O. concolor. r e m a r k s : The epithet concolor Wagner (1845a) was a forgotten name in oryzomyine taxonomy until Tate (1932e) tentatively identified it as a species of Oryzomys and Hershkovitz (1960) recognized it as a member of Oecomys. The highly variable morphology and pantropical range of O. concolor as defined by Hershkovitz reflected its composite nature, which embraced entirely or partly at least nine valid species among his synonyms (O. auyantepui, O. catherinae, O. concolor, O. flavicans, O. mamorae, O. roberti, O. speciosus, O. superans, O. trinitatis, as per Musser and Carleton, 2005). Among species of Oecomys, the derived circulatory plan of O. concolor is shared only with O. mamorae and O. sydandersoni and offers a morphological basis to hypothesize their closer relationship (Weksler 2006; Carleton et al. 2009). The geographic occurrence of O. concolor proper is confined to the Rio Negro West subregion of northern Amazonia, an area of endemism delineated from phylogeographic and distributional studies of neotropical birds (Cracraft and Prum 1988; Stotz et al. 1996).

Map 207

Selected localities for Oecomys concolor (●). Contour line = 2,000 m.

Oecomys flavicans (Thomas, 1894) Tawny Oecomys sy n o n y m s : Oryzomys flavicans Thomas, 1894b:351; type locality “Merida, [Mérida,] Venezuela.” Oryzomys flavicans illectus Bangs, 1898:164; type locality “Pueblo Viejo, [Sierra Nevada de Santa Marta, Magdalena,] Colombia, altitude 8000 ft.” Oecomys mincae J. A. Allen, 1913c:603; type locality “Minca (altitude 2000 feet), Santa Marta region, [Magdalena,] Colombia.” Oryzomys flavicans flavicans: Gyldenstolpe, 1932a:22; name combination. Oecomys illectus: Gyldenstolpe, 1932a:42; name combination, elevation to species. Oryzomys [(Oecomys)] mincae: Ellerman, 1941:358; name combination. O[ryzomys] flavicens: Goodwin, 1953:310; spelling lapsus for flavicans. Oryzomys (Oecomys) concolor concolor: Hershkovitz, 1960: 545–547; name combination (flavicans, illectus, and mincae allocated as full synonyms, invalid as subspecies). Oryzomys trinitatis flavicans: Cabrera, 1961:407; name combination. Oryzomys trinitatis illectus: Cabrera, 1961:408; name combination. Oecomys flavicans: Musser and Carleton, 1993:716; first use of current name combination (illectus and mincae allocated as synonyms without indication of rank). d e s c r i p t i o n : Medium large in body size (e.g., larger than O. paricola and O. specious but smaller than O. trinitatis and O. superans). Dorsal pelage soft, dense, and moderately long (8–10 mm over middle rump); head

404 Mammals of South America

and back bright ochraceous tawny that transforms to rich ochraceous lateral line along sides of body. Ventral pelage typically dull white spattered with buff in some individuals, with encroachment of basally gray hairs over middle abdomen; demarcation between bright lateral line and whitish venter sharp, with ochraceous tones wash along borders of ventral fur in some specimens. Tail longer than combined head and body (tail length ≈ 115% of head and body length), brown on top, sides and all around distal one-fourth but pale brown below; caudal hairs short, revealing scale rows, without formation of tuft at tip. Skull chunky, with relatively short rostrum and narrow interorbit. Distinct supraorbital ridges outline interorbital and postorbital margins and sweep caudad to join prominent temporal ridges. Zygomatic arches converge little toward rostrum; zygomatic plates broad and dorsal notches moderately incised. Incisive foramina moderately long and impressively broad, their posterior margins situated anterior to molar rows. A pair of large posterolateral palatal pits marks each side of bony palate behind toothrows; mesopterygoid fossa broad, U-shaped at anterior margin, with roof entirely osseous. Postglenoid foramen moderately large but subsquamosal fenestra typically closed (hamular process fused with squamosal). Alisphenoid struts typically present (ca. 70% of sample), and carotid circulatory plan primitive (pattern 1 of Voss 1988). Ectotympanic bullae small, revealing much of medial periotic. d i s t r i b u t i o n : Oecomys flavicans occurs across northeastern Colombia and northern Venezuela; known elevation range from sea level to 2,000 m. s e l e c t e d l o c a l i t i e s (Map 208): COLOMBIA: Cesar, Colonia Agrícola de Caracolicito (USNM 280595), Pueblo Viejo, Sierra Nevada de Santa Marta (type locality of Oryzomys flavicans illectus Bangs); Huila, 5 km N of Villavieja (MVZ 113378); Magdalena, Minca, Santa Marta region (type locality of Oecomys mincae J. A. Allen); Norte de Santander, San Calixto, Río Tarrá (USNM 280593, 280594). VENEZUELA: Aragua, Camp Rafael Rangel (USNM 317713–317715); Carabobo, El Trompillo (BM 14.9.1.43–14.9.1.45), San Esteban, near Venezuela Hills (BM 11.5.25.145); Mérida, Mérida (type locality of Oryzomys flavicans Thomas); Miranda, Hacienda La Guapa, 6 km S of Río Chico (USNM 387867); Portuguesa, La Hoyada, near Guanarito (AMNH 266915, 266916); Trujillo, Isnotú, 10 km WNW of Valera (USNM 371165); Zulia, Misión Tukuko (USNM 448580–448582). s u b s p e c i e s : Oecomys flavicans is provisionally regarded as monotypic. n a t u r a l h i s t o ry: Linares (1998) recorded O. flavicans as an inhabitant of dense, multistrata forest with abundant bromeliads, lianas, and epiphytes, in both sub-

Map 208

Selected localities for Oecomys flavicans (●). Contour line = 2,000 m.

montane and montane zones; it is occasionally numerous in agricultural settings such as cafetales. r e m a r k s : Cabrera (1961) arranged flavicans as a subspecies of trinitatis, but the two forms occur in sympatry or altitudinal parapatry in the coastal ranges of northern Venezuela. Morphological differences between the two are slight: specimens of O. flavicans typically have a brighter tawny dorsum and flanks (usually darker brown in O. trinitatis), with a whitish venter (usually some shade of gray in O. trinitatis), and average smaller in external and cranial dimensions (Table 1), in particular length of the molar row (CLM usually < 5 mm in O. flavicans; CLM usually ≥ 5 mm in O. trinitatis).

Oecomys mamorae (Thomas, 1906) Mamore Oecomys sy n o n y m s : Oryzomys (Oecomys) mamorae Thomas, 1906c: 445; type locality “Mosetenes, Upper Mamoré, Yungas, [Cochabamba,] Bolivia”; but see Remarks. Oecomys mamorae: Osgood, 1916b:206; first use of current name combination. Oryzomys [(Oecomys)] mamorae: Ellerman, 1941:358; name combination. Oryzomys mamorae mamorae: Cabrera, 1961:405; name combination. Oryzomys concolor roberti: Hershkovitz, 1960:559; part (mamorae allocated as full synonym, invalid as subspecies). Oecomys concolor roberti: S. Anderson, 1985:12; part (mamorae listed as full synonym, invalid as subspecies). d e s c r i p t i o n : Combination of medium-large size, absolutely and relatively long tail (Table 1), and moderately long pelage (7–9 mm) characterizes examples of O. mamorae. Dorsal pelage generally medium buffy brown,

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 405

dominated by gray hues in some series that range from gray to grayish buff; ventrum appears dull white from chin to inguen in most specimens, although some individuals exhibit encroachment of gray-based hairs over middle abdomen. Dorsal-ventral pelage contrast tends to be sharply marked, in most specimens accentuated by buff to bright ochraceous lateral strip that demarcates upper and under parts. Long tail (≈ 115–118% of head and body length) brown to dusky brown for most of its length, proximal section slightly paler beneath; short caudal hairs weakly obscure scale rows, without expression of terminal pencil. Within the genus, cranium exhibits weakest expression of supraorbital ridging, which is confined more to rear of orbit and weakly diverges posteriorly. Interorbital shape thus appears more amphoral and its span narrow compared with constriction observed in other large-bodied species. Zygomatic plates broad for genus, with dorsal notches clearly incised. Incisive foramina relatively long, more nearly parallel sided, and relatively narrow without pronounced outward bowing. Rear termination of hard palate more or less even with caudal margins of M3s; perhaps in correlation with shorter palate, pit construction simpler, usually consisting of single opening. Alisphenoid struts typically absent and carotid circulatory plan derived (pattern 3 of Voss 1988; Carleton et al. 2009). Development of auditory bullae is exceptional for the genus: ectotympanic shell slightly more inflated, and less of posteromedial periotic exposed. d i s t r i b u t i o n : Subhumid and gallery forests in savanna and Chaco zones of central and eastern Bolivia, contiguous west-central Brazil, and northern and eastern Paraguay. The known elevational range is from sea level to 2,100 m, with most localities between 200–500 m. s e l e c t e d l o c a l i t i e s (Map 209; from Carleton et al. 2009, except as noted): BOLIVIA: Beni, Baures, Puerto Salinas, Río Beni, Río Mamoré, Río Tijamuchi; Chuquisaca, Ticucha, Río Capirenda, Tola Orko, 40 km from Padilla; Cochabamba, Mosetenes, upper Rio Mamoré (type locality of Oryzomys (Oecomys) mamorae Thomas); La Paz, 1 mi W of Puerto Linares; Santa Cruz, Camiri, 5 km S of Choreti, Punta Rieles, Santa Ana. BRAZIL: Mato Grosso, Caiçara; Mato Grosso do Sul, Urucum de Corumbá. PARAGUAY: Amambay, Colonia Sargento Duré, 3 km E of Río Apa; Chaco, Cerro León, 50 km WNW of Fortín Madrejón; Misiones, 40 km S of San Ignacio. n a t u r a l h i s t o ry: A specimen from the Chaco of Paraguay was captured on the ground in thorn forest (Myers and Wetzel 1979, reported as Oryzomys concolor roberti). s u b s p e c i e s : Carleton et al. (2009) offered no data that indicate geographic variation, but the possibility of recognizable subspecies should be revisited with the fresh redefinition of O. mamorae; we provisionally regard it as monotypic.

r e m a r k s : Systematists recognized this distinctive species as valid until Hershkovitz (1960) confused matters by treating it as a full synonym of Oryzomys concolor roberti. The ranges of O. mamorae and O. roberti approach one another in eastern Bolivia, where they are strikingly different in external and cranial morphology, but sympatry has yet to be documented (Carleton et al. 2009). Specimens of Oecomys have been recovered from owl pellets in northeastern Argentina, from the provinces of Chaco (Massoia and Fornes 1965b, as O. concolor) and Formosa (Pardiñas and Ramírez-Llorens 2005, as O. sp.). By geographic proximity, these samples are plausibly referable to O. mamorae, but critical review of variation within nominal O. mamorae and comparisons with the Argentinean populations are required to verify their specific assignment. Ulyses Pardiñas (pers. comm.) kindly informed me that the type locality “Mosetenes” actually refers to an indigenous people distributed principally within the Yungas of central Bolivia, not a specific placename. The origin of the type specimen from somewhere within Cochabamba department, specifically the Cordillera de Mosetenes (Anderson 1997; Carleton et al. 2009), has been presumed since Hershkovitz’s (1960) interpretation of the locality, which regional placement plausibly followed Thomas’s (1906c) approximation of Mosetenes as the “Upper Mamoré.” However, the collector, Italian naturalist Luigi Balzan, also descended the Rio Beni, La Paz department, and had visited Mosetenes settlements along that river (Balzan 1893,

Map 209 Selected localities for Oecomys mamorae (●). Contour line = 2,000 m.

406 Mammals of South America

2008), an area where the type may conceivably have been collected. Additional archival research is required to justify formal amendment of the type locality.

Oecomys paricola (Thomas, 1904) Brazilian Oecomys sy n o n y m s : Rhipidomys paricola Thomas, 1904e:194; type locality “Igarapé-Assu, near Pará, [Para, Brazil]. Alt. 50 m.” [Oryzomys (Oecomys)] paricola: Thomas, 1906c:445; name combination. Oecomys paricola: Gyldenstolpe, 1932a:39; first use of current name combination. Oryzomys [(Oecomys)] paricola: Ellerman, 1941:358; name combination. Oryzomys bicolor bicolor: Hershkovitz, 1960:535; part (paricola allocated as full synonym). Oryzomys bicolor paricola: Cabrera, 1961:404; name combination. d e s c r i p t i o n : Like O. auyantepui and O. phaeotis, dorsal coat of O. paricola thick, silky in texture, and long (8–10 mm) for size of body. Dorsal color ranges from ochraceous brown to rich dark brownish red; flanks tend to be paler and faint ochraceous line may occur between upper and under parts. Venter generally dull grayish white, showing more white on throat, neck, and chest in some specimens, or having strong buffy wash across belly and chest in others. Tail dark brown over its circumference; caudal hairs lengthen over distal half of tail, obscuring scale rows and forming modest terminal pencil. Skull resembles that of O. auyantepui—stockily built with blunt rostrum, well-defined supraorbital ridges, and typical cuneate interorbital constriction. Zygomatic arches converge anteriorly from their widest expanse toward braincase, and zygomatic plates relatively narrow with shallow dorsal notches. Moderately long and wide incisive foramina terminate anterior to front rims of M1s in most specimens, or extend even with anterior borders in some. Mesopterygoid fossa short and wide, with U-shaped anterior margin; roof either entirely osseous or perforated by short, narrow sphenopalatine vacuities. In contrast to O. auyantepui, cranium of O. paricola typically lacks alisphenoid struts and retains short, narrow subsquamosal fenestrae. Carotid circulatory pattern primitive (pattern 1 of Voss 1988), and ectotympanic bullae small, as typical of genus. d i s t r i b u t i o n : Central Brazil, south of the Amazon River, and northeastern Peru; range limits uncertain. s e l e c t e d l o c a l i t i e s (Map 210): BRAZIL: Pará, 52 km SSW of Altamira, right bank Rio Xingu (USNM 549531, 549532), Capim (AMNH 203391, 203392, 203394), Igarapé-Assu, near Pará (type locality of Rhipidomys paricola Thomas), Km 217, BR 165, Santarem to

Map 210

Selected localities for Oecomys paricola (●). Contour line = 2,000 m.

Cuiabá (USNM 544601), Porto Jatobal, 73 km N and 45 km W of Marabá (USNM 521453, 521528); Mato Grosso, 264 km N of Xavantina, Serra do Roncador Base Camp (BM 81.380, 81.595, 86.1127); Mato Grosso do Sul, Maracaju (AMNH 134510, 134511). PERU: Loreto, Estación Biológica Allpahuayo, 25 km SW of Iquitos, on Iquitos-Nauta Highway (TTU [CLH 2348, 2846]), San Jacinto (KU 158190). s u b s p e c i e s : Oecomys paricola is provisionally regarded as monotypic. n a t u r a l h i s t o ry: Carleton et al. (1986) recorded O. paricola from primary lowland forest along the Rio Xingu, central Brazil. r e m a r k s : The geographic range of O. paricola (south of the Amazon River) is allopatric to that of O. auyantepui (north of the Amazon River) and to that of O. phaeotis (western Amazonia); the status of the three as valid species needs verification. Chromosomal variation (2n = 68, 70; FN = 72, 76) has been reported for geographically close populations of O. paricola located at the mouth of the Amazon River (C. C. Rosa et al. 2012); the authors suspected the existence of cryptic species, although accompanying morphological or molecular differentiation was not demonstrable.

Oecomys phaeotis (Thomas, 1901) Dusky Oecomys sy n o n y m s : Rhipidomys phaeotis Thomas, 1901b:181; type locality “Segrario, 13°5′S., 70°5′W., Upper Inambari, [Puno,] S.E. Peru. Alt. 1000 m.” [Oryzomys (Oecomys)] phaeotis: Thomas, 1906c:445; name combination.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 407

Oecomys phaeotis: Gyldenstolpe, 1932a:40; first use of current name combination. Oryzomys [(Oecomys)] phaeotis: Ellerman, 1941:358; name combination. Oryzomys bicolor phaeotis: Hershkovitz, 1960:540; name combination. d e s c r i p t i o n : Medium-sized species—larger than O. bicolor, about same as O. auyantepui and O. paricola, and smaller than all other species (Table 1). Pelage luxuriant: soft, dense, and long (10–12 mm over middle rump). Dorsal fur rich tawny brown in most specimens, darker along top of head and back than on sides. Ventral pelage typically dull white (hairs white from tips to roots); demarcation between dorsal and ventral pelage coloration sharp and usually accentuated by bright ochraceous strip. Tail longer than combined head and body (≈110% of HBL) and dark brown on all surfaces; caudal hairs relatively long, typically obscuring scale rows and forming noticeable tuft at tip (6–8 mm). Skull compactly built, with relatively short rostrum and narrow interorbit. Conspicuous supraorbital ridges outline interorbital and postorbital regions and sweep caudad to join distinct temporal beading. Zygomatic arches narrower rostrally and wider toward braincase; zygomatic plates relatively narrow and dorsal notches shallow. Incisive foramina moderately long and broad, with posterior margins situated about even with anterior faces of M1s or extend just beyond them. A pair of prominent posterolateral palatal pits and smaller vascular perforations adorn bony palate behind molars; mesopterygoid fossa wide and U-shaped at anterior margin, its roof entirely osseous. Postglenoid foramen and subsquamosal fenestra large. Alisphenoid struts typically absent (present in 1 of 7 specimens), and carotid circulatory plan primitive (pattern 1 of Voss 1988). Ectotympanic bullae small, exposing much of medial periotic. d i s t r i b u t i o n : Eastern Andean slopes from Peru to northern Bolivia; limits unresolved. s e l e c t e d l o c a l i t i e s (Map 211): BOLIVIA: Cochabamba, Alto Palmar, Chaparé (AMNH 119406). PERU: Cusco, Hacienda Villa Carmen, Cosñipata (FMNH 84314); Junín, 10 km WSW of San Ramón (MVZ 172649); Loreto, Quebrada Oran, 5 km N of Río Amazonas, 85 km NE of Iquitos (LSUMZ 27975); Puno, Segrario, upper Río Inambari (type locality of Rhipidomys phaeotis Thomas). s u b s p e c i e s : Too few specimens of O. phaeotis exist to allow rigorous analysis of intraspecific variation and delineation of subspecies. n a t u r a l h i s t o ry: There is no published information on the ecology or behavior of this species. Most collecting localities appear to be in lower montane forest. r e m a r k s : See comments in accounts of O. auyantepui and O. paricola.

Map 211

Selected localities for Oecomys phaeotis (●). Contour line = 2,000 m.

Oecomys rex Thomas, 1910 Regal Oecomys sy n o n y m s : Oecomys rex Thomas, 1910d:504; type locality “R. Supinaam [= Supenaam], Lower Essequibo, Demerara [= Georgetown],” Demerara-Mahaica, Guyana. Oryzomys [(Oecomys)] rex: Ellerman, 1941:359; name combination. Oryzomys subflavus regalis Hershkovitz, 1960:543; unnecessary replacement name for Oecomys rex Thomas, 1910, mistakenly viewed as a junior synonym of Oryzomys subflavus [= Cerradomys subflavus (Wagner)]. Oryzomys catherinae rex: Cabrera, 1961:405; name combination. d e s c r i p t i o n : Large, morphologically distinctive species that exhibits several features whose expression is unique within genus. In size, O. rex is surpassed only by individuals of O. superans and approximates those of O. catherinae (Table 1). Dorsal pelage thick and long (10– 12 mm), its texture very fine and more luxurious than that characteristic of long-furred O. trinitatis. Upper parts generally dark in tone, ranging from dull ochraceous brown to deep chestnut, finely intermixed with black-tipped hairs over middle dorsum and grading to brighter on flanks. Ventral pelage uniformly dark grayish white (hairs with gray bases and white tips) in most specimens, although some display overwash of buff to ochraceous on belly and dingy white on gular and inguinal regions. Tail brown all around,

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caudal hairs short and inconspicuous without formation of terminal pencil or tuft. Tops of forefeet and hindfeet fuscous brown, becoming dingy white over phalanges. Robust skull bears exaggerated supraorbital shelves and strong temporal ridges that extend across braincase and reach supraoccipital. An angular postorbital process at lateral union of frontal and parietal accentuates orbital-temporal ridging, and flaring supraorbital ridges account for extreme width of interorbit (Table 1). Nasolacrimal opening slit-like, capsules more nearly flat than bulging; rostrum consequently appears narrow relative to cranial size. Unlike other species of Oecomys, tegmen tympani well developed, adnate to squamosal and essentially occluding postglenoid foramen; subsquamosal fenestra absent or persists as short, narrow slit. Incisive foramina terminate noticeably anterior to M1s, except subequal with the anterior roots in old individuals. Carotid circulatory plan complete (pattern 1 of Voss 1988). d i s t r i b u t i o n : Southeastern Venezuela (Bolívar), the Guianas, and northeastern Brazil (Amapá, Amazonas); no elevational records. s e l e c t e d l o c a l i t i e s (Map 212): BRAZIL: Amapá, Rio Amapari de Macapá (MPEG 6704, 6725), Serra do Navio, Rio Amapari (USNM 394254–394256); Amazonas, Fazenda Dimona, 80 km N of Manaus (INPA [JRM 2107]). FRENCH GUIANA: Riviere Approuague (MNHN 1983.389, 1983.390), Trois Sauts (MNHN 1982.621, 1983.391). GUYANA: Demerara-Mahaica,

Map 212

Selected localities for Oecomys rex (●). Contour line = 2,000 m.

Demerara, Supinaam River (type locality of Oecomys rex Thomas); Potaro-Siparuni, 40 km NE of Surama (ROM 98033). SURINAM: Marowijne, 3 km SW of Albina (CM 76867); Sipaliwini, Avanavero (CM 68459). VENEZUELA: Bolívar, Serranía Imataca (MHNLS [JO 562]). s u b s p e c i e s : Oecomys rex is provisionally regarded as monotypic. n a t u r a l h i s t o ry: In southeastern Venezuela, Linares (1998) associated O. rex with humid, evergreen forest that harbors a lush undergrowth of bromeliads, epiphytes, and lianas. r e m a r k s : Like O. auyantepui and O. rutilus, the geographic range of O. rex adheres to the Guiana subregion of Amazonia.

Oecomys roberti (Thomas, 1904) Robert’s Oecomys sy n o n y m s : Rhipidomys roberti Thomas, 1904a:237; type locality “Santa Ana de Chapada, a village situated at an altitude of about 800 m, on the Serra do Chapada, some thirty miles N.E. of Cuyabá [Cuiabá],” Mato Grosso, Brazil. [Oryzomys (Oecomys)] roberti: Thomas, 1906c:445; name combination. Oecomys tapajinus Thomas, 1909:378; type locality “Santa Rosa, R. Tamauchim [= Rio Jamanxim], right bank of the Upper Tapajoz [= Tapajós],” Pará, Brazil. Oecomys guianae Thomas, 1910b:187; type locality “River Supinaam, Demerara,” Demerara–Mahaica, Guyana. Oecomys roberti: Gyldenstolpe, 1932a:40; first use of current name combination. Oecomys guianae guianae: Tate, 1939:193; name combination. Oryzomys [(Oecomys)] roberti: Ellerman, 1941:358; name combination. Oryzomys [(Oecomys)] guianae: Ellerman, 1941:358; name combination. Oryzomys [(Oecomys)] tapajinus: Ellerman, 1941:359; name combination. Oryzomys (Oecomys) concolor concolor: Hershkovitz, 1960: 546; part (tapajinus allocated as full synonym); not concolor Wagner. Oryzomys concolor speciosus: Hershkovitz, 1960:553; part (guianae allocated as full synonym); not speciosus J. A. Allen and Chapman. Oryzomys concolor roberti: Hershkovitz, 1960:559; name combination. Oryzomys marmosurus guianae: Cabrera, 1961:405; name combination. Oryzomys marmosurus tapajinus: Cabrera, 1961:406; name combination.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 409

Oecomys roberti: Musser and Carleton, 1993:716; name combination (guianae and tapajinus allocated as synonyms without indication of rank). d e s c r i p t i o n : Moderately large species that possesses absolutely and relatively long tail (≈ 123% of HBL) and relatively short fur for its body size (5–7 mm over middle rump). Dorsal pelage texture soft, thought slightly harsh to touch. Upper parts bright in tone, tawny to fulvous brown, grading to ochraceous on flanks, although without obvious lateral line. Appearance of venter ranges from all white (hairs self-colored) to grayish white (hairs with gray bases and white tips), with varying degrees of intermediacy depending upon extent of gray-based hairs, or sometimes tinted with buffy or ochraceous overwash on chest and belly; dorsal-ventral pelage contrast sharp in individuals with mostly white under parts but only moderately defined in examples with grayish white or grayish buff venters. Tail wholly dark brown; caudal hairs so short that tail appears naked macroscopically, revealing fine scale rows; no tuft formed at tip. Pinnae relatively short and brown; tops of hindfeet white or tinged with ochraceous. Chunky skull characterized by relatively short rostrum and wide interorbit. Supraorbital shelves distinctive but moderately developed compared with O. trinitatis and have fairly straight edges that do not diverge as strongly posteriorly; temporal ridges of low relief present, becoming poorly defined over parietals. Nasolacrimal capsules conspicuously bulge laterally and contribute to short-broad appearance of rostrum. Zygomatic arches converge little from braincase toward rostrum; zygomatic plates relatively narrow, and dorsal notches shallow. Incisive foramina relatively short, terminating well anterior to M1 roots and expanding widely over their middle section. Posterolateral palatal pits well expressed; mesopterygoid fossa broad, Vor U-shaped at anterior margin, and roof entirely osseous in some specimens, broken by slits in others. Tegmen tympani may touch rear edge of squamosal, but postglenoid foramen remains open, larger than tiny or absent subsquamosal fenestra (hamular process fused with the squamosal). Occurrence of alisphenoid struts variable, but typically absent; carotid circulatory plan complete (pattern 1 of Voss 1988). Ectotympanic bullae small, revealing much of medial periotic. d i s t r i b u t i o n : Southern Venezuela (Amazonas), Guyana, Surinam, northern and west-central Brazil, eastern Colombia, eastern Peru, and extreme eastern Bolivia; known elevational range sea level–800 m. s e l e c t e d l o c a l i t i e s (Map 213): BOLIVIA: Pando, Remanso (Anderson 1997); Santa Cruz, 2.5 km NE of El Refugio, Parque Nacional Noel Kempff Mercado (Carleton et al. 2009). BRAZIL: Amazonas, Colocação Vira-Volta, left bank Rio Juruá (Patton et al. 2000),

Manacapuru, Rio Solimões (BM 1920.7.1.15), Sacado, right bank Rio Juruá (Patton et al. 2000); Pará, Campos do Ariramba, Igarapé Jaramacaru (MZUSP 69145), Capim (MZUSP 9896, 9897), Santa Rosa, Rio Jamanxim, upper Rio Tapajós (type locality of Oecomys tapajinus Thomas); Mato Grosso, Santa Ana do Chapada, Serra do Chapada, 30 mi NE of Cuiabá (type locality of Rhipidomys roberti Thomas), 264 km N of Xavantina, Serra do Roncador Base Camp (BM 81.412–81.417); Rondônia, Barão de Melgaço, Rio Commemoração, upper Rio Ji-Paraná (AMNH 37115, 37116, 37118). COLOMBIA: Caquetá, Tres Troncas, Río Caquetá (FMNH 72024). GUYANA: Demerara-Mahaica, Demerara, Supinaam River (type locality of Oecomys guianae Thomas); Upper Takutu–Upper Essequibo, Quarter Mile Landing, 5 km S of Annai (ROM 98125). PERU: Amazonas, Río Cenepa, vicinity of Huampami (MVZ 153528, 155005); Loreto, Boca Río Peruate (FMNH 88937); Madre de Dios, Itahuania, right bank Río Madre de Dios (FMNH 84303); Pasco, San Pablo (AMNH 231133); Puno, La Pampa, Limbani-Asterillos road (MCZ 39499). SURINAM: Paramaribo, Paramaribo (USNM 319968, 319969); Sipaliwini, Sipaliwini airstrip (CM 64562). VENEZUELA: Amazonas, Cerro Neblina, Base Camp (USNM 560822); Bolívar, Río Yuruani, 12 mi from mouth (AMNH 30726). s u b s p e c i e s : Although broad in distribution, no evaluation of variation has been conducted to rigorously delimit infraspecific units; we provisionally treat O. roberti as monotypic. n a t u r a l h i s t o ry: Patton et al. (2000) obtained samples of O. roberti primarily in várzea forest (88%) along the Rio Juruá, western Brazil, and rarely at the edges of second-growth forest; individuals were captured in equal numbers on the ground and in the canopy. Along the Rio

Map 213

Selected localities for Oecomys roberti (●). Contour line = 2,000 m.

410 Mammals of South America

Xingu, central Brazil, trap success was notable in ecotones of dense growth that proliferated around natural tree-falls within primary forest and in viney forest with low canopy (Carleton et al. 1986). Within the Cerrado biome of eastern Bolivia, examples of O. roberti were captured in semideciduous forest (Emmons et al. 2006). Litter size, as based on fetal counts and embryo scars, is only two or three (Patton et al. 2000). r e m a r k s : Hershkovitz (1960) retained roberti as a subspecies of O. concolor, but submerged the otherwise dissimilar mamorae within his construct of O. concolor roberti. Patton et al. (2000) reported the karyotype to consist of a high diploid count (2n = 80) and intermediate number of biarmed chromosomes (FN = 114).

Oecomys rutilus Anthony, 1921 Reddish Oecomys sy n o n y m s : Oecomys rutilus Anthony, 1921a:4; type locality “Kartabo, [Cuyuni-Mazaruni,] British Guiana” [Guyana]. Oryzomys [(Oecomys)] rutilus: Ellerman, 1941:359; name combination. Oryzomys bicolor bicolor: Hershkovitz, 1960:535; part (rutilus allocated as full synonym); not bicolor Tomes. Oryzomys bicolor nitedulus: Cabrera, 1961:404; part (rutilus allocated as full synonym); not nitedulus Thomas. d e s c r i p t i o n : Smallest species of Oecomys so far recognized, suggesting dainty facsimile of O. bicolor. Pelage soft and dense, lax to touch, and moderately long compared with body size (6–8 mm over middle rump). Dorsal coat rich ochraceous tawny (nearly orange brown), and slightly paler along lower sides of head and body, bright buffy gray. Ventral pelage pure white, hairs white from root to tip, and sharply demarcated from dorsum. Tail only slightly longer than combined head and body (TL ≈ 111% of HBL) and dark brown on all surfaces; tail hairs relatively long, typically concealing distal scale rows and forming conspicuous terminal tuft (5–11 mm per Voss et al. 2001). Small skull delicately but compactly built with relatively short rostrum and narrow interorbit. Conspicuous supraorbital ridges (narrowly ledge-like) outline interorbital and postorbital regions and sweep caudad to join distinct temporal ridges. Zygomatic arches converge slightly toward rostrum; zygomatic plates relatively narrow and dorsal notches shallow. Short and narrow incisive foramina terminate posteriorly about even with anterior faces of M1s. Rear of bony palate contains pair of prominent posterolateral palatal pits; mesopterygoid fossa narrow and U-shaped at anterior margin, and roof entirely osseous. Postglenoid foramen and subsquamosal fenestra spacious. Alisphenoid

Map 214

Selected localities for Oecomys rutilus (●). Contour line = 2,000 m.

struts typically present, and carotid circulatory plan primitive (pattern 1 of Voss 1988). Ectotympanic bullae small, exposing much of medial periotic. d i s t r i b u t i o n : Extreme eastern Venezuela, Guyana, Surinam, and French Guiana, to Amazonas, Brazil; single elevational record at 60 m. s e l e c t e d l o c a l i t i e s (Map 214; from Voss et al. 2001, except as noted): BRAZIL: Amazonas, 80 km N of Manaus. FRENCH GUIANA: Nouragues, Paracou. GUYANA: Cuyuni-Mazaruni, Kartabo, lower Essequibo (type locality of Oecomys rutilus Anthony). SURINAM: Paramaribo, Carolina Kreek. VENEZUELA: Bolívar, San Ignacio Yuruaní, 5.2 km NE via La Toma de Agua. s u b s p e c i e s : Oecomys rutilus is provisionally regarded as monotypic. n a t u r a l h i s t o ry: In French Guiana (Voss et al. 2001), nearly all examples of O. rutilus were captured in primary forest, one in roadside secondary growth; settings in primary vegetation included well-drained sites as well as swampy forest and along creeks; specimens issued about equally from terrestrial (pitfall lines) and arboreal (lianas, canopy platform) trapping stations. Adler et al. (2012) also captured this species most commonly on lianas, especially at lower heights in the forest at Paracou, French Guiana. r e m a r k s : As so far documented, the geographic range of O. rutilus adheres to the Guiana subregion of Amazonia, along with those of O. auyantepui and O. rex.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 411

Oecomys speciosus (J. A. Allen and Chapman, 1893) Savanna Oecomys sy n o n y m s : Oryzomys speciosus J. A. Allen and Chapman, 1893:212; type locality “Princestown, Trinidad,” Trinidad and Tobago. Oryzomys trichurus J. A. Allen, 1899b:206; type locality “El Libano plantation, near Bonda (alt. 500 ft.), Santa Marta District,” Magdalena, Colombia. Oecomys caicarae J. A. Allen, 1913c:603; type locality “Caicara, Rio Orinoco, [Bolívar,] Venezuela.” Oecomys guianae caicarae: Tate, 1939:193; name combination. Oryzomys [(Oecomys)] caicarae: Ellerman, 1941:357; name combination. Oryzomys (Oecomys) concolor concolor: Hershkovitz, 1960: 546–547; part (caicarae and trichurus allocated as full synonyms); not concolor Wagner. Oryzomys concolor speciosus: Hershkovitz, 1960:553; name combination. Oryzomys marmosurus marmosurus: Cabrera, 1961:406; part (caicarae allocated as full synonym); not marmosurus Thomas. Oryzomys trinitatis illectus: Cabrera, 1961:408; part (trichur us allocated as full synonym), not illectus Bangs. Oecomys speciosus: Musser and Carleton, 1993:716; first use of current name combination (caicarae and trichurus allocated as synonyms without indication of rank). d e s c r i p t i o n : Medium-sized, orange-brown mouse with bright ochraceous sides and pure white venter. Larger than examples of O. bicolor or O. auyantepui but appreciably less robust than those of O. concolor or O. trinitatis (Table 1). Dorsal fur soft, dense, and medium in length (5–8 mm over middle rump). Dorsal coloration usually rich ochraceous tawny, grading to bright ochraceous orange along sides of body from nose to rump. Individual variation occurs, some specimens showing redder dorsal coat and others darker upper parts, approaching brownish tawny; in many examples, bright ochraceous hue confined to cheeks and attenuates as distinctive lateral line bordering ventral pelage. Venter typically pure white and contrasts sharply with dorsum. Feet buffy, ears dark brown. Tail relatively long (≈ 118% of HBL) and brown throughout; caudal hairs short over most of tail, lengthen toward tip to end in barely perceptible tuft. Although medium in size, skull presents sturdy conformation and moderately long rostrum. Low supraorbital shelves extend posteriorly to merge with temporal ridges. Long and narrow incisive foramina extend between M1s, and bony palate projects beyond third molars to form moderately wide shelf. Large postglenoid fissure and small but obvious subsquamosal foramen penetrate lateral wall

of braincase. Alisphenoid struts typically absent; carotid circulatory plan primitive (pattern 1 of Voss 1988). d i s t r i b u t i o n : Northeastern Colombia, northern Venezuela, and Trinidad; known elevational range from sea level to 1,250 m; most site records below 400 m. s e l e c t e d l o c a l i t i e s (Map 215): COLOMBIA: Cesar, Valledupar, Río Guaimaral (USNM 280521); Magdalena, El Libano plantation, near Bonda (type locality of Oryzomys trichurus J. A. Allen). TRINIDAD AND TOBAGO: Trinidad, Princestown (type locality of Oryzomys speciosus J. A. Allen and Chapman). VENEZUELA: Apure, Hato Cariben, 60 km NE of Puerto Paez, Río Cinaruco (USNM 374314–374316), Hato El Frio, 30 km W of El Samán (MHNLS 7923; USNM 448583); Bolívar, Caicara, Río Orinoco (type locality of Oecomys caicarae J. A. Allen), Hato San José, 20 km W La Paragua (USNM 406009); Falcón, Capatárida (USNM 442297–442300); Guárico, San José de Tiznados, 52 km NNW of Calabozo (USNM 545116–545119); Monagas, Hato Mato de Bejuco, 54 km SE of Maturín (USNM 442141–4421450); Sucre, near Hacienda Tunantal, 21 km E of Cumaná (USNM 405999), Ensenada Cauranta, 7 km N and 5 km E of Guira (USNM 409856–409860); Trujillo, Agua Santa, 23 km NW of Valera (USNM 371152, 371153); Yaracuy, 19 km NW of Urama, Km 40 (USNM 372514, 372515). s u b s p e c i e s : Substantial variation in pelage color is apparent among the samples referred to O. speciosus, but whether this variation reflects broad geographic patterns that concord with any of the available junior synonyms as subspecies invites further study. Among Venezuelan populations, Linares (1998) recognized two subspecies, O. s. speciosus and O. s. caicarae, but we provisionally view O. speciosus as monotypic in lieu of studies across the entire distribution.

Map 215 Selected localities for Oecomys speciosus (●). Contour line = 2,000 m.

412 Mammals of South America

n a t u r a l h i s t o ry: Linares (1998) associated O. speciosus with palm and woodland savannas, semideciduous forest, and gallery forest. r e m a r k s : Hershkovitz’s (1960) concept of the subspecies O. concolor speciosus was an amalgam of four species (O. speciosus proper plus O. auyantepui, O. roberti, and O. trinitatis).

Oecomys superans Thomas, 1911 Large Oecomys sy n o n y m s : Oecomys superans Thomas, 1911c:250; type locality “Canelos, Rio Bobonaza, [Pastaza,] Oriente of Ecuador. Alt. 2100′.” Oecomys palmeri Thomas, 1911c:251; type locality “Canelos, [Pastaza,] Oriente of Ecuador. Alt. 2100′.” Oecomys melleus Anthony, 1924b:4; type locality “Zamora, [Zamora-Chinchipe,] eastern Ecuador, altitude about 3250 feet.” Oecomys superans: Gyldenstolpe, 1932a:42; name combination (palmeri allocated as synonym without indication of rank). Oryzomys [(Oecomys)] melleus: Ellerman, 1941:358; name combination. Oryzomys [(Oecomys)] superans: Ellerman, 1941:359; name combination (palmeri allocated as synonym without indication of rank). Oryzomys (Oecomys) superans: Sanborn, 1951:21; name combination. Oryzomys concolor superans: Hershkovitz, 1960:556; name combination (melleus and palmeri allocated as full synonyms, invalid as subspecies). Oryzomys mamorae superans: Cabrera, 1961:405; part (palmeri allocated as full synonym). Oecomys superans: Musser and Carleton, 1993:716; name combination (melleus and palmeri allocated as synonyms without indication of rank). d e s c r i p t i o n : As attested by the majority of dimensions measured, largest species of Oecomys (Table 1). Fur soft and fine in texture and moderately long (8– 10 mm over middle rump); dorsal-ventral pelage transition moderately defined, usually without ochraceous lateral line. Overall, upper parts somber in tone, dark ochraceous brown, generally stronger concentration of blackish-brown over middle dorsum and paler toward sides. Under parts dull grayish white to dirty gray, tinged or washed with buff in some specimens whose venters appear dark grayish buff; individual hairs gray basally and tipped with buff. Tail moderately longer than combined head and body (TL ≈ 111% of HBL) and uniformly dark brown above and below; caudal hairs short and expose fine scale rows, without formation of terminal tuft

or pencil. Pinnae appear small and closely rounded for size of species. Skull large and stoutly built, with moderately long and broad rostrum and relatively narrow interorbit. Supraorbital ledges well developed, distinctly diverging to sweep caudad and join prominent temporal ridges. Zygomatic arches noticeably expand toward rear and strongly taper rostrally; zygomatic plates relatively broad and dorsal notches well defined. Incisive foramina relatively short and narrow, slightly oval in shape, their posterior margins situated well anterior to molar rows. Posterolateral-palatal pits are well expressed; the mesopterygoid fossa broad, V- or U-shaped at anterior border, roof entirely osseous in some specimens or broken by narrow slits in others. Postglenoid foramen small; subsquamosal fenestra usually tiny or absent (hamular process fused with squamosal). Alisphenoid struts typically absent, and carotid circulatory plan primitive (pattern 1 of Voss 1988). Tegmen tympani contacts squamosal but does not overlap its posterior margin. Ectotympanic bullae small, revealing much of medial periotic. d i s t r i b u t i o n : Lower Andean slopes and foothills in south-central Colombia, eastern Ecuador and Peru, and westernmost Brazil (Amazonas); known elevational range from sea level to 1,800 m; most localities below 400 m. s e l e c t e d l o c a l i t i e s (Map 216): BRAZIL: Amazonas, Altamira, right bank Rio Juruá (Patton et al. 2000), Penedo, right bank Rio Juruá (Patton et al. 2000). COLOMBIA: Caquetá, Florencia, Río Bodoquera (FMNH 72013), Tres Troncas, La Tiqua, Río Caquetá (FMNH 72015, 72025). ECUADOR: Pastaza, Canelos, Río Bobonaza (type locality of Oecomys superans Thomas and Oecomys palmeri Thomas), Río Tigre (BM 54.473); Sucumbios, Santa Cecilia (KU 135117, 135150), Lagarto Yaco (MCZ 52609); Zamora-Chinchipe, Zamora (type locality of Oecomys melleus Anthony). PERU: Amazonas, vicinity of Huampami, Río Cenepa (MVZ 155010–155013); Cusco, Quincemil, Río Marcapata (FMNH 68636; LSUMZ 19276); Huánuco, Tingo Maria (BM 27.11.1.131–27.11.1.137); Junín, Satipo (MCZ 39676); Loreto, Boca del Río Curaray (AMNH 71589–71591), Santa Elena, Río Samiria (FMNH 87195, 87196); Madre de Dios, Reserva Cuzco Amazonico, 14 km NE of Puerto Maldonado (Woodman et al. 1991); San Martín, Yurac Yacu (BM 27.1.1.117–27.1.1.121); Ucayali, Balta, Río Curanja (LSUMZ 12330–12332), Sarayacu, Río Ucayali (AMNH 76175, 76298, 76456). s u b s p e c i e s : Oecomys superans is provisionally regarded as monotypic. n a t u r a l h i s t o ry: Although generally associated with lowland tropical forest, little detailed habitat information is available for O. superans. Along the Rio Juruá, western Brazil, the few specimens were collected on the ground in highly disturbed secondary growth (Patton et al. 2000).

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 413

Map 216

Selected localities for Oecomys superans (●). Contour line = 2,000 m.

r e m a r k s : Hershkovitz (1960) viewed superans as the largest and darkest of the five subspecies he identified within O. concolor. His morphological definition and distribution of the subspecies largely conform to our understanding of the species O. superans, including the recent documentation of the species in westernmost Brazil (Patton et al. 2000). The karyotype has been uniformly recorded as 2n = 80, FN = 108 (A. L. Gardner and Patton 1976; Patton et al. 2000; A. F. B. Andrade and Bonvicino 2003). The geographic ranges of O. superans and O. roberti overlap along the Andean foothills, where both have been trapped at the same localities, and the two are superficially similar and often misidentified in collections. Oecomys roberti is smaller in external and craniodental dimensions (Table 1), its ventral pelage is grayish white without any buffy overlay (although a few specimens from elsewhere in the range of O. roberti show a buffy tinge), and the incisive foramina are relatively shorter and broader, more tear-dropped shaped.

Oecomys sydandersoni Carleton, Emmons, and Musser, 2009 Anderson’s Oecomys sy n o n y m s : Oecomys concolor: Musser and Carleton, 1993:716; part (provisional identification and range extension). Oecomys sydandersoni Carleton, Emmons, and Musser, 2009:8; type locality “Bolivia, Departamento de Santa

Cruz, Provincia Velasco, El Refugio Huanchaca, 210 m; 14°46′01′′S/61°02′02′′ W.” d e s c r i p t i o n : Medium-size for genus (e.g., larger than O. bicolor or O. paricola, smaller than O. roberti or O. mamorae). Pelage soft and fine in texture and moderately short (about 5–7 mm over middle rump). Dorsal color ochraceous brown to pale tawny, generally bright in tone with more grayish showing on head and flanks; ventral pelage pale to medium gray, with hairs of chin, throat, and inguinum entirely white to base in most specimens; dorsalventral pelage transition moderately defined, without an ochraceous lateral line. Tail only slightly longer than head and body (TL ≈ 106% of HBL), brown to dark brown all around for most of length; short caudal hairs scarcely visible to unaided eye, revealing fine scale pattern, and rudimentary pencil expressed at tip. Skull ruggedly built for its size, with short rostrum and relatively broad interorbit. Supraorbital shelves strongly convergent anteriad, with free ledge approaching incipient bead. Zygomatic arches noticeably expand toward rear and strongly taper rostrally; zygomatic plates relatively broad and dorsal notches well defined. Medium-long incisive foramina very broad toward rear, posterior ends obtuse (blunt) and anterior ends acute. Posterolateral-palatal pits well expressed; mesopterygoid fossa broad, bluntly U-shaped at anterior margin, and roof entirely osseous. Alisphenoid struts typically present, and carotid circulatory plan derived (pattern 3 of Voss 1988). Ectotympanic bullae small, revealing much of medial periotic. d i s t r i b u t i o n : Extreme eastern Bolivia, departments of Beni and Santa Cruz; single elevational record at 210 m. s e l e c t e d l o c a l i t i e s (Map 217): BOLIVIA: Beni, 4 km above Costa Marques, Río Iténez (Carleton et al. 2009), Bahía de los Casara, 20 km W of Larangiera, Río Iténez (Carleton et al. 2009); Santa Cruz, El Refugio Huanchaca (type locality of Oecomys sydandersoni Carleton, Emmons, and Musser). s u b s p e c i e s : Oecomys sydandersoni is monotypic. n a t u r a l h i s t o ry: Most specimens have been captured in small clumps of woody vegetation surrounded by seasonally flooded grasslands, typically in traps placed above ground on vines, trunks, or branches within arm’s reach (Carleton et al. 2009). One individual was captured in closed riverine forest, taken on a vine snaking through a shrub along the river’s edge. r e m a r k s : Specimens of O. sydandersoni were tentatively reported as O. concolor based on their superficial similarity (Musser and Carleton 1993). As in O. concolor and O. mamorae, O. sydandersoni possesses a derived carotid circulatory pattern (Carleton et al. 2009), a condition that may indicate closer relationship among the three relative to other species of Oecomys. The species has been collected

414 Mammals of South America

Map 217 Selected localities for Oecomys sydandersoni (●). Contour line = 2,000 m.

near to but not in syntopy with O. bicolor, O. roberti, and O. trinitatis in the Parque Nacional Noel Kempff Mercado, eastern Bolivia (Emmons et al. 2006; Carleton et al. 2009).

Oecomys trinitatis (J. A. Allen and Chapman, 1893) Long-furred Oecomys sy n o n y m s : Oryzomys trinitatis J. A. Allen and Chapman, 1893:213; type locality “Princestown, Trinidad,” Trinidad and Tobago. Oryzomys flavicans subluteus Thomas, 1898f:268; type locality “W. Cundinamarca,” western slope of Cordillera Oriental, Cundinamarca, Colombia. Oryzomys palmarius J. A. Allen, 1899b:210; type locality “Quebrada Secca, [Sucre,] Venezuela.” Oryzomys fulviventer J. A. Allen, 1899b:212; type locality “Quebrada Secca, [Sucre,] Venezuela (altitude about 3000 feet).” Oryzomys tectus Thomas, 1901f:251; type locality “Bogava [Bugaba], Chiriqui, Panama. Altitude 250 m.” Oryzomys klagesi J. A. Allen, 1904b:327; type locality “El Llagual, [Bolívar,] Venezuela.” Oryzomys frontalis Goldman, 1912a:6; type locality “Corozal, Canal Zone, Panama.” Oryzomys helvolus J. A. Allen, 1913c:597; type locality “Villa Vicencio [Villavicencio] (altitude 1600 feet), about 50 miles southeast of Bogota, [Meta,] Colombia.” Oryzomys vicencianus J. A. Allen, 1913c:598; type locality “Villa Vicencio [Villavicencio] (alt. 1600 ft, about 50

miles southeast of Bogota), at base of eastern Andes, [Meta,] Colombia.” Oryzomys tectus tectus: Goldman, 1918:84; name combination. Oryzomys tectus frontalis: Goldman, 1918:85; name combination. Oecomys osgoodi Thomas, 1924f:287; type locality “Moyobamba, [Amazonas,] N. Peru. Alt. 2700′.” Rhipidomys(?) klagesi: Gyldenstolpe, 1932a:50; name combination (provisional generic allocation). Oecomys splendens Hayman, 1938:381; type locality “Mayaro, S.E. Trinidad,” Trinidad and Tobago. Oryzomys trinitatis: Tate, 1939:190; name combination (palmarius and fulviventer listed as synonyms without indication of rank). Oryzomys [(Oecomys)] osgoodi: Ellerman, 1941:358; name combination. Oryzomys (Oecomys) concolor concolor: Hershkovitz, 1960: 546; part (frontalis, helvolus, klagesi, subluteus, tectus, and vicencianus allocated as full synonyms, invalid as subspecies); not concolor Wagner. Oryzomys concolor speciosus: Hershkovitz, 1960:553; part (fulviventer, palmarius, splendens, and trinitatis allocated as full synonyms, invalid as subspecies); not speciosus J. A. Allen and Chapman. Oryzomys concolor superans: Hershkovitz, 1961:556; part (osgoodi allocated as full synonym, invalid as subspecies); not superans Thomas. Oryzomys trinitatis frontalis: Cabrera, 1961:408; name combination. Oryzomys trinitatis helvolus: Cabrera, 1961:408; name combination (vicencianus allocated as full synonym, invalid as subspecies). Oryzomys trinitatis klagesi: Cabrera, 1961:408; name combination. Oryzomys trinitatis trinitatis: Cabrera, 1961:409; name combination (fulviventer and palmarius allocated as full synonyms, invalid as subspecies). O[ryzomys]. c[oncolor]. tectus: Handley, 1966:781; name combination (frontalis indicated as full synonym, invalid as subspecies). Oecomys trinitatis: Musser and Carleton, 1993:716–717; first use of current name combination (frontalis, fulviventer, helvolus, klagesi, osgoodi, palmarius, splendens, subluteus, tectus, and vicencianus allocated as synonyms without indication of rank). d e s c r i p t i o n : Medium-large species, similar in size to O. roberti and O. concolor. Dorsal fur soft and dense, palpably luxuriant and lustrous, and deep (10–13 mm over middle rump). Head and back dark tawny brown, commonly grading to brighter ochraceous-brown over cheeks and shoulders and along flanks; some individuals exhibit

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 415 Table 1.

Size variation among Oecomys species, as indexed by select external and craniodental variables and roughly graded from smaller to larger.

Species

HBL

TL

HFL

MASS

ONL

ZB

IOB

CLM

O. rutilus

84 82–86

93 88–98

20 18–21

17 16, 18

24.2 23.4–25.0

12.8 12.2–13.4

4.4 4.2–4.6

3.3 3.2–3.4

O. bicolor

100 94–107

109 99–119

22 21–23

31 25–37

27.0 25.9–28.1

14.3 13.6–15.0

4.7 4.5–4.7

3.9 3.8–4.0

O. cleberi

105 92–117

111 99–123

23 21–29

— —

28.2 26.7–30.1

14.6 14.3–16.0

4.9 4.6–5.3

4.1 3.9–4.3

O. auyantepui

111 101–121

118 108–128

24 23–25

39 30–48

27.9 26.8–29.0

14.9 14.2–15.6

5.3 5.1–5.5

4.1 4.0–4.2

O. paricola

109 101–117

128 117–139

24 22–25

41 32–50

28.5 27.2–29.7

15.0 14.3–15.7

5.2 4.9–5.5

4.2 4.1–4.3

O. phaeotis

110 102–118

115 107–123

23 22–24

48 43, 54

29.2 28.3–30.1

15.5 15.0–16.0

4.9 4.8–5.1

4.3 4.2–4.4

O. speciosus

117 107–127

138 126–150

25 24–27

40 30–50

29.3 27.6–30.8

15.5 14.5–15.5

5.0 4.7–5.3

4.4 4.2–4.6

O. sydandersoni

125 113–137

132 124–140

24 23–26

44 37–52

29.8 28.6–31.0

16.5 15.9–17.1

5.3 5.1–5.5

4.6 4.4–4.7

O. flavicans

123 106–140

141 132–150

26 25–27

60 50–70

31.1 29.8–32.4

16.1 15.6–16.8

5.3 5.0–5.6

4.7 4.6–4.8

O. roberti

123 111–135

151 138–164

27 26–28

56 46–66

32.2 30.8–33.6

17.1 16.2–18.0

5.6 5.3–5.9

4.9 4.7–5.1

O. trinitatis

127 117–137

150 135–165

27 25–29

61 48–74

32.3 30.9–33.7

16.6 15.7–17.5

5.3 5.1–5.5

5.0 4.8–5.2

O. concolor

125 119–131

148 141–155

27 26–28

58 49–67

32.2 31.3–33.1

17.7 17.1–18.3

5.5 5.3–5.7

4.9 4.8–5.0

O. mamorae

136 127–145

159 146–172

27 26–28

61 49–73

32.4 31.0–33.8

17.0 16.2–17.8

4.9 4.7–5.1

5.0 4.8–5.2

O. catherinae

130 121–139

154 143–165

29 28–30

59 47–71

33.5 32.5–34.5

17.4 16.8–18.0

5.8 5.6–6.0

5.1 5.0–5.2

O. rex

128 121–135

155 142–168

28 27–29

59 47–71

34.0 32.8–35.2

17.6 16.8–18.4

6.5 6.0–7.0

5.3 5.1–5.5

O. superans

150 135–165

167 150–184

30 28–31

85 66–104

35.8 34.3–37.2

18.3 17.4–19.2

5.9 5.5–6.3

5.4 5.2–5.6

Abbreviations: CLM, coronal length of maxillary toothrow (M1–M3); HBL, length of head and body; HFL, length of hindfoot (including claw); IOB, least interorbital breadth; ONL, occipitonasal length; TL, length of tail; WT, weight; ZB, zygomatic breadth. Notes: Sample statistics include the mean and range based on ±1 standard deviation, which encompasses about 70% of observed cases; units of external and craniodental variables are in millimeters and mass in grams. Species samples were coarsely defined to convey broad limits of measurement variation as follows: O. auyantepui—Amapá, Brazil, French Guiana, Guyana, and Surinam (N = 26–48); O. bicolor—Amazonas and Madre de Dios, Peru (N = 36–46) ; O. cleberi—southcentral Brazil (N = 14; R. G. Rocha et al. 2012); O. catherinae—Federal District and Minas Gerais, Brazil (N = 23–27); O. concolor—Amazonas, Brazil (N = 23–24); O. flavicans—Venezuela (N = 7–55); O. mamorae—Beni and Santa Cruz, Bolivia (N = 13–49); O. paricola—Para, Brazil (N = 36–61); O. phaeotis—Peru (N = 2–12); O. rex—Amapá, Brazil, French Guiana, Guyana, and Surinam (N = 8–21); O. roberti—Amazonas, Mata Grosso, and Para, Brazil (N = 87–104); O. rutilus—French Guiana and Guyana (N = 2–16); O. speciosus—Venezuela (N = 26–51); O. superans—Colombia, Ecuador, and Peru (N = 20–86); O. sydandersoni—Beni and Santa Cruz, Bolivia (N = 21–24); O. trinitatis—Venezuela (N = 33–76). In general, sample sizes are larger for the craniodental variables, smaller for external measurements, and smallest for weight.

416 Mammals of South America

bright buffy orange dorsum; dorsal surfaces of forefeet and hindfeet dark brownish. Ventral pelage chromatically ranges from dark grayish white, through grayish white tinged with buff, to rich ochraceous gray. Demarcation between dorsal and ventral fur not well defined, occasionally marked by ochraceous lateral line in some specimens, whereas in others ochraceous tones wash along borders with grayish ventral fur. Tail longer than combined head and body (TL ≈ 118% of HBL), dark brown and unicolor or slightly paler below; caudal hairs short, scalation thus visible to eye, and form slight pencil at tip. Robust skull with relatively long rostrum, narrow interorbit, and strongly opisthodont upper incisors. Distinct supraorbital ridges or shelves delineate interorbital edges and strongly diverge caudad to join prominent temporal ridges. Zygomatic arches narrow toward rostrum but widen toward braincase; zygomatic plates broad and dorsal notches relatively deep. Incisive foramina moderately long and narrow to moderately broad, posterior margins situated anterior to molar rows. Large posterolateral palatal pits mark each side of bony palate beyond toothrows; mesopterygoid fossa broad, U-shaped at anterior margin, and its roof entirely osseous. Postglenoid foramen medium sized, but subsquamosal fenestra either closed (hamular process fused with squamosal) or very small in most specimens. Alisphenoid struts present in about 40% of sample, and carotid circulatory plan primitive (pattern 1 of Voss 1988). Tegmen tympani usually contacts rear edge of squamosal. Ectotympanic bullae small, revealing much of medial periotic. d i s t r i b u t i o n : Trinidad and Tobago, eastern, central and southern Venezuela, Guyana and Surinam, eastern Ecuador and Peru, northern and central Brazil; known elevational range from sea level to 2,150 m. s e l e c t e d l o c a l i t i e s (Map 218): BOLIVIA: Santa Cruz, El Refugio, Parque Nacional Noel Kempff Mercado (Carleton et al. 2009). BRAZIL: Acre, opposite Igarapé Porongaba, left bank Rio Juruá (Patton et al. 2000); Amazonas, Villa Bella da Imperatriz, Boca Rio Andirá (AMNH 93532, 93533), Colocação Vira Volta, left bank Rio Juruá (Patton et al. 2000); Goiás, Annapolis (AMNH 134571, 134659, 134676); Mato Grosso, Humboldt Laboratory, Rio Roosevelt, Aripuanã (USNM 545275–545277), 264 km N of Xavantina, Serra do Roncador Base Camp (BM 81.418–81.420); Mato Grosso do Sul, Maracaju (AMNH 134904); Pará, Porto Jatobal, 73 km N and 45 km W of Marabá (MPEG 15360, 15361; USNM 521532). COLOMBIA: Cauca, Sabanetas (FMNH 90281); Córdoba, Socorre, upper Río Sinu (FMNH 69197–69199); Cundinamarca, western slope of Cordillera Oriental (type locality of Oryzomys flavicans subluteus Thomas); Meta, Villa Vicencio, about 50 mi SE of Bogotá (type locality of Oryzomys helvolus J. A. Allen and Oryzomys vicencianus

J. A. Allen). GUYANA: Upper Demerara-Berbice, Comackpea, Rio Cunerara (BM 6.1.1.14). PERU: Amazonas, Moyobamba (type locality of Oecomys osgoodi Thomas); Huánuco, Río Cayamba, Hacienda Exito (FMNH 24574, 24576); Loreto, San Jacinto (KU 158192). SURINAM: Para, Carolina Kreek (FMNH 95577–95579). TRINIDAD AND TOBAGO: Tobago, Pigeon Peak, Tobago Forest Preserve (USNM 538101); Trinidad, Mayaro (type locality of Oecomys splendens Hayman), Princestown (type locality of Oryzomys trinitatis J. A. Allen and Chapman). VENEZUELA: Amazonas, Cerro Neblina, Camp V (USNM 560648–560650); Aragua, Rancho Grande Biological Station, 13 km NW of Maracay (USNM 517572–517576); Bolívar, El Llagual, near Maripa, lower Río Caura (type locality of Oryzomys klagesi J. A. Allen), San Ignacio de Yuruaní (USNM 448577–448579); Sucre, Quebrada Secca (type locality of Oryzomys palmarius J. A. Allen and Oryzomys fulviventer J. A. Allen). s u b s p e c i e s : Oecomys trinitatis is provisionally regarded as monotypic. In Venezuela, however, Linares (1998) retained O. t. klagesi along with O. t. trinitatis as recognizable subspecies. n a t u r a l h i s t o ry: In Panama, Handley (1966) considered the species (reported as Oryzomys concolor) as semiarboreal and associated with tall grass and herbaceous growth in savannas and forest openings; another Panamanian example was obtained on a log in lowland forest characterized as Dry Tropical Forest (Fleming 1970). In Venezuela, Linares (1998) considered O. trinitatis an inhabitant of dense, evergreen forests with lush undergrowth. In western Brazil, specimens were taken in terre firme and at the edge of flooded forest (Patton et al. 2000).

Map 218

Selected localities for Oecomys trinitatis (●). Contour line = 2,000 m.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 417

r e m a r k s : This nominal species forms the core of Hershkovitz’s (1960) O. concolor in terms of distributional extent and the large number of synonyms included. Even after peeling away clearly diagnosable species (see accounts of O. auyantepui, O. catherinae, O. concolor, O. flavicans, O. mamorae, O. roberti, O. speciosus, and O. superans), based on morphological differences and/or evidence of sympatry, the residuum now comprising O. trinitatis remains a composite. For example, the relationship of the senior taxon trinitatis, described from Trinidad, to mainland forms, the status of trans-Andean populations (tectus and frontalis), and level of differentiation of populations to the north and south of the Amazon River will all require attention in unraveling the heterogeneity evident within O. “trinitatis.” Patton et al. (2000) reported a karyotype of 2n = 58, FN = 96 for populations of O. trinitatis in western Amazonia.

Genus Oligoryzomys Bangs, 1900 Marcelo Weksler and Cibele R. Bonvicino

Members of the genus Oligoryzomys, commonly known as Colilargos or Pygmy Rice Rats, are found from northeastern Mexico to extreme southern Chile and Argentina, and across an elevation from sea level to around 3,500 m. Species of the genus are present in lowland and montane forests (humid and dry), such as the Atlantic Forest, lowland Amazonian rainforest, and Andean cloud forest, openvegetation habitats (grasslands and wetlands) such as the Cerrados, Pampas, Llanos, Pantanal, Chaco, and in drier environments such as Patagonia, Caatinga, and the Peruvian Pacific coast. We recognize 19 species of Colilargos for South America: O. andinus, O. arenalis, O. brendae, O. chacoensis, O. delicatus, O. destructor, O. flavescens, O. fornesi, O. griseolus, O. longicaudatus, O. magellanicus, O. mattogrossae, O. messorius, O. microtis, O. moojeni, O. nigripes, O. rupestris, O. stramineus, and O. utiaritensis. The genus contains four additional species extralimital to the continent, O. costaricensis, O. vegetus, and O. fulvescens in Central America, and O. victus from Saint Vincent Island and Martinique in the Lesser Antilles, now probably extinct (Musser and Carleton 2005; Hanson et al. 2011). An undescribed species, also extinct, is reported from Guadeloupe (Lorvelec et al. 2001). The earliest known fossils are from the Ensenadense (middle Pleistocene) in Argentina (Pardiñas et al. 2002). Species of Oligoryzomys are very small (head and body ranges between 70 and 110 mm) cursorial mice. The dorsal pelage is coarsely or homogeneous yellowish to orangishbrown; the ventral pelage is paler (superficially whitish or pale yellow). The fur is soft, without subauricular patches (as in Microryzomys, with which Oligoryzomys species have been historically confused; see Carleton and Musser 1989).

The hindfeet lack well-developed natatory fringes and interdigital webs, and have short tufts of ungual hairs at bases of claws on digits II through V. The plantar surface is densely covered with distinct squamae distal to thenar pad (the heel is smooth); the hypothenar pad is large, and interdigital pads are small and fleshy (pads 1 and 4 displaced proximally relative to 2 and 3). The claw of digit I extends to the middle of the first phalanx of digit II, and the claw of digit V extends just beyond first interphalangeal joint of digit IV. The tail is usually longer than the combined head and body length, sparsely haired, and covered with more or less conspicuous epidermal scales; it lacks a long tuft of terminal hairs, and is weakly to distinctly bicolored (dark above, pale below). Four pairs of mammae are present in most species, one each in inguinal, abdominal, postaxial, and pectoral positions, except in O. griseolus with three pairs. The skull has a delicate rostrum flanked by moderate zygomatic notches; the interorbital region is symmetrically constricted (hourglass or amphoral in shape), with rounded supraorbital margins; the braincase is squared or rounded, without well-developed temporal, lambdoidal, or nuchal crests. The zygomatic plates lack an anterodorsal spinous processes, and their posterior margins lie anterior to the M1 alveolus. Jugals are absent or reduced to slivers of bone (maxillary and squamosal processes are in contact). The nasal bones have blunt posterior margins and do not extend posteriorly beyond the lacrimals, which are equally sutured to the maxillary and frontal bones. The posterior wall of the orbit is smooth. The frontosquamosal suture is colinear with the frontoparietal suture, and the parietals lack or have small lateral expansions. The bony palate between the molar rows is smooth and long, and the mesopterygoid fossa does not extend anteriorly between the third molars. The posterolateral palatal pits are variable in size, number, and morphology but are usually not recessed in fossae. The bony roof of the mesopterygoid fossa is perforated by very large sphenopalatine vacuities. The alisphenoid strut is absent (buccinator-masticatory foramen and accessory foramen ovale are confluent), and the alisphenoid canal has a large anterior opening. The stapedial foramen and the posterior opening of the alisphenoid canal are large, but the squamosoalisphenoid groove and the sphenofrontal foramen are absent (carotid circulatory pattern 2 of Voss 1988) in all species except O. rupestris, which either lack or have only a vestigial stapedial foramen (= pattern 3). The posterior suspensory process of the squamosal is absent. The postglenoid foramen is large and rounded, and the subsquamosal fenestra is always patent. The periotic is exposed posteromedially between the ectotympanic and the basioccipital, and usually extends anteriorly to the carotid canal. The mastoid is perforated by conspicuous posterodorsal fenestra. In the mandible, the capsular process is well developed in most adults, and the superior and inferior masseteric ridges converge anteriorly as

418 Mammals of South America

an open chevron below m1. The basihyal lacks the entoglossal process. The upper incisors have smoothly rounded enamel bands, and the maxillary toothrows are parallel. The molars are bunodont, with labial flexi enclosed by a cingulum. The labial and lingual flexi of M1 and M2 do not (or shallowly) interpenetrate. The anterocone of M1 is divided into anterolabial and anterolingual conules by a distinct anteromedian flexus; the anteroloph is well developed and separated from the anterocone by a persistent anteroflexus; a protostyle is absent; mesolophs are present on all upper molars in most species, but absent in some specimens of O. rupestris; the paracone is connected by an enamel bridge to the anterior moiety of protocone; a median mure is connected to the protocone. The protoflexus of M2 is present in most species; a mesoflexus is present as a single internal fossette; the paracone is without an accessory loph. M3 has a posteroloph; hypoflexus is diminutive (tending to disappear with moderate to heavy wear) in some species, but persistent in others. An accessory labial root of M1 is absent. The anteroconid of m1 is usually without an anteromedian flexid; an anterolabial cingulum is present on all lower molars; the anterolophid is present on m1 but absent on m2 and m3; an ectolophid is absent on m1 and m2 in most species; the mesolophid is distinct on unworn m1 and m2 in most species, but reduced or absent in specimens of O. mattogrossae; the posteroflexid is present on m3. Accessory roots are absent for m1, but both m2 and m3 have one large anterior root and one large posterior root. The stomach is unilocular-hemiglandular (Carleton 1973), and the glandular epithelium does not reach the corpus; the gall bladder is absent. The distal bacular cartilage of the glans penis is large and trifid, with a robust central digit; the nonspinous tissue on rim of the terminal crater does not conceal the bacular mounds. sy n o n y m s : Mus: Olfers, 1818: 209; part (description of nigripes); not Mus Linnaeus. Hesperomys: Waterhouse, 1839:74; part (description of flavescens). Hesperomys (Calomys): Wagner, 1843a:528; part (listing of flavescens and longicaudatus); not Hesperomys Waterhouse. Hesperomys (Oryzomys): Milne-Edwards, 1890:27; part (listing of longicaudatus); not Hesperomys Waterhouse. Oryzomys: Thomas: 1894b:357; part (description of stolzmanni); not Oryzomys Baird. Oligoryzomys Bangs, 1900a:94; type species Oryzomys navus Bangs (= Oligoryzomys delicatus), by original designation. Oryzomys (Oligoryzomys): J. A. Allen, 1910b:100; name combination.

r e m a r k s : Oligoryzomys was variously considered as a full genus, subgenus, or synonym of Oryzomys, and its status as full genus was established only recently (Carleton and Musser 1989). Monophyly of Oligoryzomys is supported by phylogenetic analyses of allozymes (Dickerman and Yates 1995), mitochondrial and nuclear gene sequences (Myers et al. 1995; Weksler 2003; Agrellos et al. 2012), and morphological characters (Weksler 2006). The taxonomy of the genus, however, is in much disarray, and comprehensive studies on this widely distributed and specious genus are lacking. The taxonomic arrangement employed here is based on Carleton and Musser (1989), Musser and Carleton (1993, 2005), Bonvicino and Weksler (1998), Weksler and Bonvicino (2005), and Agrellos et al. (2012); it should be viewed as provisional. Microakodontomys was included as a junior synonym of Oligoryzomys by Weksler et al. (2006), but molecular and genetic data have indicated that this taxon might merit generic recognition (see account of Microakodontomys transitorius for additional information). Carleton and Musser (1989) identified three undescribed species (“sp. A” from Caparaó, “sp. B” from Bolivian and Peruvian Andes, and “sp. C” from the Altiplano of southern Peru). The “sp. A” from Caparaó is identified here as O. flavescens, the other two cannot be allocated to any species, despite the karyological data from “sp. B” (2n = 68, FN = 74, A. L. Gardner and Patton 1976). Another undescribed species reported by Agrellos et al. (2012) from the Brazilian state of Amapá and French Guiana, is here considered as O. messorius (see that account). KEY TO THE SOUTH AMERICAN SPECIES OF OLIGORYZOMYS:

1. Large opening of stapedial foramen (carotid circulation pattern 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1′. Small or vestigial opening of stapedial foramen (carotid circulation pattern 3); undivided anterocone; endemic to high elevations in central Brazil; 2n = 44–46, FN = 52–53 . . . . . . . . . . . . . . . . Oligoryzomys rupestris 2. With eight mammae . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2′. With six mammae; fur thick and long (length almost 1 cm); found only in the Táchira Andes of Venezuela, and Cordillera Oriental of easternmost Colombia . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Oligoryzomys griseolus 3. Tail shorter, equal or slightly longer than head and body length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3′. Tail considerably longer than head and body length. . 5 4. Ventral color whitish; tail length approximately equal to head and body length; found only south of 45°S in Tierra del Fuego; 2n = 54, FN = 56 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oligoryzomys magellanicus

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 419

4′. Ventral color whitish or buffy with perigenital and gular patches of pure white hairs; found in forested habitats in Amazonian basin; 2n = 64, FN = 66 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oligoryzomys microtis 5. Limit between ventral and dorsal coloration well defined . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5′. Limit between ventral and dorsal coloration scarcely defined or absent . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 6. Ventral coloration creamy or yellowish white . . . . . . . 7 6′. Ventral coloration whitish . . . . . . . . . . . . . . . . . . . . . 9 7. Tail clearly bicolored on proximal half . . . . . . . . . . . . 8 7′. Tail unicolored, slightly bicolored near the base; dorsal color reddish brown; found in the Andes at elevations between 600–3,350 m; 2n = 60, FN = 76 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Oligoryzomys destructor 8. Dorsal color pale ochraceous darkened by numerous fine dusky lines, head color grayish; found in Andes; 2n = 60, FN = 70 . . . . . . . . . . . . Oligoryzomys andinus 8′. Dorsal color fawn-colored or pale rufous, head color similar to body color; distributed along eastern and western flanks of Andes in Chile and Argentina; 2n = 56, FN = 66. . . . . . . . . . . . . . .Oligoryzomys longicaudatus 9. Orange or yellowish pectoral band present . . . . . . . . 10 9′. Pectoral band absent . . . . . . . . . . . . . . . . . . . . . . . . 11 10. Smaller zygomatic plate, darker overall dorsal coloration, head color similar to body color; found in eastern Brazil, Paraguay, Uruguay, and Argentina; 2n = 62, FN = 82. . . . . . . . . . . . . . . . . . . Oligoryzomys nigripes 10′. Larger zygomatic plate, paler overall dorsal coloration, head color gray, especially in sides; endemic to central and northeastern Brazil; 2n = 52, FN = 68 . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oligoryzomys stramineus 11. Hair on skin and throat regions with gray base; distinctive tufts of orangish hairs anterior to the ears absent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 11′. Hair on skin and throat regions all white, including on the base; distinctive tufts of orangish hairs anterior to the ears present; occurs in northern Argentina, eastern Bolivia, southwestern Brazil, and Paraguay; 2n = 58, FN = 74. . . . . . . . . . . . . . . . . Oligoryzomys chacoensis 12. Tail unicolored or slightly bicolored; 2n = 72, FN = 76 . . . . . . . . . . . . . . . . . . . . . . . Oligoryzomys utiaritensis 12′. Tail sharply bicolored; 2n = 58, FN = 74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oligoryzomys brendae 13. Dorsal coloration darker or orangish brown . . . . . . 14 13′. Dorsal coloration clay-colored; found only in hydromorphic vegetation patches in arid and semiarid coastal plains of Peru . . . . . . . . . . . . . . Oligoryzomys arenalis 14. Dorsal coloration grayish, ventral coloration whitish with large gray basal band; found in montane regions of northernmost Brazil, southern Venezuela, and Guyana; 2n = 66, FN = 74 . . . . . . . . . . . Oligoryzomys messorius

14′. Dorsal coloration orangish brown or dark brown, ventral coloration buffy or cream . . . . . . . . . . . . . . . 15 15. Smaller incisive foramen, never extending posteriorly beyond alveolar line of M1. . . . . . . . . . . . . . . . . . . . 16 15′. Longer incisive foramen, extending posteriorly beyond alveolar line of M1; 2n = 64–66, FN = 66–68 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oligoryzomys flavescens 16. Very small size, head and body length 84 mm; 2n = 70, FN = 74 . . . . . . . . . . . . . . . . . . . . . . . . . . Oligoryzomys moojeni 17. Dorsal pelage strongly lined with dark hairs, general heterogeneous coloration, head color gray . . . . . . . . 18 17′. Dorsal pelage coloration homogeneous, head color similar as the body color, orange hair around the nose; sides lack guard hairs; distributed in northern South America, 2n = 60, FN = 74. . . . .Oligoryzomys delicatus 18. Distributed in Brazil and Paraguay (and possibly Bolivia); 2n = 62, FN = 64 . . . Oligoryzomys mattogrossae 18′. Restricted to Formosa province, Argentina . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oligoryzomys fornesi

Oligoryzomys andinus (Osgood, 1914) Andean Colilargo sy n o n y m s : Oryzomys andinus Osgood, 1914b:156; type locality “Hacienda Llagueda [= Llaugueda, Stephens and Traylor 1983], upper Rio Chicama, [Libertad,] Peru. Altitude 6,000 ft.” Oligoryzomys andinus: Gyldenstolpe, 1932a:29; first use of current name combination. d e s c r i p t i o n : Medium-sized mouse allied to O. destructor but with longer hindfoot and very long tail. Coloration of upper parts pale ochraceous darkened by numerous fine dusky lines; slight ochraceous lateral line present; face and head somewhat grayish; and under parts creamy white, sharply differentiated, hairs with slaty bases. Ears thinly haired with ochraceous basally and internally, brownish distally and externally. Dorsal surfaces of both forefeet and hindfeet white. Tail thinly clothed with very short hairs, brownish above, whitish below for proximal half, gradually becoming dusky toward tip. Skull similar in general form to that of O. destructor but relatively narrower with smaller teeth and bullae; incisive foramina compressed; braincase angled and truncate rather than rounded behind; and interorbital region at base of nasals slightly concave between sharply angled edges. d i s t r i b u t i o n : Oligoryzomys andinus occurs on the dry Pacific slopes of the Peruvian Andes and the western margins of the Altiplano of Peru and Bolivia, between 1,700 and 4,000 m. An isolated population occurs in the eastern Peruvian Andes in Cusco department (Carleton and Musser 1989). The precise distributional limits of this species are unknown (Musser and Carleton 2005).

420 Mammals of South America

Oligoryzomys arenalis Thomas, 1913

Map 219 Selected localities for Oligoryzomys andinus (●). Contour line = 2,000 m.

s e l e c t e d l o c a l i t i e s (Map 219; from Carleton and Musser 1989, except as noted): BOLIVIA: Oruro, 1 km W of Huancaroma; Potosí, 31 km SW Acacio on road to Uncia (S. Anderson 1997), 3 km SE of Pocoata. PERU: Ancash, I km N and 12 km E of Pariacoto; Callon, 2 km S and 11 km W of Huarás; Cusco, 94 km W of Cuzco on road to Abancay; La Liberdad, Hacienda Llaugueda (type locality of Oryzomys andinus Osgood); Lima, below Huaros, 6.3 mi W of Casapalca, Zarate, 6 km E of Pueblo San Bartolomé; Piura, Porculla Pass. s u b s p e c i e s : Oligoryzomys andinus is monotypic. n a t u r a l h i s t o ry: Oligoryzomys andinus is used as prey by the Barn Owl (Tyto alba) in Bolivia (S. Anderson 1997). No other aspect of ecology, behavior, reproductive biology, or other life history attributes is known. r e m a r k s : Samples of this species used in morphometric (Olds and Anderson 1987:269) and allozyme analyses (Dickerman and Yates 1995:188) were misidentified as Oryzomys longicaudatus and Oligoryzomys destructor, respectively. The karyotype of Oligoryzomys andinus is characterized by 2n = 60 and FN = 70 (A. L. Gardner and Patton 1976). The species was recorded sympatrically with O. arenalis in Lima department, Peru (Arana-Cardó and Ascorra 1994, in Musser and Carleton 2005).

Sandy Colilargo sy n o n y m s : Oryzomys arenalis Thomas, 1913c:571; type locality “Eten [= Etén]; sea-level,” Lambayeque, Peru. Oligoryzomys arenalis: Gyldenstolpe, 1932a:27; first use of current name combination. d e s c r i p t i o n : Smaller than any allied species. General dorsal color clay over underlying buffy, lined with dark brown; head slightly grayer and less buffy; sides buffy, with somewhat buffy line separating dorsal from ventral pelage; under surfaces creamy white, with slight buffy tint and with slaty bases to hairs; ear only slightly darker than dorsum; chin white; dorsal surfaces of forefeet and hindfeet white; tail long and bicolored, brown above and creamy white below. Skull similar to but smaller than that of O. destructor; zygomatic plates well developed and projecting forward; braincase not especially enlarged; interorbital space narrow, narrow part long and evenly curved, not especially divergent posteriorly, and supraorbital edges sharply square. d i s t r i b u t i o n : Oligoryzomys arenalis is found in the arid and semiarid coastal plains of Peru (Musser and Carleton 2005). s e l e c t e d l o c a l i t i e s (Map 220): PERU: Arequipa, Atiquipa (Zeballos et al. 2000), Lomas, 7 km E of Matarani (MVZ 150165); Cajamarca, 35 mi WNW of

Map 220 Selected localities for Oligoryzomys arenalis (●). Contour line = 2,000 m.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 421

Cajamarca (MVZ 137918); La Libertad, Menocucho (FMNH 19422), Pacasmayo (Osgood 1914b), Trujillo (Osgood 1914b); Lambayeque, Etén (type locality of Oryzomys arenalis Thomas); Lima, Matucana (FMNH 53058); Piura, 15 km by road E of Canchaque (LSUMZ 19261), Faique, Los Potreros (FMNH 84442), Palambla (AMNH 63712), 33 road km SW of Huancabamba, W slope (LSUMZ 19256). s u b s p e c i e s : Oligoryzomys arenalis is monotypic. n a t u r a l h i s t o ry: Oligoryzomys arenalis is a rare species with an insectivorous-granivorous diet (Zeballos et al. 2000). This species is found in the dry coast of Peru in hydromorphic vegetation patches close to rivers and lagoons, at the edges of small swamps or irrigating ditches (Osgood 1914b), but it is not found in gallery forest (H. Zeballos, pers. comm.). r e m a r k s : Oligoryzomys arenalis was recorded sympatrically with O. andinus in Lima department (AranaCardó and Ascorra 1994, in Musser and Carleton 2005).

Oligoryzomys brendae Massoia, 1998 San Javier’s Colilargo sy n o n y m : Oligoryzomys brendae Massoia, 1998:243; type locality “Cerro San Javier, Dpto. Tafí Viejo (aprox. 1000m. de altura),” Tucumán, Argentina. d e s c r i p t i o n : Size large for genus (mean head and body length 89.7 mm; tail length 126.0 mm; hindfoot length [with claw] 26.5 mm; condyloincisive length of skull 22.9 mm; maxillary toothrow length 3.9 mm); dorsal color orangish brown, somewhat grizzled in appearance; ventral hairs with gray bases and white to ochraceous tips; ears short (mean 18.2 mm in length), rounded, and dark brown; and tail longer than head and body (140% of length), sharply bicolored. Skull relatively robust with short, broad rostrum; well-expanded zygomatic arches; inflated and broad braincase; narrow and hourglass-shaped interorbital region with slightly defined supraorbital ridges; and relatively long incisive foramina extending anterior margins of M1s (emended diagnosis from Teta, Jayat et al. 2013). d i s t r i b u t i o n : Oligoryzomys brendae is found mainly in forested and highland grassland environments of the Yungas from northernmost Salta province southward to Catamarca province, Argentina, between 700 and 2,900 m. It extends farther to the south in La Rioja province where it is restricted to isolated humid ravines at the ecotone between the xeric Chaco Seco and Monte desert formations (Teta, Jayat et al. 2013). s e l e c t e d l o c a l i t i e s (Map 221; from Teta, Jayat et al. 2013, except as noted): ARGENTINA: Catamarca, Las Chacritas, ca. 28 km NNW of Singuil, Las Juntas (MIC 203), Mogote Las Trampas, ca. 15 km NW of Chumbicha;

Jujuy, ca. 3 km S Bárcena, La Herradura, 12 km SW of El Fuerte, Quyegrada Alumbriojo, ca. 8 km NE of Santa Ana, Parque Nacional Calilegua; La Rioja, Pampa de la Viuda, km 19 Rte 73; Salta, El Corralito, ca. 25 km SW of Campo Quijano, 1.6 km W of Los Toldos, Metán (CML-PIDBA 986); Tucumán, Alberdi, ca. 10 km S of Hualinchay, Cerro San Javier (type locality of O. brendae). s u b s p e c i e s : Oligoryzomys brendae is monotypic. n a t u r a l h i s t o ry: Published information on the natural history of this species is lacking. r e m a r k s : Recent phylogenetic analyses of mtDNA sequences (Gonzalez-Ittig et al. 2010; Palma et al. 2010; Teta, Jayat et al. 2013) suggested that O. brendae is a member of a destructor species group, and we recognize it as a valid species based on these data. Nevertheless, both the taxonomic status and geographic distribution of brendae needs to be re-evaluated in a comprehensive revision of destructor species group, particularly with respect to those southern Bolivian specimens from Potosi and Tarija departments assigned herein to O. destructor (see also Teta, Jayat et al. 2013). Palma et al. (2010) considered brendae as a nomen nudum because Massoia’s work was published in a meeting presentation. However, we agree with Musser and Carleton (2005) that brendae is a valid name because the International Code of Zoological Nomenclature (ICZN 1985, 1999) does not exclude this type of publication as valid. Furthermore, although the description is very short, it contains all formal requirements, such as holotype and

Map 221 Selected localities for Oligoryzomys brendae (●). Contour line = 2,000 m.

422 Mammals of South America

type locality designations, and comparisons to other species. Selected localities are from Gonzalez-Ittig et al. (2010; specimens identified as O. destructor); Palma et al. (2010; specimens identified as Oligoryzomys sp.1), and Teta, Jayat et al. (2013), who recently reviewed this species. Specimens with a 2n = 58, FN = 74 karyotype described by Espinosa and Reig (1991) as Oligoryzomys cf. longicaudatus belong to O. brendae (see Teta, Jayat et al. 2013).

Oligoryzomys chacoensis (Myers and Carleton, 1981) Chacoan Colilargo sy n o n y m s : Oryzomys (Oligoryzomys) chacoensis Myers and Carleton, 1981:19; type locality “419 km by road NW Villa Hayes (alongside the Trans Chaco Highway), Dept. Boquerón, Paraguay.” Oligoryzomys chacoensis: Carleton and Musser, 1989: 72; first use of current name combination. d e s c r i p t i o n : Medium sized, distinguished from congeners by combination of whitish under parts, with hairs white to base on chin and throat, relatively long ears with hairs on inner surface with unusually short or absent dark basal bands, small but distinctive tuffs of orange hairs anterior to ears, and karyotype with 2n = 58, FN = 74. d i s t r i b u t i o n : Oligoryzomys chacoensis occurs in the Cerrado, Chaco, and semidry forests of northern Argentina, eastern Bolivia, southwestern Brazil, and Paraguay (Weksler and Bonvicino 2005). s e l e c t e d l o c a l i t i e s (Map 222): ARGENTINA: Formosa, Riacho Pilagá (USNM 236243); Jujuy, San Salvador (INEVH [JY 1332]); Salta, Orán (INEVH [OR 22498]). BOLIVIA: Chuquisaca, Porvenir (AMNH 262120); Santa Cruz, 7 km E and 3 km N of Ingeniero Mora (AMNH 247769), San Ignacio de Velasco (USNM 391524); Tarija, Entre Rios (USNM 271412), Taringuiti (Weksler and Bonvicino 2005). BRAZIL: Mato Grosso, Cáceres (USNM 390126); Mato Grosso do Sul, Corumbá, 10 km NE Urucum (USNM 390124). PARAGUAY: Alto Paraguay, Agua Dulce (Weksler and Bonvicino 2005); Boquerón, Fortín Guachalla (Weksler and Bonvicino 2005), Fortín Teniente Pratts Gil (Weksler and Bonvicino 2005), 419 km by road NW of Villa Hayes (type locality of Oryzomys [Oligoryzomys] chacoensis Myers and Carleton); Presidente Hayes, Estancia Laguna Porá (Weksler and Bonvicino 2005), 8 km NE of Juan de Zalazar (UMMZ 134358), Puerto Pinasco (USNM 236293). s u b s p e c i e s : Oligoryzomys chacoensis is monotypic. n a t u r a l h i s t o ry: Specimens of O. chacoensis have been caught in bushes and low trees in the Paraguayan Chaco (Myers and Carleton 1981); the same authors reported an average of 4.6 embryos (range: 2–5) in 10 pregnant females from Paraguay, and suggested that reproduction occurred in January, February, July, with few births

Map 222 Selected localities for Oligoryzomys chacoensis (●). Contour line = 2,000 m.

in June (winter). S. Anderson (1997) reported two females with three embryos each, and one with five embryos, from Bolivia. Andean and Bermejo hantaviruses are associated with O. chacoensis (González Della Valle et al. 2002; Fulhorst et al. 2004). r e m a r k s : Thomas (1925b:578) referred to specimens of this species as Oryzomys sp., flavescens group. The karyotype of O. chacoensis is characterized by 2n = 58, FN = 74 (Myers and Carleton 1981). Two specimens from northeastern Brazil (USNM 528416, 304583) identified by Carleton and Musser (1989) as O. chacoensis are actually O. stramineus (see Bonvicino and Weksler 1998). The distribution of O. chacoensis given by Weksler and Bonvicino (2005) mistakenly included specimens from Tucumán and Jujuy provinces, Argentina, as O. chacoensis based on a wrong interpretation of karyotype provided by Espinosa and Reig (1991); these specimens are herein considered as O. brendae (see that account).

Oligoryzomys delicatus (J. A. Allen and Chapman, 1897) Delicate Colilargo sy n o n y m s : Oryzomys delicatus J. A. Allen and Chapman, 1897a:19; type locality “Caparo, Trinidad,” Trinidad and Tobago.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 423

Oryzomys navus Bangs, 1899:9; type locality “Pueblo Viejo [= El Pueblito; Paynter 1997], Sierra Nevada de Santa Marta, [La Guajira,] Colombia. Altitude, 8000 feet.” Oryzomys tenuipes J. A. Allen, 1904b:328; type locality “Merida (alt. 1630 m.), [Mérida,] Venezuela.” Oryzomys (Oligoryzomys) munchiquensis J. A. Allen, 1912: 85; type locality “La Florida (alt. 7700 ft.),” Cauca, Colombia. Oligoryzomys navus navus: Gyldenstolpe, 1932a:27; name combination. Oligoryzomys delicatus: Gyldenstolpe, 1932a:28; first use of current name combination. Oligoryzomys tenuipes: Gyldenstolpe, 1932a:28; name combination. Oligoryzomys munchiquensis: Gyldenstolpe, 1932a:28; name combination. Oligoryzomys delicatulus Tate, 1939:191; incorrect subsequent spelling of Oryzomys delicatus J. A. Allen and Chapman. Oryzomys delicatus navus: Cabrera, 1961:388; name combination. Oryzomys delicatus tenuipes: Cabrera, 1961:389; name combination. Oligoryzomys fulvescens: Carleton and Musser, 1989:70; part, specimens from northern South America. d e s c r i p t i o n : Small with yellowish brown fur above, darker and more rufus brown medially, mixed sparingly with blackish-tipped hairs; rump clear yellowish rufus; sides paler, yellowish buff; under parts clear buff; legs like adjoining parts of body; and dorsal surfaces of both forefeet and hindfeet yellowish white. d i s t r i b u t i o n : Oligoryzomys delicatus is distributed in South America throughout Colombia, northernmost Ecuador, northern Venezuela, and Trinidad and Tobago, and the coastal region of the Guianas. In Venezuela and the Guianas, the species is limited to coastal lowlands and llanos. s e l e c t e d l o c a l i t i e s (Map 223): COLOMBIA: Cauca, Almaguer (AMNH 33860), Cocal (AMNH 32600); Cundinamarca, Paime (AMNH 71367); Huila, La Palma (AMNH 33858), near Villavieja (MVZ 113373); La Guajira, San Miguel (AMNH 38920); Magdalena, Palomino (AMNH 38917); Meta, 7 km NE of Villavicencio (AMNH 207936), Puerto López (ROM 90530); Quindio, Salento (AMNH 32925); Valle del Cauca, Pichindé (USNM 483980). ECUADOR: Napo, Santa Cecilia (KU 112879). SURINAM: Paramaribo, Paramaribo (USNM 319970). TRINIDAD AND TOBAGO: Trinidad, Caparo (type locality of Oryzomys delicatus J. A. Allen and Chapman), Nariva, Nariva Swamp (AMNH 189372). VENEZUELA: Apure, Hato El Frio (AMNH 257241); Aragua, Rancho Grande Biological Station (USNM 517581); Falcón, Río Socopo, 80 km NW Carora (USNM 442175); Guárico,

Hato Las Palmitas (USNM 442154); Lara, near El Tocuyo (USNM 495473); Mérida, Mérida (type locality of Oryzomys tenuipes J. A. Allen), Timotes (USNM 270814); Miranda, Río Chico (USNM 387881); Monagas, Hato Mata de Bejuco (USNM 442192), San Agustín (USNM 416707); Portuguesa, La Arenosa (AMNH 269143); Sucre, Cumaná, 2 km E (USNM 406024), Manacal (USNM 409911); Yaracuy, near Urama (USNM 374693); Vargas, Los Venados (USNM 371167); Zulia, near Cerro Azul (USNM 442176). s u b s p e c i e s : Cabrera (1961) regarded three of the names we list above in the synonymy of O. delicatus as valid subspecies (navus Bangs and tenuipes J. A. Allen, in addition to the nominotypical form), with another considered a valid species (munchiquensis J. A. Allen). However, because none of these taxa have been evaluated, we believe it is premature to comment on the validity of any names as recognizable geographic races. n a t u r a l h i s t o ry: Oligoryzomys delicatus was one of the most frequently captured rodents of the Llanos of Venezuela, being trapped in Paspalum savanna and lowland savanna (Utrera et al. 2000, as O. fulvescens). This species is a natural host of Maporal hantavirus in Venezuela (Bayard et al. 2004; Fulhorst et al. 2004; Hanson et al. 2011). r e m a r k s : We recognize O. delicatus as a valid species distinct from O. fulvescens based on phylogenetic assessments of Rogers et al. (2009) and Hanson et al. (2011), which show that Oligoryzomys specimens from northern South America (i.e., O. delicatus) form a clade separate from O. fulvescens from Mexico and Honduras. Therefore, we considered most taxa from South America previously treated as junior synonyms of O. fulvescens (e.g., Musser and Carleton, 2005) as belonging to O. delicatus, with O. fulvescens restricted to Mexico and Central America. We note, however, that neither Hanson et al. (2011) nor we have examined relevant type material to support of

Map 223 Selected localities for Oligoryzomys delicatus (●). Contour line = 2,000 m.

424 Mammals of South America

this taxonomic arrangement. Karyotypes of O. delicatus are reported as 2n = 62, FN = 74, 76 (Venezuela, Bolívar, as Oryzomys [Oligoryzomys] longicaudatus, variant 3, A. L. Gardner and Patton 1976) and 2n = 60, FN = 72 (as O. fulvescens from Miranda, Venezuela [Kiblisky 1969] and Surinam [R. J. Baker et al. 1983]). We also recognize O. messorius, listed as a subspecies of O. delicatus by Cabrera (1961), as a valid species based on the distinct karyotype and morphology of specimens from Mt. Roraima and elsewhere in southern Guyana (see that account), and phylogenetic results (G. B. Miranda et al. 2009; Agrellos et al. 2012).

Oligoryzomys destructor (Tschudi, 1844) Tschudi’s Colilargo sy n o n y m s : Hesperomys destructor Tschudi, 1844:182; type locality “im Oststriche” (= east region), Peru; restricted by Cabrera, 1961:390 to “las haciendas junto al río Chinchao, departamento de Huánuco, entre los 900 y los 1000 m de altitude” based on Hershkovitz (1940a:81). Hesperomys melanostoma Tschudi, 1844:182; type locality “im Oststriche” (= east region), Peru; restricted by Cabrera, 1961:393 to “Departamento de Huánuco” based on Hershkovitz (1940a:81). Oryzomys stolzmanni Thomas, 1894b:357; type locality “Huambo, [Amazonas,] N. Peru, 3700 feet.” Oryzomys destructor: E.-L. Trouessart, 1897:528; name combination. Oryzomys melanostoma: E.-L. Trouessart, 1897:528; name combination. Oryzomys stolzmanni maranonicus Osgood, 1914b:155; type locality “Hacienda Limon [= Hacienda Limón], near Balsas, Marañon River,” upper Río Marañón, Cajamarca, Peru. Oryzomys longicaudatus destructor: Thomas, 1928b:261; name combination. Oryzomys (Oligoryzomys) destructor: Tate, 1932f:9; name combination. Oryzomys (Oligoryzomys) stolzmanni stolzmanni: Tate 1932f:10; name combination. Oligoryzomys stolzmanni: Gyldenstolpe, 1932a:28; name combination. Oligoryzomys minutus maranonicus: Gyldenstolpe, 1932a: 29; name combination. Oryzomys (Oligoryzomys) spodiurus Hershkovitz, 1940a: 79; type locality “Hacienda Chinipamba near Peñaherrera, Intag, in the subtropical forest of the western slope of the western cordillera of the Andes, Imbabura Province, Ecuador. Altitude, about 1500 meters.” Oryzomys (O[ligoryzomys].) longicaudatus destructor: Hershkovitz, 1940a:81; name combination.

Oryzomys (O[ligoryzomys].) longicaudatus stolzmanni: Hershkovitz, 1940a:81; name combination. Oryzomys stolzmanni stolzmanni: Sanborn, 1950:2; name combination. Oryzomys longicaudatus maranonicus: Cabrera, 1961:391; name combination. Oryzomys longicaudatus stolzmanni: Cabrera, 1961:392; name combination. Oryzomys spodiurus: Cabrera, 1961:395; name combination. Oligoryzomys destructor: Carleton and Musser, 1989:73; first use of current name combination. d e s c r i p t i o n : Upper body reddish brown, interspersed with numerous black hairs and some gray with light tips; sides of body and outer part of hindlimbs reddish yellow; hair color behind ears lighter, while on head black hair more frequent; throat and chest whitish gray, while belly yellowish white; dorsal surfaces of feet covered by short silver-gray hair, with hairs of nail base very long; soles light brown, and nails are yellowish brown; tail brown and slightly shorter than the head and body length; internal ear surfaces with short, light brown hair, external surface covered with longer, blackish hairs; vibrissae black on basal-half and white toward tip; nose hair silver white. d i s t r i b u t i o n : Oligoryzomys destructor occurs in the Andes from southernmost Colombia to Bolivia, through Ecuador (on both eastern and western slopes) and Peru (eastern slopes and Amazonian drainage), over an elevational range from 600 to 3,350 m (Carleton and Musser 1989). s e l e c t e d l o c a l i t i e s (Map 224): ARGENTINA: Jujuy, San Salvador (Rivera et al. 2007); Salta, Metán (Rivera et al. 2007); Tucumán, Monteros (OMNH 18656). BOLIVIA: Chuquisaca, Tola Orko (S. Anderson 1997); Cochabamba, Incachaca (S. Anderson 1997); La Paz, La Reserva (S. Anderson 1997), Ñequejahuira (S. Anderson 1997), Sorata (S. Anderson 1997), Ticunhuaya (S. Anderson 1997); Oruro, Poopo (S. Anderson 1997); Potosí, Tupiza (S. Anderson 1997); Santa Cruz, 1 km N and 8 km W of Comarapa (S. Anderson 1997), Vallegrande (S. Anderson 1997); Tarija, Tarija, 3 km SE of Cuyambuyo (S. Anderson 1997). COLOMBIA: Nariño, Ricaurte (AMNH 34233). ECUADOR: Chimborazo, Pallatanga (Carleton and Musser 1989); El Oro, Pinas (AMNH 61356); Loja, Puyango, Alamor (AMNH 61358); Pichincha, Gualea (AMNH 36297), Mojanda region (Carleton and Musser 1989), near Mount Illiniza (Carleton and Musser 1989); Zamora-Chinchipe, Zamora (AMNH 60546). PERU: Amazonas, 6 road km SW of Lake Pomacochas (LSUMZ 19265), Uscho (AMNH 73197); Apurimac, 10 km SSE of Abancay (MVZ 115650); Ayacucho, Huanhuachayo (A. L. Gardner and Patton 1976); Cajamarca, Hacienda

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 425

Limón (type locality of Oryzomys stolzmanni maranonicus Osgood); Cusco, directly below Marcapata (LSUMZ 19252), Bosque Aputinye above Huyro (LSUMZ 19285); Huánuco, E slope Cordillera Carpish, Carretera Central (LSUMZ 14361), Río Chinchao (type locality of Hesperomys destructor Tschudi); Junín, near San Ramón, 22 mi E of Tarma (AMNH 231676), Perené (AMNH 61817); Puno, 3 mi N of Limbani (MVZ 116065), 11 km NNE of Ollachea (MVZ 172610), 14 km W of Yanahuaya (MVZ 173423). s u b s p e c i e s : Several subspecies have been recognized in the literature (Hershkovitz 1940a; Cabrera 1961), but the validity of these must wait an appropriate evaluation of geographic variation based on adequate samples of museum specimens. n a t u r a l h i s t o ry: Most Bolivian records of O. destructor are from the Yungas forests (S. Anderson 1997:394). Three pregnant females were recorded from Bolivia in May and April with three, four, and five embryos each (S. Anderson 1997). Recorded ectoparasites include

Map 224 Selected localities for Oligoryzomys destructor (●). Contour line = 2,000 m.

the mites Gigantolaelaps wolffsohni, Laelaps paulistanensis, and Mysolaelaps microspinosus, and the flea Craneopsylla minerva (Lareschi et al. 2003). r e m a r k s : The karyotype of O. destructor is characterized by 2n = 60 and FN = 76 (A. L. Gardner and Patton 1976, as Oryzomys (Oligoryzomys) longicaudatus, variant 4). Olds and Anderson (1987), in their review of Oligoryzomys, included specimens of this species under O. longicaudatus. Both the taxonomy and distributional limits are poorly understood (Musser and Carleton 2005:1140).

Oligoryzomys flavescens (Waterhouse, 1837) Flavescent Colilargo sy n o n y m s : Mus flavescens Waterhouse, 1837:19; type locality “Maldonado,” Maldonado, Uruguay. Hesperomys flavescens: Waterhouse, 1839:74; name combination. H[esperomys]. (Calomys) flavescens: Wagner, 1843a:530; name combination. Oryzomys longicaudatus flavescens: E.-L. Trouessart, 1897: 527; name combination. Oryzomys flavescens: Thomas, 1926d:603; name combination. Oryzomys flavescens: J. R. Contreras and Rosi, 1980a:157; first use of current name combination. Oligoryzomys flavescens occidentalis J. R. Contreras and Rosi, 1980a: 158; type locality “Colonia Alto del Algarrobal, Departamento San Rafael, Provincia de Mendoza,” Argentina. Oligoryzomys flavescens antoniae Massoia, 1983; type locality “República Argentina, provincia de Misiones, departamento de Capital, arroyo Itaembé Mini, debajo del puente sobre la Ruta Nacional Nº 12.” Oligoryzomys microtis: Carleton and Musser, 1989:71; part; not Oryzomys (Oligoryzomys) microtis J. A. Allen. Oligoryzomys sp. A: Carleton and Musser, 1989:72; name combination. d e s c r i p t i o n : Small species characterized by dorsal color bright brownish-orange finely intermixed with dark hairs and lateral color of brighter orange. Skull with long incisive foramina that usually reach M1s, and short mesopterygoid fossa that does not reach M3s. d i s t r i b u t i o n : Oligoryzomys flavescens occurs in northern Argentina, eastern Paraguay, throughout Uruguay, and eastern Brazil, from sea level to about 1,800 m (Bonvicino et al. 1997). s e l e c t e d l o c a l i t i e s (Map 225; from Weksler and Bonvicino 2005, except as noted): ARGENTINA: Buenos Aires, Balcarce, Berazategui, Diego Gaynor, Ezeiza, Punta Lara, General Lavalle, Monte Hermoso; Córdoba, Río Cuarto;

426 Mammals of South America

Jujuy, Maimará; Misiones, Arroyo Itaembé Mini (type locality of Oligoryzomys flavescens antonia Massoia); Tucumán, Concepción. BOLIVIA: Tarija, Tarija. BRAZIL: Bahia, Rio Una, 10 km ESE of São José); Minas Gerais, Itamonte, Viçosa; Paraná, Piraquara, Ponta Grossa; Rio Grande do Sul, Esmeralda, Sapiranga, Taím, Tôrres; Santa Catarina, Itá (MNRJ [CRB 1932]); São Paulo, Americana, Caçapava, Casa Grande. PARAGUAY: Canendiyú, 6.3 km by road N of Curuguaty (Myers and Carleton 1981); Misiones, San Pablo; Presidente Hayes, La Golondrina. URUGUAY: Artigas, Artigas; Colonia, Colonia del Sacramento; Maldonado, Maldonado (type locality of Mus flavescens Waterhouse); Montevideo, Montevideo; Río Negro, Fray Bentos. s u b s p e c i e s : Musser and Carleton (2005) regarded Oligoryzomys flavescens to be monotypic. n a t u r a l h i s t o ry: Oligoryzomys flavescens is found in the Pampas, Chaco, Atlantic Forest (pristine and second-growth communities), and gallery forests in the Cerrado near the limits with Atlantic Forest. This species is also found along cropland borders in Argentina (M. Busch and Kravetz 1992). Population levels of O. flavescens dramatically increased during the flowering of taquara-lixa bamboo (Merostachys skvortzovii) in a possible ratada event (Galiano et al. 2007). Ectoparasites of O. flavescens include the mites Gigantolaelaps wolffsohni, Laelaps paulistanensis, and Mysolaelaps microspinosus, and the sucking louse Hoplopleura travassosi (Lareschi et al. 2003; Lareschi, 2010). This species is also the principal carrier of the Andean hantavirus in northern Argentina (Gonzalez Della Valle et al. 2002), and

Map 225 Selected localities for Oligoryzomys flavescens (●). Contour line = 2,000 m

is a natural host of the Lechiguanas hantavirus in both Argentina and Uruguay (Fulhorst et al. 2004). r e m a r k s : The basic chromosomal complement of Oligoryzomys flavescens is 2n = 64, FN = 66, but its diploid and fundamental numbers are variable (2n = 64–67, FN = 66–70) due to the presence of acrocentric or metacentric supernumerary chromosomes (Espinosa and Reig 1991; Sbalqueiro et al. 1991). Myers and Carleton (1981) erroneously regarded their specimens with this karyotype to be Oligoryzomys fornesi (here recognized as O. mattogrossae; see that account).

Oligoryzomys fornesi (Massoia, 1973) Fornes’s Colilargo sy n o n y m : Oryzomys fornesi Massoia, 1973a:22; type locality “Ceibo 13, Naineck, Departamento de Río Pilcomayo, provincia de Formosa, República Argentina.” d e s c r i p t i o n : Another small species with small and pale ears covered on outer surface with ochre hairs, orangish brown or grayish brown dorsal pelage, with paler venter varying from pale ochre to yellowish white. d i s t r i b u t i o n : By current understanding, O. fornesi is limited to the vicinity of the type locality in Argentina. s e l e c t e d l o c a l i t i e s (Map 226): ARGENTINA: Formosa, near Laguna Blanca (CEM 3436), Naineck (type locality of Oryzomys fornesi Massoia).

Map 226 Selected localities for Oligoryzomys fornesi (●). Contour line = 2,000 m.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 427

s u b s p e c i e s : Oligoryzomys fornesi is monotypic. n a t u r a l h i s t o ry: Oligoryzomys fornesi has been collected in open vegetation areas used as pasture for domestic livestock; numerous nests were found in banana trees (Massoia 1973a). r e m a r k s : The taxonomic status of this species needs to be reassessed in relation to O. mattogrossae, with particular attention paid to study of the type specimen. See Remarks for O. mattogrossae.

Oligoryzomys griseolus (Osgood, 1912) Grizzled Colilargo sy n o n y m s : Oryzomys griseolus Osgood, 1912:49; type locality “Paramo de Tama, head of Tachira River, Venezuela. Alt. 6,000–7,000 ft.” Oligoryzomys griseolus: Gyldenstolpe, 1932a:27; first use of current name combination. Oryzomys delicatus griseolus: Cabrera, 1961:388; name combination. d e s c r i p t i o n : Overall ground color of upper parts pale clay, much duller than ochraceous or ochraceous buff of related forms, with abundant mixture of black-tipped hairs producing somewhat grizzled effect which is most pronounced on forehead and sides of face with fulvous minimized and gray predominates; small preauricular tuft of ochraceous-tipped hairs usually present; under parts mostly between clay color and ochraceous buff, almost or quite concealing slaty bases of hairs; middle of chin and throat white or whitish to bases of hairs; forefeet and hindfeet white above, with outer sides of tarsal joints dusky; tail bicolored, dusky above and dull whitish below. Only three pairs of mammae present. Skull with slender rostrum, welldeveloped zygomatic plates project forward farther than in related forms, and elongated incisive foramina that extend posteriorly beyond plane of M1s. d i s t r i b u t i o n : Oligoryzomys griseolus occurs in the Táchira Andes of westernmost Venezuela and in the Cordillera Oriental of easternmost Colombia (Musser and Carleton 2005). s e l e c t e d l o c a l i t i e s (Map 227): VENEZUELA: Táchira, Buena Vista, 41 km SW of San Cristóbal (USNM 442155), Páramo de Tamá (type locality of Oryzomys griseolus Osgood), Buena Vista (USNM 442155). s u b s p e c i e s : Oligoryzomys griseolus is monotypic. n a t u r a l h i s t o ry: Specimens comprising the type series were collected in a small grassy swamp (Osgood 1912); others were found in lower montane very humid forest (Handley 1976). r e m a r k s : No karyotypic data are available. Osgood (1912) and Musser and Carleton (2005) stated that O. griseolus sharply contrasts with O. fulvescens and resembles

Map 227 Selected localities for Oligoryzomys griseolus (●). Contour line = 2,000 m.

Central American O. vegetus, especially “in the extent of white on the throat and in the forwardly projecting zygomatic plate” (Osgood 1912:50). In the description of the species, Osgood (1912) stated that O. griseolus had six pairs of mammae, but all Oligoryzomys species examined to date have eight pairs (Steppan 1995; Weksler 2006); the only Oryzomyini taxa with six mammae are Handleyomys and Scolomys (Patton and da Silva 1995; Voss et al. 2002; Weksler 2006). A recent examination of the type series (B. D. Patterson, pers. comm.) confirms Musser and Cartleton’s (2005) assignment of griseolus to the genus Oligoryzomys. Further examination is necessary to confirm Osgood’s mammae count. Although Musser and Carleton (2005) included the Cordillera Oriental of easternmost Colombia within the range of the species, we are unable to confirm the allocation of specimens from this region from our personal examination of specimens. Hence, possible records from Colombia are neither listed nor mapped as selected localities here.

Oligoryzomys longicaudatus (Bennett, 1832) Long-tailed Colilargo sy n o n y m s : Mus longicaudatus Bennett, 1832a:2; type locality: “Chiliæ”; restricted to Valparaíso, Chile by Osgood (1943b:143). H[esperomys]. (Calomys) longicaudatus: Wagner, 1843a:529; name combination.

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Mus philippii Landbeck, in Philippi, 1857:361; type locality “Valdivia,” Chile. Hesperomys (Calomys) coppingeri Thomas, 1881b:4; type locality “Cockle Cove, Trinidad Channel, Madre de Dios Island, W. Patagonia,” Magallanes y Antártica Chilena; fixed by lectotype selection (Thomas 1927b: 549). Oryzomys longicaudatus: E.-L. Trouessart, 1897:527; name combination. Oryzomys coppingeri: E.-L. Trouessart, 1897:529; name combination. Mus dumetorum Philippi, 1900:14; type locality “provincia Valdivia,” Chile. Mus exiguus Philippi, 1900:19; type locality “Andibus provinciae Santiago,” [= Andes of Santiago,] Chile.” Mus commutatus Philippi, 1900:25; type locality “Valdivia,” Chile. Mus macrocercus Philippi, 1900:30; type locality “provincia Colchagua,” Chile. Mus nigribarnis Philippi, 1900:31; type locality “ Andibus de Talcaregüe,” [= Talcaregue Andes,] Chile. Mus amblyrrhynchus Philippi, 1900:36; type locality “provincia Valdivia,” Chile. Mus melanizon Philippi, 1900:39; type locality “Chile.” Mus diminutivus Philippi, 1900:43; type locality “Illapel et provincia O’Higgins,” Chile. Mus agilis Philippi, 1900:44; type locality “Illapel,” Chile. Mus (Rhipidomys) araucanus Philippi, 1900:46; type locality “Conceptione,” [= Concepción,] Chile. Mus pernix Philippi, 1900:48; type locality “La Ligua,” Chile. Mus glaphyrus Philippi, 1900:51; type locality “provincia Maule,” Chile. Mus peteroanus Philippi, 1900:56, type locality “Andibus de Peteroa,” Peteroa, Curicá Province, Chile. Mus malaenus Philippi, 1900:62; type locality “provincia Maule,” Chile. Oryzomys magellanicus mizurus Thomas, 1916b:186; type locality “Koslowsky Valley, 46°S., 71°W., Central Patagonia,” Chubut, Argentina. Oryzomys longicaudatus pampanus Massoia, 1973a:34; type locality “Estación Experimental Hilario Ascasubi (INTA), partido de Villarino, provincial de Buenos Aires, República Argentina.” O[ryzomys]. l[ongicaudatus]. philippii: M. H. Gallardo and Patterson, 1985:49; name combination. Oligoryzomys longicaudatus: Carleton and Musser, 1989: 74; first use of current name combination. d e s c r i p t i o n : Extremely long tail, nearly double length of head and body (head and body length of holotype given as 3 inches [76.2 mm], tail length 51⁄2 inches [139.7 mm]). Fur soft, smooth, and luxuriant; hairs deep

ashy gray at base; those of the upper surface fawn-colored or pale rufous toward their points, tip frequently black; those of under surface tipped with white slightly tinged with fawn; face covered with short hairs of mingled fawn and black; lips nearly white; vibrissae extremely long, black at their base and silvery at tip; ears rounded and of moderate size, covered on inside with short hairs same color as those of face, and on outside with very short whitish hairs scarcely discernible on blackish skin; color of back mixed fawn and black, black disappearing on almost purely fawn-colored sides; front of forelegs and the outside of hind legs fawn-colored; tail scaly, furnished with numerous very short bristly hairs, brownish above and nearly white beneath; hairs of upper surface of tarsi short, very pale fawn approaching white; those of toes still more white; and lengthened bristles covering claws almost silvery. d i s t r i b u t i o n : Oligoryzomys longicaudatus occurs along the eastern and western flanks of the Andes in Chile and Argentina, from Tierra del Fuego to Atacama (Chile) and Tucumán (Argentina) in the north; isolated populations are reported from the lowland areas in the provinces of Buenos Aires, La Pampa, and Rio Negro. s e l e c t e d l o c a l i t i e s (Map 228): ARGENTINA: Buenos Aires, Bahía San Blas (Palma, Rivera-Milla et al. 2005), Villarino, Estación Experimental INTA Hilario Ascasubi (type locality of Oryzomys longicaudatus pampanus Massoia); Chubut, Cushamen (LSUMZ 16882), Parque Nacional Los Alerces (MVZ 188421); La Pampa, Parque Nacional Lihue Calel (MVZ 182026); Neuquén, 2 km SE of La Rinconada (MVZ 163775), 5 km N of Las Coloradas (MVZ 159332); Río Negro, Chimpay (FMNH 50909), Choele Choel (FMNH 129276), Pichi Leufú (Rivera et al. 2007); Santa Cruz, 52 km WSW of El Calafate (MVZ 150983); Tierra del Fuego, Bahía Lapataia (Espinosa and Reig 1991). CHILE: Aysén, 20 km S of Chile Chico (FMNH 133384), Coyhaique (TTU 30185), Isla Gunther (FMNH 127745), Parque Nacional Queulat (FMNH 133358), Río Aysén (FMNH 22561); Araucanía, 7 km NNW of Los Álamos (MSU 6403), 1.7 km W of Paso Pino Hachado (MSU 6737), 11 km SE of Temuco (MSU 6739), Termas de San Luis (UMMZ 155906), 2 km NE of Tirúa (MSU 6708), 11 km N of Villa Ranquil (MSU 6402); Atacama, Ramadilla (FMNH 22660), 40 km E of Vallenar (TTU 30170); Biobío, Concepción (FMNH 22624), 13 km E of Recinto (FMNH 119489); Coquimbo, Conchalí (TTU 30180), Parque Nacional Fray Jorge (FMNH 133210), La Serena (FMNH 133211), Paihuano (FMNH 22644); Los Lagos, 2 km S of Bahía Mansa (FMNH 133313), Cuesta El Moraga (FMNH 133808), Isla Grande de Chiloé, Quellón (FMNH 22574), Parque Nacional Puyehue (FMNH 133264); Los Ríos, Valdivia (type locality of Mus philippii Landbeck); Magallanes y Antártica Chilena, Cockle Cove [= Caleta Cockle], Isla Madre

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 429

de Dios (type locality of Hesperomys [Calomys] coppingeri Thomas), Puerto del Hambre (Belmar-Lucero et al. 2009), Reserva Nacional Magallanes (Belmar-Lucero et al. 2009), San Martín (M. H. Gallardo and Palma 1990), Torres del Paine (Palma, Rivera-Milla et al. 2005); Maule, Pilén Alto (FMNH 22615); O’Higgins, Baños de Cauquenes (FMNH 22631); Santiago, La Parva (TTU 30183); Valparaíso, Valparaíso (type locality of Mus longicaudatus Bennett). s u b s p e c i e s : We regard Oligoryzomys longicaudatus to be monotypic, although an adequate assessment of geographic trends for any character set that might indicate valid races has not been achieved to date.

n a t u r a l h i s t o ry: Large-scale outbreaks (ratadas) of O. longicaudatus have been observed in both Chile (Gonzalez et al. 2000; Murúa et al. 1986) and Argentina (Sage et al. 2007), both associated with cyclical masting of the arborescent bamboo Chusquea quil and C. culeou, respectively. This species was found to select microsites with high foliage density and thick understory, which offer protection from horizontal view of predators (Gonzalez et al. 2000). Oligoryzomys longicaudatus have a single, limited reproduction period each year in Chile (Murúa et al. 1996). Ectoparasites of O. longicaudatus include the mites Gigantolaelaps wolffsohni and Mysolaelaps microspinosus (Lareschi et al. 2003). This species is also host to the nematode Litomosoides pardinasi (Notarnicola and Navone 2011) and to Andes hantavirus in the Chilean Andes and Oran hantavirus in Argentina (Belmar-Lucero et al. 2009; Fulhorst et al. 2004). r e m a r k s : The karyotype of O. longicaudatus is 2n = 56, FN = 66 (Espinosa and Reig 1991). M. H. Gallardo and Palma (1990) provided the morphological basis for the current classification of colilargos from Chile, including the lack of differentiation of previously identified philippii populations (e.g., Osgood 1943b). Mus philippii is usually assigned to Landbeck and Philippi (1858), but this species was actually described by Luis Landbeck within the article by Philippi (1857). Palma, Rivera-Milla et al. (2005) presented a phylogeographic study using mtDNA sequences of the species and discussed its relationship with O. magellanicus. Thomas (1916b:186) noted that his original designation of the type locality of Hesperomys (Calomys) coppingeri to the Straits of Magellan was incorrect, and that Cockle Cove (= Caleta Cockle) is “in the Trinidad Channel, at the north end of Madre de Dios Island, West Patagonia, in 50° S. lat.” Belmar-Lucero et al. (2009) showed that the distribution of O. longicaudatus extends into Tierra del Fuego, where it is sympatric with O. magellanicus (see also the account of this species).

Oligoryzomys magellanicus (Bennett, 1836)

Map 228 Selected localities for Oligoryzomys longicaudatus (●); the disjunct populations in eastern Argentina are mapped separately from the main distribution. Contour line = 2,000 m.

Patagonian Colilargo sy n o n y m s : Mus magellanicus Bennett, 1836:191; type locality “apud Portum Famine dictum, in fretu Magellanicus,” Port Famine [= Puerto del Hambre], Magallanes y Antártica Chilena, Chile. Hesperomys (Oryzomys) longicaudatus: Milne-Edwards, 1890:27; part; not Mus longicaudatus Bennett. Oryzomys magellanicus: J. A. Allen, 1905:47; name combination. Oryzomys longicaudatus magellanicus: Gyldenstolpe, 1932a: 11; name combination. Oryzomys (Oligoryzomys) magellanicus magellanicus: Tate, 1932f:10; name combination.

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d e s c r i p t i o n : Head and body length similar to tail length; dorsal color saturated with grayish buff; ventral color whitish; and dorsal surfaces of forefeet and hindfeet white, ears of moderate size, rounded, and hairy. d i s t r i b u t i o n : Oligoryzomys magellanicus is limited to the Patagonian region of Chile and Argentina, including Tierra del Fuego. s e l e c t e d l o c a l i t i e s (Map 229): ARGENTINA: Terra del Fuego, Estancia Via Monte (Osgood 1932), Lago Fagnano (= Lago Cami; Osgood 1932), Lago Yehuin (= Lago Yerwin; Osgood 1932). CHILE: Magallanes y Antártica Chilena, Harrison Island (M. H. Gallardo and Patterson 1985), Puerto del Hambre (type locality of Mus magellanicus Bennett), Punta Arenas (M. H. Gallardo and Patterson 1985), Lago Sarmiento, Parque Nacional Torres del Paine (M. H. Gallardo and Palma 1990). s u b s p e c i e s : Oligoryzomys magellanicus is monotypic. n a t u r a l h i s t o ry: Osgood (1932) found this species to be fairly common at some localities on Tierra del Fuego, but in the vicinity of Punta Arenas and northward in western Patagonia it was found with difficulty and only in small numbers. It co-occurs with Abrothrix olivacea in forest communities but not with this species in the brush or open pampa. r e m a r k s : Oligoryzomys magellanicus is characterized by 2n = 54, FN = 66 (M. H. Gallardo and Patterson 1985). M. H. Gallardo and Palma (1990) described external, cranial, bacular, chromosomal, and allozyme characters that differentiate O. magellanicus from O. longicaudatus. Palma, Rivera-Milla et al. (2005) and Belmar-Lucero et al. (2009), however, showed, based on molecular and karyological characters, that specimens from southern Chile (including from Puerto Hambre, type locality of O. magellanicus) and Tierra del Fuego, in the range of O. magellanicus as proposed by M. H. Gallardo and Palma (1990), actually belong to O. longicaudatus. Palma, Rivera-Milla et al. (2005) also showed an outlier haplotype from Rio Penitente, which they regarded to be O. magellanicus. We recognize O. magellanicus as a valid species based on its distinctive short tail (same length as head and body, compared to the much longer tail of O. longicaudatus), its different karyotype, and the molecular results of Palma, Rivera-Milla et al. (2005). Our assessment is that O. magellanicus and O. longicaudatus are sympatric in southernmost Chile and Tierra del Fuego (based on molecular and karyological results), the first being rare (and thus not collected by Belmar-Lucero et al. 2009). Nevertheless, Palma et al. (2012) argued, based on their molecular data, that O. magellanicus is a subspecies of O. longicaudatus; the taxonomic and distributional limits of these species need reevaluation, especially in a more integrative approach that combines molecular, karyotypic, and morphological data.

Map 229 Selected localities for Oligoryzomys magellanicus (ᇲ). Contour line = 2,000 m.

Oligoryzomys mattogrossae (J. A. Allen, 1916) Mato Grosso Colilargo sy n o n y m s : Oryzomys (Oligoryzomys) mattogrossae J. A. Allen, 1916c: 528; type locality “Utiarity, [Rio Papagaio, 2,500 ft,] Matto Grosso [= Mato Grosso], Brazil.” Oligoryzomys mattogrossae: Gyldenstolpe, 1932a: 29; first use of current name combination. Oryzomys [(Oligoryzomys)] mattogrossae: Ellerman, 1941: 355; name combination. Oryzomys utiaritensis: Cabrera 1961:396; part; not Oligoryzomys utiaritensis J. A. Allen. Oligoryzomys microtis: Carleton and Musser, 1989:71; part; not Oryzomys (Oligoryzomys) microtis J. A. Allen. Oryzomys (Oligoryzomys) fornesi: Myers and Carleton, 1981:25; not Oryzomys fornesi Massoia. Oligoryzomys fornesi: Bonvicino and Weksler, 1998:90; not Oryzomys fornesi Massoia. d e s c r i p t i o n : Characterized by rufous tone, especially on rump; under parts pale ochraceous buff instead of grayish white; tail relatively long. d i s t r i b u t i o n : Oligoryzomys mattogrossae occurs in the open-vegetation belt throughout Paraguay, and central and northeastern Brazil; this species also possibly occur in Bolivia (e.g., Santa Cruz specimens listed as O. microtis by Olds and Anderson [1987] and S. Anderson [1997]) and Argentina, but no voucher material was analyzed to confirm identification. s e l e c t e d l o c a l i t i e s (Map 230): BRAZIL: Alagoas, Matriz de Camaragibe (UFPB 977); Bahia, Fazenda Sertão do Formoso, Jaborandi (MNRJ 62637); Distrito Federal, Brasília (UNB 279); Goiás, Aporé (LBCE 8579), Corumbá de Goiás (MNRJ 34440), Fazenda Vão dos Bois, Teresina de Goiás (MNRJ [CRB 674]), Mambaí (LBCE 10851), Serranópolis (LBCE 8509); Mato Grosso, Utiariri (type locality of Oryzomys [Oligoryzomys] mattogrossae

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 431

J. A. Allen); Mato Grosso do Sul, Cassilândia (LBCE 12111), Corumbá (LBCE 5718); Paraíba, Mamanguape (UFPB [MPS 72]); Pernambuco, Bom Conselho (UFPBPMN 60), Buíque (UFPB 1893), Macaparana (UFPB [MPS 34]). PARAGUAY: Caaguazú, 24 km NNW of Carayaó, Estancia San Ignacio (UMMZ 133818), Canindeyú, 6.3 km NE by road of Curuguaty (UMMZ 124218). s u b s p e c i e s : Oligoryzomys mattogrossae is monotypic. n a t u r a l h i s t o ry: Oligoryzomys mattogrossae is an inhabitant of open-vegetation biomes such as the Cerrado, Caatinga, and Chaco, but can also be found in forest formations in the transition with Amazonian forest. It can occur in sympatry with O. nigripes, O. stramineus (see Weksler and Bonvicino 2005), O. utiaritensis (see J. A. Allen 1916c), and maybe with O. flavescens (see Myers and Carleton, 1981, and below). Oligoryzomys mattogrosae (specimens identified as O. fornesi) was the reservoir of Anajatuba hantavirus in the Brazilian state of Maranhão (E. S. T. Rosa et al. 2005). r e m a r k s : Oligoryzomys mattogrossae was described by J. A. Allen (1916c) based on two specimens, the holotype from Utiariti and one paratype from “Guatsué” (not located by Painter and Traylor 1991, but presumably on middle Rio Papagaio), both in Mato Grosso state. Later, Cabrera (1961:396) considered this taxon a junior synonym of O. utiaritensis. However, morphologic and phylogenetic analyses (C. R. Bonvicino and M. Weksler, in prep.) showed that O. mattogrossae is an independent lineage; in particular, O. mattogrossae has a yellow-ochraceous ventral coloration that contrasts with the whitish venter of O. utiaritensis (as previously noted by Myers and Carleton 1981). Some authors (e.g., Carleton and Musser 1989) also considered O. mattogrossae a junior synonymous of O. microtis, but these two species differ in a number of attributes, including distinct karyotypes (2n = 64, FN = 66 for O. microtis; A. L. Gardner and Patton 1976 [as Oryzomys (Oligoryzomys) longicaudatus, variant 2]; Aniskin 1994; Patton et al. 2000), nonsister status in molecular phylogenetic analyses (C. R. Bonvicino and M. Weksler, in prep.), and distinct habitats (O. mattogrossae is found mostly in open-vegetation biomes, whereas O. microtis is found only in the forested environments). We recognize Oligoryzomys mattogrosae as a valid species based on the examination of the holotype and the discovery of a specimen from Sapezal (same municipality as Utiariti, type locality of O. mattogrossae) that shares the same traits of the holotype and that is a member of a wellsupported clade within Oligoryzomys; specimens of this clade were previously referred to as O. fornesi (e.g., Weksler and Bonvicino 2005), a name that we restrict here to the type locality and vicinity (see that account). Therefore, the small body size and yellow belly of specimens, with 2n = 62, FN = 64, found in the Cerrado and Caatinga domains, pre-

Map 230 Selected localities for Oligoryzomys mattogrossae (●). Contour line = 2,000 m.

viously identified by us (e.g., Bonvicino and Weksler 1998; Weksler and Bonvicino 2005) as O. fornesi, are here considered as O. mattogrossae. The karyotype of this species is frequently mistaken as a variant of the karyotype of O. flavescens (2n = 64–66, FN = 66–68; e.g., Myers and Carleton 1981; Sbalqueiro et al. 1991). However, O. mattogrossae (2n = 62, FN = 64) and O. flavescens (2n = 64–66, FN = 66– 68) karyotypes are discontinuous because a 2n = 63 karyotype has not been reported. Furthermore, these two taxa appear to differ in morphological traits, such as the incisive foramen length (longer in O. flavescens). The 2n = 62, FN = 64 karyotype has also been attributed to O. eliurus (Svartman 1989; Andrades-Miranda, Oliveira, Lima-Rosa et al. 2001), but examination of the karyotyped specimens listed by these authors confirmed them as O. mattogrossae.

Oligoryzomys messorius (Thomas, 1901) Hairy Colilargo sy n o n y m s : Oryzomys navus messorius Thomas, 1901e:151; type locality “Kanuku Mountains, about 59° W. and 3° N., and on the savannas near their base, at altitudes varying from 240 to 2000 feet,” Upper Takutu–Upper Essequibo, Guyana. Oligoryzomys navus messorius: Gyldenstolpe, 1932a:27; name combination.

432 Mammals of South America

Oryzomys delicatus messorius: Cabrera, 1961:388; name combination. Oligoryzomys fulvescens: Carleton and Musser, 1989:70; part, specimens from northern South America. d e s c r i p t i o n : Color above grizzled grayish fawn, varying towards rufous; rump more rufous than back; face grayer; ears comparatively short, but little darker than general color of head, very different therefore to blackish ears of O. fulvescens; under surface dull whitish, with scarcely trace of buff, not sharply defined laterally, hairs all grayish basally; dorsal surfaces of hands and feet white. Tail short for group, thinly haired, brown above, lighter beneath; not sharply contrasted as in O. fulvescens. d i s t r i b u t i o n : Oligoryzomys messorius is distributed primarily in higher elevations of southern Venezuela, Guyana, Surinam, and northeastern Brazil. s e l e c t e d l o c a l i t i e s (Map 231): BRAZIL: Amapá, Tartarugalzinho (MNRJ 35967); Roraima, Parque Nacional do Viruá (MNRJ 70475), Rio Cotinga, Limão (AMNH 75411). GUYANA: Upper Takutu–Upper Essequibo, near Awarawaunowa (ROM 38522), near Dadanawa (ROM 36021), Kanuku Mountains (type locality of Oryzomys navus messorius Thomas), Nappi Creek (ROM 31529), 5 km SE of Surama (ROM 103348). SURINAM: Sipaliwini, Sipaliwini airstrip (CMNH 76892). VENEZUELA: Amazonas, Pozón, 50 km NE of Puerto Ayacucho (ROM 107871); Bolivar, Auyán-Tepuí (AMNH 130883), Mount Roraima, Arabopo (AMNH 75662). s u b s p e c i e s : Oligoryzomys messorius is monotypic. n a t u r a l h i s t o ry: Nothing is known about the ecology, population biology, or behavior of this species. r e m a r k s : We recognize O. messorius as a valid species distinct from O. delicatus based on morphological differences of specimens of both taxa in the AMNH and

Map 231 Selected localities for Oligoryzomys messorius (●). Contour line = 2,000 m.

MNRJ collections (M. Weksler and colleagues, unpubl. data), karyotypic data (2n = 66, FN = 74) of specimens identified as Oligoryzomys sp. by Andrades-Miranda, Oliveira, Lima-Rosa et al. (2001; see also R. J. Baker et al. 1983 for specimens from Surinam with 2n = 66), and the phylogenetic position relative to other species in the genus (G. B. Miranda et al. 2009; Agrellos et al. 2012). Based on our ongoing morphological, karyotypic, and molecular analyses, the specimen reported as Oligoryzomys cf. messorius by Andrades-Miranda, Oliveira, Lima-Rosa et al. (2001), with karyotype of 2n = 56, FN = 58, is distinct from the concept of O. messorius we espouse herein.

Oligoryzomys microtis (J. A. Allen, 1916) Small-eared Colilargo sy n o n y m s : Oryzomys (Oligoryzomys) microtis J. A. Allen, 1916c:525; type locality “Lower Rio Solimoens [= Solimões] (fifty miles above mouth),” Amazonas, Brazil; restricted to Manacapuru, north bank of lower Rio Solimões, 70 km WSW Manaus (Voss et al. 2001:118–119, footnote). Oryzomys chaparensis Osgood, 1916:205; type locality “Todos Santos, Chaparé River, [Cochabamba,] Bolivia. Altitude about 1200 feet.” Oligoryzomys microtus Gyldenstolpe, 1932a:27; incorrect subsequent spelling of Oryzomys (Oligoryzomys) microtis J. A. Allen. Oryzomys [(Oligoryzomys)] microtis: Ellerman, 1941:355; name combination. Oligoryzomys microtis: Carleton and Musser, 1989:71; first use of current name combination. d e s c r i p t i o n : Similar in size and general coloration to O. delicatus but very much less rufous above and clearer white below, and with very much smaller ears. Upper parts dull yellowish brown, finely lined with blacktipped hairs; under parts white (in holotype, but faintly tinged with buff in some specimens); upper surfaces of feet thinly clothed with light buffy brown hairs; soles dark brown; tail shorter than head and body, brown, nearly naked, finely annulated, with tip not distinctly tufted; ears small, brownish, and nearly naked. Patton et al. (2000:Table 33) provided mean, standard error, and range for external and cranial measurements for large series of adults from Rio Juruá in western Amazonian Brazil; total length 168–233 mm, tail length 80–125 mm, hindfoot length 21–26, and ear length 11–15 mm; series as smallbodied, long-tailed, and short-haired mouse, yellowish brown above and grayish white below; skull with elongated braincase, broad but long rostrum, and hourglassshaped interorbital region with squared edges. d i s t r i b u t i o n : Oligoryzomys microtis occurs broadly in the Amazon Basin of eastern Peru, northeastern

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 433

Bolivia, and western Brazil, extending eastward along the floodplain of the Rio Amazonas in Pará state. s e l e c t e d l o c a l i t i e s (Map 232): BOLIVIA: Beni, El Triunfo (USNM 391298), La Penas (USNM 460741); Cochabamba, Todos Santos (type locality of Oryzomys chaparensis Osgood); La Paz, Mapiri (AMNH 72697); Pando, La Cruz (AMNH 262901), Pemanso (AMNH 262912), Río Nareuda (AMNH 248982); Santa Cruz, El Refugio (AMNH 268971). BRAZIL: Acre, Igarapé Porongaba, right bank Rio Juruá (Patton et al. 2000); Amazonas, Jainú, right bank Rio Juruá (Patton et al. 2000), Manacaparu, north bank Rio Solimões, 70 km WSW of Manaus (type locality of Oryzomys [Oligoryzomys] microtis J. A. Allen), Parintins (AMNH 92899), Rio Madeira, Rosarinho, Lago Miguel (AMNHN 92705), Seringal Condor, left bank Rio Juruá (Patton et al. 2000); Pará, Belém (USNM 461069), Capim, 150 mi SE of Belém (AMNH 188964), Marabá, Serra do Norte (USNM 543345), Villarinho do Monte, Rio Xingu (AMNH 95984). PERU: Loreto, Jenaro Herrera (Aniskin 1994), Mishana Allpahuayo (Aniskin 1994); Madre de Dios, Río Manu, 57 km above mouth (USNM 559399), Río Tambopata, 30 km above mouth (USNM 530925); Pasco, ca. 10 km N of Puerto Bermudez (AMNH 245551); Ucayali, Balta, Río Curanja (LSUMZ 14360). s u b s p e c i e s : We treat Oligoryzomys microtis as monotypic. n a t u r a l h i s t o ry: Oligoryzomys microtis is a terrestrial inhabitant of edge habitats within the lowland rainforest of the Amazon Basin. Population genetic analyses of O. microtis from the Brazilian Amazon (Patton et al. 1996, 2000) showed weak isolation by distance occurring only over large geographical distances. Migration rates (Nm) were high, and most (about 80%) of haplotype variation was observed within local populations. Specimens of O. microtis captured in Bolivia and Peru were positive for the Río Mamoré hantavirus (Carroll et al. 2005; Powers et al. 1999; Richter et al. 2010). Pregnant females were recorded in March, May, August, and September in Bolivia; the number of embryos vary from three to five (S. Anderson 1977). Along the Rio Juruá in the western Amazon of Brazil, individuals reached reproductive maturity quickly, some while still in juvenile pelage, pregnancy rates were high (with litter size, based on embryo counts, ranging from two to eight [modal number = 4]), and reproduction was recorded throughout the dry season. They inhabit mainly seasonally flooded habitats along river margins (várzea) exposed during the dry season, but also occur in terra firme forest (Patton et al. 2000). r e m a r k s : A. L. Gardner and Patton (1976) reported a karyotype of 2n = 64, FN = 66 for specimens from eastern Peru (as Oryzomys (Oligoryzomys) longicaudatus, variant

Map 232 Selected localities for Oligoryzomys microtis (●). Contour line = 2,000 m.

2). Aniskin and Volobouev (1999) and Patton et al. (2000) both reported the same karyotype from additional localities in the Peruvian and the western Brazilian Amazon, respectively. Other karyotypes are found in colilargos from the Brazilian Amazon within the geographic range of O. microtis (C. R. Bonvicino, unpubl. data), and it is likely that this is a karyotypically polytypic species. Voss et al. (2001:118–119, footnote) discussed the location of the type locality, north of the Rio Solimões, and the lack of morphological differentiation between the type series and topotypes of O. fulvescens. Oligoryzomys species, however, are very similar to one another, and we cannot discard that such is the case for O. microtis and O. fulvescens. Additional morphological comparisons are necessary to resolve this problem, and we keep the name microtis in this account. This species needs an in-depth taxonomic assessment.

Oligoryzomys moojeni Weksler and Bonvicino, 2005 Moojen’s Colilargo sy n o n y m : Oligoryzomys moojeni Weksler and Bonvicino, 2005:116; type locality “Fazenda Fiandeira in ‘Morro do Chapéu’ region, in the lowest part of the Chapada dos Veadeiros National Park, 65 km SSW Cavalcante (14°04′S 47°45′W, altitude ranging from 550 to 740m), Goiás State, Brazil.” d e s c r i p t i o n : Medium sized, characterized by brownorange dorsal pelage that does not contrast sharply with creamy ventral pelage, notably short incisive foramina, and second highest diploid number (2n = 70) for genus.

434 Mammals of South America

Map 233

Selected localities for Oligoryzomys moojeni (●).

d i s t r i b u t i o n : Central Brazil, in the Cerrado of Goiás and Tocantins states, at elevations below 800 m. s e l e c t e d l o c a l i t i e s (Map 233; from Weksler and Bonvicino 2005, except as noted): BRAZIL: Goiás, Cavalcante, Colinas do Sul, Mimoso de Goiás, Minaçu, Uruaçu; Tocantins, Lajeado (J. F. S. Lima et al. 2003), Porto Nacional (J. F. S. Lima et al. 2003). s u b s p e c i e s : Oligoryzomys moojeni is monotypic. n a t u r a l h i s t o ry: Oligoryzomys moojeni occurs at elevations between 500 and 800 m in the Brazilian Cerrado, primarily in open vegetation formations such as cerrado sensu stricto and campo úmido, but also in open gallery forest (Weksler and Bonvicino 2005). Two pregnant females were captured at the type locality in August (dry season), each with three embryos. r e m a r k s : The karyotype of Oligoryzomys moojeni is characterized by 2n = 70 and FN = 74–76; variation in the autosomal fundamental number is due to a pericentric inversion affecting a medium chromosome pair (J. F. S. Lima et al. 2003). In their respective karyotypic analyses, AndradesMiranda, Oliveira, Lima-Rosa et al. (2001), and F. J. S. Lima et al. (2003) referred to this species as Oligoryzomys sp.

Oligoryzomys nigripes (Olfers, 1818) Black-footed Colilargo sy n o n y m s : Mus nigripes Olfers, 1818:209; type locality fixed by neotype designation to “Ybycuí National Park, Department Paraguarí, approximately 85 km SSE Atyrá, Paraguay” (Myers and Carleton 1981:14).

Mus longitarsus Rengger, 1830:232; type locality “Ufer des Paraguaystromes, nördlich von Villa-Real.” Hesperomys eliurus Wagner, 1845a:147; type locality “Ytarare [= Itararé],” São Paulo, Brazil. Hesperomys pygmaeus Wagner, 1845a:147; type locality “Ypanema” (= Floresta Nacional de Ipanema, 20 km NW Sorocaba, São Paulo, Brazil, 23°26′7′′S 47°37′41′′ W, 701 m; L. P. Costa et al. 2003). Hesperomys (Calomys) pygmaeus: Burmeister, 1854:173; name combination. Oryzomys pygmaeus: E.-L. Trouessart, 1897:527; name combination. Oryzomys nigripes: E.-L. Trouessart, 1897:528; name combination. Oryzomys eliurus: E.-L. Trouessart, 1897:528; name combination. Oryzomys longitarsus: E.-L. Trouessart, 1897:528; name combination. Oryzomys delticola Thomas, 1917c:96; type locality “Isla Ella, in the delta of the Rio Parana, at the top of the La Plata Estuary,” Buenos Aires, Argentina. Oryzomys (Oligoryzomys) delticola: Tate, 1932f:10; name combination. Oryzomys (Oligoryzomys) longitarsus: Tate, 1932f:10; name combination. Oryzomys (Oligoryzomys) nigripes: Tate, 1932f:10; name combination. Oryzomys (Oligoryzomys) eliurus: Tate, 1932f:10; name combination. Oryzomys (Oligoryzomys) pygmaeus: Tate, 1932f:10; name combination. Oligoryzomys eliurus: Carleton and Musser, 1989:73; name combination. Oligoryzomys nigripes: Carleton and Musser, 1989:73; first use of current name combination. Oligoryzomys delticola: Carleton and Musser, 1989:75; name combination. d e s c r i p t i o n : Large, characterized by dark-brown to dark-yellowish dorsal pelage color, with sharply defined transition to whitish ventral coloration, and often with orange pectoral band; long ears; 2n = 62, FN = 78–82 karyotype. d i s t r i b u t i o n : Oligoryzomys nigripes occurs in eastern Brazil (from Pernambuco in the north to Rio Grande do Sul in the south along the coast, and in the southern portion of the Cerrado in Minas Gerais and São Paulo states and the Distrito Federal), Paraguay (east of the Río Paraguay), Uruguay (Salto, Durazno, Colonia, and Maldonado departments), and Argentina (Buenos Aires, Misiones, and Chaco provinces). s e l e c t e d l o c a l i t i e s (Map 234; from Weksler and Bonvicino 2005, except as noted): ARGENTINA: Buenos

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 435

Aires, Isla Ella, delta of Río Paraná (type locality of Oryzomys delticola Thomas); Chaco, Las Palmas; Misiones, Caraguatay. BRAZIL: Bahia, Rio Una, 10 km ESE of São José; Distrito Federal, Brasília; Espírito Santo, Venda Nova; Goiás, Flores de Goiás; Minas Gerais, Fazenda Canoas, Juramento, Passos, Peirópolis; Paraíba, Pirauá; Pernambuco, Bom Conselho, Buíque; Rio de Janeiro, Itaguaí, Nova Friburgo; Rio Grande do Sul, Faxinal, Pontal do Morro Alto; Santa Catarina, Florianópolis, Itá; São Paulo, Araraquara, Guaratuba, Iguapé, Itapetininga, Pedreira. PARAGUAY: Amambay, 4 km (by road) SW of Cerro Corá (Myers and Carleton 1981), 28 km SW of Pedro Juan Caballero (Myers and Carleton 1981); Caaguazú, Sommerfield Colony; Canindeyú, 6.3 km by road N of Curuguaty; Central, Asunción; Itapúa, Encarnación; Misiones, San Francisco. URUGUAY: Durazno, Durazno; Maldonado, Punta del Este; Salto, Salto. s u b s p e c i e s : Oligoryzomys nigripes is monotypic. n a t u r a l h i s t o ry: Oligoryzomys nigripes had an average of 4.7 embryos (range: 4–6) in 21 pregnant females from the Brazilian states of Rio de Janeiro and São Paulo collected in September and November (C. R. Bonvicino, unpubl. data). Myers and Carleton (1981) reported an average of 3.57 embryos (range 2 to 5) in 32 pregnant females from Paraguay collected around June and August (with a hiatus in July). Oligoryzomys nigripes is the most habitat-generalist of all Brazilian Oligoryzomys species, occurring in primary and secondary vegetation in Atlantic Forest and Cerrado. It can be sympatric with O. stramineus (see Bonvicino and Weksler 1998), though the two species have never been caught in the same trapline. It can be syntopic with O. flavescens and O. mattogrossae. Oligoryzomys nigripes is more commonly trapped on the ground, but Myers and Carleton (1981) mentioned specimens collected in trees and suggested some arboreal activity. Püttker, Pardini et al. (2008) found the species at sites with a low canopy and a dense understory. In southern Brazil, population levels peaked in the cold and dry months and reached null values during the warmest months, with the population increase connected to greater availability of food resources, especially of grass seeds (Antunes et al. 2009). This colilargo can reach a density of 33 animals per hectare during population explosions (study population in Buenos Aires province, Argentina; Jaksic and Lima 2003). In the Rio de la Plata delta (and probably elsewhere), O. nigripes is prey of the Barn Owl (Tyto alba) and host to the ectoparasitic mites Haemolaelaps glasgowi, Gigantolaelaps mattogrossensis, Laelaps paulistanensis, and Mysolaelaps microspinosus (see Massoia and Fornes 1964b). The species is also host to the nematodes Stilestrongylus lanfrediae in Rio de Janeiro, Brazil (J. G. R. Souza et al. 2009) and Syphacia kinsellai in Misiones, Argentina (M. Robles and Navone 2007), and individuals are a reservoir for the Araucaria hantavirus (R. C. Oliveira et al. 2011).

Map 234 Selected localities for Oligoryzomys nigripes (●). Contour line = 2,000 m.

r e m a r k s : The name nigripes was first given to Azara’s (1801:98) le rat à tarse noir by Olfers (1818:209; see Desmarest 1819f; Hershkovitz 1959b; Myers and Carleton 1981). As no type specimen was selected in the original or in subsequent publications, Myers and Carleton (1981:14) designated a neotype from Ybycuí National Park, 85 km SSE Atyrá (which is approximately where Azara obtained his specimens), in the department of Paraguaí, Paraguay. Oligoryzomys nigripes has a diploid number of 62 chromosomes but a variable autosome fundamental number ranging from 79 to 82 due to pericentric inversions (Bonvicino, D’Andrea, and Borodin 2001). Because Bonvicino and Weksler (1998) and Weksler and Bonvicino (2005) were unable to separate samples of O. nigripes from those of delticola Thomas or eliurus Wagner on morphological and karyological grounds, we consider both delticola and eliurus as equivalent to O. nigripes herein. Recent analyses of mtDNA sequence data (D-loop and cytochrome-b) corroborate that delticola is best considered a synonym of O. nigripes (Francés and D’Elía 2006; Rivera et al. 2007). L. F. Machado et al. (2011) presented further characters that differentiate sympatric O. nigripes from O. flavescens.

Oligoryzomys rupestris Weksler and Bonvicino, 2005 Highlands Colilargo sy n o n y m : Oligoryzomys rupestris Weksler and Bonvicino, 2005:119; type locality “Pouso Alto (14°01′S 47°31′W), in the

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highest part of the Chapada dos Veadeiros National Park, at 1,500m altitude, 14 km NNW of Alto Paraíso, Goiás State, Brazil.” d e s c r i p t i o n : Small sized, characterized by gray head that contrasts with lighter yellow-brownish dorsal body coloration; small tufts of whitish hairs anterior to base of pinna; reduced or absent stapedial foramen, squamosal-alisphenoid groove, and sphenofrontal foramen that characterizes carotid circulatory pattern 3 (sensu Voss 1988); and lowest known diploid number (2n = 44–46) among species in the genus. d i s t r i b u t i o n : Oligoryzomys rupestris occurs in central Brazil, where it is known from only three localities, one each in Goiás, Minas Gerais, and Bahia states, at elevations above 1,000 m. s e l e c t e d l o c a l i t i e s (Map 235): BRAZIL: Bahia, Pico das Almas (MZUSP 29015); Goiás, Pouso Alto (type locality of Oligoryzomys rupestris Weksler and Bonvicino); Minas Gerais, Serra do Cipó (MZUSP 27423). s u b s p e c i e s : Oligoryzomys rupestris is monotypic. n a t u r a l h i s t o ry: This species occurs only in highelevation areas characterized by campos rupestre vegetation in the Cerrado Biome (Weksler and Bonvicino 2005). No female was found pregnant in November (end of dry season) at the type locality (Bonvicino, Lemos, and Weksler 2005). No other natural history information is available. r e m a r k s : Oligoryzomys rupestris has the lowest diploid number of all species in the genus, with 2n = 44 to 46 and an autosomal fundamental number varying from 52 to 53 (M. J. de J. Silva and Yonenaga-Yassuda 1997; as Oligoryzomys sp. 1 and sp. 2). The derived carotid circulation

Map 235 Selected localities for Oligoryzomys rupestris (●). Contour line = 2,000 m.

pattern (pattern 3 of Voss 1988) of O. rupestris is unique among Oligoryzomys species.

Oligoryzomys stramineus Bonvicino and Weksler, 1998 Straw-colored Colilargo sy n o n y m : Oligoryzomys stramineus Bonvicino and Weksler, 1998: 98; type locality “Fazenda Vão dos Bois (13°34′29′′S 47°10′57′′ W, 424 m), Terezina de Goiás, Goiás State, Brazil, 24 km N of Terezina de Goiás, 15 km SW of Rio Paranã, a tributary of the upper Rio Tocantins, road GO-118, km 275.” d e s c r i p t i o n : Large species characterized by pale dorsal color, with defined transition between lateral and whitish ventral pelage, long incisive foramina, broad zygomatic plates, and 2n = 52, FN = 68–70 karyotype. d i s t r i b u t i o n : Oligoryzomys stramineus occurs in central and northeastern Brazil, from Goiás and Minas Gerais states in the south to Ceará, Piauí, Paraíba, and Pernambuco states in the north, in both Cerrado and Caatinga vegetational domains. s e l e c t e d l o c a l i t i e s (Map 236): BRAZIL: Bahia, Caetité (MNRJ 63416); Ceará, Russas (Fernandes et al. 2012), Santanopole (USNM 304583); Goiás, Fazenda Vão dos Bois, Teresina de Goiás (type locality of Oligoryzomys stramineus Bonvicino and Weksler), Mambaí (Weksler and Bonvicino 2005); Minas Gerais, Fazenda Canoas, Juramento (Weksler and Bonvicino 2005); Paraíba, Pirauá (UFPB [LFS 49]); Pernambuco, Agrestina (UFPE [PMN 62]), Buíque (UNPE [PMN 147]), Correntes (Weksler and Bonvicino 2005), Exu (Weksler and Bonvicino 2005). s u b s p e c i e s : Oligoryzomys stramineus is monotypic. n a t u r a l h i s t o ry: Oligoryzomys stramineus is primarily found in gallery forests within the Cerrado. Young juveniles were collected in August, suggesting that reproduction occurred around June–July; one pregnant female was captured in September with four embryos (Weksler and Bonvicino 2005). This species is sympatric with O. fornesi (with both obtained in the same trapline) and O. nigripes (but never in the same trapline) at some localities in central Brazil (Weksler and Bonvicino 2005). r e m a r k s : The karyotype of Oligoryzomys stramineus is characterized by 2n = 52, FN = 68 to 69 (Furtado 1981; Maia et al. 1983; both as Oligoryzomys aff. eliurus). Differences in autosomal fundamental number are due to an inversion in a small acrocentric pair (Bonvicino and Weksler 1998). See remarks in the account for Oligoryzomys chacoensis for the confusion over the distributional range of that species due to misidentification with specimens of O. stramineus (e.g., Carleton and Musser 1989:72).

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 437

Map 236 Selected localities for Oligoryzomys stramineus (●) and Oligoryzomys utiaritensis (❍). Contour line = 2,000 m.

Oligoryzomys utiaritensis J. A. Allen, 1916 Utiariti Colilargo sy n o n y m s : Oryzomys (Oligoryzomys) utiaritensis J. A. Allen, 1916c: 527; type locality “Utiarity [= Utiariti], Rio Papagaio, Matto Grosso, Brazil.” Oligoryzomys utiaritensis: Gyldenstolpe, 1932a:29; first use of current name combination. Oryzomys [(Oligoryzomys)] utiaritensis: Ellerman, 1941: 356; name combination. Oligoryzomys eliurus: Carleton and Musser, 1989:73; part; not Hesperomys eliurus Wagner. d e s c r i p t i o n : Upper parts clay-colored, finely lined with black-tipped hairs over back, nearly pure clay-color on sides; front of head and nose darker and slightly grayish; under parts grayish white, hairs darker at base; upper surfaces of forefeet and hindfeet paler, about flesh color, soles dark brown; ears large, light brown, nearly naked; and tail longer than head and body, finely annulated, light brown, and nearly naked, apical portion with short, bristly grayish hairs. Agrellos et al. (2012) diagnosed O. utiaritensis by the following characters: grizzled yellowish-brown dorsal pelage contrasting with whitish ventral pelage and tail weakly bicolored; long incisive foramina with posterior borders reaching or almost reaching alveoli of first upper molars, but never extending posteriorly; highest diploid number for genus (2n = 72); and three putative synapomorphies in mtDNA cytochrome-b and one in nuclear intron 7 of betafibrinogen gene sequences.

d i s t r i b u t i o n : Oligoryzomys utiaritensis is distributed across the northwest of Mato Grosso and southwest of Pará states, an area that includes the Chapada dos Parecis, a massive plateau in northwestern Mato Grosso that marks the transition between the Cerrado and Amazonian domains in central Brazil. s e l e c t e d l o c a l i t i t e s (Map 236): BRAZIL: Pará, Castelo dos Sonhos, Altamira (MNRJ 75609); Mato Grosso, Campo Novo do Parecis (MNRJ 75616), Feliz Natal (MNRJ [SVS 819]), Peixoto de Azevedo (MNRJ 75600), Utiariti, Rio Papagaio (type locality of Oryzomys [Oligoryzomys] utiaritensis J. A. Allen). s u b s p e c i e s : Oligoryzomys utiaritensis is monotypic. n a t u r a l h i s t o ry: Specimens of Oligoryzomys utiaritensis were captured between 110 and 570 m elevation, in secondary semideciduous forest at the limits of corn and soy plantations, in eucalypt plantations with herbaceous vegetation, and in very altered vegetation near plantations (Agrellos et al. 2012). This species is sympatric with O. mattogrossae at the type locality (J. A. Allen 1916c). Individuals serve as a reservoir of the Castelo dos Sonhos hantavirus (E. S. T. Rosa et al. 2011). r e m a r k s : Recent karyotypic, morphologic, and molecular analyses (Agrellos et al. 2012) demonstrated that O. utiaritensis and O. nigripes (= O. eliurus; see the species account) were different species. Oligoryzomys utiaritensis had a karyotype with 2n = 72 and FN = 76, unlike O. nigripes with 2n = 62, FN = 78–82. Analyses of mtDNA and nucDNAmarkers indicated that O. nigripes and O. utiaritensis were not sister taxa.

Genus Oreoryzomys Weksler, Percequillo, and Voss, 2006 Alexandre R. Percequillo

Oreoryzomys balneator, the sole species in the genus, is endemic to high-elevation montane forests in Ecuador and northern Peru. It is currently known from very few specimens and localities. Externally, O. balneator has a small body size, with head and body length ranging from 75–94 mm; the tail is longer than head and body (tail length 95–120 mm); hindfeet are narrow and delicate (length 23.5–27 mm); and ears are short and rounded. The dorsal pelage is dense and compact, with short hairs (aristiforms reaching 12 mm in length), and darkly colored, ochraceous densely grizzled with dark brown. The ventral pelage is shorter, sharply distinct from the dorsum and sides of the body in color, grayish to buffy gray. The tail is whitish along its basal half, with the distal half uniformly dark brown; the tail tip may be white in some specimens. Hindfeet are covered dorsally with short,

438 Mammals of South America

bicolored (brown proximally and white distally), and selfcolored hairs (entire white); ungual tufts are short, and do not conceal the claws. Mystacial vibrissae are dense, thick, and long, surpassing the tip of ears when laid back. The skull of O. balneator is very small and delicate (greatest length range: 22.2–25.7 mm). The rostrum is long and narrow, flanked by small and discrete nasolacrimal foramina, and has very shallow and narrow zygomatic notches. The zygomatic plates are narrow, with their anterior margins straight; zygomatic arches are slightly divergent posteriorly, and jugals are absent. The interorbital region is anteroposteriorly short and wide, with an hourglass shape; the anterior half has rounded supraorbital margins, and the posterior half shows squared margins. The braincase is rounded and globose, without temporal crests; in occipital view, the braincase is well rounded, and both the foramen magnum and occipital condyles are oriented more ventrally. Incisive foramina are short (length 2.8–3.8 mm), with convex lateral margins and rounded anterior and posterior margins. The palate is long and wide, with or without small and inconspicuous palatal excrescences; the posterolateral palatal pits are large and deep. The anterior border of mesopterygoid fossa is rounded; its roof is perforated by long and narrow sphenopalatine vacuities present at the presphenoidbasisphenoid suture. An alisphenoid strut is absent. The stapedial foramen, squamosoalisphenoid groove, and sphenofrontal foramen are present, configuring carotid circulatory pattern 1 (sensu Voss 1988). Both the subsquamosal fenestra and postglenoid foramen are large. Auditory bullae are small but globose, with long and flat bony tubes; the stapedial process is small; the tegmen tympani varies in size, and may or may not marginally overlap the squamosal. The mandible is shallow; the coronoid process is very short and triangular, and positioned lower than the condyloid process, thus defining an extremely shallow superior notch. The angular process is shorter than the condyloid process, so the inferior notch is also shallow. A capsular process is well developed. Upper incisors are orthodont. Molars are pentalophodont, although some specimens may have tetralophodont lower molars, with a reduced to absent mesolophid. Molars have low crowns with the main cusps arranged in opposite pairs. Labial and lingual flexi interpenetrate moderately at the median molar plane; the labial flexus is deep and wide, while the lingual flexus is relatively shorter. The anterocone of M1 is divided by a deep anteromedian flexus; the paracone is connected to the protocone by its medial portion, configuring a very long mesoflexus and thus a long and narrow mesoloph (the anteroloph is also very long); with wear, it forms a long mesofossette. M2 is similar in shape and occlusal details, except for the absence of anterocone, but the anteroloph is well developed. M3 is

smaller, but similar to the other teeth. A deep anteroflexid is present on m1 as is a long and narrow mesolophid (although this latter structure is absent in one specimen). The second lower molar exhibits individual variation in the presence of a mesolophid, conspicuous in most specimens, but others lack a noticeable trace, even in unworn molars. sy n o n y m s : Oryzomys: Thomas, 1900c:273; part; not Oryzomys Baird. Oreoryzomys Weksler, Percequillo, and Voss, 2006:21; type species Oryzomys balneator Thomas, by original designation. r e m a r k s : Oreoryzomys is recovered as the sister taxon to Microryzomys in phylogenetic analyses of oryzomyine rodents based on molecular and morphological data (Weksler 2003, 2006). In fact, the two genera are morphologically similar (as first observed by M. D. Carleton, pers. comm.); both share a deep anteromedian flexus on M1, a short, convexly shaped incisive foramina, type 1 carotid circulatory pattern, a rounded interorbital region hourglass in shape, a rounded brain case, and a posteroventral oriented foramen magnum.

Oreoryzomys balneator (Thomas, 1900) Ecuadorean Oreoryzomys sy n o n y m s : Oryzomys balneator Thomas, 1900c:273; type locality “Mirador,” Baños, Tungurahua, Ecuador. Oryzomys ([Oryzomys]) balneator: E.-L. Trouessart, 1904: 418; name combination. Oryzomys balneator hesperus Anthony, 1924b:7; type locality “El Chiral, Western Andes, Provincia del Oro, Ecuador, elevation 5350 ft.” Oryzomys balneator balneator: Gyldenstolpe, 1932a:13; name combination. [Oreoryzomys] balneator: Weksler, Percequillo, and Voss, 2006:21; first use of current name combination. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : This species is known from a few localities on both western and eastern slopes of the Andes in Ecuador and northern Peru, at intermediate elevations (from 1,500 to 1,586 m). s e l e c t e d l o c a l i t i e s (Map 237): ECUADOR: El Oro, El Chiral (Oryzomys balneator hesperus Anthony); Napo, Baeza (BM 15.7.12.9); Tunguruhua, Mirador (type locality of Oryzomys balneator); Zamora-Chinchipe, 4 km E of Sabanilla (USNM 513570). PERU: Cajamarca, 4 km W of Chaupe (AMNH 268144). s u b s p e c i e s : I treat Oreoryzomys balneator as monotypic. n a t u r a l h i s t o ry: This species occurs in Andean montane and cloud forest. According to Musser et al. (1998), Mirador, the type locality of O. balneator, has a

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 439

Map 237 Selected localities for Oreoryzomys balneator (●). Contour line = 2,000 m.

matrix of vegetation with sharp contrasts, including páramo mixed with temperate plants in the valleys interdigitating with extensive areas of subtropical forest. The climate is rainy, cold, and windy. There are no published details on the habitat where specimens were caught, but museum skin labels (BM) indicate that individuals were “trapped amidst the roots on a tree,” found “at old stump,” “among dead logs,” and “in woods,” suggesting that they are terrestrial. No other information on natural history is available. r e m a r k s : The validity of Oryzomys balneator hesperus Anthony remains to be determined, pending examination of the type material. Until that definition has been achieved, I provisionally recognize Anthony’s name as a synonym of Oreoryzomys balneator. It is noteworthy that the type and only known locality of hesperus represents the single western slope site for O. balneator, which is otherwise distributed along the eastern Andean gradient.

Genus Oryzomys Baird, 1857 Alexandre R. Percequillo

Until very recently, the genus Oryzomys was one of the most taxonomically diverse of the many genera within the subfamily Sigmodontinae, comprising some 43 species distributed from the southern United States in North American to northern Argentina in South America (Musser and Carleton 2005). However, the extensive taxonomic rearrangement proposed by Weksler et al. (2006), based on morphological (Percequillo 1998, 2003; Weksler 2006) and

molecular analyses (Weksler 2003, 2006), restricted the genus Oryzomys in its taxonomic content and thus substantially narrowed its geographic range, especially in South America. Currently five species are attributed to this genus (Musser and Carleton 2005; Voss and Weksler 2009). Three of these (O. antillarum, O. dimidiatus, and O. palustris) are restricted to North and Central America (see Hall 1981; Weksler et al. 2006) and are not considered further here. Two species either extend into northwestern South America (O. couesi) or are limited to this continent (O. gorgasi). The South American species of genus Oryzomys (based on Hall 1981; H. Sánchez et al. 2001) are medium-sized oryzomyine rats, with the tail ranging from shorter to longer than head and body length, with conspicuous epidermal scales, and with ventral caudal hairs longer than dorsal ones and a small pencil of terminal hairs. Hindfeet are long and narrow, with webs of skin connecting digits II, III, and IV, and a fringe of stiff and short hairs along the metatarsal margins; ungual tufts are sparse and short, and do not conceal the claws; plantar surfaces are covered with squamae, and the hypothenar pads are small and inconspicuous. Ears are small and rounded. The pelage is harsh and dense, usually short; dorsal pelage is grizzled grayish brown to ochraceous tawny, mixed with black; color of the sides is paler and with less black; ventral pelage is white to ochraceous buff. The tail is distinctly bicolored at its base or throughout most of its length. The skull is strongly built although not very long. The rostrum is short and strong, with deep and wide zygomatic notches and well-projected and inflated nasolacrimal capsules. The interorbital region is broad and strongly divergent posteriorly with heavily beaded supraorbital margins or with well-developed supraorbital crests; temporal crests are well developed and collinear with the supraorbital margins. Incisive foramina are very long and narrow, with their posterior margins penetrating between the first molars; lateral margins are widest medially. The palate is long and wide (sensu Hershkovitz 1962); posterolateral palatal pits are complex, numerous, and recessed in deep and rounded depressions. The anterior border of the mesopterygoid fossa is rounded, and its roof is completely ossified without a trace of sphenopalatine vacuities (except in O. palustris, which has very large and wide vacuities). The stapedial foramen is minute or absent, and both the squamosoalisphenoid groove and sphenofrontal foramen are absent, configuring carotid circulatory pattern 3 (sensu Voss 1988). The buccinator-masticatory and accessory oval foramina are confluent, thus an alisphenoid strut is absent. The postglenoid foramen is narrow, and the subsquamosal fenestra is a small aperture in most species, due to a broad hamular process of the squamosal, obliterated in both South American species. The suspensory process of the squamosal is absent and the tegmen tympani is short,

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and may or may not overlap the squamosal. Auditory bullae are small but globose, with a distinct dorsostapedial process that may or may not overlap the squamosal; bony tubes are abruptly constricted, and ectotympanic capsules are globose. The mandible is strong, with or without the capsular projection of lower incisors; superior and inferior notches are shallow. Upper incisors are strongly opisthodont. Molars are pentalophodont, and brachydont; toothrows are parallel and appear smaller in relation to the remaining parts of the skull; main cusps are arranged in opposite pairs; and labial and lingual flexi interpenetrate only slightly at the median molar plane. Carleton and Musser (1989) described occlusal topology in detail. The first upper and lower molars have accessory roots. sy n o n y m s : Mus: Harlan, 1837:385; part (description of palustris); not Mus Linnaeus. [Hesperomys] Oryzomys Baird, 1857:458; as subgenus; type species Mus palustris Harlan, by monotypy. Hesperomys: Alston, 1877:756; part (description of couesi); not Hesperomys Waterhouse. Oryuzomys: Coues, 1890:4165; elevation to generic rank. Nectomys: Thomas, 1905a:586; part (description of dimidiatus); not Nectomys Peters. Micronectomys: Hershkovitz, 1948:55; nomen nudum. r e m a r k s : The number of species within the genus Oryzomys is in flux. Weksler et al. (2006:4,Table 1) recognized five (O. antillarum Thomas, O. couesi Alston, O. dimidiatus Thomas, O. gorgasi Hershkovitz, and O. palustris Harlan). Carleton and Arroyo-Cabrales (2009) reviewed the couesi complex from western Mexico, and recognized three other species in addition to O. couesi (O. albiventer Merriam, O. nelsoni Merriam, and O. peninsulae Thomas). Most recently, Hanson et al. (2010), based on molecular phylogenetic analysis of samples from throughout the North and Middle American range, increased this number by four. These authors split O. texensis J. A. Allen from O. palustris and O. mexicanus J. A. Allen from O. couesi while identifying two undescribed species from Costa Rica and Panama. To date, no samples from South America have been included in any molecular phylogenetic study. KEY TO THE SOUTH AMERICAN SPECIES OF ORYZOMYS:

1. Rostrum long and slender; incisive foramina wider posteriorly; hamular process of squamosal slender, configuring a large subsquamosal fenestra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Oryzomys couesi 1′. Rostrum stout and blunt; incisive foramina wider medially, tapering posteriorly; hamular process of squamosal broad, configuring a small subsquamosal fenestra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oryzomys gorgasi

Oryzomys couesi (Alston, 1877) Coues’s Marsh Rice Rat sy n o n y m s : Hesperomys couesi Alston, 1877:756; type locality “Cobán, Guatemala.” Oryzomys aquaticus J. A. Allen, 1891c:289; type locality “Brownsville, Cameron Co., Texas.” H[esperomys]. (O[ryzomys].) couesi: J. A. Allen, 1891c:290; name combination. [Oryzomys] Couesi: Thomas, 1893b:403; first use of current name combination. Oryzomys couesi: J. A. Allen, 1893:240; name combination. Oryzomys fulgens Thomas, 1893b:403; type locality “Mexico.” Oryzomys mexicanus J. A. Allen, 1897b:52; type locality “Had. San Marcos, 3550 ft., Tonila, Jalisco,” Mexico. Oryzomys bulleri J. A. Allen, 1897b:53; type locality “Valle de Banderas, Terro Tepic, Jalisco, Mexico.” Oryzomys peninsulae Thomas, 1897:548; type locality “Santa Anita, Baja California,” Mexico. Oryzomys jalapae J. A. Allen and Chapman, 1897b:206; type locality “Japala, 4400 ft., Veracruz,” Mexico. Oryzomys cozumelae Merriam, 1901:103; type locality “Cozumel Island, Quintana Roo,” Mexico. Oryzomys albiventer Merriam, 1901:279; type locality “Ameca, 4000 ft., Jalisco,” Mexico. Oryzomys crinitus Merriam, 1901:281; type locality “Tlalpan, Distrito Federal, Mexico.” Oryzomys crinitus aztecus Merriam, 1901:282; type locality “Yautepec, Morelos,” Mexico. Oryzomys peragrus Merriam, 1901:283; type locality “Río Verde, San Luis Potosi,” Mexico. Oryzomys richmondi Merriam, 1901:284; type locality “Escondido River, 50 mi, above Bluefields, Nicaragua.” Oryzomys jalapae rufinus Merriam, 1901:285; type locality “Catemaco, 1000 ft., Veracruz,” Mexico. Oryzomys goldmani Merriam, 1901:288; type locality “Coatzacoalcos, Veracruz,” Mexico. Oryzomys rufus Merriam, 1901:287; type locality “Santiago, 200 ft., Nayarit,” Mexico. Oryzomys teapensis Merriam, 1901:286; type locality “Teapa, Tabasco,” Mexico. Oryzomys zygomaticus Merriam, 1901:285; type locality “Nenton, Guatemala.” Oryzomys molestus Elliot, 1903:145; type locality “Ocotlan, State of Jalisco, Mexico.” Oryzomys japalae apatelius Elliot, 1904a:266; type locality “San Carlos, State of Vera Cruz, Mexico.” [Oryzomys (Oryzomys)] couesi: E.-L. Trouessart, 1904:416; name combination. Oryzomys richardsoni J. A. Allen, 1910b:99; type locality “Peña Blanca, Nicaragua.”

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 441

Oryzomys gatunensis Goldman, 1912a:7; type locality “Gatún, Canal Zone, Panama.” Oryzomys couesi regillus Goldman, 1915:129; type locality “Los Reyes, Michoacán,” Mexico. Oryzomys couesi pinicola A. Murie, 1932:1; type locality “pine ridge, 12 mi. S El Cayo, Belize.” Oryzomys couesi lambi Burt, 1934:107; type locality “San José de Guaymas, Sonora,” Mexico. Oryzomys azuerensis Bole, 1937:165; type locality “Paracoté, 11⁄2 mi. S mouth Río Angulo, Mariato-Suay lands, Veraguas, Panama.” Oryzomys palustris couesi: Hall, 1960:173; name combination. Oryzomys [(Oryzomys)] palustris couesi: Hall, 1981:609; name combination. d e s c r i p t i o n : Large and robust skull, with short and wide rostrum; incisive foramina penetrate between procingula of first upper molars; posteriorly strongly divergent interorbital region with strongly beaded to shelved supraorbital margins; prominent posterolateral palatal pits recessed in medium to deep palatal depressions; and completely ossified roof of mesopterygoid fossa (see Weksler 2006). Hershkovitz (1987a) noted typical ochraceous orange color of body (dorsal, lateral, and ventral) throughout species’ range and entirely whitish mystacial facial region. d i s t r i b u t i o n : This species is widespread throughout North and Central America (Hall 1981; Musser and Carleton 2005), with only a single record from South America, in northwestern Colombia (Hershkovitz 1987a). s e l e c t e d l o c a l i t i e s (Map 238): COLOMBIA: Córdoba, Montería (Hershkovitz 1987a). s u b s p e c i e s : Substantial subspecies diversity is currently recognized within the North and Central American range of O. couesi (Hall 1981, as Oryzomys palustris). n a t u r a l h i s t o ry: Nothing is known about the natural history of this species in South America, aside from the comment made by Hershkovitz (1987a) that the single specimen he obtained was collected in a rice field. r e m a r k s : Long considered a subspecies of a very wide-ranging Oryzomys palustris (e.g., Hall 1960, 1981), O. couesi is now widely recognized as a valid species based on a number of morphological, karyotypic, and molecular geographic analyses (see summaries in Musser and Carleton 2005; Hanson et al. 2010). Hershkovitz (1971) regarded O. couesi as distinct from O. gorgasi, based on comparisons he made in the original description of the latter. H. Sánchez et al. (2001) also compared O. couesi to O. gorgasi, pointing out their differences. However, none of theses authors directly compared the voucher of O. couesi (FMNH 127250) from Montería, Colombia, to the holotype or the Venezuelan series of O. gorgasi. Thus, there remains a remote possibility that only one species of Ory-

Map 238 Single known South American locality for Oryzomys couesi (●); range in Panama from Hall (1981). Contour line = 2,000 m.

zomys is present at South America. If this is correct, the appropriate name applied to the South American species would be O. gorgasi (see H. Sánchez et al. 2001). The diploid number of the Colombian specimen is 2n = 56 (Hershkovitz 1987a), the same as that recorded for specimens from Middle American localities (Haiduk et al. 1979; R. J. Baker et al. 1983; Burton et al. 1987).

Oryzomys gorgasi Hershkovitz, 1971 Gorgas’s Marsh Rice Rat sy n o n y m s : Oryzomys gorgasi Hershkovitz, 1971:700; type locality “Loma Teguerre (7°54′N, 77°W), Departamento Antioquia, northwestern Colombia, between Río Atrato and mouth of a caño (channel) of the east bank ciénaga just below and opposite Sautatá (Chocó), Interoceanic Canal Survey Route 25 (Golfo de Urabá [sic] to Bahía Humboldt, via Ríos Atrato-Truandó); altitude, 1 meter above sea level.” Oryzomys curasoae McFarlane and Debrot, 2001:182; type locality “Fissure, 30 m below edge of north face of Tafelberg Santa Barbara, (UTM coordinates: 19–518570, 13–34570),” Curaçao, Caribbean Netherlands.

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d e s c r i p t i o n : Same external and craniodental traits typical of genus Oryzomys, as presented earlier. H. Sánchez et al. (2001:210) stated that O. gorgasi differed from other species (specifically O. couesi, O. dimidiatus, and O. palustris) by presence of stout and blunt rostrum, posteriorly tapering incisive foramina, absence of sphenopalatine vacuities, and broad hamular process of squamosal, which reduces subsquamosal fenestra to small opening. However, Weksler (2006) scored the roof of mesopterygoid fossa of O. couesi as completely ossified, the same condition as O. gorgasi, thus suggesting that this trait may be polymorphic in samples of O. couesi. Consistency in the lack of sphenopalatine vacuities and thus the utility of an unossified mesopterygoid fossa roof as diagnostic of O. gorgasi warrant further evaluation by examination of more extensive series of specimens of all species in the genus. d i s t r i b u t i o n : Oryzomys gorgasi is known from two localities in the trans-Andean portion of northern South America, one each in Colombia and Venezuela. This species is not known to extend into Panama, despite the close proximity of the single Colombian locality to that country. It is apparently extinct from Curaçao, off the northwestern Venezuelan coast. s e l e c t e d l o c a l i t i e s (Map 239): COLOMBIA: Antioquia, Loma Teguerre (Hershkovitz 1971). VENEZUELA: Zulia, El Caimito, Refugio de Fauna Silvestre y Reserva de Pesca Ciénaga de Los Olivitos, 40 km NE of Maracaibo (H. Sánchez et al. 2001). n a t u r a l h i s t o ry: In Colombia, the only known specimen was collected in the “swamp, or ciénaga, forests in the Río Atrato basin” (Hershkovitz 1971:701) “at least 60 km upriver from the gulf of Urubá in an area of high annual rainfall, . . . a freshwater swamp” (H. Sánchez et al. 2001:210). The series from Venezuela were obtained at El Caimito, a small coastal island covered by xerophytic vegetation and by mangroves along swampy lagoon margins (H. Sánchez et al. 2001). Here, the species was omnivorous, feeding on crustaceans, insects, seeds, and other plant tissues. Endoparasites observed included the onchocercid filariod Litomosoides sygmodontis and the recitulariid genus Pterygodermatites (subgenus Paucipectines). Despite being common in Neotropical cricetids, neither oxyurid nor trychostrongylid nematode endoparasites were found in examined stomachs. Oryzomys gorgasi is a species apparently uncommon in Venezuela, as considerable trapping effort at three localities near El Caimito has produced no other specimens (H. Sánchez et al. 2001). Instead, the black rat (Rattus rattus) was commonly captured, suggesting that this more aggressive exotic species may be competing with and displacing O. gorgasi. Similarly, Voss and Weksler (2009), based on paleontological (McFarlane and Debrot 2001) and ecologi-

cal data (H. Sánchez et al. 2001) for O. gorgasi, suggested that black rats were possibly responsible for the extinction of this species on the island of Curaçao. r e m a r k s : Since its description by Hershkovitz (1971) and, at the time, only known from the holotype, O. gorgasi has been considered a valid species, closely related to O. palustris and O. couesi (Honacki et al. 1982; Musser and Carleton 1993). In 2001 H. Sánchez et al. reported on a series of specimens from the coastal mangroves of northwestern Venezuela, supplemented Hershkovitz’s description of O. gorgasi, and solidified its specific status relative to other species of Oryzomys. They noted, however, that the markedly wide rostrum of the holotype might be due to allometric growth of the facial region during captivity. More recently, Oryzomys curasoae, an extinct species based on remains obtained from limestone fissures, was described from the continental shelf island of Curaçao off the northern Venezuelan coast (McFarlane and Debrot 2001). In the original description, these authors suggested that their species was close to Oryzomys, subgenus Oecomys, but refrained from addressing phylogenetic relationships. Subsequently, Voss and Weksler (2009), based on an extensive comparative analysis of several members of tribe Oryzomyini, constructed a phylogenetic hypothesis in which O. curasoae was nested with other species of Oryzomys (sensu Weksler et al. 2006), specifically as sister to O. gorgasi.

Map 239

Selected localities for Oryzomys gorgasi (●). Contour line = 2,000 m.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 443

Because quantitative traits also highlight the similarity between these two forms, these authors considered both taxa as “strict synonyms,” with priority for the name O. gorgasi. They limited the name curasoae “solely to refer to the subfossil material from Curaçao” (Voss and Weksler 2009:5). Musser and Carleton (2005) incorrectly gave the type locality of O. curasoae as “Venezuela, Curaçao Isl.” This island is, however, part of the Caribbean Netherlands, although on the continental shelf just north of the Venezuelan mainland (map, Fig. 1).

Genus Pseudoryzomys Hershkovitz, 1962 Robert S. Voss

The genus Pseudoryzomys contains a single species, P. simplex, which occurs in tropical and subtropical grassland habitats below 1,000 m elevation in Brazil, northern Argentina, western Paraguay, eastern Bolivia, and extreme southeastern Peru. Although Hershkovitz (1962), Reig (1984, 1986), and Braun (1993) classified Pseudoryzomys as a phyllotine, other morphological researchers have suggested that the genus is more closely related to oryzomyines (Olds and Anderson 1990; Voss and Myers 1991; Langguth and Neto 1993; Voss and Carleton 1993; Steppan 1995). Recent phylogenetic analyses (e.g., Weksler 2003, 2006; Percequillo, Weksler, and Costa 2011; Parada et al. 2013) unequivocally support the hypothesis that Pseudoryzomys is an oryzomyine closely related to Holochilus. Subfossil material of Pseudoryzomys is known from Brazilian cave deposits (Winge 1887)—some of which may date from the late Pleistocene—and from an archaeological site in Buenos Aires province, Argentina (Pardiñas 1995a). As far as known, the genus is not a member of any island fauna. Except as noted otherwise below, the following account is abstracted from Voss and Myers (1991), which should be consulted for additional details concerning taxonomy, morphology, and geographic distribution. Pseudoryzomys simplex is a medium-sized (30–60 g; Pine and Wetzel 1976; J. R. Contreras and Berry 1982) sigmodontine with coarsely grizzled-brownish dorsal fur and gray-based yellowish or buffy ventral fur. The pinnae are small, covered with short hairs that are colored like the fur of the head, and do not appear naked. The hindfeet are long and narrow with the middle three digits (II–IV) much longer than the outer two (I and V); the heel is smooth and hairless, but the rest of the naked plantar surface is densely covered with small tubercles, among which one or two metatarsal pads (the hypothenar may be present or absent) and four very small interdigital pads can be distinguished. The tail, distinctly bicolored (dark above and pale below) is about as long as the combined length of the head and body; it is covered with short hairs, but the underlying

epidermal scales are clearly visible, and there is no terminal tuft of distinctly longer hairs. There are eight mammae in inguinal, abdominal, postaxial, and pectoral pairs. The skull is distinctively proportioned in dorsal view, with a short rostrum, deep zygomatic notches, and a narrow interorbital region. The posterior supraorbital margins are anteriorly convergent and either sharp-edged or beaded; the zygomatic arches are widest across their squamosal roots and converge anteriorly. In lateral view, the zygomatic plates are very broad, with straight or concave anterior margins, and sometimes bearing blunt anterodorsal processes. The incisive foramina are narrow, parallel sided, and long, usually extending posteriorly to or between the anterocones of the first molars. The palate is smooth, without deep lateral gutters or median keels, and long (extending posteriorly well behind the third molars); prominent posterolateral palatal pits are present. The bony roof of the mesopterygoid fossa is perforated by large sphenopalatine vacuities; the parapterygoid fossae are shallow (not deeply excavated) and narrow (without expanded lateral margins). An alisphenoid strut separating the buccinator-masticatory foramen from the foramen ovale accessorius may be either present or absent. The carotid arterial pattern is derived (pattern 3 of Voss 1988). The auditory bullae are small, and the tegmen tympani does not overlap the squamosal. A very large postglenoid foramen and a smaller subsquamosal fenestra perforate the lateral surface of the braincase above the bulla on either side of the skull. The mandible is short and deep, with a large falciform coronoid process; the tip of the angular process is below or slightly behind the condyle. The lower incisor alveolus terminates in a welldeveloped capsular process below or just behind the base of the coronoid process. The upper incisors are narrow, strongly opisthodont, and smooth (ungrooved), with yellow-orange enamel bands. The upper molar rows are parallel, and the teeth themselves are low-crowned and bunodont (even when unworn). The principal labial and lingual cusps of the upper molars are arranged in opposite pairs connected by transverse lophs. The anterocone of M1 is undivided, as is the anteroconid of m1. Small mesolophs are present on M1 and M2 but do not connect with mesostyles on the labial cingulum; mesolophids are absent on all of the lower molars. M1 and m1 each have four roots, but all the remaining molars have only three roots each. Axial skeletal elements include 12 ribs, 19–20 thoracolumbar vertebrae, 3–4 sacral vertebrae, and 29 caudal vertebrae. The tuberculum of the first rib articulates with the transverse processes of the seventh cervical and first thoracic vertebrae, and the second thoracic vertebra has a greatly elongated neural spine. Each ring-shaped hemal arch on the undersides of the caudal vertebrae has

444 Mammals of South America

a distinct spinous process on its posterior margin (Steppan 1995). The entepicondylar foramen of the humerus is absent. The stomach is unilocular and hemiglandular, and the gall bladder is absent. One pair of preputial glands is present, but other male accessory secretory organs remain undescribed. The glans penis (illustrated by Langguth and Neto 1993) conforms to the complex bauplan, with a spinous exterior and a deep terminal crater containing three bacular mounds (supported by a tridigitate bacular cartilage), a dorsal papilla, and a bifurcate urethral flap. The karyotype consists of 56 diploid chromosomes, all of which appear to be acrocentric; the fundamental number (FN) is 54. sy n o n y m s : Hesperomys: Winge, 1887:11; part (description of simplex); not Hesperomys Waterhouse. Oryzomys: E.-L. Trouessart, 1897:528; part (listing of simplex); not Oryzomys Baird. Oecomys: Moojen, 1952b:55; part (listing of simplex); not Oecomys Thomas. Pseudoryzomys Hershkovitz, 1959a:8; nomen nudum (see Pine and Wetzel 1976). Calomys: Hershkovitz, 1962:123; part; (listing of simplex); not Calomys Waterhouse. Pseudoryzomys Hershkovitz, 1962: 208; type species Oryzomys wavrini Thomas, by original designation. r e m a r k s : Hershkovitz (1959a) originally proposed the name Pseudoryzomys, but the name was not made formally available until three years later, when Hershkovitz (1962) provided a generic diagnosis (Pine and Wetzel 1976).

Pseudoryzomys simplex (Winge, 1887) False Oryzomys sy n o n y m s : Hesperomys simplex Winge, 1887:11; type locality (fixed by lectotype selection; Voss and Myers, 1991) “Lapa da Escrivania [= Escrivânia] Nr. 5,” a cave excavated by P. W. Lund near Lagoa Santa, Minas Gerais, Brazil. Oryzomys simplex: E.-L. Trouessart, 1897:528; name combination. Oryzomys wavrini Thomas, 1921b:177; type locality “Jesematathla [= Jesamatathla], west of Concepción,” Presidente Hayes, Paraguay. Oecomys simplex: Moojen, 1952b:55; name combination. Pseudoryzomys wavrini: Hershkovitz, 1959a:8; name combination, but Pseudoryzomys a nomen nudum with this date (see Remarks, above). Calomys simplex: Hershkovitz, 1962:123; name combination. Pseudoryzomys wavrini: Hershkovitz, 1962:208; first valid use of this name combination.

Pseudoryzomys wavrini reigi Pine and Wetzel, 1976:649; type locality “Pampa de Meio, Río Itenez, Depto. Beni, Bolivia.” Pseudoryzomys simplex: Massoia, 1980c:282; first use of current name combination. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : Pseudoryzomys simplex is known from low-lying areas below 900 m from northeastern Argentina, western Paraguay to eastern Bolivia and the Pampas del Heath in extreme southeastern Peru, and from there eastward through Brazil to the eastern margin of the Amazon Basin and the northeastern Atlantic coast. The species is largely confined to lowland areas with strongly seasonal rainfall, such as the grasslands and wetlands (campo úmido) found throughout the Chaco, Cerrado, and Caatinga domains (Voss and Myers 1991; L. G. Lessa and Talamoni 2000; F. F. Oliveira and Langguth 2004; Pardiñas, Cirignoli, and Galliari 2004; Bezerra et al. 2009; Prada and Percequillo 2013). Subfossils document a Holocene distribution that once extended southward to the Argentinean province of Buenos Aires (Pardiñas 1995a). selected localities (Map 240): ARGENTINA: Chaco, Predisencia Roque Sáenz Peña (Prado and Percequillo 2013); Formosa, Estancia Guayacolec (Massoia, Heinonen Fortabat, and Diéguez 1997); Santa Fe, Pedro Gómez Cello (Pardiñas, Cirignoli, and Galliari 2004), Santa Margarita (Massoia et al. 1995b). BOLIVIA: Beni, Estación Biológica del Beni (AMNH 262048); Santa Cruz, Pampa de Meio, Río Itenéz (Prado and Percequillo 2013), Parque Nacional Noel Kempff Mercado (Prado and Percequillo 2013), Santa Ana (Prado and Percequillo 2013). BRAZIL: Amapá, Fazenda Asa Branca, Tartarugalzinho (Prado and Percequillo 2013); Amazonas, Humaitá, Escola Agrotécnica (Prado and Percequillo 2013); Bahia, Mata do Zé Leandro (L. G. Pereira and Geise 2009); Goiás, Moro da Baleia, Alto Paraíso, Parque Nacional da Chapada dos Veadeiros (Prado and Percequillo 2013); Mato Grosso, Posta Leonardo (Prado and Percequillo 2013); Mato Grosso do Sul, Gruta São Miguel (Prado and Percequillo 2013), Rio Sucuriú (Prado and Percequillo 2013); Minas Gerais, Lagoa Santa (Voss and Myers 1991); Pernambuco, 40 km W of Recife (UMMZ 164995), Vila Feira Nova (Prado and Percequillo 2013); São Paulo, Estação Ecológico Jataí (L. G. Lessa and Talamoni 2000); Tocantins, Parque Nacional do Araguaia (Bezerra et al. 2009), Peixe (Prado and Percequillo 2013). PARAGUAY: Presidente Hayes, Fortín Juan de Zalazar (CONN 16487). PERU: Madre de Dios, Pampas del Heath (MUSM 11732). s u b s p e c i e s : I treat Pseudoryzomys simplex as monotypic. natural history: All known collection localities for Pseudoryzomys simplex are from tropical and subtropical landscapes characterized by open vegetation (e.g., in the Cerrado, Chaco, and Pantanal biomes). The few specimens

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 445

Map 240 Selected localities for Pseudoryzomys simplex (●). Contour line = 2,000 m.

accompanied by explicit habitat information were captured on the ground in grassy habitats, usually seasonally flooded savannas, marshes, and river floodplains. For some reason, P. simplex is hard to trap, and most known specimens have been recovered from Barn Owl (Tyto alba) pellets (e.g., by Pardiñas, Cirignoli, and Galliari 2004; Teta, Pereira, Muschetto, and Fracassi 2009). Nothing has been recorded in the literature concerning diet, reproduction, or other natural history topics.

Genus Scolomys Anthony, 1924 James L. Patton

Described in 1924 by H. E. Anthony from the eastern slope of the Ecuadorean Andes, the genus Scolomys remained an enigmatic taxon for the next 60 years, known in the published literature only from the original series of six specimens collected by G. H. H. Tate that comprised the single, and during that time, only known species, S. melanops Anthony. Following in rapid succession, and based on surveys at several sites in the western Amazon Basin, Pacheco (1991) described a second species (S. ucayalensis) from northern Peru, Patton and da Silva (1994) described a third species (S. juruaense) from western Brazil, and Gómez-Laverde et al. (2004) recorded specimens from southern Colombia and reviewed the systematics of the genus. These latter authors extended the range of S. melanops from the upper Río Pastaza and the Río Napo in Ecuador southeast to include three localities in northern Peru to the left (= north) bank of

the Río Amazonas near Iquitos. They assigned newly collected specimens from the Río Caquetá and Río Rumiyaco to the Peruvian taxon S. ucayalensis Pacheco, and extended the range of this species to a second locality in northeastern Peru. Finally, they argued that S. juruaense Patton and da Silva was not specifically distinct from S. ucayalensis. Species of Scolomys are small (head and body length range: 80–90 mm), short-tailed (tail length 55–77 mm), and short-eared (pinna height 15–17 mm) mice with a short and broad head and distinctly spiny fur both above and below (Patton and da Silva 1995; Gómez-Laverde et al. 2004). The body pelage is short and close, colored grizzled pale reddish-black to nearly totally black dorsally and gray ventrally. Dorsal hairs are of two types: long (averaging 12 mm), stout, flat, and broad (averaging 0.6 mm) spines with a medial trough on both surfaces, with the terminal one-third to one-quarter increasingly dark to the tip and proximal portion clear; and long, thin hairs equal in length to the spines and with tips reddish or blackish. Ventral hairs of both types are uniformly gray from base to tip. Mystacial, superciliary, genal, submental, interramal, and carpal vibrissae are present. Pinnae are small, appearing somewhat thickened and thus stiff, and, while appearing naked from a distance, are clothed externally and internally with short reddish-brown hairs. The manus has five large, fleshy plantar pads (two carpal and three interdigital), with toes pale in color. Digit I is reduced but has a small nail; digits II through V are long and well developed with short, stout, and curved claws. Hindfeet are rather short and broad, although the metatarsus is nearly twice as long as digit III; the heel is haired, and the naked sole begins at about one-quarter the length of the plantar surface (not including the digits). The outer digits are shorter than the middle three (with the claw of digit I extending to or just past the base of digit II and that of digit V extends to the proximal phalanx of digit IV). Conspicuous tufts of long, silvery hairs are present at dorsal base of each claw, extending past their tips, but the claw is visible from above. The claws are short, stout (about twice as long as deep) and strongly curved along their dorsal surface. There are five to six plantar pads, with the thenar and four interdigital pads large, fleshy, always present; the hypothenar pad is either absent or only weakly developed. The tail is shorter than head and body length, is sparsely haired, and lacks any terminal tuft or pencil or long hairs. There are 15–18 scale annuli per centimeter at midlength of the tail, with annual hairs broad, blackish, and 2.5–4 scale rows in length, but sparsely distributed so that the tail scales are conspicuous. Females possess only three pairs of mammae (one thoracic, one abdominal, and one inguinal), in contrast the four pairs typical of other genera of the tribe Oryzomyini.

446 Mammals of South America

The skull, in dorsal view, has a short and broad or tapering rostrum flanked by shallow, barely perceptible zygomatic notches, laterally expanded nasolacrimal capsules (especially so in S. melanops), a broad interorbital region hourglass in shape, and with well-developed beaded ledges overhanging the margins from the middle of the frontals and continuing along the posterior margins of the orbit onto the braincase just above the squamosoparietal suture as moderately developed temporal ridges. The braincase is distinctly rounded and globular, dominating the dorsal aspect of the skull (length of braincase is about one-half the length of the skull). Nasals are somewhat expanded and taper posteriorly to a median point that terminates well behind the premaxillofrontal sutures. The interparietal is large, one-half to one-third as deep as wide. In lateral view, the nasals extend onto or just beyond the anterior curvature of the incisors. The zygomatic plates are narrow, vertical to slightly angled posteriorly from its base, and without a distinct, free dorsal edge (thus, the zygomatic notches are markedly shallow when viewed from above). The zygomatic arch is thin, with a reduced jugal. The postglenoid foramen is moderate to small, hamular processes of the squamosal are stout, the subsquamosal foramen is reduced to totally occluded, and the mastoid fenestra is very small to nonexistent. The tegmen tympani of the periotic either does not contact or abuts but does not overlap the squamosal. Tympanic bullae are small and inflated ventrally only to the level of the molar series. In ventral view, the incisive foramina are moderate in size (occupying about 60% of the diastemal distance), distinctly teardrop in shape, and pointed anteriorly with diverging sides and expanded, rounded posterior margins. The premaxillary-vomerine septum is greatly swollen, nearly filling the entire cavity of the incisive foramina. The bony palate is long (sensu Hershkovitz 1962), without a median ridge or palatal excrescences, with only weakly evident lateral folds, but with large and complex posterolateral pits. The mesopterygoid fossa is wide with parallel sides and a rounded or squared anterior margin ending well behind the third upper molars. The bony roof of the fossa is complete or perforated only by barely perceptible sphenopalatine vacuities along the presphenoid. Parapterygoid fossae are well developed, with their lateral margins straight to slightly convex and strongly divergent toward the bullae, devoid of vacuities except for a small foramen ovale, and moderately excavated, not flat in appearance. An alisphenoid strut is absent, but only the foramen ovale is present laterally, without an anterior opening of the alisphenoid canal. A shallow trough indicating the passage of the masticatory-buccinator branch of the maxillary nerve is visible; it emanates from the anterior margin of the foramen ovale and obliquely crosses the alisphenoid onto the

squamosal. Facial circulation is apparently derived from the internal carotid artery (pattern 3, sensu Voss 1988), as indicated by a greatly reduced to absent stapedial foramen, no squamosoalisphenoid groove along the internolateral wall of the braincase, and no sphenofrontal foramen. The mandible is short and stout, with a short coronoid process with a weakly to moderately curved posterior projection. A capsular process is weakly developed. Lower incisors are thin, elongate, and with enamel essentially devoid of pigment. Upper incisors are asulcate and faced with yellow to pale yellow enamel. These are small, deeper than wide, and proodont (in S. melanops) to orthodont (in S. ucayalensis). Maxillary toothrows converge slightly posteriorly and are angled obliquely downward and outward at about 40°. Upper and lower molars are small and form a graded series with the third molar greatly simplified. Upper teeth are pentalophodont with their principal cusps arranged transversely and slightly obliquely. Labial and lingual reentrant folds do not interdigitate or contact, with the major labial folds of M1 and M2 (paraflexus and metaflexus) deep, extending at least two-thirds across the tooth, lingual folds reduced, with protoflexus only evident as a shallow lateral indentation in M1 and not visible at all in M2. The procingulum of M1 and m1 is well developed but not divided into separate anterolabial and anterolingual conules (no anteriormedial flexus[id] present). An anteroflexus on M1 is absent, so the anteroloph is not separated from the labial anteroconule. The anteroloph of M2 is well developed. Distinct mesolophs are present and extend to the labial margin of all three molars. The posteroloph is well developed on M1 but barely perceptible on M2 and absent on M3. The paracone and metacone of M1 and M2 is tall and well developed, with the protocone and hypocone proportionately reduced in size and much lower in topography. Only the paracone and weakly developed protocone are present on M3. The stomach is unilocular and hemiglandular. The male phallus (of S. ucayalensis, this structure has not been described for S. melanops) is cylindrical with an incomplete crater rim, terminally exposed urethral flaps, lateral mounds of distal baculum hidden by tissue of the crater rim, and an epidermis with widely spaced small spines. sy n o n y m : Scolomys Anthony, 1924b:1; type species Scolomys melanops, by original designation. r e m a r k s : Scolomys possesses each of the seven putative synapomorphies that diagnose the tribe Oryzomyini (Weksler 2006; see above), but of the remaining characters shared by most members of the tribe, Scolomys has only six rather than eight mammae in females (Patton and da Silva 1995) and acutely angled posterior nasal margins rather than rounded or squared ones (Weksler 2006).

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 447

Initial molecular sequence analyses of both mitochondrial and nuclear genes failed to support the placement of Scolomys as a member of the Oryzomyini (M. F. Smith and Patton 1999; D’Elía 2003). However, more taxon dense molecular analyses (L. F. García 1999; Weksler 2003), especially when combined with a cladistic analysis of morphological characters (Weksler 2006), firmly placed Scolomys within the Oryzomyini as the sister to Zygodontomys but near the base of the radiation. The apparent sister relationship between these two genera was unexpected, as noted by Weksler (2006:75): “Scolomys and Zygodontomys are two of the most distinctive clades of oryzomyines, and they are ecologically and morphologically dissimilar from one another. Whereas species of Scolomys are rainforest specialists (Patton and da Silva 1995; Gómez-Laverde et al. 2004), species of Zygodontomys are highly specialized for savannas and other open vegetation formations (Voss 1991a). The IRBP sequence divergence of both lineages was also high, suggesting an early split within oryzomyine evolution. Although the clade lacks IRBP synapomorphies, analyses using faster-evolving mitochondrial genes have also recovered the same grouping (L. F. García 1999). This suggests an early cladogenetic event between the Scolomys and Zygodontomys lineages after the appearance of the Scolomys-Zygodontomys ancestor.” I follow Gómez-Laverde et al. (2004) and recognize two species in the genus.

Laverde et al. 2004). Cranially, however, two species readily distinguished. Scolomys melanops with short, wide, and blunt rostrum; wide and rounded zygomatic arches circumscribing wide and short orbital openings; laterally expanded nasolacrimal capsules; an open subsquamosal fenestra; proodont upper incisors; and short and deep mandible with short coronoid process. Hypothenar pad on plantar surface of hindfoot also well developed. d i s t r i b u t i o n : Scolomys melanops is known from three localities in eastern Ecuador and four in northeastern Peru, all between the Río Pastaza and Río Napo and north of the Río Amazonas. Elevation ranges from about 150 m to 1200 m. s e l e c t e d l o c a l i t i e s (Map 241): ECUADOR: Orellana, Parque Nacional Yasuní, 38 km S of Pompeya Sur (ROM 104537); Pastaza, Mera (type locality of Scolomys melanops Anthony), Puyo (YPM 823); Sucumbios, Limoncocha (USNM 513581). PERU: Loreto, Estación Biológica Allpahuayo (Hice 2001), Quebrada Orán, ca. 5 km N of Río Amazonas, 85 km NE of Iquitos (LSUMZ 27927), San Jacinto (KU 158212), 1.5 km N of Teniente Lopez (KU 158214). s u b s p e c i e s : Scolomys melanops is monotypic. n a t u r a l h i s t o ry: This species has been trapped in cultivated fields and at the edge of mature forest (Rageot and Albuja 1994) and in patches of remnant forest (Gómez-Laverde et al. 2004) in eastern Ecuador, and in

KEY TO THE SPECIES OF SCOLOMYS:

1. Incisors proodont; rostrum short and blunt; nasolacrimal capsules expanded when viewed from above; zygomatic arches rounded; subsquamosal fenestra open; mandible short and deep; coronoid process short; hypothenar pad usually present; 2n = 60 . . . . . . . . . . Scolomys melanops 1′. Incisors orthodont; rostrum longer and more tapering; nasolacrimal capsules not expanded; zygomatic arches straight, converging anteriorly; subsquamosal fenestra occluded; mandible gracile, with elongated coronoid process; hypothenar pad reduced to absent; 2n = 50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scolomys ucayalensis

Scolomys melanops Anthony, 1924 Gray Spiny Mouse sy n o n y m : Scolomys melanops Anthony, 1924b:2; type locality “Mera, about 3800 feet elevation, eastern [Pastaza] Ecuador.” d e s c r i p t i o n : Karyologically and molecularly well differentiated from S. ucayalensis, although externally both species share same small body, short and nearly naked tail, distinctly spiny fur, and grizzled pale reddish-brown to dark reddish-black finely streaked with black color above and below (Anthony 1924; Patton and da Silva 1994; Gómez-

Map 241 Selected localities for Scolomys melanops (●) and Scolomys ucayalensis (ᇲ). Contour line = 2,000 m.

448 Mammals of South America

undisturbed forest as well as in selectively logged forest types at localities in northeastern Peru (Hice 2001; Hice and Velazco 2012). Except for two individuals caught on fallen logs, all others were on the ground, where the species was obtained on pitfall lines as commonly as in traps (Hice and Schmidly 2002). Hice (2001) recorded this species in all months of the wet season but never captured individuals in the four drier months of the year. She noted that reproductively active males were captured in March, October, and November, and pregnant females in March and April. The average litter size was 2.5 embryos. Anthony (1924b) reported pregnant females in March, with a litter size of three. Rengifo and Aquino (2012) described the nest, noting in particular the use of fiber taken from the palm Lepidocaryum tenue. Little else is known of the ecology or behavior of S. melanops. r e m a r k s : Patton and da Silva (1995) described the karyotype of specimens from the Río Napo, Ecuador, with 2n = 60, FN = 78, a large submetacentric X chromosome and large subtelocentric Y chromosome.

Scolomys ucayalensis Pacheco, 1991 Ucayali Spiny Mouse sy n o n y m s : Scolomys ucayalensis Pacheco, 1991:1; type locality “Centro de Invesgicationes ‘Jenaro Herrera’, 2.8 km E of Jenaro Herrera, department of Loreto, right bank of the Ucayali river; at 135 m elev.; 73°39′W, 04°52′S.” Scolomys juruaense Patton and da Silva, 1994:324; type locality “Seringal Condor, left bank Rio Juruá, Amazonas, Brazil 70°51′W, 6°45′S.” d e s c r i p t i o n : Small mouse with short, nearly naked tail (83% of head and body length); short and broad head with distinctly pointed snout; short and relatively broad hindfeet; greatly reduced to absent hypothenar pad but welldeveloped thenar and interdigital pads; small and rounded ears; and dorsal color varying from grizzled pale reddishbrown to dark reddish-black finely streaked with black. Skull with rounded and inflated braincase; short and basally broad rostrum that tapers distally; narrowed and straight zygomatic arches; narrow but long orbital openings; subsquamosal fenestra totally occluded by stout hamular process of squamosal; short and distally broad incisive foramina; and wide mesopterygoid fossa with parallel sides and squared, as opposed to rounded, anterior margin. d i s t r i b u t i o n : Scolomys ucayalensis occurs largely in lowland rainforest from extreme southern Colombia to northeastern Peru, western Brazil, and southern Ecuador, across an elevational range from 200 to 1,400 m. The distribution circumscribes that of its congener S. melanops, and the two are likely to be found in sympatry with additional collecting north of the Río Marañón-Río Amazonas axis.

s e l e c t e d l o c a l i t i e s (Map 241): BRAZIL: Acre, Sobral, left bank Rio Juruá (INPA 2485); Amazonas, Seringal Condor, left bank Rio Juruá (type locality of Scolomys juruaense Patton and da Silva), Penedo, right bank Rio Juruá (MVZ 183165), Barro Vermelho, left bank Rio Juruá (MVZ 183170). COLOMBIA: Amazonas, Corregimiento Puerto Santander, cerca de la Quebrada Bocaduché, margen sur Río Caquetá (ICN 16233); Nariño, cuenca alta del Río Rumiyaco (IAvH 6203). ECUADOR: Morona-Santiago, Domono (M. Brito and Arguero 2012); Zamora-Chinchipe, Alto Machinaza (M. Brito and Arguero 2012). PERU: Loreto, 2.8 km E of Jenaro Herrera (type locality of Scolomys ucayalensis Pacheco), Nuevo San Juan, Río Gálvez (AMNH 272668); Ucayali, Reserva Nacional Sierra del Divisor (H. Quintana et al. 2009). s u b s p e c i e s : Scolomys ucayalensis is monotypic, with little expressed variation in mensural characters among the known samples (Gómez-Laverde et al. 2004). n a t u r a l h i s t o ry: Pacheco (1991) obtained his two specimens at the type locality in dense undergrowth at the edge of primary forest artificially cut for regeneration studies, suggesting that this species naturally occurs in disturbed or secondary forest. Patton et al. (2000), however, collected their specimens along the Rio Juruá in western Brazil in undisturbed terra firme forest, though where there were often areas of local, natural disturbances (such as tree falls) and thus with a dense understory. There, pregnant females were captured from August through March, which spans both the wet and dry seasons. Embryo counts ranged from one to three. In contrast, the two Ecuadorean localities are both on the eastern Andean slope, one in mature subtropical rainforest dominated by the cauchillo tree (Ficus [Moraceae]) and the second in cloud forest with trees that reach 20 m in height and covered by bryophytes and bromeliads. r e m a r k s : Gómez-Laverde et al. (2004), with the availability of much larger and geographically more expansive samples, showed that the presumptive distinctive characters differentiating S. juruaense to S. ucayalensis were primarily age related. Combined with very limited mitochondrial sequence divergence (about 1%), they argued that the two taxa were conspecific, a decision followed here. M. Brito and Arguero (2012) provided cranial measurements for the four known Ecuadoran specimens of S. ucayalensi and contrasted the morphological characteristics of this species with those of M. melanops. Patton and da Silva (1995) described a karyotype of western Brazilian specimens as 2n = 50, FN = 68, with a large acrocentric X chromosome and small acrocentric Y chromosome. These authors also figured and described the male phallus.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 449

Genus Sigmodontomys J. A. Allen, 1897 Marcelo Weksler

Sigmodontomys is a monotypic genus found in lowland and lower montane trans-Andean forests in northwestern South America (Colombia, Venezuela, and Ecuador) and from Honduras to Panama in Central America. Until recently (e.g., Musser and Carleton 2005), Sigmodontomys included the two species S. alfari J. A. Allen, 1897 and S. aphrastus (W. P. Harris 1932), but phylogenetic analyses did not recover the two taxa as sister species (Weksler 2006; Pine et al. 2012), and aphrastus is now placed in its own genus: Tanyuromys Pine, Timm, and Weksler, 2012 (see Tanyuromys account). The following morphological description is based on AMNH and USMN specimens supplemented by information extracted from Hershkovitz (1944), Arata (1964; male accessory reproductive glands), Hooper and Musser (1964, glans penis), and Voss (1991a; gall bladder). Sigmodontomys are medium-sized rodents, with moderate head and body size (range 120–152 mm). The tail is longer than the combined head and body length (length 149– 190 mm), and the hindfeet are long and robust (length 34– 37 mm). The body pelage is long, dense, and glossy; coloration of the upper parts ranges from dark ochraceous-orange to grizzled-yellowish brown, and the under parts from gray, white, or ochraceous, but hairs always with a dark gray base. The pinnae are small, slightly hairy, and dark, contrasting with paler dorsal coloration. The manus and pes are covered dorsally with short, dark hairs. Digits II–IV of the hindfeet are much longer than dI and dV (claw of dI reaches the medial portion of first phalanx of dII; claw of dV extends to interphalangeal joint of dIV). The plantar surface of the hindfoot is naked, densely covered with small epidermal tubercles distally, and has one or two small metatarsal pads (the thenar pad is always present, but the hypothenar pad is either absent or extremely reduced) and four very small interdigital pads. Small webs of skin are present between the digits II, III, and IV, but seldom extending more than about half the length of the first phalanx. Both forefeet and hindfeet have sparse ungual tufts covering but seldom extending beyond the tips of the claws (the tufts are absent on the hallux); the hindfeet lack natatory fringes. The tail is unicolored and sparsely haired, without a terminal pencil or tuft of distinctly longer hairs. Females have four pairs of mammae, one each in inguinal, abdominal, postaxial, and pectoral positions. The skull is medium sized and robust. The rostrum is short and wide, and flanked by deep zygomatic notches. The nasals have squared or gently rounded posterior margins that extend posteriorly approximately to the same level as or slightly beyond the lacrimals; lacrimals usually have a longer maxillary than frontal suture. The interorbital margins converge anteriorly and possess strongly beaded

supraorbital edges; the braincase is squared and relatively narrow, with well-developed temporal, lambdoidal, and nuchal crests. The posterior wall of the orbit is smooth. The frontosquamosal suture is anterior to the frontoparietal suture (the dorsal facet of the frontal is in broad contact with the squamosal). The parietal has a broad lateral expansion, a large portion of which dips below the temporal ridge posteriorly. The zygomatic arches are rounded or slightly convergent anteriorly, widest across middle portion of the arch or more posteriorly. The zygomatic plates lack anterodorsal spinous processes, and their posterior margins lie level to the alveolus of M1. Incisive foramina are broad and short, terminating well anterior to the alveoli of the M1s. The palatal bridge lacks deep furrows or median ridges, and extends slightly behind the third molars; conspicuous posterolateral palatal pits are present. The bony roof of the mesopterygoid fossa is perforated by reduced and narrow sphenopalatine vacuities. The postglenoid foramen is large and rounded, but the subsquamosal fenestra is absent or vestigial. The mastoid is completely ossified, or has only a small perforation (mastoid fenestra absent). The mandible is robust, with a large falciform coronoid process slightly higher than the condyloid process, and a rounded angular process. The capsular process is developed, situated below or just posterior to the base of the coronoid process. The upper incisors are ungrooved and opisthodont. The molars are pentalophodont and bunodont. Maxillary toothrows are parallel; the molar series is robust and long, ranging from 5.3–6 mm in length; the labial and lingual flexi of upper molars shallowly penetrate at molar midline; the labial and lingual flexi are arranged in opposite pairs. Labial cingula are present, obliterating the lateral view of labial folds. The anterocone of M1 is undivided (anteromedian flexus absent); the anteroloph is well developed and fused with the anterocone by a labial cingulum; a protostyle is absent; an enamel bridge connects the paracone to the posterior portion of the protocone. M2 usually lacks a protoflexus and the mesoflexus is present as single fossette. M3 has a mesoloph, posteroloph, and shallow hypoflexus (that disappears with wear); the paracone and protocone are distinguishable on the molar surface, the hypocone is reduced, and the metacone is greatly reduced and completely fused with the posteroloph. The labial accessory root of M1 is present (four roots total). Lower molars have the labial and lingual cusps in an opposite orientation. The anteroconid of m1 is undivided but contains a large internal fossetid; an anterolabial cingulum is developed in m1 but is absent on m2 and m3; an anterolophid is absent on m2, and the mesolophid is present in all lower molars; the ectolophid is absent, but an ectostylid is observed in the m1 of some specimens; the posteroflexid on m3 is large and persistent. There are four roots on m1, one

450 Mammals of South America

anterior, one posterior, one lingual (below the metaconid), and one labial (below the metaconid); both m2 and m3 possess three roots each (two anterior and one posterior). The axial skeleton consists of 12 ribs and 7 cervical, 19 thoracolumbar, 4 sacral, and 33–36 caudalvertebrae. The hemal arch between the second and third caudal vertebrae rarely forms a posterior spinous process. The entepicondylar foramen is absent, and the supratrochlear is present. The trochlear process of the calcaneus is noticeably posterior to the articular facet. The gall bladder is absent. The glans penis has a deep terminal crater with three bacular mounds containing a tridigitate distal cartilaginous apparatus, with the central digit more slender than lateral ones; the dorsal papilla exhibits one apical spine, and a spineless urethral process without lateral lobule. The preputial glands are large. sy n o n y m s : Sigmodontomys J. A. Allen, 1897a:38; type species Sigmodontomys alfari J. A. Allen, by original designation. Nectomys: Thomas, 1897f:547; part (description of russulus); not Nectomys Peters. Oryzomys: J. A. Allen, 1908:635; part (description of ochraceous); not Oryzomys Baird. Nectomys (Sigmodontomys): Hershkovitz, 1944:21; part (listing of alfari, efficax, russulus, and emeraldarum); subgeneric designation. Oryzomys (Sigmodontomys): A. L. Gardner and Patton, 1976:11; subgeneric designation. r e m a r k s : Hershkovitz (1944, 1948b) included Sigmodontomys as a subgenus of Nectomys, and considered Sigmodontomys alfari as the single species, with four subspecies. Cabrera (1961) proposed a similar taxonomic arrangement, but A. L. Gardner and Patton (1976), on the basis of karyology and bacular morphology, considered Sigmodontomys to be a subgenus of Oryzomys (Baird 1857). Musser and Carleton (1993, 2005) regarded Sigmodontomys as a full genus, an arrangement corroborated by Weksler’s (2003, 2006) phylogenetic analyses. Cadena et al. (1998) reported a distinct species from Nariño in the Colombian Chocó as “Sigmodontomys sp.,” but ongoing research (M. Pinto and M. Weksler, unpubl. data) suggests that this specimen belongs to a new taxon phylogenetically close to Mindomys hammondi (see Pine et al. 2012). Bonvicino (1999) placed Nectomys parvipes (Petter 1979) in the genus Sigmodontomys, but following Voss et al. (2001: 94–95), I treat this taxon as a synonym of Nectomys rattus (see Nectomys account). Recent molecular phylogenetic analyses (Hanson and Bradley 2008; Pine et al. 2012) recovered Sigmodontomys alfari as nested within Melanomys, rendering the latter taxon polyphyletic. Pine et al. (2012) suggested that the

non-monophyly of Melanomys was due to incomplete lineage sorting as their cladistic analysis of morphological characters corroborated the monophyly of this genus relative to other Oryzomyini. Herein, I retain both Melanomys and Sigmodontomys as separate genera, but additional analyses are required to confirm this arrangement.

Sigmodontomys alfari J. A. Allen, 1897 Alfaro’s Water Rat sy n o n y m s : Sigmodontomys alfari J. A. Allen, 1897a:39; type locality “Jimenez (altitude, 700 feet), [Limón,] Costa Rica.” Nectomys russulus Thomas, 1897f:547; type locality “Valdivia, [Antioquia,] Colombia, alt. 1200 metres.” Nectomys esmeraldarum Thomas, 1901f:250; type locality “St. Javier, Esmeraldas Prov., N.W. Ecuador. Altitude 20 m.” Sigmodontomys alfaroi Thomas, 1901f:251; incorrect subsequent spelling of Sigmodontomys alfari J. A. Allen. Oryzomys ochraceus J. A. Allen, 1908:655; type locality “Rio Grande, [León,] Nicaragua.” Nectomys alfari alfari: Goldman, 1913:7; name combination. Nectomys alfari efficax: Goldman, 1913:7; type locality “Cana (Altitude 1,800 feet), [Panamá,] Eastern Panama.” Oryzomys barbacoas J. A. Allen, 1916a:85; type locality “Barbacoas, [Nariño,] Altitude 75 feet, Southwestern Colombia.” Oryzomys barbacoas ochrinus Thomas, 1921f:449; type locality “Ecuador, [Esmeraldas,] west of Quito (Hershkovitz [1948b:54] wrote: “The original specimen of ochrinus ‘collected’ by Söderström from ‘west of Quito’ could very well have originated in the Río Mira region on the western slope of the Cordillera Occidental.” Nectomys esmeraldorum Gyldenstolpe, 1932a:68; incorrect subsequent spelling of Nectomys esmeraldarum Thomas. Nectomys [(Sigmodontomys)] alfari alfari: Hershkovitz, 1944:74; name combination. Nectomys [(Sigmodontomys)] alfari efficax: Hershkovitz, 1944:75; name combination. Nectomys [(Sigmodontomys)] alfari russulus: Hershkovitz, 1944:77; name combination. Nectomys [(Sigmodontomys)] alfari esmeraldarum: Hershkovitz, 1944:78; name combination. Oryzomys (Sigmodontomys) alfari: A. L. Gardner and Patton, 1976:11; name combination. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : Sigmodontomys alfari is found throughout trans-Andean lowland and lower montane forests in Colombia, Venezuela, and Ecuador; most collecting localities range from sea level to 1,300 m; this species also

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 451

occurs in Central American lowland forests from Panama to Honduras. s e l e c t e d l o c a l i t i e s (Map 242): COLOMBIA: Antioquia, La Tirana (USNM 499611), Valdivia (type locality of Nectomys russulus Thomas); Caldas, Samaná, Río Hondo (FMNH 71639); Cauca, Güengüé (AMNH 32183), Sabanetas (FMNH 90282); Chocó, Teresita, Río Truando (FMNH [B-185]); Córdoba; Socorré, upper Río Sinú (FMNH 69192); Nariño, Barbacoas (type locality of Oryzomys barbacoas J. A. Allen), Guayacana (FMNH 89563); Norte de Santander, San Calixto, Río Tarrá (USNM 279742); Valle del Cauca, Buenaventura, Palmares del Pacifico (USNM 483981), Virology Field Station, Río Raposo (USNM 334703). ECUADOR: Esmeraldas, Río Blanco, near Mindo (BM 34.9.10.214), San Javier (type locality of Nectomys esmeraldorum Gyldenstolpe); Guayas, Bucay (AMNH 61355). VENEZUELA: Zulia, Novito, 19 km WSW of Machiques (USNM 442251). s u b s p e c i e s : I treat Sigmodontomys alfari as monotypic. n a t u r a l h i s t o ry: In Panama, Handley (1966) recorded Sigmodontomys alfari as a common species, occurring in marshes, abandoned cane fields, and other for-

est openings. In Venezuela, Handley (1976) secured specimens on the ground under low bushes in a banana patch, both near streams and at dry sites. The species is said to be semiaquatic (F. A. Reid 1997; Lord 1999), but no factual report on its swimming ability was found; analysis of morphological characters (e.g., interdigital webbing reduced, natatory fringes absent), however, indicate that it has fewer semiaquatic adaptations than Nectomys (Thomas 1897f; Weksler 2006). Handley (1966) reported S. alfari at lower elevations in Panama, but Goodwin (1946: 402) stated that in Costa Rica, “[S.] alfari occupies higher regions”; most South American records of S. alfari are from localities between 200 and 1,300 m (Musser et al. 1998; McCain et al. 2007), but one locality (Sabanetas) is situated at 1,900 m (Musser et al. 1998). Recorded parasites include the flea Polygenis roberti, the chiggers Crotiscus desdentatus, Eutrombicula goeldii, and Pseudoschoengastica bulbifera, the laelapids mites Echinolaelaps lowei and Gigantolaelaps spp., the tick Teratothrix higae, and the nematodes Hypocristata anguillula, Stilestrongylus barusi, and Syphacia alata (Quentin 1969; Durette-Desset and Guerrero 2006; Digiani and Durette-Desset 2007; Goff 1981; Wenzel and Tipton 1966). r e m a r k s : A. L. Gardner and Patton (1976) reported a 2n = 56 FN = 54 karyotype for Costa Rican specimens.

Genus Sooretamys Weksler, Percequillo, and Voss, 2006 Alexandre R. Percequillo

Map 242 Selected localities for Sigmodontomys alfari (●); range in Panama from F. A. Reid (2009). Contour line = 2,000 m.

The only known species of this genus, Sooretamys angouya, is widely distributed in eastern South America, from the Brazilian Atlantic rainforest to the humid forests of eastern Argentina and Paraguay. Sooretamys angouya is easily distinguished from other sympatric oryzomyines (such as Euryoryzomys russatus, Hylaeamys laticeps, Hylaeamys megacephalus, and Nectomys squamipes) by its larger size (head and body length 125– 215 mm), a tail much longer than head and body (range: 160–240 mm), and nonwebbed, robust, and wide hindfeet (length 25–42 mm). The body pelage is soft, long, and very dense; wool hairs are thin, long, and wavy; cover hairs are longer and thicker on their distal half; and guard hairs are much longer, stiffer, and thicker over their distal third. The dorsal body color varies from buffy yellow grizzled with dark brown to buffy orange grizzled with black. Ventral color grades from a whitish or buff weakly grizzled with gray to an almost pure white, buff, or buffy yellow. The tail is covered with short hairs, which do not conceal large scales; tail scales and hairs are blackish or dark brown, and the tail is unicolored. Internal and external surfaces of ears are well

452 Mammals of South America

furred, with hairs entirely brown. Forefeet and hindfeet are covered above by short hairs, and the ungual tufts of the toes are dense and long, almost concealing the claws. Brown hairs typically cover the dorsal surface of the hindfeet although some specimens have only a dark brown line or diffuse patch along the length of the foot. Ungual tuft hairs are proximally brown but white at their tips. Mystacial vibrissae are very dense and long, surpassing the ears when laid back; the most dorsal vibrissae are dark brown with golden tips, and the most ventral are entirely white. The skull of Sooretamys is unique among genera of the Oryzomyini, easily recognized by its larger size (skull length 35.6–44.3 mm); longer incisive foramina (length 7.3– 9.5 mm) that reach the alveolus of M1 in many specimens; long and narrow interorbital region (breadth 4.9–6.0 mm), hourglass in shape, with squared supraorbital margins; and very robust molars (toothrow length 5.6–6.5 mm; M1 breadth 1.5–1.8 mm). The rostrum is long and wide, flanked by well-inflated capsular projections of the nasolacrimal foramen. The zygomatic plates are wide, with straight or concave free anterior margins well projected anteriorly. The zygomatic arches are expanded laterally and wider near their squamosal roots. The braincase has a rounded profile, with the temporal border squared but without crests or beads. The palate is long with deep and complex posterolateral pits; palatal excrescences are absent. The roof of the mesopterygoid fossa is perforated by long and wide sphenopalatine vacuities that expose the orbitosphenoid bone. The stapedial foramen is minute or absent and, with the lack of both a squamosoalisphenoid groove and sphenofrontal foramen, configures the derived carotid circulatory pattern 3 (sensu Voss 1988). The buccinator-masticatory and accessory oval foramina are confluent, so all specimens lack an alisphenoid strut. Both the postglenoid foramen and subsquamosal fenestra are large apertures. Auditory bullae are large (breadth of one bulla range: 4.9–5.9 mm), with short stapedial processes and well-developed dorsostapedial processes overlapping the squamosal. The suspensory process of the squamosal is absent, and the tegmen tympani is short and may or may not overlap the squamosal. The mandible has a low coronoid process, nearly triangular in shape and equal in height to the condyloid process; the angular process does not exceed the condyloid process. Both superior and inferior notches are shallow. Upper incisors are opisthodont. Molars are pentalophodont and low-crowned with the main cusps arranged in opposite pairs, and with labial and lingual flexi interpenetrating only slightly at the median molar plane. On M1 and M2, the paracone is connected medially to the protocone, not to the median mure, defining a long and obliquely oriented parafossette that fuses to the metacone only with heavy wear. M1 has four roots, one anterior, one

posterior, and two accessory rootlets; M2 and M3 each has two roots. The axial skeleton comprises 7 cervical, 12–13 thoracic, 6–7 lumbar, 4 sacral, and 31–36 caudal vertebrae. Hemal arches have a distinct median posterior process. The stomach is unilocular and hemiglandular; the bordering fold between gastric and glandular epithelium is well developed and oriented at 45° to the right of stomach. The gall bladder is absent. The glans penis is complex (terminology of Hooper and Musser 1964). The proximal bony baculum has a wide and flattened basal portion and long and rounded apical portion. The cartilaginous terminal baculum is tridigitate and well developed, about half the length of the bony baculum; the central cartilaginous digit is longer than the laterals, with its distal apex extending past the glans body. sy n o n y m s : Mus: G. Fischer, 1814:71; part (description of angouya; not Mus Linnaeus. Holochilus: Brandt, 1835:96; part (listing of anguya [=angouya]); not Holochilus Brandt. Hesperomys: Wagner, 1843a:534; part (listing of anguya [=angouya]); not Hesperomys Waterhouse. Hesperomys (Oryzomys): Thomas, 1884:448; part (listing of angouya); not Oryzomys Baird. Calomys: Winge, 1887:50; part (description of rex); not Calomys Waterhouse. Sooretamys Weksler, Percequillo, and Voss, 2006:23; type species Mus angouya G. Fischer, by original designation.

Sooretamys angouya (G. Fischer, 1814) Angouya Sooretamys sy n o n y m s : Mus angouya G. Fischer, 1814:71; no type locality given; based on Azara’s (1801:86) “rat troisième ou rat angouya”; type locality “Paraguay east of the Río Paraguay, Departamento de Misiones, 2.7 km (by road) N of San Antonio,” based on neotype designation (Musser et al. 1998:300). Mus ? buccinatus Illiger, 1815:70; nomen nudum. M[us]. buccinatus Olfers, 1818: 209; validation of Mus buccinatus Illiger 1815; based on Azara’s (1801, 1802) “rat troisième ou rat angouya” and “del anguyá,” respectively. Mus angouya Desmarest, 1819b:62; based on Azara’s (1801, 1802) “rat troisième ou rat angouya” and “del anguyá,” respectively; a homonym of Mus angouya G. Fischer. mus angouya: Desmarest, 1820:305; name combination. Mus Anguya Rengger, 1830:229; unjustified emendation of Mus angouya G. Fischer.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 453

Mus (Holochilus) Anguya Brandt, 1835:428; name combination and unjustified emendation of Mus angouya Desmarest (= Mus angouya G. Fischer). Hesperomys Anguya: Wagner, 1843a:534; name combination and unjustified emendation of Mus angouya G. Fischer. H[olochilus]. canellinus Wagner, 1843a:552; substitute name for Mus anguya Brandt. Mus canellinus: Schinz, 1845:192; name combination. Hesperomys leucogaster Wagner, 1845a:147; type locality “Ypanema” (= Floresta Nacional de Ipanema, 20 km NW Sorocaba, São Paulo, Brazil, 23°26′7′′S 47°37′41′′W, 701 m; L. P. Costa et al. 2003). Hesperomys ratticeps Hensel, 1872b:36, plate 1, Figs. 25a and 25b; plate 2, Figs. 15a and 15b; type locality “Rio Grande do Sul, Brasil.” H[esperomys. (Oryzomys)] angouya: Thomas, 1884:448; name combination. Calomys rex Winge, 1887:50, plate 3, Fig. 8; type locality “Rio das Velhas, Lagoa Santa, Minas Gerais, Brasil.” Hesperomys (Calomys) ratticeps: Ihering, 1893:15 (108); name combination. [Oryzomys] anguya: E.-L. Trouessart, 1897:525; name combination and unjustified emendation of Mus angouya G. Fischer. [Oryzomys] ratticeps: E.-L. Trouessart, 1897:525; name combination. [Oryzomys (Oryzomys)] anguya: E.-L. Trouessart: 1904: 420; name combination and unjustified emendation of Mus angouya G. Fischer. [Oryzomys (Oryzomys)] ratticeps: E.-L. Trouessart, 1904: 420; name combination. Oryzomys angouya: J. A. Allen, 1916d:570; name combination, reference to Mus angouya Desmarest, 1919; not Mus angouya G. Fischer. O[ryzomys]. angouya: Thomas, 1921b:177; name combination. Oryzomys ratticeps ratticeps: Thomas, 1924e:143; name combination. Oryzomys ratticeps tropicius Thomas, 1924e:143; type locality “Piquete, São Paulo, Brasil.” Oryzomys ratticeps paraganus Thomas, 1924e:144; type locality “Sapucay, Paraguari, Paraguai,” Paraguay. Oryzomys [(Oryzomys)] angouya: Tate, 1932e:18; name combination. Oryzomys [(Oryzomys)] ratticeps ratticeps: Tate, 1932e: 18; name combination. Oryzomys [(Oryzomys)] ratticeps tropicius: Tate, 1932e: 18; name combination. Oryzomys [(Oryzomys)] ratticeps paraganus: Tate, 1932e: 18; name combination. Oryzomys buccinatus: Hershkovitz, 1955b:660; name combination.

[Holochilus] anguyu: Musser and Carleton, 2005:1119; lapsus calami. [Sooretamys] angouya: Weksler, Percequillo, and Voss, 2006: 23; first use of current name combination. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : Sooretamys angouya is distributed along the forested foothills and slopes of the Serra do Mar, Serra da Mantiqueira, and eastern hillsides of the Serra do Espinhaço (all in the Atlantic Forest), and coastal lowland forests (restinga) from Espírito Santo to Rio Grande do Sul states, Brazil, including some of the coastal islands in Santa Catarina and São Paulo states. To the west, this species reaches the Argentinean provinces of Misiones, Corrientes, and Entre Ríos, on the right (= east) bank of the Río Paraguay and the Argentinean provinces of Formosa and Chaco and the Paraguayan state of Presidente Hayes, on the left (= west) bank of the Río Paraguay. s e l e c t e d l o c a l i t i e s (Map 243): ARGENTINA: Corrientes, Santa Tecla, Rte 12, km 1287 (MLP 1.X.94.5); Entre Ríos, Isla Chapetón, Río Paraná (Teta, Pardiñas et al. 2007); Formosa, Estancia Guaycolec (Teta, Pardiñas et al. 2007). BRAZIL: Espírito Santo, Hotel Faz Monte Verde, 24 km SE of Venda Nova do Imigrante (UFPB 334); Rio São José (MZUSP 6210); Minas Gerais, Lagoa Santa (type locality of Calomys rex Winge), Passos (MNRJ 32745); Rio de Janeiro, Fazenda do Tenente, São João de Marcos (MNRJ 5768); Rio Grande do Sul, Capão do Leão, Mostardas (UFRGS 2114), Fazenda Aldo Pinto, São Nicolau (MPEG 23275), Tôrres (UFRGS 8); Santa Catarina, Florianópolis (UFRGS 2042); São Paulo, Iguapé (MZUSP 26799), Ilha do Mar Virado (MZUSP AUC 165), Rio Feio (MZUSP 1910), Teodoro Sampaio (MZUSP 25324). PARAGUAY: Amambay, 4 km by road SW of Cerro Corá (UMMZ 125457); Paraguarí, Sapucay (type locality of Oryzomys ratticeps paraganus Thomas); Presidente Hayes, 24 km NW of Villa Hayes (UMMZ 133795). s u b s p e c i e s : I treat Sooretamys angouya as monotypic. n a t u r a l h i s t o ry: Sooretamys angouya is a scansorial species that can be captured both on the ground, on vines, and in trees (data from skin tags and collector field journals). Olmos (1992) reported that S. angouya is an aggressive species that, when caught in the same trap with another species, always killed and ate the individual, and that fights were commonplace when conspecifics were together. Olmos (1992:561) also reported that this species moved on the ground by meter-long leaps, and that individuals were good climbers of both trees and rock walls, as well good diggers, producing “extensive tunnels, even in hard, rocky ground.” In the eastern part of its range, S. angouya inhabits mature and undisturbed portions of the Atlantic Forest, but is more commonly observed in secondary forests (Pardini

454 Mammals of South America

and Umetsu 2006). In westernmost regions (Formosa, Argentina, and Presidente Hayes, Paraguay), the species occurs in patches and remnants of semideciduous and gallery forests amid Chaco vegetation (G. D’Elía, pers. comm.). Females were reproductively active during October and November (Olmos 1992), with juveniles being trapped in June (dry season). r e m a r k s : The taxonomic history of S. angouya is long and contorted, confounded especially by the several names proposed for the rat described by D. Felix de Azara (1801, 1802) as the “rat troisième ou rat angouya” and “del anguyá,” the specimens of which have been lost since the nineteenth century (see also Desmarest 1804, who referred to Azara’s “rat angouya”). Some authors have suggested that the epithet “angouya” should refer to a Paraguayan species of the genus Cerradomys (specifically Cerradomys maracajuensis; e.g., Avila-Pires 1960a; Myers et al. 1995; Percequillo 1998) or was best considered a nomen dubium (Weksler 1996). Musser et al. (1998), on the other hand, resolved the conundrum by defining a neotype for Mus angouya G. Fischer and associating it to the species then formerly known as Oryzomys ratticeps Hensel. This nomenclatural act brought stability to the taxon, although the official availability of G. Fischer’s names has not as yet been accepted by explicit action of the International Commission on Zoological Nomenclature (see Langguth 1966b; Sabrosky 1967; Musser et al. 1998). Winge (1887) named as Calomys rex those specimens of S. angouya obtained by Peter W. Lund, preserved as fossil or subfossil material from the caves of Lagoa Santa, Minas Gerais. There are, however, no recent records of S. angouya from this region. The specimen Avila-Pires (1960b) recorded from the “Lagoa Santa region” actually came from Conceição do Mato Dentro, which is located nearly 110 km northeast of Lagoa Santa on the eastern slope of Serra do Espinhaço, a more humid area predominantly covered by forests. Today, the region of Lagoa Santa is covered mostly by Cerrado vegetation or is transitional between semideciduous forest and Cerrado. The same distributional pattern of typical forest-dwelling species registered in the caves of Lagoa Santa as fossils and subfossils is also observed for many other sigmodontine and echimyid genera, such as Blarinomys breviceps, Brucepattersonius, Delomys sp., Euryoryzomys russatus, and Callistomys pictus (Voss 1993; Emmons and Vucetich 1998; Voss and Carleton 1993; Musser et al. 1998; C. R. Silva et al. 2003; Pardiñas and Teta 2013a; see also Voss and Myers 1991 for a summary of the Lagoa Santa cave fauna). C. O. da C. Vieira (1953:134) identified specimens of this species from São Paulo state, Brazil, as Holochilus physodes physodes, a name combination confusingly applied histori-

Map 243

Selected localities for Sooretamys angouya (●). Contour line = 2,000 m.

cally to both Holochilus and Reithrodon (see Musser et al. 1998:280–284, and accounts of those genera). The karyotype of S. angouya is polymorphic, with diploid numbers ranging from 57–60 and fundamental numbers from 60–64 arms (E. J. C. Almeida 1980; Zanchin 1988; M. J. de J. Silva 1994; Geise 1995).

Genus Tanyuromys Pine, Timm, and Weksler, 2012 Marcelo Weksler

Tanyuromys is a monotypic genus found at a few midelevation forest sites in Costa Rica, Panama, and Ecuador. To date, only eight specimens are known for the genus, and thus our distributional and ecological knowledge of this taxon is quite sparse (e.g., we do not know whether the lack of collecting sites in Colombia is a sampling artifact or real). Until recently (Musser and Carleton 2005), aphrastus W. P. Harris was included in Sigmodontomys. Phylogenetic analyses (Weksler 2006; Pine et al. 2012), however, demonstrated that aphrastus was not closely related to S. alfari J. A. Allen, and Pine et al. (2012) thus erected Tanyuromys to contain aphrastus. The following morphological description is a synthesis of the recent work on this taxon by Weksler (2006), McCain et al. (2007), and Pine et al. (2012). Tanyuromys are medium-sized rodents (adult head and body length range: 116–152 mm). The tail is much longer than the combined head and body length (length

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 455

176–235 mm), and the hindfeet are long and robust (length 35–40 mm). The dorsal pelage is long, thick, and soft. Coloration of the upper parts is grizzled dark brown with orange highlights, and that of the under parts is paler gray with pronounced ochraceous highlights but always with a dark gray base. The dorsoventral countershading is subtle, not as strong as in many other oryzomyines. The pinnae are small and sparsely to moderately covered with blackish, dark brown, or reddish-brown hairs both internally and externally. The mystacial and superciliary vibrissae are very long (extending posteriorly beyond caudal margins of the pinnae). The manus and pes have a sparse to moderate coverage of pale brown to dark brown hairs dorsally. Digits II–IV of the hindfeet are longer than dI and dV (claw of dI reaches the proximal portion of first phalanx of dII; claw of dV extends to the distal portion of second phalanx of dIV). The plantar surface of the hindfoot is naked, densely covered with small epidermal tubercles distally, and has one or two small metatarsal pads (the thenar pad is always present, but the hypothenar pad may be absent or extremely reduced) and four large and fleshy interdigital pads. The hindfeet lack well-developed natatory fringes and interdigital webs, and have sparse ungual tufts covering, but seldom extending beyond, the tips of claws (the tufts are absent on the hallux). The tail is unicolored brown and sparsely haired, terminating in a short tuft of hairs but without a distinctly longer terminal pencil. Four pairs of mammae are present, one each in inguinal, abdominal, postaxial, and pectoral positions. The skull is medium sized and robust. The rostrum is short and stout, and flanked by very shallow zygomatic notches. The nasals have acutely angled posterior margins extending posteriorly beyond the premaxillae and behind lacrimals, nearly reaching the interorbital constriction level; the lacrimals have longer maxillary than frontal sutures. The interorbital margins converge anteriorly and possess overhanging supraorbital edges; the braincase is rounded and broad, with well-developed temporal, lambdoidal, and nuchal crests. The frontosquamosal suture is anterior to the frontoparietal suture (the dorsal facet of the frontal is in broad contact with the squamosal). The parietal has a broad lateral expansion, a large portion dipping below the temporal ridge posteriorly. The zygomatic arches are convergent anteriorly, relatively unbowed, and widest at the squamosal root; the jugal is large, and the maxillary and squamosal zygomatic processes are widely separated, not overlapping in lateral view. The zygomatic plates lack anterodorsal spinous processes, and their posterior margins lie anterior to the alveoli of the M1s. The incisive foramina are short and terminate far anterior of the alveoli of the M1s. The palatal bridge lacks deep furrows or median ridges, extends only slightly behind the M3s, and is perforated by small

and simple posterolateral palatal pits. The bony roof of the mesopterygoid fossa is usually perforated by narrow sphenopalatine vacuities. The stapedial foramen and posterior opening of alisphenoid canal are very small, and the squamosoalisphenoid groove and sphenofrontal foramen are absent, with secondary anastomosis of the internal carotid across the dorsal surface of the pterygoid plate (= carotid circulatory pattern 3 of Voss 1988). The postglenoid foramen is large and rounded, but the subsquamosal fenestra is absent or vestigial. The mastoid is completely ossified, or has only a small perforation (mastoid fenestra absent). The mandible is robust, with a large falciform coronoid process slightly higher than the condyloid process, and with a rounded angular process. The capsular process is usually absent, or present as a slight rounded elevation not protruding above the level of the coronoid-condylar notch. Superior and inferior masseteric ridges join anteriorly as a single crest below m1. The upper incisors are ungrooved and opisthodont. The molars are pentalophodont and bunodont, with an apomorphic and complex occlusal pattern having extensive, deep, steep-sided flexi and fossettes (enamel islands) with irregular and jagged borders. The maxillary toothrows are mostly parallel, with a slight divergence posteriorly. The molar series is robust and long, ranging from 5.6–6.2 mm in length. Labial and lingual flexi of the upper molars are deeply interpenetrating; labial flexi are convoluted and enclosed by a cingulum. The anterocone of M1 is undivided, the anteroloph is well developed and fused with the anterocone by a labial cingulum, and the protostyle absent; an enamel bridge connects the paracone to the posterior portion of the protocone. The M2 protoflexus is usually absent, the mesoflexus is usually present as a single fossette. M3 has a mesoloph, posteroloph, and shallow hypoflexus (which disappears with wear); the paracone and protocone are distinguishable on the molar surface; and the hypocone is reduced, and the metacone is greatly reduced and completely fused with the posteroloph. The labial accessory root of M1 is present (four roots total). On the lower molars, the labial and lingual cusps are opposite. The anteroconid of m1 is undivided but contains a large internal fossetid; the anterolabial cingulum and a small anterolophid are present on all lower molars, the latter disappearing with moderate to heavy wear. The mesolophid is present in all lower molars, and the ectolophid is absent. The posteroflexid on m3 is large and persistent. The first lower molar has four roots, one anterior, one posterior, one lingual (below the metaconid), and one labial (also below the metaconid). The gall bladder is absent. The stomach is unilocularhemiglandular with glandular epithelium extending into corpus.

456 Mammals of South America

sy n o n y m s : Oryzomys: W. P. Harris, 1932:5; part (description of aphrastus); not Oryzomys Baird. Sigmodontomys: Musser and Carleton 1993:748; part (listing of aphrastus); not Sigmodontomys J. A. Allen. Tanyuromys Pine, Timm, and Weksler, 2012:858; type species Oryzomys aphrastus W. P. Harris, by original designation. r e m a r k s : Phylogenetic analyses (Weksler 2006; Pine et al. 2012) indicate that Tanyuromys is a member of an oryzomyine clade that also includes Aegialomys, Nesoryzomys, Melanomys, and Sigmodontomys, all trans-Andean taxa distributed in southern Central America and northern South America (especially west of the Andes), and the Galapagos Islands.

Tanyuromys aphrastus (W. P. Harris, 1932) Long-tailed Montane Rat sy n o n y m s : Oryzomys aphrastus W. P. Harris, 1932:5; type locality “Joaquin de Dota, Costa Rica. This locality is southeast of Santa Maria de Dota in the Pacific rain forest at an altitude of about 4,000 feet”; [= San Joaquín de Dota, Cordillera de Talamanca, San José, Costa Rica, 1,220 m; 09°35′N, 83°59′W]. Sigmodontomys aphrastus: Musser and Carleton 1993:748; name combination. Tanyuromys aphrastus: Pine, Timm, and Weksler, 2012: 859; first use of current name combination. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : Tanyuromys aphrastus is known only from six middle-elevation (700–2,000 m) localities in north-central Costa Rica, western Panama, and northwestern Ecuador. s e l e c t e d l o c a l i t i e s (Map 244; South American only): ECUADOR: Imbabura, 10 km E of Santa Rosa (QCAZ 10427); Pichincha; Guarumos (MCZ 50396), Mindo (UMMZ 155808). s u b s p e c i e s : Tanyuromys aphrastus is monotypic. n a t u r a l h i s t o ry: McCain et al. (2007) provided almost all known information about the natural history of this species, a synthesis of which is presented here. All eight known specimens were collected in traps set on the ground. In Costa Rica and Pichincha (Ecuador), specimens were taken in intact, mature montane forest; in Imbabura (Ecuador), one specimen “was collected in a mixed forest and tall-grass area within 10 m of a stream” (T. E. Lee et al. 2010:10); and in Panama, two specimens were captured “in disturbed, fairly open, relatively dry habitat, which included mixed grass, weeds, brush, oaks, and other trees” (R. H. Pine, pers. comm., cited in McCain et al. 2007:131). It is unclear from the few specimens available despite substantial trapping effort whether T. aphrastus occurs in very

Map 244 Selected localities for Tanyuromys aphrastus in South America (●). Contour line = 2,000 m.

low densities or is simply difficult to trap using standard methods. Of the eight available specimens, three are females, and five are males. Six specimens are adults; one adult male caught at Monteverde, Costa Rica, had descended testes measuring 7 × 5 mm and another from Chiriquí, Panama, had testes measuring 5 mm in length. The remaining two specimens include a juvenile female caught in Monteverde Cloud Forest Reserve and a young adult male from Chiriquí. One species of tick (Ixodes sinaloa) was collected from an adult at Monteverde. r e m a r k s : The karyotype of Tanyuromys aphrastus is unknown. Tanyuromys differs from all other extant Oryzomyini (sensu Weksler 2003; Weksler et al. 2006; Weksler and Percequillo 2011) in the degree of lophodonty and the complicated enamel folding pattern of flexi and flexids of the molars (Pine et al. 2012).

Genus Transandinomys Weksler, Percequillo, and Voss 2006 Michael D. Carleton

Transandinomys contains two species (bolivaris J. A. Allen, 1901; talamancae J. A. Allen, 1891) that inhabit lowland to premontane wet forests in Central America and northwestern South America. They are medium sized (head and body length ranges from 100 to 140 mm) and possess a nearly naked, finely scaled tail that is as long as to slightly longer than the head and body. Conformation of

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 457

the hindfoot indicates scampering, terrestrial habits: relatively long (about 26 to 32 mm) and narrow; digits I and V short relative to II–IV; ungual tufts ample; plantar pads six in number, 1 and 4 displaced proximally from 2 and 3, hypothenar small but discrete. The long arrays of cephalic vibrissae constitute the most definitive external trait, notably the sweeping superciliary vibrissae that extend posteriorly well behind the pinnae. Eight teats are present. The cranium is moderate in build and size (occipitonasal length about 28 to 32 mm) and elongate in conformation, displaying a long, attenuate rostrum, nearly parallel-sided zygomatic arches, moderately incised zygomatic notch, and a rectangular, boxy braincase. Distinct supraorbital shelves with beaded edges mark the frontal borders and impart a cuneate shape to the interorbital constriction. The subsquamosal fenestra penetrates the posterior wall of the braincase as a narrow cleft, notably smaller than the companion postglenoid foramen. The incisive foramina are intermediate in length (i.e., not as long as in Oryzomys proper but longer than Hylaeamys), but do not extend between the alveoli of the M1s. The bony palate is narrow and long, as characteristic of most oryzomyines, and posterolateral palatal pits are well defined. The anterior border of the mesopterygoid fossa is evenly rounded, and sphenopalatine vacuities are consistently patent as short, narrow slits. The ectotympanic bulla is small, revealing a narrow posteromedial wedge of the periotic. The carotid arterial pattern of both species is complete (pattern 1 of Voss 1988: stapedial foramen, squamosal-alisphenoid groove, and sphenofrontal foramen present. Alisphenoid struts are absent). The molar rows in both species of Transandinomys (coronal length of M1–3 range: 4.3–4.7 mm) are brachydont and cuspidate, the primary cusps positioned as opposite pairs, and the occlusal configuration is fundamentally pentalophodont (anterolophs, mesolophs, mesolophids present). The anterocone of the M1 is broad and undivided (anteromedian flexus absent). M2 has a long paraflexus and single median fossette, and the m2 has a long hypoflexid that crosses the midline of the tooth. The upper molars possess three roots (labial accessory root absent), and the lowers have two. The upper incisors are moderately robust, asulcate, and opisthodont. Most taxonomic, nomenclatural, morphological, and distributional information on the component species is contained in the studies of Goldman (1918), Pine (1971), Musser and Williams (1985), and Musser et al. (1998), all as reported under Oryzomys in its formerly all-inclusive sense. sy n o n y m s : Oryzomys: J. A. Allen, 1891a:193; part (description of talamancae); not Oryzomys Baird. Transandinomys Weksler, Percequillo, and Voss 2006:25; type species Oryzomys talamancae J. A. Allen, by original designation.

r e m a r k s : No special relationship between bolivaris and talamancae was perceived in the early taxonomic literature on oryzomyine rodents. Goldman (1918) segregated the two into monotypic species groups, talamancae and bombycinus (= bolivaris), within the genus Oryzomys sensu lato. The identity of each was lost following Hershkovitz’s (1960) precipitous allocation of forms believed to be synonymous with Oryzomys capito, a footnoted opinion formalized by Cabrera (1961) in his influential classification of South American mammals. Musser et al. (1998) differentiated bolivaris and talamancae in detail because of their close morphological resemblance and overlapping trans-Andean distributions, and compared the two to members of the megacephalus and nitidus complexes. In separate and combined analyses of morphological and molecular data, Transandinomys talamancae regularly emerged in a large oryzomyine clade that also included species of Euryoryzomys, Handleyomys, Hylaeamys, Nephalemys, and Oecomys (Weksler 2003, 2006; Percequillo, Weksler, and Costa 2011; Pine et al. 2012). See Weksler et al. (2006, especially Table 3) for morphological traits that discriminate these groups. As noted by those authors, the exceptionally long superciliary vibrissae offer the most persuasive synapomorphy for associating bolivaris with talamancae in a monophyletic genus. KEY TO THE SPECIES OF TRANSANDINOMYS:

1. Dorsal pelage longer, dark brown and somber, under parts dark gray; mystacial and superciliary vibrissae extremely long (>45 mm); tail as long as head and body; supraorbital ridges well defined; parietal rarely contributes to the lateral braincase wall below the temporal ridge; incisive foramina long relative to bony palate, nearly reaching level of M1s . . . . . . . . . . . . . Transandinomys bolivaris 1′. Dorsal pelage shorter, tawny and brightly colored, under parts bright whitish-gray; mystacial and superciliary vibrissae long (27 mm, upper molar toothrow >4.6 mm, breadth of braincase (measured just above squamosal zygomatic roots) >12.2 mm; in side-byside comparisons with sympatric Z. brevicauda, with slightly more hypsodont molars, more oblique mures and murids, less opisthodont upper incisors, shallower zygomatic notches, and less inflated nasolacrimal capsules . . . . . . . . . . . . . . . . . . . Zygodontomys brunneus 1′. Measurements and qualitative characters overlapping those of Z. brunneus except in the upper Magdalena valley, where length of hindfoot 25% of the total length; incisors broad; molars hypsodont or at least subhypsodont; plantar surface of hindfoot naked; six unfused plantar pads; skulls not markedly vaulted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 9. Tail relatively short (36–46% of total length), body stocky built and size small to medium (head and body length 6.4 mm in length, and >4.8 mm in depth, width of bullae >5.8 mm; m3 length >0.80 mm; length of interparietal usually 13.0 mm; width of zygomatic plate >2.7 mm; length of mandible generally >15.0 mm; known from the Chaco of Bolivia and Paraguay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Andalgalomys pearsoni 2′. Dorsum grayish brown; length of skull generally 39 mm in Brazil); adult hindfoot length (with claw) ≥28 mm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 9′. Size generally smaller; upper molar row and occipitonasal lengths smaller than in couplet 9; adult hindfoot length (with claw) ≤30 mm (≤32 in the southern Atlantic Forest) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 10. Tail abundantly furred distally, with long, bushy pencil (extending >15 mm beyond tail tip); adult body pelage sleek or somewhat woolly, especially ventrally; size large to very large; upper molar row 6.2–7.2 mm (>5.8 mm in the Brazilian and Ecuadorian Amazon); skull large, robust, with well-developed supraorbital ridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Rhipidomys leucodactylus 10′. Tail less well furred, with shorter, sparser pencil (150 mm); dorsal pelage color ranges from gray-brown to yellowish or reddish brown; interorbital region from hourglass in shape with rounded sides (no

beading) to constricted anteriorly with beaded edges; molars variable, small to moderately large . . . . . . . . 19 18. Tail pencil short, 33 mm; supraorbital region with moderately developed beading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rhipidomys ipukensis 19. Interorbital region hourglass in shape (constricted centrally), with slight or no supraorbital beading (rather more prominent in Mato Grosso do Sul and Paraguay); braincase rounded and slightly inflated; incisive foramina bullet shaped. . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 19′. Interorbital region constricted anteriorly, with moderate to prominent supraorbital beading; braincase narrower and flatter, especially in older and larger specimens; incisive foramina elliptical to diamond shaped . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 20. Tail proportionally medium to long, mean 124% of head and body length (range: 107–148%); tail pencil short to moderate, ≤10 mm in length; dorsal pelage yellowish brown to dark reddish brown; braincase and interorbit broad; supraorbital edges with slight beading; molars medium size, mean toothrow length 5.2 mm (range: 4.9–5.4 mm) . . . . . . . . . . . . . Rhipidomys itoan 20′. Tail proportionally short, mean 113% of head and body length (range: 96–133%, longer in some eastern populations); tail pencil short to moderate 5–15 mm (sometimes longer in southwestern population, i.e., Mato Grosso do Sul and Paraguay); dorsal pelage dull, reddish gray-brown; braincase average breadth; interorbit narrow; supraorbital region rounded, without beading, or beaded in southwestern population; molars medium to large, mean toothrow length 5.1 mm (range: 4.8– 5.5 mm) in central and eastern Brazil, and 5.6 mm (range: 5.3– 5.9 mm) in southwestern population . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rhipidomys macrurus 21. Body size moderate to large (adult head and body length range: 120–190 mm); dorsal color yellowish-gray brown with conspicuous agouti effect; skull larger and more robust than in other eastern Brazilian species (mean occipitonasal length 35.5 mm, range: 33.6–36.7 mm); interorbit rather narrow, occiput broad; palatal bridge shorter than upper toothrow; bullae large for the genus; molars moderate in size (mean upper toothrow length 5.3 mm, range: 5.0–5.7 mm). . . . . . . . ... . . . . .Rhipidomys cariri 21′. Body size moderate (adult head and body length 105– 160 mm); dorsal color gray-brown or more intense reddish brown; interorbit broad; palatal bridge often longer than upper toothrow; bullae moderate in size; average toothrow length smaller than in (21) . . . . . . 22

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 589

22. Dorsal color dull grayish brown; skull slightly smaller on average, mean occipitonasal length 33.3 mm (observed range: 28.2–36.9 mm); molars rather small, upper toothrow rarely exceeding 5 mm (mean 4.8 mm, range: 4.5–5.1 mm); hypocone of upper M3 usually greatly reduced; karyotype with low FN = 46–52 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Rhipidomys emiliae 22′. Dorsal color grayish brown to reddish brown; skull slightly larger on average, mean occipitonasal length 34.2 mm (observed range: 29.8–38.5 mm); molars a little larger than (22) (mean upper toothrow length 5.0 mm, range: 4.6–5.5 mm); hypocone of upper M3 slightly reduced; karyotype with high FN = 70–80 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rhipidomys mastacalis Although the species of Rhipidomys are treated alphabetically in the accounts that follow, their membership in the three sections recognized herein is as follows: (1) “fulviventer” section, including R. caucensis, R. fulviventer, R. ochrogaster, R. similis, R. tenuicauda, R. venustus, and R. wetzeli; (2) “leucodactylus” section, including R. austrinus, R. cariri, R. couesi, R. emiliae, R. gardneri, R. itoan, R. ipukensis, R. latimanus, R. leucodactylus, R. macrurus, R. mastacalis, R. modicus, R. nitela, R. tribei, and R. venezuelae; and (3) “macconnelli” section, including only R. macconnelli. The majority of these assignments follow Tribe (1996); of the five species described since then, only R. ipukensis was explicitly assigned by its authors (R. G. Rocha, Costa, and Costa 2011) to the “leucodactylus” section. Although Patton et al. (2000), Tribe (2005), and B. M. de A. Costa et al. (2011) made no such assignments for R. gardneri, R. cariri, R. itoan, or R. tribei, each of these species are best considered part of the same section based both on the diagnostic characters mentioned herein and on their phylogenetic linkage to other species in that complex. It remains for future analyses of morphological or molecular characters, or both, to determine whether these sections reflect true phylogenetic relationships.

Rhipidomys austrinus Thomas, 1921 Southern Andean Rhipidomys sy n o n y m s : Rhipidomys austrinus Thomas, 1921d:183; type locality “Sierra de Santa Barbara, S.E. Jujuy [ . . . ] Sunchal, 1200 m,” Argentina. Rhipidomys collinus Thomas, 1925b:578; type locality “Sierra Santa Rosa, 1000 m,” near Itaú, Tarija, Bolivia. Rhipidomys leucodactylus austrinus: Cabrera, 1961:420; name combination. Rhipidomys leucodactylus collinus: Cabrera, 1961:421; name combination. Rhipidomys auritus M. M. Díaz, Braun, Mares, and Barquez, 1997:8; incorrect subsequent spelling of Rhipidomys austrinus Thomas.

d e s c r i p t i o n : Size moderate to large (head and body length up to 170 mm) with soft and dense grayish-brown to bright orange-brown agouti dorsal pelage and sharp lateral transition line; ventral pelage also soft with creamy white tips and medium to dark gray hair bases. Hindfeet medium to large (28–33 mm in length), broad, with distinctly outlined dark patch extending to bases of digits II to V (less distinct and more extensive in northwestern samples). Tail long (110–135% of head and body length), medium to dark brown, with short hairs on shaft and short to medium terminal pencil. Ears large and oval. Skull moderate in size and robustness, with short, deep rostrum that does not taper greatly; nasals narrow sharply behind tips, then taper gently to their posterior ends; interorbital region narrow, either hourglass in shape with squared edges or waisted anteriorly with slightly raised supraorbital ridges; braincase rather flattened or only very slightly inflated; auditory bullae prominent; carotid circulation pattern derived (small stapedial foramen, no squamosalalisphenoid groove, no sphenofrontal foramen); molars generally large compared with skull length, with maxillary toothrow length ranging from 5.3–6.3 mm. See Massoia (1989) for further details of skull, and Carrizo and Díaz (2011) for comparison of postcranial skeleton with that of Graomys griseoflavus. d i s t r i b u t i o n : Rhipidomys austrinus occurs in the eastern Andean foothills and valleys and adjacent forested plains at elevations from 360 to 2,000 m, from southern Salta province, Argentina, northward to Santa Cruz department, Bolivia; farther northwest in La Paz department it has been found in the same valley system as R. gardneri, but at higher elevations (1,500 to 1,770 m). s e l e c t e d l o c a l i t i e s (Map 308): ARGENTINA: Jujuy, Cerro Calilegua (Olrog 1979); Salta, Aguaray (Ojeda and Mares 1989), Anta, Parque Nacional El Rey ( Jayat, Ortiz, Teta et al. 2006), Río de las Conchas, 5.7 km W of Metán (Carrizo and Díaz 2011). BOLIVIA: Chuquisaca, Cerro Bufete (Emmons 1997b), Porvenir (AMNH 262259); La Paz, Pitiguaya (AMNH 72632); Santa Cruz, Ingenio Mora, 7 km E and 3 km N (AMNH 247782), Río Ariruma, 7 km by road SE of Ariruma (AMNH 264199); Tarija, Cuyambuyo, 4 km N by road, Fábrica de Papel, Río Sidras (UMMZ 155864). s u b s p e c i e s : Rhipidomys austrinus is monotypic. n a t u r a l h i s t o ry: Rhipidomys austrinus occurs in the densely forested valleys of the Yungas on the eastern Andean slopes. For example, the collecting locality at Villa Montes (8 km S, 10 km E), Tarija department, Bolivia, 467 m, was described on the specimen tag as “E. bank Río Pilcomayo. Habitat: dense forest 15 m height, dense understory of 6 m shrubs, 86% ground cover of forbs, grasses and bromeliads.” At the southern limit of its range

590 Mammals of South America

Map 308 2,000 m.

Selected localities for Rhipidomys austrinus (●). Contour line =

in Argentina, R. austrinus inhabits lowland, montane, and transitional forests; Ojeda and Mares (1989) provide general habitat information for that area. The two specimens from the Sierra Santa Bárbara, Sunchal, Jujuy, Argentina, were collected in tall nut trees (nogales), and the two from the Chimasi Yungas, La Paz, Bolivia, were found “in corn sack” (specimen tags). r e m a r k s : This member of the “leucodactylus” section of Rhipidomys is the most southerly of the species that replace each other (with a certain amount of overlap) along the eastern Andean piedmont (from north to south: R. couesi, R. leucodactylus, R. modicus, R. gardneri, and R. austrinus). The name R. couesi has sometimes been misapplied to this species (e.g., Emmons and Feer 1990:184). Specimens from Pitiguaya are distinguished by their rather more slender, less robust skulls from those from Chijchipani, some 800 to 900 m lower in the same valley, here referred to R. gardneri. This distinction requires confirmation from molecular and karyotype evidence.

Rhipidomys cariri Tribe, 2005 Cairi Rhipidomys sy n o n y m s : Rhipidomys cariri Tribe, 2005:137; type locality “BRAZIL– CEARÁ: Crato (07°14′S 39°23′ W), Sítio Caiana.” Rhipidomys cariri baturiteensis Tribe, 2005:141; type locality “BRAZIL–CEARÁ: Pacoti (04°13′S 38°56′ W), Sítio Cebola.”

d e s c r i p t i o n : Moderate to large bodied, with adult head and body length usually 130–160 mm (observed range: 120–190 mm). Tail length equals 110–140% of head and body length. Dorsal pelage yellowish gray brown, often somewhat grayer, sometimes redder, but always with conspicuous flecking from dark guard hairs and dark tips to body hairs; dorsal body hairs with mid-gray bases (about 62% of length), orange subterminal bands (about 29%), and dark tip (8–9%). Ventral pelage white or pale cream; some specimens with pale to mid-gray hair bases especially toward sides and occasionally across abdomen, as well as midline pectoral spot. Pelage texture slightly coarse and woolly, especially on ventral surface. Mystacial vibrissae noticeably long and coarse. Tail uniformly colored, varying from pale to rather dark; caudal hairs are dark and short (1–2 mm), especially along proximal half of tail, but may be longer at tip forming terminal tuft up to 15 mm in length. Hindfeet broad and relatively long compared with other species of similar size, averaging 27–30 mm (with claw). Dark patch on dorsal surface of metatarsals varies from narrow to broad, often poorly defined; ungual tufts usually about same length as claws. Ears seem larger than in other similar-sized Brazilian species, but average only a millimeter longer. Mystacial vibrissae long (>50 mm) and coarse; genal and supraorbital vibrissae sparse. Skull large (occipitonasal length averages 35.5 mm) and robust with well-developed, straight supraorbital ridges diverging from front of interorbital region; rostrum moderately long and zygomatic plates broad, generally with shallow zygomatic notches visible in dorsal view; braincase large and angular rather than rounded, with broad occiput relative to greatest breadth across squamosals; lateral process of parietal rectangular; hamular process of squamosal long and almost horizontal; roughly elliptical incisive foramina terminate between anterior roots of M1s, while mesopterygoid fossa penetrates between posterior roots of M3s, making palatal bridge shorter than molar toothrow; sphenopalatine vacuities absent; auditory bullae relatively large for genus and slightly inflated; carotid circulation pattern derived (pattern 3 of Voss 1988), with small stapedial foramen, no translucent internal groove across the squamosal and alisphenoid, and no sphenofrontal foramen. Upper incisors robust and more opisthodont than in most other Rhipidomys; molars moderate in size but generally larger than in other eastern Brazilian species, with maxillary toothrow averaging 5.1–5.5 mm in length; M1 and m1 both have well-defined anteromedian flexus/ flexid; oblique paralophules present in M1–M3; and M3 not greatly reduced in size or occlusal structure. d i s t r i b u t i o n : Rhipidomys cariri occurs in mesic enclaves surrounded by semiarid caatinga thorn scrub in

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 591

northeastern Brazil, including the Serra de Baturité and Chapada do Araripe in Ceará state, the Parque Nacional do Catimbau in Pernambuco state, and the Morro do Chapéu in central Bahia state. s e l e c t e d l o c a l i t i e s (Map 309): BRAZIL: Bahia, Morro do Chapéu (MNRJ 67779); Ceará, Sítio Caiana, Crato (type locality of Rhipidomys cariri Tribe), Pacoti, Serra de Baturité (type locality of Rhipidomys cariri baturiteensis Tribe); Pernambuco, Buíque, Parque Nacional do Catimbau (Geise, Paresque et al. 2010). s u b s p e c i e s : See comment under Remarks. n a t u r a l h i s t o ry: Rhipidomys cariri occurs within the semiarid Caatinga in isolated mesic forests (brejos), which are maintained by orographic rainfall (AndradeLima 1982). Individuals have been caught in forests, palms, and crops, particularly sugar cane and coffee. Two females from Pacoti each had four embryos in late July; six out of seven males captured between mid-August and early September had enlarged testes (Tribe 2005). The specimen from Buíque was captured in wet forest along a dry seasonal riverbed within the Caatinga. r e m a r k s : Specimens of this recently described species were included in prior studies under a variety of different name combinations, such as Rhipidomys cearanus (Moojen 1943a:10), Holochilus sciureus (C. A. de Freitas 1957:131), and Rhipidomys mastacalis (Mares, Willig et al. 1981:84). Rhipidomys cariri is a member of the “leucodactylus” section of the genus. Mitochondrial DNA studies using cytochrome-b (B. M. de A. Costa 2007; B. M. de A. Costa

Map 309 Selected localities for Rhipidomys cariri (ᇲ), Rhipidomys emiliae (●), and Rhipidomys ipukensis (ഋ).

et al. 2011) and cytochrome oxidase I (Thomazini 2009) sequences place specimens of R. cariri from Crato (southern Ceará) and Buíque (central Pernambuco) as the sister group to a clade containing certain specimens currently included in R. macrurus from central Bahia, eastern Tocantins, northern Goiás, and northern and eastern Minas Gerais states. In view of this and the expansion of R. cariri to include specimens from Pernambuco and Bahia, the subdivision of the species into the nominotypical subspecies and R. cariri baturiteensis, based on distinctions occurring solely within the state of Ceará (Tribe 2005), requires reevaluation. Together, the above-mentioned clade and R. cariri form the sister clade to R. macrurus (sensu stricto) (B. M. de A. Costa 2007; Thomazini 2009; B. M. de A. Costa et al. 2011). The karyotype of R. cariri from Crato (type locality) and Buíque is 2n = 44, FN = 50 (Thomazini 2009; Geise, Paresque et al. 2010), whereas that of a specimen from Pacoti (type locality of R. cariri baturiteensis) is 2n = 44, FN = 48 (M. J. de J. Silva et al. 2000a).

Rhipidomys caucensis J. A. Allen, 1913 Lesser Colombian Rhipidomys sy n o n y m : Rhipidomys caucensis J. A. Allen, 1913c:601; type locality “[Cerro] Munchique (altitude 8225 feet), Western Andes, Cauca, Colombia.” d e s c r i p t i o n : Very small (about 100 mm in head and body length) with bright orange-brown dorsal pelage and ventral pelage with cream or pale orange hair tips over dark-gray bases. Tail longer than head and body (130 mm), medium to dark brown in color, with hairs lengthening over the distal 25% and terminating in moderately long pencil (10–15 mm). Ears very dark. Hindfeet short and proportionately narrower than in most other Rhipidomys species, with poorly defined dorsal dark patch that, nevertheless, contrasts sharply with pale digits. Skull with hourglass-shaped interorbit, very slight supraorbital ridges, globose braincase, and derived carotid circulation pattern (small stapedial foramen, no groove on the inner surface of the squamosal and alisphenoid, and no sphenofrontal foramen). Mandible with pronounced incisor root capsule. Molars small (maxillary toothrow length 3.8–4.3 mm), even in comparison with skull length; first two upper molars with strong oblique paralophules paralleling mesoloph; part of third upper molar posterior to hypoflexus greatly reduced in size. d i s t r i b u t i o n : Rhipidomys caucensis is known from middle to high elevations in the Western Cordillera of Colombia (departments of Antioquia, Valle and Cauca) and, disjunctly, on the eastern flanks of the Central Cordillera at the head of the Magdalena valley (department of Huila) and in the department of Caldas.

592 Mammals of South America

s e l e c t e d l o c a l i t i e s (Map 310): COLOMBIA: Antioquia, Páramo Frontino (FMNH 71738); Caldas, Bosque de Florencia (Castaño et al. 2003); Cauca, Cerro Munchique (type locality of Rhipidomys caucensis J. A. Allen); Huila, San Antonio (FMNH 71736); Valle del Cauca, El Cairo, Cerro del Inglés (M. Alberico, in litt.). s u b s p e c i e s : Rhipidomys caucensis is monotypic. n a t u r a l h i s t o ry: Specimens of R. caucensis were taken at elevations of 2,800–3,500 m in Antioquia and at 2,540 m on the eastern and 1,830 m on the western slope of the Western Cordillera in Cauca; on the eastern slope of the Central Cordillera they were collected at 2,200–2,350 m in Huila and below 1,800 m in Caldas. These elevations generally correspond to cloud forest. r e m a r k s : Rhipidomys caucensis is placed in the “fulviventer” section of the genus on the basis of cranial and pelage characters, despite its derived carotid circulation pattern. Apart from this and its usually shorter tail, it is morphologically similar to R. wetzeli to the extent that in a cladistic analysis of thomasomyine species based on morphological characters, which included seven Rhipidomys species, these were the only two of the seven that formed a clade to the exclusion of the others (Pacheco 2003). In both Cauca and Huila, R. caucensis occurs sympatrically with the larger R. similis at the same elevations but occupying higher elevations than R. latimanus.

Map 310 2,000 m.

Selected localities for Rhipidomys caucensis (●). Contour interval =

Rhipidomys couesi ( J. A. Allen and Chapman, 1893) Coues’s Rhipidomys sy n o n y m s : Tylomys couesi J. A. Allen and Chapman, 1893:211; type locality “Princestown [i.e., Princes Town], Trinidad,” further restricted to “a point twelve miles north of the southern coast and seven miles southeast of Princestown” ( J. A. Allen and Chapman 1893:203). Rhipidomys couesi: J. A. Allen and Chapman, 1897a:18; first use of current name combination. Rhipidomys couesii Rendall, 1897:343; incorrect subsequent spelling of couesi J. A. Allen and Chapman. Rhipidomys venezuelae cumananus Thomas, 1900c:271; type locality “Ipure, altitude 700 m,” Sucre, Venezuela. Rhipidomys sclateri couesi: Cabrera, 1961:42; name combination. R[hipidomys]. sclateri cousei Furman and Tipton, 1961: 192; incorrect subsequent spelling of couesi J. A. Allen and Chapman. d e s c r i p t i o n : Large to very large (head and body length 150–210 mm) with yellowish to reddish brown agouti dorsal pelage, conspicuously flecked with dark brown or black guard hairs; ventral pelage white or creamy yellow, sometimes with rarely noticeable pale to medium gray hair bases; pelage moderately coarse and short. Tail relatively short (100–120% of head and body length), unicolored, with rather large, dark scales and dark brown to reddishbrown hairs; well haired distally, terminating in pencil of hairs up to 20 mm in length. Hindfeet long (29–32 mm with claw) and broad, with distinctly or indistinctly outlined dark patch that extends at least to bases of digits II to IV. Skull large, robust, and rather narrow for genus, with flattened profile such that interparietal nearly horizontal, especially in older specimens; supraorbital ridges well developed, usually straight and weakly divergent posteriorly; braincase narrow, not inflated, with squamosals oriented dorsolaterally rather than laterally; auditory bullae small; carotid circulation pattern is derived (stapedial foramen small, no internal squamosal-alisphenoid groove, no sphenofrontal foramen). Maxillary toothrow long for genus, ranging typically from 5.6–6.1 mm, but relatively short in comparison to skull length. d i s t r i b u t i o n : Rhipidomys couesi is known from the island of Trinidad, the Venezuelan island of Margarita (Nueva Esparta state), the coastal region of Sucre, Anzoátegui, and Vargas states up to approximately 1,000 m elevation, the southeast-facing lower slopes of the Mérida Andes in Barinas state, and the foothills of the Eastern Cordillera near Villavicencio, Meta, Colombia. By extrapolation, it can be expected to occur throughout the narrow belt of lowland moist forest that borders the llanos along the southern and eastern foothills of the Venezuelan coastal

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 593

range, Mérida Andes and Eastern Cordillera from Sucre in northeastern Venezuela to Meta in Colombia. From this point southward, where the Amazon-Orinoco forests reach the Andes, this species is replaced by the larger R. leucodactylus. s e l e c t e d l o c a l i t i e s (Map 311): COLOMBIA: Meta, Villavicencio (AMNH 75239). TRINIDAD AND TOBAGO: Trinidad, Cumaca (AMNH 235071), 7 mi SE of Princes Town (AMNH 5956/4685). VENEZUELA: Barinas, Altamira (USNM 442302), Reserva Forestal de Ticoporo (Ochoa et al. 1988); Nueva Esparta, Isla Margarita, Cerro Matasiete, 3 km NE of La Asunción (USNM 406100); Sucre, Ensenada Cauranta, 7 km N and 5 km E of Guiria (USNM 409936), Ipure, near Cumaná (type locality of Rhipidomys venezuelae cumananus Thomas); Vargas: Los canales de Naiguatá, P. N. El Ávila (Rivas and Salcedo 2006). s u b s p e c i e s : Rhipidomys couesi is monotypic. n a t u r a l h i s t o ry: The monograph by Montserin (1937) includes data on reproduction, life history, nesting habits, and diet of R. couesi in Trinidad, as well as its status as a pest of cacao and the control measures taken against it. The species was found to be relatively common in plantations but difficult to trap. Trap-shyness may mean that abundance estimates based on trapping success are inadequate. Other reports (Urich 1911; Everard and Tikasingh 1973b) suggest it is a common arboreal species in Trinidad plantations and forests. In Barinas state, Venezuela, R. couesi was captured in dense rainforest (Ochoa et al. 1988), while in Sucre and Nueva Esparta it was found mainly in evergreen forest or plantations, and in one case inside a house (Handley 1976). For parasites of the species in Venezuela, see Brennan and Reed (1974a), Furman (1972a), Furman and Tipton (1961), P. T. Johnson (1972), and Saunders (1975). r e m a r k s : Rhipidomys couesi is a large-bodied species in the “leucodactylus” section of the genus. Specimens from the islands of Trinidad and Margarita are larger on average than those from the Venezuelan mainland. If on the basis of new data the mainland form is demonstrated to be sufficiently distinct, the name cumananus Thomas is available. At the southwestern end of the range of the species, Colombian specimens have rather more slender skulls. This character, together with their shorter molar row, helps to distinguish skulls of R. couesi from the generally more robust skulls of R. leucodactylus. Aguilera et al. (1994) described the karyotype of R. couesi from Anzoátegui, Venezuela (under the name “R. sclateri”; note that R. sclateri is here considered a junior synonym of R. leucodactylus) as 2n = 44, FN = 48. Subfossil material from Tobago (off the northeast coast of Trinidad) identified by Eshelman and Morgan (1985)

Map 311

Selected localities for Rhipidomys couesi (●). Contour line = 2,000 m.

as Rhipidomys leucodactylus likely represents R. couesi instead. Fossilized teeth and skull fragments from the island of Bonaire (Caribbean Netherlands), some 90 km from the Venezuelan coast, which were identified by Hooijer (1959) as “Thomasomys spec.” and compared by Tribe (1996) with Rhipidomys couesi, have recently been described as the oryzomyine species Agathaeromys donovani and A. praeuniversitatis (Zijlstra et al. 2010).

Rhipidomys emiliae ( J. A. Allen, 1916) Snethlage’s Rhipidomys sy n o n y m s : Oecomys emiliæ J. A. Allen, 1916c:525; type locality “Rio Mojú, Pará, Brazil.” Oryzomys [(Oecomys)] emiliae: Ellerman, 1941:358; name combination. Rhipidomys emiliae: Goodwin, 1953:306; first use of current name combination. d e s c r i p t i o n : Medium sized (head and body length 120–150 mm) with dull grayish-brown to brighter orangebrown agouti dorsal pelage and cream or white ventral fur. Tail moderately long, medium to dark brown, moderately well haired, and ends in medium-length pencil (10–15 mm). Ears large, brown, and bare; some specimens have pale postauricular patch. Hindfeet moderate in length (25–28 mm), broad, with relatively long toes, and with narrow or broad dorsal dark patch, usually ill defined, leaving sides of feet and toes pale. Skull with moderately developed supraorbital ridges diverging posteriorly from point well forward, resulting in broad interorbital region; braincase narrow and somewhat angular, especially in older specimens, and moderately flattened; palatal bridge in adults often longer than molar row; auditory bullae small; carotid circulation pattern derived (small stapedial foramen, no internal groove on squamosal and alisphenoid, no spheno-

594 Mammals of South America

frontal foramen); molars small, particularly in comparison with skull length, maxillary toothrow not exceeding 5 mm in length. d i s t r i b u t i o n : Rhipidomys emiliae occurs in the eastern Brazilian Amazon Basin, south of the Amazon River, from the west bank of the Rio Tapajós eastward to the state of Maranhão and southward to southern Mato Grosso state. It has not been found east of the Rio Araguaia in the states of Tocantins or Goiás. s e l e c t e d l o c a l i t i e s (Map 309): BRAZIL: Maranhão, Alto da Alegria (BM 25.5.21.8); Mato Grosso, Chapada dos Guimarães, Casa de Pedra (MNRJ 24914), Estação Ecológica Serra das Araras (Santos-Filho et al. 2012), Fazenda Noirumbá, 34 km NW of Ribeirão Cascalheira (UFMG 2953), Fazenda São Luis, 30 km N of Barra do Garças (UFMG 2946), Vila Rica (MZUSP [APC 286]); Pará, Aramanaí, Rio Tapajós (AMNH 94810), Belém, Utinga (MNRJ 24195), Melgaço, Floresta Nacional de Caxiuaña (MPEG 34000), Parauapebas, Fazenda São Luiz (B. M. de A. Costa et al. 2011), Parque Nacional da Amazônia (T. K. George et al. 1988). s u b s p e c i e s : Rhipidomys emiliae is monotypic. n a t u r a l h i s t o ry: Emilie Snethlage, who collected the holotype of Rhipidomys emiliae, noted on the specimen tag that this rat was often found in houses and plantations. Pine (1973a) considered the species somewhat uncommon at Utinga, Belém. In the Serra do Roncador, Mato Grosso, one specimen was caught in a house, two in gallery forest, and one at the cerrado-dry forest ecotone; Fry (1970) provided details of the Roncador study area. r e m a r k s : Rhipidomys emiliae is a member of the “leucodactylus” section of the genus. Specimens from south of the Amazon between the Tapajós and Tocantins rivers that were tentatively included by Tribe (1996) in R. nitela are here reallocated to R. emiliae on the basis of their karyotype (2n = 44, FN = 52: M. J. de J. Silva and Yonenaga-Yassuda 1999; Andrades-Miranda, Oliveira et al. 2002 [as “R. leucodactylus cytotype 1” from locality 5, Caxiuanã]; 2n = 44, FN = 46: M. S. Mattevi, pers. comm.) and molecular data (L. P. Costa 2003; R. G. Rocha, Ferreira, Costa et al. 2011; B. M. de A. Costa et al. 2011). They include the “R. nitela” sequenced by M. F. Smith and Patton (1999) and by L. P. Costa (2003). Specimens from this area are morphologically intermediate between R. nitela from north of the Amazon and R. emiliae from the Belém region. The size difference in specimens from Serra do Roncador considered by Tribe (1996) to represent two species (R. nitela and R. emiliae) is here attributed instead to individual variation within the latter species. Pine et al. (1970; also Pine 1973a) referred to specimens of this species from Serra do Roncador, Mato Grosso, and the Belém region of the eastern Amazon as R. mastacalis. Subfossil

Rhipidomys material from the Serra dos Carajás, southeastern Pará state, dated to between 2,000 and 8,000 ybp (Toledo et al. 1999), may be referable to R. emiliae. In phylogeographic analyses based on the mtDNA cytochrome-b gene, Rhipidomys emiliae is most closely related to R. ipukensis, then R. mastacalis, followed by R. gardneri, then more distantly to a clade comprising R. leucodactylus, R. itoan, and R. tribei (= Rhipidomys “sp. nov.” in L. P. Costa 2003), and more remotely still to R. macrurus, which is geographically its neighbor (M. F. Smith and Patton 1999 and L. P. Costa 2003 [both reported as “R. nitela”]; R. G. Rocha, Ferreira, Costa et al. 2011; B. M. de A. Costa et al. 2011). The observation by R. G. Rocha, Ferreira, Costa et al. (2011) that the Rio Araguaia appears to separate R. emiliae in the states of Pará and Mato Grosso (to the west of the river) from R. ipukensis in the state of Tocantins (to the east) suggests that the identification of all these specimens needs confirmation by a phylogenetic analysis that includes material from the type locality of R. emiliae at Rio Moju, just south of Belém, which lies to the east of the Rio Tocantins below its confluence with the Rio Araguaia. The situation is further complicated by reports that specimens collected even farther east in Pará (Ourém) and Maranhão (Bacabal), which are here provisionally referred to R. emiliae, have karyotypes with FN = 64 (C. R. Bonvicino, pers. comm.), substantially different from the FN = 46 and 52 mentioned above for this species.

Rhipidomys fulviventer Thomas, 1896 Tawny-bellied Rhipidomys sy n o n y m s : Rhipidomys fulviventer Thomas, 1896:304; type locality “Agua Dulce, W. Cundinamarca, Colombia.” Rhipidomys fulviventer elatturus Osgood, 1914a:140; type locality “Paramo de Tama, head of Tachira River, Venezuela. Alt. 7,000 ft.” [Rhipidomys] fulviventris Tate, 1939:195; incorrect subsequent spelling of fulviventer Thomas. Rhipidomys fulviventer fulviventer: Gyldenstolpe, 1932: 48; name combination. Rhipidomys latimanus elatturus: Cabrera, 1961:419; name combination. d e s c r i p t i o n (amended from Tribe 1996, including his R. f. fulviventer and R. f. elatturus accounts): Small to medium sized with long, soft, and sleek fur; dorsal pelage mid-brown, often with olive tint, while gray-based ventral hairs have pale tips usually with orange suffusion throughout. Tail longer than head and body and generally medium to dark with slightly paler proximal area on ventral surface. Ears darker than the dorsal pelage. Hindfeet relatively narrow for genus, with dark metatarsal patch often indistinctly delineated. Skull with weakly developed

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 595

supraorbital ridges and thus with rounded, hourglassshaped interorbital region; braincase rounded, with poorly developed, curved parietal ridges and broad occiput; incisive foramina and mesopterygoid fossa typically narrow and almost parallel sided; posterior medial spine of palate small or absent, resulting in a posterior edge; parapterygoid fossae usually fenestrated; small sphenopalatine fissures usually present; carotid circulatory pattern primitive (large stapedial foramen, internal groove across squamosal and alisphenoid, and sphenofrontal foramen). Mandible with prominent incisor root capsule. Molars fairly large in comparison with skull length (maxillary toothrow length mostly 4.4–4.8 mm). d i s t r i b u t i o n : Rhipidomys fulviventer is known from elevations between 1,800 and 3,100 m in the Eastern Cordillera of the Colombian Andes, from Norte de Santander (and the Páramo de Tamá just across the Venezuelan border) southward to Cundinamarca and the Distrito Especial of Bogotá. In addition, a single specimen from the Serranía de la Macarena, an isolated tableland situated some 40 km east of the Eastern Cordillera in the department of Meta, is provisionally referred to this species. s e l e c t e d l o c a l i t i e s (Map 312): COLOMBIA: Boyacá, Paipa, Parque Natural Ranchería (ViancháSánchez et al. 2012); Cundinamarca, Guasca, Río Balcones (FMNH 71731), La Aguadita (BM 15.1.3.3); Meta, Serranía de la Macarena (AMNH 142140); Santander, Cachirí (CM 3192). VENEZUELA: Táchira, Páramo de Tamá (FMNH 18691). s u b s p e c i e s : See comments under Remarks. n a t u r a l h i s t o ry (information from MontenegroDíaz et al. 1991, except where noted): Rhipidomys fulviventer (referred to as “Rhipidomys latimanus”) inhabits relatively undisturbed cloud forest and the forest-páramo ecotone in the Eastern Cordillera of the Andes. The home range was found to be 0.2 ha in forest 25 m in height. Reproductive activity was fairly constant throughout the study period (February to August), two females having two embryos each (one Venezuelan specimen had three; USNM specimen tag); gestation lasted roughly one month. The content of five stomachs was 68% fruit and seeds, 26% leaves and other plant matter, and 6% insects. See also López-Arévalo et al. (1993). The individual from La Macarena was taken at 1,140 m (specimen tag). For parasites from the Venezuelan specimens, see Brennan and Reed (1974a), Furman (1972a), E. K. Jones et al. (1972), and Tipton and Machado Allison (1972). r e m a r k s : This species belongs to the “fulviventer” section of the genus. Specimens representing the northern known population are smaller on average than those from Cundinamarca, although examined sample sizes are very

small. If the northern population is found to be genetically distinct and to warrant species status, the name elatturus Osgood is available. Its range is separated by the Táchira Depression (roughly 1,000 m elevation) from that of the next member of the “fulviventer” section, the moderately large Rhipidomys venustus in the Mérida Andes of Venezuela. Southward, lower elevations in the Eastern Cordillera separate R. fulviventer from R. similis, which also belongs to the same section. The single known specimen from the Serranía de la Macarena is provisionally referred to Rhipidomys fulviventer although it is a little larger and differs slightly in skull morphology. Tribe (1996) treated all these forms as subspecies of Rhipidomys fulviventer; here, however, tenuicauda, venustus, fulviventer, and similis are considered sufficiently isolated and morphologically distinct to warrant separate species status. See also the remarks under Rhipidomys tenuicauda. Cabrera (1961) regarded Rhipidomys fulviventer and R. venustus as subspecies of R. latimanus, but Handley (1976) recognized that they are clearly distinct from the latter species. Two specimens resembling Rhipidomys fulviventer have recently been collected in Bongará, Amazonas department, Peru, 1,000 km south of La Macarena (C. F. Jiménez and Pacheco 2012). They are not included in the species range given here pending their formal identification.

Map 312 Selected localities for Rhipidomys fulviventer (●) and Rhipidomys similis (ᇲ). Contour line = 2,000 m.

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Rhipidomys gardneri Patton, da Silva, and Malcolm, 2000 Gardner’s Rhipidomys sy n o n y m : Rhipidomys gardneri Patton, da Silva, and Malcolm, 2000: 165; type locality “Reserva Cusco Amazónico, left (= north) bank of the Río Madre de Dios, 14 km east of Puerto Maldonado, Departamento de Madre de Dios, Perú, elevation about 200 m (12°33′S, 69°03′ W).” d e s c r i p t i o n : Large-bodied (head and body length 150–190 mm) with relatively short and coarse dorsal fur, gray to orange-brown agouti in color; ventral hairs fulvous to yellow, with gray-based hairs limited to midline of throat and chest. Tail proportionately short to medium in length (110–140% of head and body length), uniformly brown in color, clothed with short hairs, and terminating in short pencil that does not exceed 6 mm. Ears moderate in size and dark brown in color. Hindfeet long (33–34 mm) but broad, with narrow dark dorsal patch limited to metatarsals (not extending onto digits). Skull robust with short, tapering rostrum, deep zygomatic notches when viewed from above, and moderately developed supraorbital ridges that extend imperceptibly onto elongated braincase; mesopterygoid fossa long and narrow, with scalloped anterior border with distinct, posteriorly projecting median spine; auditory bullae very small; carotid circulatory pattern derived (small stapedial foramen, no internal groove on squamosal or alisphenoid, no sphenofrontal foramen). Maxillary toothrow long (>6 mm, with few exceptions), but average in comparison to length of skull. d i s t r i b u t i o n : Rhipidomys gardneri occurs in the upper reaches of the Juruá, Ucayali, Madre de Dios, and Beni drainages (western Brazil, eastern Peru and northeastern Bolivia) from below 200 m to above 2,500 m elevation. s e l e c t e d l o c a l i t i e s (Map 313): BOLIVIA: La Paz, Chijchipani (AMNH 262991). BRAZIL: Acre, left bank of the Rio Juruá opposite Igarapé Porongaba (Patton et al. 2000). PERU: Cusco, 2 km SW of Tangoshiari (B. M. de A. Costa 2007), Machu Picchu, San Miguel Bridge (USNM 194493), Centro de Investigación Wayqecha (C. E. Medina et al. 2012), Hacienda Cadena (FMNH 68647); Loreto, San Jerónimo, W bank Río Ucayali (BM 28.5.2.180); Madre de Dios, Albergue Cusco Amazónico, Río Madre de Dios, ca. 12 km E of Puerto Maldonado (type locality of Rhipidomys gardneri Patton, da Silva, and Malcolm); Puno, La Pampa (MCZ 39498). s u b s p e c i e s : Rhipidomys gardneri is monotypic. n a t u r a l h i s t o ry: Terborgh et al. (1984) and Woodman et al. (1995) provided ecological information on this species at Cocha Cashu and Cuzco Amazónico, Peru, and Patton et al. (2000) described the capture site on the upper Juruá. Specimens herein referred to Rhipidomys

gardneri from San Jerónimo, southern Loreto, Peru, were captured in houses or thatched roofs. Stomach analysis of a specimen from mature forest at the San Martín gas well site in Ucayali, Peru, indicated that it had been feeding on insect larvae living in bamboo stems. Females may become pregnant while still lactating: one individual (USNM 559408, Pakitza, Río Manu, Peru), captured when nursing a litter of three young in a desk drawer, was pregnant with four 20-mm embryos. r e m a r k s : Rhipidomys gardneri belongs to the “leucodactylus” section of the genus. Tribe (1996) placed the future holotype and a paratype of R. gardneri within R. leucodactylus on the grounds that there were morphological intermediates between “typical” R. leucodactylus and these slightly smaller specimens with less hairy tails from southeastern Peru. Karyotype and molecular data confirmed the species status of this form (Patton et al. 2000). Some morphologically intermediate specimens from the Ucayali-Urubamba and Madre de Dios drainages (also previously included in R. leucodactylus by Tribe, 1996) are provisionally referred to R. gardneri in the absence of diagnostic molecular or karyotype data, despite their slightly larger molars and, in some cases, rather hairier tails. Likewise, the Rhipidomys specimens from Chijchipani, at 850 m elevation in the upper Beni drainage of La Paz, Bolivia (“Rhipidomys sp. 1” in Tribe 1996), are here tentatively included in R. gardneri pending further analysis. Molecular data link R. gardneri with the eastern

Map 313 2,000 m.

Selected localities for Rhipidomys gardneri (●). Contour line =

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 597

Brazilian species R. mastacalis and R. emiliae (reported as R. nitela), rather than with R. leucodactylus (L. P. Costa 2003). It should be noted that GenBank sequence U03550 (MVZ 196059), sometimes cited as R. leucodactylus, in fact corresponds to R. gardneri.

Rhipidomys ipukensis R. G. Rocha, Costa, and Costa, 2011 Ipuca Rhipidomys sy n o n y m : Rhipidomys ipukensis R. G. Rocha, Costa, and Costa, 2011: 24; type locality “Fazenda Lago Verde, municipality of Lagoa da Confusão, state of Tocantins, Brazil, 10°52′09.1′′S, 49°41′52.1′′W, elevation 180 m.” d e s c r i p t i o n : Small to medium sized with adult head and body length averaging 121 mm (observed range: 99– 141 mm), tail longer than head and body (114–124%), and short and coarse dorsal pelage. Overall coloration yellowish gray brown to orangish brown, with dorsal hairs gray-based with yellowish to orangish tips mixed with completely black guard hairs; sides of body lighter than dorsum and with well-defined transition to the venter; ventral pelage woolly, varying from whitish to cream in color (some specimens have dark cream ventral midline). Juveniles completely light gray dorsally and white ventrally. Tail completely dark gray and covered with short hairs along anterior half, becoming more elongate along posterior half, ending in medium pencil 10–15 mm in length. Hindfeet broad, with dark dorsal metatarsal markings that vary from narrow and flanked with white fur to broad with poorly defined lateral limits. Ungual hairs white, completely covering but not surpassing claw tips. Ears large (20–23 mm), brown, often with small cream patch of fur at base. Skull varies from small and more delicate in younger specimens to medium sized and more robust in older ones (occipitonasal length of adults averages 33.7 mm, range: 29.9–36.2 mm); rostrum moderately long (average 9.6 mm); zygomatic notches relatively shallow but visible in dorsal view; zygomatic plates broad with their posterior margins anterior to M1 alveoli; alisphenoid struts present and subsquamosal fenestrae small, almost occluded by hamular process of squamosal; carotid circulation pattern 3 (of Voss 1988), with small stapedial foramen, no squamosalalisphenoid groove, and no sphenofrontal foramen; palatal bridge short and wide; incisive foramina bullet-shaped with parallel margins extending posteriorly to anterior edge of M1s; anterior margin of mesopterygoid fossa with median spine and extending to midline of M3s; posterior palatal pits simple and small on each side of mesopterygoid fossa; sphenopalatine vacuities either present as small slits or absent, such that mesopterygoid roof completely ossified; auditory bullae small.

Upper incisors opisthodont; molars rather small (maxillary toothrow length 4.5–5.0 mm); M1 with labial accessory root; m1 with both labial and lingual accessory roots; anterocones/conids of upper and lower molars divided into two conules/conulids by anteromedian flexus(id); relatively small, oblique paralophules present in all upper molars; posterior part of M3 reduced. Mental foramen opens laterally on mandibular body; capsular process well developed as conspicuous swelling. d i s t r i b u t i o n : This species is known from three localities in Tocantins state, Brazil. It is believed to be endemic to the Araguaia-Tocantins basin east of the Rio Araguaia in the Cerrado of central Brazil. s e l e c t e d l o c a l i t i e s (Map 309): BRAZIL: Tocantins, Lagoa da Confusão, Fazenda Lago Verde (type locality of Rhipidomys ipukensis R. G. Rocha, Costa, and Costa), Pium, Parque Estadual do Cantão (MNRJ 73744), Rio Santa Teresa, 20 km NW of Peixe (UFMG 2952). s u b s p e c i e s : Rhipidomys ikpukensis is monotypic. n a t u r a l h i s t o ry: Little is known of the ecology or other aspects of the population biology of this species. Specimens were captured primarily in ipucas, seasonally flooded forest fragments, in traps placed both on the ground and in the understory, including pipe traps used as arboreal refuges for tree frogs. Adult males had scrotal testes, and adult females were lactating when captured in the month of September (R. G. Rocha, Ferreira, Costa et al. 2011). r e m a r k s : Rhipidomys ipukensis is a member of the “leucodactylus” section of the genus. It has a close sisterrelationship with R. emiliae, according to a phylogenetic analysis of mtDNA cytochrome-b sequences, with the two species differing by an average of 5.1%; together they form a clade with R. mastacalis from the Atlantic Forest (R. G. Rocha, Ferreira, Costa et al. 2011). The karyotype of R. ipukensis is as yet unknown. Should Rhipidomys specimens from northern Goiás state here provisionally referred to R. mastacalis because of their high FN = 76 and 80 (Andrades-Miranda, Oliveira et al. 2002) prove instead to belong within R. ipukensis, it will not only extend the distribution of the species but also indicate that high fundamental numbers probably arose independently more than once in this group, given the low-FN karyotype of R. emiliae, the closest relation of R. ipukensis. R. G. Rocha, Ferreira, Costa et al. (2011) noted that R. ipukensis was found to the east of the Rio Araguaia whereas R. emiliae was found to the west. Stability of the name ipukensis and the identity of the specimens found to the west of the river may depend on phylogenetic comparison with material from the type locality of R. emiliae at Rio Moju, Pará, which lies to the east of the Araguaia-Tocantins.

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Rhipidomys itoan B. M. de A. Costa, Geise, Pereira, and L. P. Costa, 2011 Sky Rhipidomys sy n o n y m : Rhipidomys itoan B. M. de A. Costa, Geise, Pereira, and L. P. Costa, 2011:950; type locality “Garrafão (hillside of the Iconha River in Parque Nacional da Serra dos Órgãos), Guapimirim municipality, state of Rio de Janeiro, Brazil, 22°28′28′′S, 42°59′86′′W [sic], 700 m.” d e s c r i p t i o n : Medium sized (mean head and body length = 136.4 mm) with tail varying from 107–148% of head and body length, mean 124% (n = 18). Dorsal pelage reddish or yellowish brown to dark reddish brown, with short (ca. 8 mm) body hairs and longer (ca. 16 mm) guard hairs; ventral pelage plain white or white with small areas of light gray at sides of abdomen, sometimes extending to forelimbs, with or without gray spots in pectoral region; dorsal pelage extends for short distance onto tail base; tail unicolored along length, covered by short, brown to black hairs that increase in length distally and terminate in short pencil extending up to 10 mm beyond its tip. Ears small to medium, ranging from 12–22 mm in length, externally brown in color with brown or whitish hairs internally. Hindfeet covered dorsolaterally with white hairs that extend onto toes; mid-dorsal surface of toes with patch of light brown or gray hairs. Skull small to moderate in size (mean condyloincisive length 31.4 mm); in comparison with other species in eastern and southeastern Brazil, similar in size to Rhipidomys macrurus and R. mastacalis, and larger than R. tribei. Rostrum short and somewhat broad (mean length = 10.6 mm, mean width = 6.6 mm); lacrimal capsules slightly inflated; gnathic process present, nasal bones broad anteriorly but narrow posteriorly, and not contacting or extending posteriorly beyond maxillary-frontal sutures; anterior edges of zygomatic plates slightly rounded to rectangular but do not protrude anterior to maxillary roots of zygomatic arches; zygomatic notches narrow and quite deep; dorsal projections of lacrimal bones comparatively small, narrow, and slightly prominent; interorbital region broad with rounded, hourglass-shaped edges and slight supraorbital crests; braincase broader in relation to skull length than in other species occurring south of Amazon River; hamular process of squamosal divides postglenoid foramen and subsquamosal fenestra unequally; carotid circulation derived (pattern 3 of Voss 1988), with small stapedial foramen, no translucent internal groove across squamosal and alisphenoid, and no sphenofrontal foramen; thin alisphenoid strut present, as are oval and buccinator-masticatory foramina; incisive foramina long, bullet shaped, with parallel margins that converge anteriorly and also slightly posteriorly, especially in specimens from state of São Paulo, ex-

tending to plane between M1s; mesopterygoid fossa long, with small postpalatal spine at anterior margin, extending anteriorly to posterior margins of M3 alveoli; sphenopalatine vacuities either absent or greatly reduced; triangular parapterygoid plates deeply excavated; auditory bullae small but inflated. Upper incisors slightly opisthodont. Anteroflexus and anteromedian flexus in M1 usually long and deep, demarcating anterolabial and anterolingual conules; protoflexus and hypoflexus of M1 and M2 moderately long; paraflexus and metaflexus long and sharply angled, sometimes bifurcated at inner ends; both medial and labial fossettes frequently present in M2. d i s t r i b u t i o n : Rhipidomys itoan is found from the Serra da Mantiqueira southward to the coast in the Brazilian states of Rio de Janeiro and eastern São Paulo, including in the Serra dos Órgãos and Serra do Mar, and on inshore islands such as Ilha Grande and Ilha da Marambaia. Its range extends to the Serra de Paranapiacaba in southern São Paulo state. s e l e c t e d l o c a l i t i e s (Map 314): BRAZIL: Rio de Janeiro, Garrafão (type locality of Rhipidomys itoan B. M. de A. Costa, Geise, Pereira, and L. P. Costa), Parque Estadual dos Três Picos (HGB 581), Praia Vermelha, Ilha Grande (MNRJ 24389), Parque Nacional do Itatiaia (HGB-CFVC 5); São Paulo, Estação Biológica de Boracéia (MZUSP 10816), Parque Estadual Intervales, Barra Grande (E. M. Vieira and Monteiro-Filho 2003 [EM 1130]), Pilar to Sul (B. M. de A. Costa et al. 2011 [CIT 1278]), São Sebastião (MZUSP 880). s u b s p e c i e s : Rhipidomys itoan is monotypic. n a t u r a l h i s t o ry: Specimens have been trapped in dense rain forest or coastal forests of the Serra do Mar range, where continuous cover may be punctuated with streams and rocky outcrops, occasionally with an open understory, including that caused by human disturbance (B. M. de A. Costa et al. 2011). In a capture-mark-recapture study at the type locality, 24 individuals of Rhipidomys itoan were captured a total of 61 times, always in trees, and remained on the grid for an average of 10 (± 6.73) months; the breeding period was August to December, in the early wet season ( J. Macedo et al. 2007). Davis (1945a, 1947) provided life history notes on a sample from nearby Teresópolis (Rio de Janeiro state) and general ecological information on the habitat. Guitton et al. (1986), MartinsHatano et al. (2002), and Neri-Bastos et al. (2004) investigated parasites on specimens from Rio de Janeiro and São Paulo states. A specimen from Parati in southwestern Rio de Janeiro state was infected with Leishmania (Viannia) (Soares et al. 1999). r e m a r k s : With available taxon sampling, R. itoan and R. tribei form a sister-pair within the “leucodactylus”

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 599

Map 314 Selected localities for Rhipidomys itoan (●) and Rhipidomys tribei (ᇲ).

section of the genus, based on mtDNA cytochrome-b sequences. The two species are, however, quite divergent, with the average sequence difference 8.3% (B. M. de A. Costa et al. 2011). Rhipidomys itoan is the correct name for those specimens identified by R. G. Rocha, Ferreira, Costa et al. (2011) as “R. sp. 2” in their phylogenetic analysis of mtDNA sequences. Previously, specimens of R. itoan had frequently been referred to as “R. mastacalis” (e.g. Davis 1945a, 1947), “R. cf./aff. macrurus” (e.g. Tribe 1996; E. M. Vieira and Monteiro-Filho 2003) or “Rhipidomys sp.” (e.g. Zanchin, Langguth, and Mattevi 1992; Geise 1995; M. F. Smith and Patton 1999 [as “Rhipidomys sp. 2”]; L. P. Costa 2003). The karyotype is 2n = 44, with the number of autosomal arms varying from 48 to 50 due to polymorphism. The X chromosome is a large submetacentric, one of the largest of the complement; the Y chromosome is the smallest acrocentric. B. M. de A. Costa et al. (2011) also detailed the distribution of NORs within the complement.

Rhipidomys latimanus Tomes, 1860 Northwestern Rhipidomys sy n o n y m s : H[esperomys]. latimanus Tomes, 1860a:213; type locality not given, but “the greater portion of these [species] are believed to have been collected at Pallatanga, on the western slope of the Cordillera” (Tomes 1860a:211), Chimborazo province, Ecuador.

[Hesperomys ] (M[yoxomys].) latimanus: Tomes, 1861 [1862]:284; name combination. Rhipidomys microtis Thomas, 1896:304; type locality “Saliña [for “Salina”] del Vatan [possibly near Quebrada Batán], Western Cundinamarca, Colombia.” Rhipidomys pictor Thomas, 1904e:193; type locality “Rio Verde, [Pichincha,] N.W. Ecuador. Alt. 1000 m.” Rhipidomys mollissimus J. A. Allen, 1912:78; type locality “Mira Flores [= Miraflores] (alt. 6200 ft.), west slope of Central Andes, near Palmira, Cauca [now Valle del Cauca], Colombia.” Rhipidomys cocalensis J. A. Allen, 1912:79; type locality “Cocal, Cauca, Colombia, Altitude, 4000 feet.” Rhipidomys quindianus J. A. Allen, 1913c:600; type locality “El Roble (altitude 7200 feet), Central Andes [Quindío department], Colombia.” Rhipidomys scandens Goldman, 1913:8; type locality “near head of Rio Limon (altitude 5,000 feet), Mount Pirri [= Cerro Pirre], Eastern Panama.” Rhipidomys latimanus latimanus: Cabrera, 1961:419; name combination. Rhipidomys latimanus similis: Cabrera, 1961:419; part; not Rhipidomys similis J. A. Allen; attribution of cocalensis. Rhipidomys latimanus microtis: Cabrera, 1961:419; name combination. Rhipidomys latimanus mollissimus: Cabrera, 1961:419; name combination. Rhipidomys latimanus pictor: Cabrera, 1961:419; name combination. R[hipidomys]. scadens Cuervo Díaz, Hernández Camacho, and Cadena, 1986:498; incorrect subsequent spelling of scandens Goldman. d e s c r i p t i o n (amended from Tribe 1996, for the nominotypical subspecies he recognized): Medium sized (head and body length typically 120–140 mm) with intensely pigmented orange or reddish-brown dorsal pelage, finely flecked with dark brown or black guard hairs; ventral pelage creamy white, sometimes with inconspicuous gray bases to hairs. Hindfeet moderately large and often robust (26–28 mm in length) with rather narrow metatarsal dark patch, broadening at base of digits III to V but rarely extending onto digits. Tail long (120–150% of head and body length), medium to dark brown, with short hair on shaft, distally little longer, with terminal pencil 3–30 mm long but usually about 10 mm. Ears small to medium in size, and rather dark in color. Skull moderate in size and rather slender, with slender rostrum; supraorbital ledges or ridges pronounced, straight, and converge strongly to front of interorbital region; braincase oval, not angular, and not greatly flattened except in old specimens; parapterygoid fossae shallow and not fenestrated; auditory bullae small; carotid circulatory pattern derived

600 Mammals of South America

(small stapedial foramen, no squamosal-alisphenoid groove, no sphenofrontal foramen). Incisor root capsule on mandible does not form prominent knob. Upper molar toothrow length 4.7–5.3 mm, average in relation to skull length in Rhipidomys. d i s t r i b u t i o n : At the southern limit of its range, R. latimanus occurs in the Chinchipe valley of northern Peru, close to the border with Ecuador, possibly linking northward along the eastern Andean slopes with the population in the upper Napo valley, Ecuador (700 to 1,100 m elevation). It is found along the western flanks and valleys of the Ecuadorian Andes (700 to 1,700 m) and also in the Colonche range of western Ecuador (about 450 m). In Colombia, it occurs from Nariño in the south, along both sides of the upper and middle Cauca valley (Cauca, Valle del Cauca, and Antioquia departments—700 to 2,000 m), spilling over in places to the opposite slopes of the Western and Central Cordilleras (2,200 m at El Roble), and extending eastward to the eastern side of the Magdalena valley in Cundinamarca and Boyacá (1,000 to 1,300 m); an apparently isolated population exists at the head of the Magdalena valley in Huila department (1,350 to 1,400 m). An isolated population in the Darién mountains of eastern Panama (1,250 to 1,550 m) probably extends into the hills across the Colombian border. s e l e c t e d l o c a l i t i e s (Map 315, South American localities only): COLOMBIA: Antioquia, Valdivia, La Cabaña (FMNH 70255); Boyacá, Muzo (FMNH 71711); Cauca, Cocal (type locality of Rhipidomys cocalensis J. A. Allen); Huila, San Adolfo (FMNH 71704); Nariño, San Pablo (BM 99.9.3.1); Quindío, El Roble (type locality of Rhipidomys quindianus J. A. Allen); Valle del Cauca, Miraflores (type locality of Rhipidomys mollissimus J. A. Allen). ECUADOR: Chimborazo, Pallatanga (type locality of Hesperomys latimanus Tomes); Santa Elena, Cerro Manglar Alto (AMNH 66618); Napo, near Archidona (BM 34.9.10.112); Pichincha, Río Verde (type locality of Rhipidomys pictor Thomas). PERU: Cajamarca, Perico (MCZ 17043). s u b s p e c i e s : As currently understood, R. latimanus is monotypic (but see Remarks). n a t u r a l h i s t o ry: Little information has been published on the natural history of R. latimanus. Collection localities suggest that it occupies a range of habitats from moist to somewhat drier forests. Specimens from near Cali in the Cauca valley were trapped in coffee plantations and second-growth woodland and tested negative for Leishmania (Alexander et al. 1998). Specimen tags indicate that one individual from western Ecuador was taken in long grass, and one from eastern Panama was captured in cloud forest. Another Panamanian specimen was pregnant with three embryos in March.

r e m a r k s : Rhipidomys latimanus is a member of the “leucodactylus” section of the genus. Morphologically, it is closely allied to R. venezuelae (q.v.); both species encompass considerable morphological variation, with some populations of each taxon approaching the other in certain characters, especially in northern Colombia. Tribe (1996) therefore tentatively included venezuelae as a subspecies within R. latimanus, together with an unnamed subspecies corresponding to the specimens from Huila department, Colombia. As pointed out by Musser and Carleton (2005), however, the appreciable morphometric differentiation between the first two of these taxa suggests that they may be retained as separate species, and this arrangement is followed here. The Huila specimens are convergent in some characters with R. fulviventer, but a majority of features point to a position within R. latimanus (for details, see Tribe 1996). The specimens from the Darién mountains of extreme eastern Panama, considered by most authors a separate species (R. scandens), fall well within the range of variation found in Colombian R. latimanus and are therefore allocated to this species (Tribe 1996). The karyotype of a R. latimanus specimen from Peñas Blancas, Valle del Cauca, Colombia (2n = 44, FN = 48) was

Map 315 2,000 m.

Selected localities for Rhipidomys latimanus (●). Contour line =

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 601

the first Rhipidomys karyotype to be published (A. L. Gardner and Patton 1976). It remains to be seen whether karyotypes and molecular data from other localities will help to clarify the large amount of morphological variation observed in the species as understood here.

Rhipidomys leucodactylus (Tschudi, 1845) Great Rhipidomys sy n o n y m s : H[esperomys (Rhipidomys)]. leucodactylus Tschudi, 1843: 252; nomen nudum. H[esperomys (Rhipidomys)]. leucodactylus Tschudi, 1844: 16; nomen nudum. H[esperomys (Rhipidomys)]. leucodactylus Tschudi, 1845: 183; type locality “im Oststriche,” i.e., the eastern region of Peru visited by Tschudi, herein restricted to the Montaña de Vitoc area in Junín, Peru (see Remarks). Nyctomys leucodactylus: Fitzinger, 1867b:89; name combination. Hesperomys (Rhipidomys) sclateri Thomas, 1887:152 and plate XIX; type locality “Maccasseema” [= Makasima, on Pomeroon River, Pomeroon-Supinaam], Guyana. Rhipidomys Goodfellowi Thomas, 1900c:270; type locality “upper Rio Napo, at mouth of Rio Coca,” Napo, Ecuador. Rhipidomys bovallii Thomas, 1911a:114; type locality “Potaro Highlands, towards Mt Roraima, British Guiana [Guyana]. Alt. 2000′.” Rhipidomys lucullus Thomas, 1911a:115; type locality “Garita del Sol, valley of Vitoc, Upper Peréné, [Junín], Central Peru. Alt. 5700′.” Rhipidomys equatoris Thomas, 1915:312; type locality “San Domingo, [Santo Domingo de los Tsáchilas,] W. Ecuador (79°6′ W., 0°13′S.). Alt. 1600′.” Rhipidomys rex Thomas, 1927f:600; type locality “Chinchavita, 3000′,” Huánuco, Peru. Rhipidomys leucodactylus equatoris: Cabrera, 1961:421; name combination. Rhipidomys leucodactylus goodfellowi: Cabrera, 1961:421; name combination. Rhipidomys leucodactylus leucodactylus: Cabrera, 1961: 421; part, excluding Rhipidomys ochrogaster, as subspecies. R[hipidomys]. leucodactylus aratayae Guillotin and Petter, 1986:541; type locality “saut Pararé, sur la rivière Arataye [Pararé falls, on the Arataye river] (4°3′N, 52°40′ W),” French Guiana. d e s c r i p t i o n (amended from Tribe 1996, excluding specimens that are now recognized as R. gardneri [see Patton et al. 2000, and that account herein]): Largest species in genus Rhipidomys, with adult head and body length often exceeding 180 mm. Dorsal pelage typically medium-brown

agouti, varying in tone from grayish to yellowish to reddish, with conspicuous dark guard hairs; flanks somewhat paler; ventral pelage white, cream, or yellowish, with gray-based hairs and often with orange suffusion in medial pectoral region; pelage texture somewhat coarse and often slightly woolly, especially on ventral surface. Tail proportionately short, only 95% to 130% of head and body length, reddish to very dark brown in color, unicolored, with shaft well clothed in hairs and tip terminating in long bushy pencil over 15 mm in length, sometimes reaching 40 mm. Ears moderately large. Hindfeet large (32–38 mm in length) and very broad, with dark patch covering most of dorsal surface and extending onto first or even second phalanges of digits II to V, sometimes also digit I; sides of foot and tips of toes silvery to golden. Skull large and robust (adult occipitonasal length usually exceeding 40 mm), relatively broad, with deep and broad rostrum; nasals expanded at anterior end and parallel-sided in posterior half; zygomatic notches small when viewed from above; supraorbital ridges well developed, sometimes converging anteriorly on top of interorbital region, with orbital wall ventrolateral to ridges forms narrowest part of interorbital constriction, providing general hourglass shape to region; braincase moderately broad and slightly inflated, with flatter profile in older specimens; interparietal nearly horizontal and occiput vertical; parietal ridges positioned somewhat dorsally on braincase such that squamosals are oriented dorsolaterally rather than laterally; mesopterygoid fossa broad, especially anteriorly; auditory bullae small and carotid circulation pattern derived (small stapedial foramen, no internal groove on squamosal or alisphenoid, and no sphenofrontal foramen). Molars large and maxillary toothrow long (6.0–7.0 mm), although slightly smaller on average than might be expected in relation to skull length. d i s t r i b u t i o n : Rhipidomys leucodactylus occurs in the lowland rainforests of the Amazon-Orinoco basin, from the Guiana coast and lower Amazon in the northeast to the Andean piedmont between Colombia (Serranía de la Macarena) and central Bolivia (Cochabamba). It penetrates the moist valleys of the Guiana highlands of Venezuela as well as submontane forests up to 1,750 m elevation in eastern Peru, but apparently not in the upper Urubamba and Madre de Dios drainages. The range of the species as understood here also extends through the Huancabamba Depression in northern Peru to the forests of the western Andean slopes and valleys in northwestern Peru and Ecuador, from where it may be expected to reach the Chocó region of western Colombia. s e l e c t e d l o c a l i t i e s (Map 316): BOLIVIA: Cochabamba, Yungas (BM 34.9.2.172). BRAZIL: Amapá, Mazagão, Boa Fortuna, upper Igarapé Rio Branco (MPEG 2508); Amazonas, Altamira, right bank Rio Juruá (MVZ

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190592); Mato Grosso, Aripuanã (MZUSP APC 260); Pará, Amorim, Rio Tapajós (AMNH 95508); Rondônia, Usina Hidrelétrica de Samuel, Rio Jamarí (UFPB 1259). COLOMBIA: Caquetá, Florencia (AMNH 33744); Meta, Serranía de la Macarena (AMNH 142141). ECUADOR: El Oro, Los Pozos (AMNH 67508); Orellana, San José Abajo (AMNH 68189); Pastaza, Mera (USNM 548392); Santo Domingo de los Tsáchilas, Santo Domingo (type locality of Rhipidomys equatoris Thomas). FRENCH GUIANA: Saut Pararé, Rivière Arataye (type locality of Rhipidomys leucodactylus aratayae Guillotin and Petter). GUYANA: Cuyuni-Mazaruni, Potaro Highlands, Venamo River (type locality of Rhipidomys bovallii Thomas); Pomeroon-Supenaam, Makasima, Pomeroon River (type locality of Hesperomys (Rhipidomys) sclateri Thomas). PERU: Ayacucho, Huanhuachayo (AMNH 241643); Huánuco, Chinchavito (type locality of Rhipidomys rex Thomas); Junín, La Garita del Sol (type locality of Rhipidomys lucullus Thomas); Loreto, Mouth of Río Curaray (AMNH 71906); Piura, Canchaque (FMNH 81293). VENEZUELA: Amazonas, Cerro Neblina, Camp VII, 5.1 km NE of Pico Phelps (USNM 560825), Pozón, 50 km NE of Puerto Ayacucho (T. E. Lee et al. 2000); Bolívar, Embalse Guri, Isla Panorama, Río Caroní (T. D. Lambert et al. 2003). s u b s p e c i e s : As currently understood, R. leucodactylus is monotypic, but the considerable geographic variation in both morphology (Tribe 1996) and molecular sequences (B. M. de A. Costa et al. 2011) exhibited across its large range may underscore subspecific or even specific differentiation (see Remarks). As with many of the widespread species of this genus, larger series coupled with thorough analyses of this variation are needed to properly delimit geographic units. n a t u r a l h i s t o ry: As a large, rat-sized, frugivorous rodent, R. leucodactylus is listed as a pest of agricultural crops (Aguilar et al. 1977); in fact, the holotype was captured while gnawing fruit in a pineapple field (Tschudi 1845), and other specimen tags mention sugar cane and yucca. Specimens have often been caught in rural dwellings (specimen tags; Handley 1976). The species generally occurs in moist, evergreen forest (Handley 1976; Ochoa et al. 1988), including floodable riparian habitats adjacent to the llanos (T. E. Lee et al. 2000). The holotype of Rhipidomys leucodactylus aratayae was observed to nest in a hole 15 m up in a tree, have a home range of 1.35 ha, and forage on the ground (Guillotin and Petter 1986). Three females from Huánuco, central Peru, were each pregnant with two embryos in August–September, and two from Napo, eastern Ecuador, had three in September and November (specimen tags). For parasites of Venezuelan specimens, see P. T. Johnson (1972) and Saunders (1975). A

specimen of Rhipidomys leucodactylus captured in northern Brazil had uncharacterized Leishmania isolated from its skin (Lainson, Shaw, et al. 1981), and sylvatic plague (Yersinia pestis) was carried by Polygenis litargus fleas infesting individuals and nests of R. leucodactylus in Piura, northwestern Peru (Machiavello 1957 apud Pozo et al. 2005). r e m a r k s : Rhipidomys leucodactylus is the type species of the genus. As explained in the Remarks on the genus, Tschudi’s name leucodactylus, like Rhipidomys, becomes available from its use on page 183 of the Untersuchungen über die Fauna peruana (Therologie), published in the fourth installment of the work in 1845. Where it appears on page 16 of this work (published in 1844) and on page 252 of the “Mammalium conspectus” (Tschudi 1843) it is a nomen nudum. In his description of the material, Tschudi (1845:183–184) mentioned that he found this species “im Oststriche”—that is, the region east of the Andean Cordillera in central Peru—where it was associated with crop fields (his first specimen was shot while gnawing a pineapple) and human habitations. He also stated that Prof. Poeppig reported it from Tocache on the Río Huallaga. Cabrera’s (1961:421) restriction of the type locality to the upper Huallaga “on the basis of Tschudi’s text” is thus evidently based on a misinterpretation: Tschudi’s own specimens came from the region he himself visited and not from the Huallaga, which lies much farther north. Tschudi (1846, 1847) describes his excursion from Lima over the Cordillera to the Montaña de Vitoc, the area between the rivers Anamayo and Tulumayo in Junín department. There he saw many plantations, especially of pineapples. Although he did not specifically mention Rhipidomys in this context, this is the only area east of the Andes that he described from firsthand experience. Given also the close similarity between the holotype of leucodactylus and other specimens collected later in the same area, it is justifiable to restrict the type locality of this taxon to the Montaña de Vitoc and to reject Cabrera’s (1961) mistaken suggestion. Wagner (1845a:147) also described a specimen of Rhipidomys under the name Hesperomys leucodactylus, but one now referable to a species different from Tschudi’s material. I have been unable to resolve the question of which leucodactylus—Tschudi’s or Wagner’s—was published first in 1845: no month of publication appears in either work, and no clues have been found in the accession records of several libraries consulted. In the absence of any clear priority and in accordance with the principle of the first reviser (ICZN 1999:Art. 24.2), I consider that precedence should be given to leucodactylus Tschudi, 1845, over leucodactylus Wagner, 1845. This step best serves stability by retaining the name for the taxon with

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 603

which it has almost always been associated. In contrast, to my knowledge Wagner’s name has been cited only three times in the last 100 years (Tate 1932g:5; Moojen 1952b:75; and C. O. da C. Vieira 1955:419); of these authors, only Tate associated the name with Rhipidomys, the others retaining it with Hesperomys. Furthermore, it avoids the inconvenience of having to provide a replacement name for the type species of the genus. I additionally propose that leucodactylus Wagner be rejected both as a junior primary homonym (in Hesperomys) and as a secondary homonym (in Rhipidomys) (ICZN 1999:Art. 52.1– 3, 53.3, 57.2). Because I attribute Wagner’s type specimen to Rhipidomys macrurus (P. Gervais, 1955) (q.v.), the latter name replaces leucodactylus Wagner (ICZN 1999:Art. 60.2). As treated herein, Rhipidomys leucodactylus displays substantial geographic and/or individual variation in characters such as overall size, relative tail length and hairiness, and ventral color. Patton et al. (2000) clearly distinguished between R. leucodactylus and R. gardneri on the basis of karyotype and mtDNA cytochrome-b sequence data as well as morphological characters. Unfortunately, some specimens do not fit neatly with Patton et al.’s morphological descriptions and, therefore, in the absence of karyotype and molecular data, have been allocated subjectively to one species or the other. For example, an individual from the Yungas (wet, forested Andean valleys) of Cochabamba, Bolivia, is here placed in R. leucodactylus because of its very large size, long molar row, and skull shape, although in its white ventral pelage and short tail pencil it resembles R. gardneri. Most specimens of R. leucodactylus from west of the Andes in northwestern Peru and western Ecuador closely resemble populations from the eastern valleys in central Peru and eastern Ecuador, suggesting contact at some time through the Huancabamba Depression. Known karyotypes for Rhipidomys leucodactylus all show a diploid number of 2n = 44 but vary in number of autosomal arms: FN = 46 (Patton et al. 2000), FN = 48 (Zanchin, Langguth, and Mattevi 1992), and FN = 52 (M. J. J. Silva and Yonenaga-Yassuda 1999, as “R. cf. mastacalis,” from Aramanaí, Mato Grosso state). The karyotyped specimen identified by Aguilera et al. (1994) as “R. sclateri,” from the coastal region of Venezuela, represents Rhipidomys couesi and not R. leucodactylus. It should also be noted that Andrades-Miranda, Oliveira et al. (2002) identified all their specimens with low-FN from Goiás and Pará, Brazil, as “R. leucodactylus” without reference to morphology; in fact, they represent R. macrurus, R. emiliae, and possibly R. ipukensis. A molecular phylogeny of 39 Rhipidomys specimens (B. M. de A. Costa et al. 2011) placed three R. leucodactylus in a sister-group relationship to a clade compris-

Map 316 2,000 m.

Selected localities for Rhipidomys leucodactylus (●). Contour line =

ing two subgroups corresponding to R. itoan and R. tribei. Within the R. leucodactylus clade a Kimura 2-parameter distance of 9.24% separated the above-mentioned specimen from Aramanaí from two specimens from different parts of the Rio Juruá, a distance greater than that separating several sister species within the genus. GenBank sequence U03550 (MVZ 196059), sometimes cited as R. leucodactylus, in fact corresponds to R. gardneri. Rhipidomys leucodactylus has been collected at the same localities as R. modicus in central Peru, and as R. nitela, R. wetzeli, and R. macconnelli in Venezuela.

Rhipidomys macconnelli de Winton, 1900 Macconnell’s Tepui Rhipidomys sy n o n y m s : Rhipidomys Macconnelli de Winton, 1900:52; type locality “summit of Roraima, [Cuyuni-Mazaruni,] Demerara” [Guyana]. [Rhipidomys] maccomelli E.-L. Trouessart, 1904:409; incorrect subsequent spelling of macconnelli de Winton. [Thomasomys] macconnelli: Thomas, 1917d:196; name combination. Thomasomys macconnelli macconnelli: Tate, 1939:194; name combination. Thomasomys macconnelli subnubis Tate, 1939:195; type locality “South slope Mt. Auyan-tepui, 3500 feet,” Bolívar, Venezuela. Rhipidomys macconelli Hershkovitz, 1959a:9; incorrect subsequent spelling of macconnelli de Winton. d e s c r i p t i o n : Small (head and body length 115– 120 mm), resembling Thomasomys in many external characters but cranially closer to other Rhipidomys. Pelage

604 Mammals of South America

sleep, long, and soft; colored dark chocolate brown dorsally and dark slate overlaid with cream or pale brown ventrally; juveniles darker and greyer than adults. Tail much longer than head and body length (>140%) but slenderer than in most other Rhipidomys; paler on its ventral surface and almost bare over much of its length but with pronounced terminal pencil (5–20 mm long). Hindfeet less specialized for climbing, being longer (relative to body length) than in other species of Rhipidomys due to longer, narrow metatarsals; plantar pads also smaller and separated, with gap between thenar and hypothenar; dark patch on dorsal surface poorly defined but mid-brown in color and covers most of surface; heels and ankles bare. Ears dark brown, matching dorsal pelage. Cranially, nasals narrow anteriorly and rostrum long and slender in comparison to rounded braincase; interorbital region bounded by distinct, slightly concave supraorbital ridges; the lateral process of the parietal usually triangular rather than rectangular in shape and contacts the occipital barely or not at all; occipital region broad; mesopterygoid fossa broadened anteriorly, parapterygoid fossae often slightly fenestrated; carotid circulation pattern derived (small stapedial foramen, no groove on the inner surface of the squamosal and alisphenoid, and no sphenofrontal foramen); upper molar row length (5.00 ± 0.157 mm, N = 214) large in relation to skull length for the genus. d i s t r i b u t i o n : Rhipidomys macconnelli lives on the slopes and summits of the Guiana Shield table mountains (tepuis) in Venezuela and adjacent areas of Brazil and Guyana, at elevations between 750 m and more than 2,600 m. s e l e c t e d l o c a l i t i e s (Map 317): GUYANA: Cuyuni-Mazaruni, Mount Roraima, summit (type locality of Rhipidomys Macconnelli de Winton). VENEZUELA: Amazonas, Cerro Aracamuri, Cumbre Sur (MBUCV, in litt.), Cerro de Tamacuare (Ojasti, Guerrero, and Hernández 1992), Cerro Duida, Cabecera del Caño Culebra (USNM 406078), Cerro Neblina, Camp VII (USNM 560837); Bolívar, Acopán-tepuí (AMNH 176308), Auyán-tepuí (type locality of Thomasomys macconnelli subnubis Tate), km 125, 85 km SSE of El Dorado (USNM 387934). s u b s p e c i e s : Rhipidomys macconnelli is monotypic (see Remarks). n a t u r a l h i s t o ry: Rhipidomys macconnelli inhabits very moist cloud forest and dwarf vegetation on the tepuis and the evergreen forests surrounding them, where it occurs principally on the ground and on cliffs, making runways under rocks and trees (Handley 1976). Further habitat data may be found in Handley (1976), Guerrero et al. (1989), and Ojasti et al. (1992). From the large series collected, particularly on Cerro Duida, Auyán-tepui, and Roraima, R. macconnelli appears to be a common animal on the tepuis. The animals’ molar teeth, even when relatively

unworn, acquire a thick tartar coating, more so than in most other Rhipidomys specimens. Museum specimens also show a considerable ectoparasite load of louse nits and carpet-beetle egg cases. For parasites, see Furman (1972a, 1972b), P. T. Johnson (1972), E. K. Jones et al. (1972), Machado-Allison and Barrera (1972), Tipton and Machado-Allison (1972), Brennan and Reed (1974a), Saunders (1975), and Brennan and Goff (1977) . Guerrero (1985) listed the ectoparasites recorded from all species of Venezuelan Rhipidomys. r e m a r k s : Rhipidomys macconnelli is the sole member of the “macconnelli” section of the genus. Its generic allocation remained uncertain for many years because of the conflicting evidence of its Thomasomys-like external characters and Rhipidomys-like cranial morphology. Originally described as a Rhipidomys by de Winton in 1900, it was regarded as an aberrant form by Thomas (1906c), who later transferred the species to Thomasomys without explanation (Thomas 1917d). This arrangement was generally accepted for the next four decades until Hershkovitz (1959a) equally summarily restored macconnelli to Rhipidomys. His judgment was confirmed by the species’ lack of a gall bladder (Voss 1991a) and by its karyotype (2n = 44, FN = 50; Aguilera et al. 1994), which ally it with other Rhipidomys species rather than with Thomasomys. Cladistic analyses based on molecular (M. F. Smith and Patton 1999) and morphological (Pacheco 2003) data corroborate this. Tate’s (1939) description of a subspecies (subnubis) appears to have been founded on individual and clinal variation within the Auyán-tepui populations.

Map 317 2,000 m.

Selected localities for Rhipidomys macconnelli (●). Contour line =

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 605

Rhipidomys macrurus (P. Gervais, 1855) Cerrado Rhipidomys sy n o n y m s : Hesperomys leucodactylus Wagner, 1845a:147; not Hesperomys (Rhipidomys) leucodactylus Tschudi; type locality: “Rio Parana,” Porto do Rio Paraná [= Igarapava], São Paulo, Brazil. Mus (Hesperomys) macrurus P. Gervais, 1855:111, plate 16, Figs. 1, 1a; type locality “Trixas” [misspelling of Crixás], Goiás, Brazil. Hesperomys macrourus P. Gervais, 1855:112; incorrect subsequent spelling of macrurus P. Gervais. [Hesperomys (Rhipidomys)] macrurus: E.-L. Trouessart, 1880:136; name combination. Rh[ipidomys]. macrurus: Thomas, 1896:303; first use of current name combination. Rhipidomys mastacalis macrurus: Cabrera, 1961:423; name combination. d e s c r i p t i o n (amended from Tribe 1996, including his Rhipidomys sp. 2 and excluding specimens from the Serra da Ibiapaba reassigned herein to R. mastacalis): Medium sized (head and body length 125–145 mm, somewhat larger in southwestern part of range) with dull, reddish gray brown dorsal pelage; under parts white or pale cream, frequently with gray bases to hairs. Tail slightly longer than head and body length (100–120%, occasionally up to 140%) and terminates in pencil usually 5–15 mm long; tail medium to dark reddish brown, occasionally paler on proximal half. Ears large and medium brown in color. Hindfeet moderate in length (mostly 24–28 mm, but up to 33 mm in southwest), relatively broad and robust; dark dorsal patch either distinctly outlined or diffuse, either narrow or broad, occasionally extending onto digits; sides of feet and digits golden. Phallic morphology described and illustrated by Hooper and Musser (1964). Skull with short rostrum and small zygomatic notches in dorsal view; supraorbital edges squared or slightly ridged and, except in larger specimens, curved rather than straight, providing general rounded appearance to interorbital region, which is narrower than in neighboring species; braincase of average breadth and rounded, becoming more angular and flattened with age; incisive foramina roughly pear-shaped, broadening posteriorly, and palatal bridge short and broad; auditory bullae range from relatively small in southwest to moderately large elsewhere; carotid circulation pattern derived (small stapedial foramen, no internal groove on squamosal and alisphenoid, no sphenofrontal foramen). Maxillary toothrow length moderate to large in comparison with skull length and between 4.8–5.4 mm long in most of species’ range; up to 5.8 mm in southwestern part. d i s t r i b u t i o n : Rhipidomys macrurus is found in gallery forests and patches of woodland throughout most

of the Cerrado domain in Brazil, from southern Piauí state, where it has also been captured just within the Caatinga domain (M. A. N. Sousa 2005), south through eastern Tocantins state, western and central Bahia (including the semideciduous woods of the Rio São Francisco basin), Goiás, the Distrito Federal, northern and western Minas Gerais, northern and western São Paulo, and Mato Grosso do Sul. Specimens from eastern Paraguay were confirmed as R. macrurus by de la Sancha et al. (2011). s e l e c t e d l o c a l i t i e s (Map 318): BRAZIL: Bahia, Andaraí, Fazenda Santa Rita (B. M. de A. Costa 2007), São Marcelo, Rio Preto (FMNH 21162); Goiás, Anápolis (MNRJ 4323), Crixás (type locality of Mus (Hesperomys) macrurus P. Gervais), Serra da Mesa, 20 km NW of Colinas do Sul (MNRJ 36449); Mato Grosso do Sul, Maracaju (MNRJ 4296), RPPN Cabeceira do Prata (MNRJ 69787); Minas Gerais, Caratinga, Fazenda Montes Claros (B. M. de A. Costa 2007), Coronel Murta, Ponte do Colatino, left bank Rio Jequitinhonha (B. M. de A. Costa 2007), Lavras (Mesquita 2009); Piauí, Caracol, Parque Nacional da Serra das Confusões (M. A. N. Sousa 2005), Estação Ecológica de Uruçuí-Una (MZUSP 30388); São Paulo, Itararé, Fazenda Ibiti (P. S. Martin et al. 2009), São José do Rio Preto (USNM 460533); Tocantins, Lajeado, Fazenda Santa Helena (MNRJ 76732). PARAGUAY: Amambay, Parque Nacional Cerro Corá (USNM 554544); Canindeyú, Sendero Morotí, Reserva Mbaracayú (de la Sancha et al. 2011). s u b s p e c i e s : As currently understood, R. macrurus is monotypic (but see comments under Remarks). n a t u r a l h i s t o ry: Rhipidomys macrurus typically inhabits the gallery forests lining rivers through the savanna-like cerrados of Brazil, as well as areas of woodland savanna (cerradão) and semideciduous forest. Mares, Braun, and Gettinger (1989) and Mares and Ernest (1995) provided ecological and population data for the species near Brasília; Gettinger (1992a, 1992b) reported on parasites from there. Mesquita (2009) gave details of the use of space by R. macrurus in a mosaic of cerrado, woodland, and farmland near Lavras, Minas Gerais state, where the species was relatively abundant. It was very abundant in semideciduous woodland in western Mato Grosso do Sul state, where Milano (2007) studied its population ecology and use of space. Bonvicino and Bezerra (2003) and Carmignotto and Aires (2011) reported specimens captured inside houses in southwestern Bahia and eastern Tocantins states, respectively. Dietz (1983) gave brief notes on the natural history of R. macrurus (as “R. mastacalis”) in the Serra da Canastra National Park, Minas Gerais; parasites from there were described by Whitaker and Dietz (1987). M. F. S. Ribeiro et al. (2004) gave some details of water physiology in a specimen (reported as Rhipidomys mastacalis)

606 Mammals of South America

from mesic forest at Morro do Chapéu (central Bahia; see Remarks). r e m a r k s : Rhipidomys macrurus is a member of the “leucodactylus” section of the genus. Because the holotype of R. macrurus, collected by Castelnau and Deville in May 1844 (P. Gervais 1855), has not been located in the MNHN collections, the identity of this taxon is based on the hypothesis that the type locality (Crixás, Goiás), now deforested, falls within the range of this species of Rhipidomys as understood herein. A second specimen collected by Castelnau and marked “Co-type” [BM 49.10.15.32 (skin); 49.12.8.4 (skull)] has the provenance “Bahia”; this may mean that it was collected elsewhere but shipped from Bahia, where Castelnau was French consul from 1848, but equally there is no indication that it was collected at the type locality. Indeed, in his description of Rhipidomys macrurus, P. Gervais (1855) made no mention of a second specimen. Because eastern Brazilian species of Rhipidomys are morphologically very similar, there is no guarantee that the two specimens represent the same species, let alone the same population. No other specimens are known from that area. Work is in progress to select a suitable specimen to be designated as a neotype for Rhipidomys macrurus in order to clarify the identity of the taxon and ensure stability of usage (Tribe et al., in prep.). The specimen selected must not only be consistent with what is known of the geographical origin and morphology of the holotype, but also must agree in karyotype and DNA sequences with specimens assigned to R. macrurus (sensu stricto), given the importance of such evidence for species distinctions in eastern Brazil, as outlined herein. Cabrera (1961) placed all Rhipidomys smaller than R. leucodactylus from Brazil, the Guianas, and Venezuela as subspecies of R. mastacalis, reflecting the difficulty in unambiguously distinguishing between them on morphological evidence alone. The advent of karyotyping revealed a dichotomy in fundamental number (number of autosomal arms) in eastern Brazilian Rhipidomys, with specimens with 2n = 44, FN ≥ 70, being associated with the name R. mastacalis, and those with the same diploid number but FN = 48– 52, with R. macrurus (Zanchin, Langguth, and Mattevi 1992; Svartman and Almeida 1993a; Tribe 1996; M. A. N. Sousa 2005; L. G. Pereira and Geise 2007; Thomazini 2009; A. H. Carvalho et al. 2012). Accordingly, the population of Rhipidomys in the Serra da Ibiapaba, western Ceará state, tentatively included in R. macrurus by Tribe (1996, 2005), is here provisionally reassigned to R. mastacalis on the basis of its karyotype with FN = 70 (M. A. N. Sousa 2005). B. M. de A. Costa et al. (2011) also pointed out morphological differences between this population and R. macrurus from farther south in the cerrado domain, and

an mtDNA phylogeny (Thomazini 2009) suggests it belongs to a clade comprising R. emiliae, R. ipukensis, and R. mastacalis. Specimens from Morro do Chapéu, central Bahia, have yielded fundamental numbers of 56 (A. L. G. Souza et al. 2007b) and 61 (M. J. de J. Silva and Yonenaga-Yassuda 1999); they may belong to the as-yet-unnamed clade mentioned below. They are sympatric with, and morphologically distinct from, a specimen referred to R. cariri (see that account). The fundamental number of 61 is intermediate between the numbers typical of R. mastacalis (FN ≥ 70) and of R. cariri and R. macrurus (FN = 48–52), suggesting that that particular specimen might be an interspecific hybrid (M. J. de J. Silva and Yonenaga-Yassuda 1999). Recent work with molecular data has uncovered further diversity, separating additional species from the concept of R. macrurus employed by Tribe (1996), some of them overlapping geographically (L. P. Costa 2003; B. M. de A. Costa 2007; Thomazini 2009; B. M. de A. Costa et al. 2011; R. G. Rocha, Ferreira, Costa et al. 2011). For example, B. M. de A. Costa et al. (2011) have formalized the form found in Atlantic Forest of São Paulo and Rio de Janeiro states as R. itoan. Specimens from generally drier areas in central and western Bahia, northern and eastern Minas Gerais, northern Goiás, and southeastern Tocantins form a sister clade to Rhipidomys cariri, and together they are related to Rhipidomys macrurus (sensu stricto). This more inclusive clade is the sister clade to all other Brazilian Rhipidomys (L. P. Costa 2003; B. M. de A. Costa 2007; B. M. de A. Costa et al. 2011). The asyet-undescribed form is retained here within R. macrurus pending formal description. Conversely, the same molecular studies and that of de la Sancha et al. (2011) demonstrate that the population from western Mato Grosso do Sul and eastern Paraguay belongs within R. macrurus (s.s.), although on morphological and morphometric grounds (not least its larger overall size and molar row length) Tribe (1996) considered it to represent a separate species. Clearly, considerable further research is needed to elucidate the status of all the forms included here in R. macrurus. The specimen collected by Johann Natterer at Porto do Rio Paraná (now Igarapava, on the northern border of São Paulo state) and named Hesperomys leucodactylus by Wagner (1845a) was allocated to R. mastacalis by Tribe (1996) on biogeographical grounds. The distribution of the specimens used in the molecular studies mentioned herein suggests that Natterer’s specimen should be reallocated to R. macrurus. Regarding the invalidity of the species name leucodactylus Wagner, see the Remarks section under R. leucodactylus.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 607

Map 318

Selected localities for Rhipidomys macrurus (●).

Rhipidomys mastacalis (Lund, 1840) Northern Atlantic Forest Rhipidomys sy n o n y m s : [Mus] mastacalis Lund, 1839a:233; nomen nudum. Mus mastacalis Lund, 1840a:24 [1841b:240]; type locality “Rio das Velhas’s Floddal” (Lund 1841b:264, 266), Lagoa Santa, Minas Gerais, Brazil. Mus mustacalis Lund, 1840b:7 [1841c:279]; incorrect subsequent spelling of mastacalis Lund. Mus mystacalis Wagner, 1843b:750; incorrect subsequent spelling of mastacalis Lund. Mus maculipes Pictet and Pictet, 1844:67; type locality “Bahia,” Brazil. Mus masculipes Burmeister, 1854:185; incorrect subsequent spelling of maculipes Pictet and Pictet. H[esperomys (Calomys)]. mystacalis Burmeister, 1855a:7; part; name combination and incorrect subsequent spelling of mastacalis Lund. H[esperomys (Calomys)]. maculipes: Burmeister, 1855a:8; name combination. [Hesperomys (Rhipidomys)] mastacalis: E.-L. Trouessart, 1880:136; name combination. Rhipidomys mastacalis: Winge, 1887 [1888]:54; first use of current name combination. [Oryzomys] musculipes E.-L. Trouessart, 1897:528; incorrect subsequent spelling of maculipes Pictet and Pictet and name combination. Rhipidomys cearanus Thomas, 1910c:501; type locality “S[ão]. Paulo, on the top of the Serra [da Ibiapaba], at about 900 metres,” Ceará, Brazil.

Rhipidomys venezuelae cearanus: Gyldenstolpe, 1932:47; name combination. [Oecomys] maculipes: Tate, 1932g:21; name combination. Rhipidomys maculipes: Laemmert, Ferreira, and Taylor, 1946:38; name combination. Rhipidomys mastacalis cearanus: Cabrera, 1961:422; name combination. Rhipidomys mastacalis mastacalis: Cabrera, 1961:423; name combination. Rhipidomys masticalis A. L. Gardner, 1990:412; incorrect subsequent spelling of mastacalis Lund. Rhipidomys masatacalis Voss and Myers, 1991:428; incorrect subsequent spelling of mastacalis Lund. d e s c r i p t i o n : Medium sized (head and body length 125–145 mm) with gray-brown to more intensely redbrown dorsal pelage and cream or white under parts. Tail moderate to long (120–140% of head and body length), light to dark brown, with short hairs proximally but longer ones on distal half, and with short to moderatelength pencil. Ears medium to large, usually medium brown. Hindfeet broad, medium in length (26–29 mm), with medium to dark brown dorsal patch, often broad and ill-defined, which does not extend onto toes; sides of foot and toes pale. Skull with moderately long, relatively slender rostrum; nasals taper regularly from anterior to posterior; supraorbital ridges straight, diverging from front of interorbital region; braincase not greatly inflated or rounded; incisive foramen narrow; palatal bridge long and narrow; carotid circulatory pattern derived (small stapedial foramen, no internal groove on squamosal and alisphenoid, no sphenofrontal foramen). Maxillary toothrow of moderate length for size of skull, averaging about 5.0 mm. d i s t r i b u t i o n : Rhipidomys mastacalis is found in the Atlantic rainforest of eastern Brazil, from the state of Paraíba in the north along the coastline to eastern Rio de Janeiro state in the south, and also inland on the Chapada Diamantina plateau of central Bahia and in eastern and central Minas Gerais. Apparently isolated populations in western Ceará and northern Goiás are also provisionally referred to this species. s e l e c t e d l o c a l i t i e s (Map 319): BRAZIL: Alagoas, Anádia, Sítio Vale Verde (MNRJ 17450); Bahia, Fazenda Unacau, 8 km SE of São José (UFPB 425), Palmeiras, Pai Inácio (MNRJ 67751), São Felipe (MNRJ 22274); Ceará, Ibiapina, Sítio Pejuaba (MNRJ 17401); Espírito Santo, Linhares (MNRJ 34492); Goiás, Serra da Mesa, 40 km NE of Uruaçu (MNRJ 37350); Minas Gerais, Brumadinho, Rio Manso (UFMG 1649), Diamantina, Conselheiro Mata (B. M. de A. Costa 2007), Salinas (MNRJ 30015); Paraíba, Areia, Mata do Pau-Ferro (UFPB 3864); Pernambuco, Garanhuns, Sítio Cavaquinho (MNRJ 12500); Rio de Janeiro,

608 Mammals of South America

Fazenda União, Casimiro de Abreu (MNRJ 46803); Sergipe, south of Estância (Stevens and Husband 1998). s u b s p e c i e s : Rhipidomys mastacalis is monotypic. n a t u r a l h i s t o ry: Rhipidomys mastacalis occurs in remnants of Atlantic forest in eastern Brazil, including both highland enclaves (brejos de altitude) and lowland forest in the northeast (M. A. N. Sousa et al. 2004; Asfora and Pontes 2009), and less-moist forests in eastern Minas Gerais. It is also sometimes caught in the roofs of houses (data from specimen tags). Most captures of this species in forest fragments in Sergipe occurred well inside the fragments (Stevens and Husband 1998). About 59% of a large series of R. mastacalis collected for yellow fever research in the vicinity of Ilhéus, Bahia, was taken in young forest, 21% in old forest and 9% in swamp forest; Rhipidomys proved to be less important as a host for the virus than most rodents (Laemmert et al. 1946). Near Caruaru, Pernambuco, R. mastacalis was captured mainly in hillside forest both in trees and on the ground; only two females out of 17 collected were pregnant in October to December (M. A. N. Sousa et al. 2004). Cerqueira, Vieira, and Salles (1989) analyzed habitat and reproductive data for a population in the Serra da Ibiapaba (western Ceará state; see Remarks). Rhipidomys mastacalis is implicated in damage to cacao in southern Bahia, where it is relatively common in and around plantations (Cruz 1983; Cassano and Moura 2004; Pardini 2004). T. Araújo et al. (2006) described behavior in captivity. For parasites, see F. Fonseca (1959) and Hastriter and Peterson (1997). r e m a r k s : Rhipidomys mastacalis is a member of the “leucodactylus” section of the genus. Having once been applied to Rhipidomys specimens from much of northern and eastern South America (Cabrera 1961), the name R. mastacalis is now restricted to a taxon occupying a moderately small range in eastern Brazil. This change was due not only to morphological reassessments (Musser and Carleton 1993; Tribe 1996), but especially to the results of karyotype analyses and molecular phylogeographic studies (Zanchin, Langguth, and Mattevi 1992; Svartman and Almeida 1993a; L. P. Costa 2003; B. M. de A. Costa 2007; Thomazini 2009; B. M. de A. Costa et al. 2011; R. G. Rocha, Ferreira, Costa et al. 2011). See also the Remarks under Rhipidomys macrurus. The karyotype of R. mastacalis has the same diploid number (2n = 44) as the majority of other Rhipidomys species, but it has a higher fundamental number (FN ≥ 70) than other eastern Brazilian forms. On the assumption that this combination of diploid and fundamental numbers characterizes a monophyletic group, certain specimens from Serra da Mesa in northern Goiás state with FN = 76 and 80 (Andrades-Miranda, Oliveira et al. 2002) are here provi-

sionally referred to R. mastacalis, although they may well represent a distinct species (see also the Remarks under R. ipukensis). They are sympatric with low-FN specimens referred here to R. macrurus. Additionally, the population of Rhipidomys in the highland forest enclave in the Serra da Ibiapaba, western Ceará, which Tribe (1996, 2005) tentatively referred to R. macrurus on morphological grounds, is here provisionally reallocated to R. mastacalis because the first known karyotype from that population (with FN = 70) appears to be identical to that of R. mastacalis from eastern Pernambuco and Bahia (M. A. N. Sousa 2005). A phylogeny based on mitochondrial cytochrome oxidase I sequences places a specimen from Ibiapaba as a distant basal member of a clade allying R. emiliae and R. ipukensis, to which R. mastacalis forms the sister clade (Thomazini 2009). The Rhipidomys populations inhabiting isolated mesic forests (brejos) within the Caatinga domain of northeastern Brazil thus appear to be split between R. mastacalis (high FN) in the more peripheral enclaves and R. cariri (low FN) in the more central ones. Whereas specimens from the brejos in eastern Pernambuco are closely allied to R mastacalis from the coastal Atlantic Forest (Thomazini 2009), the Serra da Ibiapaba population on the far side of the Caatinga is more distantly related. Should further work demonstrate that the population in the Serra da Ibiapaba deserves species status, the name cearanus Thomas is available. The identity of specimens from Serra Negra, western Pernambuco, reported by Botêlho et al. (2001,

Map 319 Selected localities for Rhipidomys mastacalis (●); note isolated populations in central and northeastern Brazil.

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 609

2003) as “Rhipidomys cearanus” in a study of ectoparasites, has not been verified; they may represent either R. mastacalis or R. cariri.

Rhipidomys modicus Thomas, 1926 Lesser Peruvian Rhipidomys sy n o n y m s : Rhipidomys modicus Thomas, 1926g:161; type locality Pucatambo (“Puca Tambo, 5100 [feet]”), San Martín, Peru. Rhipidomys leucodactylus modicus: Cabrera, 1961:422; name combination as subspecies. d e s c r i p t i o n : Medium to large (head and body length 130–165 mm) with medium to dark yellowish to reddish brown agouti dorsal coloration, well streaked with dark guard hairs, and rather coarse and short; ventral pelage with white-tipped fur with very pale to dark gray bases; orange pectoral spot sometimes present. Tail long (up to 135% of head and body length) and medium to dark brown; shaft lightly haired and terminating in pencil that rarely exceeds 15 mm. Ears rather small. Hindfeet moderately large (28– 30 mm) and broad, with broad dark patch on dorsal surfaces that sometimes extends onto digits. Skull moderate in size and robustness; rostrum short and somewhat pointed; nasals taper gradually along length; zygomatic plates not broad and notches small; supraorbital ridges squared rather than raised, diverging strongly posteriorly; interorbital region broad, with narrowest point forward; braincase oval, moderately broad, and not greatly flattened, although interparietal oriented more dorsally than posteriorly; mesopterygoid fossa broad and penetrating between hypocones of M3s; auditory bullae small; carotid circulation pattern derived (small stapedial foramen, no internal squamosalalisphenoid groove, no sphenofrontal foramen). Maxillary toothrow 5.5–5.8 mm in length, comparatively long for size of skull. d i s t r i b u t i o n : Rhipidomys modicus is known from eastern Andean valleys in northern and central Peru, at elevations between 700 and 1,800 m. Collecting localities for R. modicus in central Peru are identical with or close to localities where specimens of R. leucodactylus have been taken. s e l e c t e d l o c a l i t i e s (Map 320): PERU: Amazonas, 12 km E of La Peca Nueva (LSUMZ 21873); Huánuco, Chinchavito (BM 27.11.1.130); Junín, Chanchamayo (BM 7.6.15.13); San Martín, Moyobamba (FMNH 19363), Pucatambo (type locality of Rhipidomys modicus Thomas). s u b s p e c i e s : Rhipidomys modicus is monotypic. n a t u r a l h i s t o ry: The holotype was “trapped in brush near stream,” and the specimen from Chinchavito was trapped in an abandoned shed (specimen tags). r e m a r k s : Rhipidomys modicus is a member of the “leucodactylus” section of the genus. It is substantially

Map 320 Selected localities for Rhipidomys modicus (●) and Rhipidomys ochrogaster (ᇲ). Contour line = 2,000 m.

smaller than R. leucodactylus in external dimensions, skull length, and molar row length, and appears to occur sympatrically with the latter species in at least part of its range. Specimens exhibit considerable variation in the extent of gray bases to their ventral pelage, even at a single locality.

Rhipidomys nitela Thomas, 1901 Guianan Rhipidomys sy n o n y m s : Rhipidomys nitela Thomas, 1901e:148; type locality Kwatata, Kanuku Mountains, Upper Takutu–Upper Essequibo, Guyana (see Remarks). Rhipidomys venezuelæ fervidus Thomas, 1904d:34; type locality “La Unión, lower Orinoco,” Caura valley, Bolívar, Venezuela. Rhipidomys venezuelæ yuruanus J. A. Allen, 1913c:601; type locality “Río Yuruán, [Bolívar], Venezuela.” Rhipidomys milleri J. A. Allen, 1913c:602; type locality “Minehaha Creek (altitude 500 feet), Lower Essequibo River, British Guiana.” R[hipidomys]. v[enezuelae]. nitela: J. A. Allen, 1913c:602; name combination. Rhipidomys venezuelae milleri: Gyldenstolpe, 1932:47; name combination. Rhipidomys mastacalis nitela: Cabrera, 1961:423; name combination. Rhipidomys mastacalis fervidus: Cabrera, 1961:423; name combination.

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Rhipidomys nitela tobagi Goodwin, 1961:16; type locality ”Little Tobago, the West Indies,” Little Tobago Island, Trinidad and Tobago. R[hipidomys]. n[itela]. milleri: Goodwin, 1961:16; name combination. d e s c r i p t i o n : Small to medium sized (head and body length typically 110–140 mm) with soft, short, dull gray brown to richer reddish or orange brown dorsal pelage; ventral fur short and creamy white to roots or with inconspicuous pale gray hair bases. Tail moderately long (110–140% of head and body length) with short to medium terminal pencil 5–15 mm in length. Ears pale to dark and moderately large in size, sometimes with pale postauricular patch. Hindfeet short (24–27 mm) and slender, with small plantar pads and dorsal dark patch of varying distinctness rarely extending onto digits. Skull small with short, rather blunt rostrum; interorbit broad with squared or ledged edges, sometimes raised; braincase oval, not inflated, and flattened in older individuals; incisive foramina usually narrow and almost elliptical in shape; mesopterygoid fossa narrow and parapterygoid fossae may be fenestrated; auditory bullae small; carotid circulation pattern derived (small stapedial foramen, no internal groove on squamosal and alisphenoid, and no sphenofrontal foramen). Maxillary toothrow short, between 3.8–5.0 mm in length, but average in size for genus in comparison with skull length. d i s t r i b u t i o n : Rhipidomys nitela as understood here occurs at lower elevations (below 1,400 m) throughout the Guiana Highlands and adjacent forested lowlands in the region bounded by the Orinoco, Negro, and lower Amazon rivers and the Atlantic coast. Specimens found on the island of Little Tobago, northeast of Trinidad, are also referred to this species. s e l e c t e d l o c a l i t i e s (Map 321): BRAZIL: Amapá, 50 km ESE of Porto Grande (MNRJ AN 188); Amazonas, Km 50 Manaus-Itacoatiara road (MNRJ 19614); Pará, Oriximiná, Porto Trombetas, Rio Saracazinho (MPEG 10113); Roraima, Ilha de Maracá (Barnett and Cunha 1998). FRENCH GUIANA: Les Nouragues (MNHN V.890), Paracou (AMNH 267021). GUYANA: Cuyuni-Mazaruni, Kalakun (AMNH 207387); Upper Takutu–Upper Essequibo, Kwatata, Kanuku Mountains (type locality of Rhipidomys nitela Thomas). SURINAM: Para, Matta, 15 km W of Zanderij airport (RMNH 21973). TRINIDAD AND TOBAGO: Tobago, Little Tobago Island (AMNH 184555). VENEZUELA: Amazonas, Cerro Duida, Caño Culebra (USNM 406109); Bolívar, La Unión, Río Caura (BM 4.5.7.34), Río Caroní, Embalse Guri, Isla Panorama (T. D. Lambert et al. 2003), Río Yuruán (type locality of Rhipidomys venezuelae yuruanus), Serranía de los Pijiguaos, 140 km SW of Caicara (Rivas and Linares 2006).

s u b s p e c i e s : As currently understood, Rhipidomys nitela is monotypic, although the population from Little Tobago Island has been regarded as a separate subspecies (Goodwin 1961). n a t u r a l h i s t o ry: Rhipidomys nitela occurs in lowland rainforest, where it is primarily arboreal but also comes down to the ground (Handley 1976, as “R. mastacalis”; Voss 1991a; Voss et al. 2001). Ecological data for the species are provided by Malcolm (1988) near Manaus in the central Amazon (see Remarks), and by Mauffrey (1999) and Mauffrey and Catzeflis (2002) at Les Nouragues, French Guiana. According to specimen tags and published reports, R. nitela is often found in the rafters or thatched roofs of buildings ( J. A. Allen 1911; Husson 1978; Barnett and Cunha 1998; Lim, Engstrom, Genoways et al. 2005). Specimens from Sinnamary (French Guiana) and Bonda (northern Colombia; see Remarks) were shot in bat roosts (Voss et al. 2001; L. Roguin, pers. comm.). For parasites, see Brennan and Yunker (1969), Furman and Tipton (1961), and Gettinger, Martins-Hatano et al. (2005). r e m a r k s : Rhipidomys nitela is a member of the “leucodactylus” section of the genus. The type locality given in the published report (Thomas 1901e:149) and the locality recorded in the accession register of the Natural History Museum, London, for the whole type series is “Kwaimattat, Kanuku Mts.”; the labels attached to all the skins, however, are marked “Quatata [or “Quatatat”], Kanuku Mts., B. Guiana, 240’ [feet].” Kwaimattat and Quatatat, now spelled Kwaimatta and Kwatata, are localities 27 km apart in the savannas north of the Kanuku Mountains in Guyana. Kwatata is here selected as the type locality, because the data accompanying the original material (in this case the specimen tags) should be taken into account first when a type locality is clarified (ICZN 1999:Recommendation 76A). Specimens from northern Bolívar state, Venezuela, including the holotypes of Rhipidomys venezuelae fervidus and R. v. yuruanus, tend to be larger and more intensely pigmented than most other Rhipidomys nitela specimens, and their skulls are more elongated with strong supraorbital ridges. They are retained here within R. nitela because the differences in character states do not appear to be consistent enough for taxonomic separation. Specimens from south of the Amazon considered by Tribe (1996) to be Rhipidomys nitela are here referred to R. emiliae (see that account); these include the “R. nitela” sequenced by M. F. Smith and Patton (1999) and by L. P. Costa (2003). A single specimen from the isolated northern Colombian locality of Bonda, which Tribe (1996) allocated to R. nitela, was considered by Voss et al. (2001:127) to represent another taxon; in line with

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 611

their judgment, it is here regarded as belonging to an as yet undescribed species of Rhipidomys. Less convincing is their suggestion that the specimens from Little Tobago possibly “represent an insular form of the adjacent mainland species R. venezuelae” (Voss et al. 2001:127): the nearest part of the known range of R. venezuelae (in Estado Guárico, Venezuela) lies farther away from Little Tobago than that of R. nitela (in Estado Bolívar, Venezuela, and in Guyana), and the Little Tobago specimens cluster morphometrically with R. nitela and not with R. venezuelae (Tribe 1996). Additional material from the northern coast of South America and adjacent islands is clearly needed to resolve these relationships fully. Rhipidomys nitela is the only species of the genus so far karyotyped to have a diploid number other than 2n = 44, with reports of 2n = 48 from southeast Venezuela (Voss et al. 2001); 2n = 48, FN = 68, from Roraima state, Brazil (Andrades-Miranda, Oliveira et al. 2002); 2n = 48, FN = 71, from French Guiana (Volobouev and Catzeflis 2000); and 2n = 50, FN = 71 and 72, from near Manaus (M. J. de J. Silva and Yonenaga-Yassuda 1999, as Rhipidomys sp. B). Based on banding analysis, Volobouev and Catzeflis (2000) found considerable differences between the French Guiana and Manaus karyotypes, leading them to question the taxonomic status of the latter population. Pending further study, specimens from near Manaus are here provisionally retained in R. nitela.

Map 321 Selected localities for Rhipidomys nitela (●); note insular population on Little Tobago Island northeast of Trinidad. Contour line = 2,000 m.

Phylogenetic analyses based on mtDNA cytochrome-b sequences place specimens of R. nitela from French Guiana as the sister group to a clade consisting of R. mastacalis, R. ipukensis, and R. emiliae (R. G. Rocha, Ferreira, Costa et al. 2011). More extensive molecular analyses of R. nitela specimens are needed to elucidate the diversity contained within the species as understood here.

Rhipidomys ochrogaster J. A. Allen, 1901 Buff-bellied Rhipidomys sy n o n y m : Rhipidomys ochrogaster J. A. Allen, 1901b:43.; type locality “Inca Mines, Peru (alt. 6000 feet),” Santo Domingo, Río Inambari, Puno, Peru. d e s c r i p t i o n : Large (head and body length 152– 176 mm), long-tailed (length 198–228 mm) species with orange-brown dorsal fur and pale orange or melon-colored ventral fur. Tail dark, considerably longer than head and body (125–148%), and terminates in long pencil of hairs (20 mm long in holotype). Hindfeet moderately long (34– 35 mm) and broad, with metatarsal patch extending onto first phalanges of toes. Skull moderately large, with rather narrow and pointed rostrum, broad interorbital region, and broad, rounded braincase; supraorbital shelf well developed and divergent posteriorly; postorbital ridges absent or weak; zygomatic plates narrow; carotid circulation pattern primitive (pattern 1, of Voss 1988), characterized by large stapedial foramen, squamosal-alisphenoid groove visible but not strong, and sphenofrontal foramen. Upper molar row long (6.1–6.3 mm), large in comparison to skull length for genus. Pacheco and Peralta (2011) provided photographs depicting external appearance (including dorsal, lateral, and ventral views of freshly dead specimen, dorsal and ventral views of hindfoot, and tail tip) as well as skull and both molar series in comparison with R. gardneri and R. leucodactylus. d i s t r i b u t i o n : Only five specimens of Rhipidomys ochrogaster are known from two localities in southeastern Peru at elevations between 1,200 and 1,940 m. Four of these are from the vicinity of the type locality in the upper Río Inambari drainage at the base of the Cordillera de Carabaya, and the fifth from the valley of the Río Tambopata. s e l e c t e d l o c a l i t i e s (Map 320): PERU: Puno, Santo Domingo (type locality of Rhipidomys ochrogaster J. A. Allen), Yanacocha, valley of Río Tambopata (Pacheco and Peralta 2011). s u b s p e c i e s : Rhipidomys ochrogaster is monotypic. n a t u r a l h i s t o ry: J. A. Allen (1900a:219) described the type locality (erroneously referred to as Juliaca; see J. A. Allen 1901b:41), quoting the collector H. H. Keays: “The country is very broken, with deep

612 Mammals of South America

narrow cañons, and is covered with a dense undergrowth of shrubs and vines, with here or there a palmetto or a cedar rising above the surrounding vegetation.” The recent specimen from the Río Tambopata drainage (Pacheco and Peralta 2011) was collected in a forest of slender trees of 15 m maximum height, dense understory, and forest floor covered with deep soil litter. Plant species included Ilex sp. (Aquifoliaceae), Viburnum sp. (Adoxaceae) Miconia sp. (Melastomataceae), Myrsine sp. (Myrsinaceae), Myrcia sp. (Myrtaceae), Clusia sp. (Clusiaceae), Cecropia sp. (Urticaceae), and Clethra sp. (Clethraceae). This habitat corresponds to the Yungas, the humid montane forest that flanks the eastern slope of the eastern cordillera of the Andes in southern Peru and Bolivia (Young and Leon 1999; Tovar Narváez et al. 2010). Pacheco and Peralta (2011) proposed that the species be classed as Endangered on account of the increasing deforestation of Yungas habitats in Puno department. Stomach contents of the Yanacocha specimen included both seeds and ants (Pacheco and Peralta 2011). r e m a r k s : Rhipidomys ochrogaster is by far the largest member of the “fulviventer” section of the genus (not the “leucodactylus” section, as stated by Musser and Carleton 2005:1171), to which it clearly belongs on morphological grounds (see Key to the species of Rhipidomys). There is a gap of approximately 1,300 km along the Andean chain from the nearest other known members of the section, which were recently discovered in Amazonas department in northern Peru (C. F. Jiménez and Pacheco 2012; see Remarks under Rhipidomys fulviventer). Although the capture elevation of the holotype is given as “6800 ft” (2,075 m) on the specimen tag (AMNH 16481), the figure given in the published type description (“6000 feet,” 1,830 m) is more plausible according to maps of the locality.

Rhipidomys similis J. A. Allen, 1912 Greater Colombian Rhipidomys sy n o n y m s : Rhipidomys similis J. A. Allen, 1912:79; type locality “Cocal, Cauca, Colombia. Altitude, 6000 feet.” Rhipidomys latimanus similis: Cabrera, 1961:419; part; name combination. d e s c r i p t i o n : Moderately large with head and body length 125–155 mm and long tail measuring 125% to 150% of head and body length. Dorsum reddish brown to yellowish rufous lined with black, and somewhat darker medially than more orange yellow sides; ventral pelage cream or more usually pale orange hair tips over long, dark gray bases. Tail covered with black hairs, nearly concealing annular scales, and terminates in a pencil. Ears dull brown. Hindfeet moderately long (29–31 mm) and broad. Skull

with rounded interorbital region with slightly developed supraorbital ridges, and broad, rounded braincase; mesopterygoid fossa expanded at anterior end; sphenopalatine vacuities small to medium; parapterygoid fossae fenestrated; carotid circulation pattern primitive (large stapedial foramen, groove on inner surface of squamosal and alisphenoid, and sphenofrontal foramen). Maxillary toothrow larger than average for genus in comparison to skull length, ranging from 5.0–5.4 mm. d i s t r i b u t i o n : Rhipidomys similis is restricted to the Andes of southwestern Colombia. It is known from high elevations on both versants of the Western Cordillera in the departments of Cauca and Valle del Cauca, and from the mountains at the head of the Magdalena valley, department of Huila, including parts of the Central and Eastern Cordilleras. It is likely to occur in the knot of mountains connecting the three cordilleras in Cauca and Nariño departments and may also extend farther north along the Western and Central Cordilleras. s e l e c t e d l o c a l i t i e s (Map 312): COLOMBIA: Cauca, Cocal (AMNH 32458); Huila, Belén (USNM 294984), San Adolfo, Río Aguas Claras (FMNH 71712), San Antonio (FMNH 71716); Valle del Cauca, Pichindé (Alberico 1983). s u b s p e c i e s : Rhipidomys similis is monotypic. n a t u r a l h i s t o ry: Specimens of Rhipidomys similis from the head of the Magdalena valley were found at between 1,600 m and 2,350 m. Specimens from the Western Cordillera were captured at elevations of 2,400 m on the eastern slope and 1,220 to 1,830 m on the cooler, moister western slope, corresponding to the differing elevations of cloud forest on the two versants. The remarkably low elevation of 1,220 m (“4000 ft”) for a specimen from Cocal is possibly an error (see Chapman 1917:31, footnote 2, regarding bird specimens from the same locality). r e m a r k s : Rhipidomys similis is the second largest species in the “fulviventer” section of the genus, after R. ochrogaster. It occurs sympatrically with R. caucensis in Cauca and Huila, and with R. latimanus in Valle, Cauca, and Huila, with its elevational range broadly overlapping that of the former and marginally that of the latter (if at all: see note on Cocal in Natural History section). Tribe (1996) treated the Western Cordillera and Huila units as separate subspecies of Rhipidomys fulviventer; see the Remarks under that species. Specimens allocated by Alberico (1983:65) to R. latimanus are of this species.

Rhipidomys tenuicauda ( J. A. Allen, 1899) Turimiquire Rhipidomys sy n o n y m s : Oryzomys tenuicauda J. A. Allen, 1899b:211; type locality “Los Palmales, [Sucre,] Venezuela.”

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 613

[Rhipidomys] tenuicauda: Tate, 1939:195; first use of current name combination. Phipidomys mastacalis tenuicauda: Cabrera, 1961 423; name combination, and incorrect subsequent spelling of Rhipidomys Tschudi. d e s c r i p t i o n : Small species similar to R. fulviventer, with head and body length 109–128 mm (holotype exceptionally small at 88 mm). Dorsal pelage often bright orange brown agouti, sometimes more chestnut brown; ventral pelage with cream hair tips on middle to dark gray bases. Tail proportionately long (115–140% of head and body length, 145% in holotype), unicolored dark brown, varying from nearly naked at base but with increasingly long hairs distally, terminating in thick pencil about 10 mm long. Ears brown and lightly haired. Hindfeet small (23– 27 mm in length) and narrow, with dorsal dark patch extending to base of toes and buff edges and digits. Skull with rounded interorbital region and slight supraorbital ridges; braincase broad, rounded; lateral processes of parietals narrow posteriorly; parapterygoid fossae sometimes fenestrated; sphenopalatine fissures variable, from long and moderately broad to short and narrow, or absent; carotid circulatory pattern primitive (large stapedial foramen, internal groove along squamosal and alisphenoid, and sphenofrontal foramen). Maxillary toothrow short, 4.2–4.6 mm, average for genus in comparison with skull length; molars proportionately somewhat narrower than average. d i s t r i b u t i o n : Rhipidomys tenuicauda appears to be restricted to the Serranía de Turimiquire of northeastern Venezuela, in the states of Sucre, Monagas, and Anzoátegui. s e l e c t e d l o c a l i t i e s (Map 322): VENEZUELA: Anzoátegui, Cerro La Laguna, cumbre (F. J. García and Sánchez-González 2013); Monagas, San Agustín, 5 km NW of Caripe (USNM 409929). s u b s p e c i e s : Rhipidomys tenuicauda is monotypic. n a t u r a l h i s t o ry: Rhipidomys tenuicauda occurs in premontane humid forest (USNM specimen tags) as well as in coffee and cacao plantations (Tate 1931), at elevations between 945 m and 2,200 m. It may be found at lower elevations than other members of the “fulviventer” section (with the exception of R. wetzeli) because the vegetation zones in the Turimiquire Range lie at substantially lower levels than in the Andes and Venezuelan coastal range farther west (Chapman 1925). Two females captured by the Smithsonian Venezuelan Project had four embryos, and one had five in June–July (USNM specimen tags). For parasites, see Furman (1972a), P. T. Johnson (1972), and Tipton and Machado-Allison (1972). Guerrero (1985) listed the ectoparasites recorded from all species of Venezuelan Rhipidomys.

Map 322 Selected localities for Rhipidomys tenuicauda (ᇲ), Rhipidomys venustus (■), and Rhipidomys wetzeli (●). Contour line = 2,000 m.

r e m a r k s : This member of the “fulviventer” section of Rhipidomys resembles Colombian R. fulviventer in its moderately small size, although the holotype is an unusually small specimen (but with molars of normal size). The xeric lowlands of the Depresión de Unare in Anzoátegui state separate its range from that of the larger R. venustus, which inhabits the higher parts of the Venezuelan coastal range farther west, and by the llanos of the lower Orinoco drainage from the range of the smaller R. wetzeli, found in the region of the tepui inselbergs to the south. Musser and Carleton (2005) considered tenuicauda a subjective junior synonym of R. fulviventer. It is hypothesized here to be a species in its own right on biogeographical grounds, insofar as it is separated from the range of R. fulviventer in the Eastern Cordillera of the Andes by approximately 1,000 km of lowlands and mountains, which are partly occupied by the allied yet distinct form R. venustus. Future molecular data may help to demonstrate whether this chain of forms has resulted from a process of vicariant isolation on mountain blocks.

Rhipidomys tribei B. M. de A. Costa, Geise, Pereira, and L. P. Costa, 2011 Tribe’s Rhipidomys sy n o n y m : Rhipidomys tribei B. M. de A. Costa, Geise, Pereira, and L. P. Costa, 2011:947; type locality “Reserva Particular do Patrimônio Natural Santuário do Caraça, 25 km SW Santa Bárbara, Minas Gerais, Brazil, 20°05′S, 43°30′ W, 1,300 m.”

614 Mammals of South America

d e s c r i p t i o n : Small, with average head and body length of 116.8 mm (observed range: 96–130 mm) and long tail 115–137% of body length. Dorsal pelage yellowish brown to reddish brown; coat comprises short (7–9 mm) tribanded hairs, black at tip, reddish brown or dark yellow in middle, with gray bases; longer guard hairs (11–15 mm) typically black but may bleach to reddish brown with translucent tips; ventral pelage white and distinct from dorsal color, sometimes with small areas of light gray hair at sides of abdomen; dorsal fur extends onto base of tail for maximum of 8 mm; tail unicolored; scales small (0.5– 0.7 mm in length), three hairs emerging from under each one; tail hairs increase in length gradually from tail base to tip, forming short terminal brush or tuft up to 7 mm in length. Ears small to medium, between 16 and 21 mm in length, sparsely covered with short brown hairs on both surfaces. Hindfeet covered dorsolaterally with white hairs that extend onto toes; mid-dorsal surfaces with patch of light brown or gray hairs. Skull with smallest average total length of all Rhipidomys species in southeastern Brazil, with mean condyloincisive length 28.5 mm. Rostrum short (less than one-third length of skull) and somewhat broad (more than one-half rostral length); lacrimal capsules slightly inflated; gnathic process present; nasal bones broad anteriorly, narrowing to posterior margin; nasals not contacting or extending posteriorly beyond maxillofrontal suture; anterior edges of zygomatic plates slightly rounded to rectangular and not protruding anterior to maxillary roots of zygomatic arches; zygomatic notches narrow and rather shallow; dorsal projections of lacrimal bones relatively large, elongated, and laterally expanded; interorbital convergent anteriorly, with slight medial constriction, strongly divergent posteriorly, with usually rounded borders and no supraorbital crest; hamular processes of squamosals separating enlarged subsquamosal fenestrae from smaller postglenoid foramina; slender alisphenoid struts present in all specimens; small stapedial foramen, no translucent groove across the inside of the braincase, and no sphenofrontal foramen signal derived carotid circulatory pattern 3 (of Voss 1988); margins of incisive foramina expanded medially but converging both anteriorly and posteriorly, giving overall diamond shape to opening; foramina extending posteriorly to line joining upper M1 alveoli; mesopterygoid fossa long, with small postpalatal projection, reaching line across posterior margins of M3 alveoli; sphenopalatine vacuities either absent or greatly reduced. Upper incisors slightly opisthodont. Anteroflexus and anteromedian flexus of M1 small and separate anteroloph into anterolabial and anterolingual conules; protoflexus and hypoflexus of M1 typically small. M2 with Protoflexus absent or reduced and hypoflexus short; both paraflexus

and metaflexus long and angled sharply, sometimes slightly bifurcated at their inner ends; medial fossette frequently present on M2, labial fossette usually absent. d i s t r i b u t i o n : Rhipidomys tribei is known from the type locality and two others in southeastern Minas Gerais state, Brazil, at middle elevations up to 1,300 m. Specimens with low-FN karyotypes from the hills of southern Espírito Santo state may be referred to this species. s e l e c t e d l o c a l i t i e s (Map 314): BRAZIL: Espírito Santo, Vargem Alta, Hotel Monte Verde (UFPB 345); Minas Gerais, Santa Bárbara, Reserva Particular do Patrimônio Natural Santuário do Caraça (type locality of Rhipidomys tribei B. M. de A. Costa, Geise, Pereira, and L. P. Costa), Viçosa, Mata do Paraíso (MZUFV 386). s u b s p e c i e s : Rhipidomys tribei is monotypic. n a t u r a l h i s t o ry: Little is known about the ecology of this species. The few available specimens were collected in riparian semideciduous submontane forest patches surrounded by grasslands. The habitat at Serra do Brigadeiro was described by J. C. Moreira et al. (2009). r e m a r k s : As mentioned in the account of R. itoan, this species and R. tribei form a sister-clade pair within the limited phylogeny of Brazilian species that have been compared using mtDNA cytochrome-b sequences. This pair of species, in turn, is sister to sequences of R. leucodactylus within the larger “leucodactylus” section of the genus (B. M. de A. Costa et al. 2011). This is the taxon referred to as “R. sp. 3” by R. G. Rocha, Ferreira, Costa et al. (2011) in their phylogenetic analysis of mtDNA cytochrome-b sequences. Specimens from southern Espírito Santo state herein referred to this species have karyotypes of 2n = 44, FN = 50 (Zanchin, Langguth, and Mattevi 1992; Thomazini 2009).

Rhipidomys venezuelae Thomas, 1896 Venezuelan Rhipidomys sy n o n y m s : Rhipidomys venezuelae Thomas, 1896:303; type locality “Merida, Venezuela, alt. 1630 metres.” R[hipidomys]. v[enezuelae]. typicus Thomas, 1900c:271; nomen nudum; referring to material from the type locality in comparison with his new subspecies Rhipidomys venezuelae cumananus (= Rhipidomys couesi herein). Rhipidomys venezuelae venezuelae: Gyldenstolpe, 1932: 46; name combination. [Rhipidomys] venezuelanus Tate, 1939:195; incorrect subsequent spelling of venezuelae Thomas. Rhipidomys mastacalis venezuelae: Cabrera, 1961: 423; name combination. d e s c r i p t i o n : Medium to large (head and body length usually 130–150 mm) with long tail (110–135% of head and body length); dorsal pelage rich reddish to duller

Suborder Myomorpha: Family Cricetidae: Subfamily Sigmodontinae 615

yellowish brown with slight to moderate agouti effect; sides of head and body generally paler; ventral pelage white or cream colored, sometimes with pale grey bases; pelage relatively soft and fine. Tail pale to medium brown, sometimes darker; shaft covered with short hairs, lengthening only close to tip, and terminal pencil short (rarely longer than 6 mm). Ears large relative to body size, pale to medium brown in color. Hindfoot length 26–29 mm; pes moderately broad with proportionally rather short and thick digits; colored pale brown with faint, darker patch over metatarsals. Skull elongated, becoming angular and flattened in older specimens; rostrum broad and nasals parallel sided along posterior half; supraorbital ridges not highly divergent, and interorbit and frontal bones both long; braincase not inflated; mesopterygoid fossa expanded anteriorly, sphenopalatine fissures small or absent; parapterygoid fossae not fenestrated and often recessed; auditory bullae moderate in size. Upper molar row generally 4.9–5.4 mm in length, rather larger in relation to skull length than average for genus. d i s t r i b u t i o n : Rhipidomys venezuelae occurs in northern Colombia and in northwestern and northern Venezuela. It is found at low to lower-middle elevations in the Sierra Nevada de Santa Marta, Serranía de Perijá, Mérida Andes (notably the Chama valley), Serranía de San Luis, and Cordillera de la Costa as far east as Guárico state as well as in the intervening and coastal lowlands. s e l e c t e d l o c a l i t i e s (Map 323): COLOMBIA: César, El Orinoco, Río César (USNM 280447); La Guajira, Fonseca, Las Marimondas (USNM 280442); Magdalena, Hacienda Cincinati (AMNH 32667). VENEZUELA: Aragua, Estación Biológica Rancho Grande (USNM 517589); Falcón, Cerro Santa Ana, Península de Paranaguá (USNM 456363), La Pastora, 14 km ENE of Mirimire (USNM 442137); Guárico, Parque Nacional Guatopo, 40 km SSE of Caracas (O’Connell 1989); Lara, Caserío Boro, 13 km W of El Tocuyo (USNM 456374); Mérida, Hacienda Santa Catalina, Río Chama (FMNH 21826); Trujillo, Isnotú (USNM 371251); Zulia, Misión Tukuko (USNM 448629). s u b s p e c i e s : As currently understood, Rhipidomys venezuelae is monotypic. n a t u r a l h i s t o ry: Rhipidomys venezuelae inhabits both moist and dry forests in northern South America, its dorsal pelage generally being redder in the former and grayer and more agouti in the latter. Handley (1976) provided habitat data for Smithsonian Venezuelan Project specimens. O’Connell (1989) discussed the population dynamics of R. venezuelae (reported as “R. mastacalis”) in premontane rainforest in Guatopo National Park, on the southern slopes of the Venezuelan coastal range. For parasites, see Ferris (1921), Hopkins (1949), Furman (1972a), P. T. Johnson (1972), E. K. Jones et al. (1972), Machado-

Map 323 2,000 m.

Selected locality for Rhipidomys venezuelae (●). Contour line =

Allison and Barrera (1972), Tipton and Machado-Allison (1972), Brennan and Reed (1974a), and Saunders (1975). Guerrero (1985) listed the ectoparasites recorded from all species of Venezuelan Rhipidomys. r e m a r k s : Rhipidomys venezuelae is a member of the “leucodactylus” section of the genus. The taxon has been variously treated as a species in its own right or as a subspecies of R. mastacalis (e.g., Cabrera 1961). Tribe (1996) tentatively placed it as a subspecies of R. latimanus, to which it is closely allied morphologically (see Remarks under that species). López-Fuster et al. (2001) described cranial allometry in R. venezuelae. A single small specimen from Bonda, on the seaward side of the Sierra Nevada de Santa Marta in northern Colombia, was found by Tribe (1996) to be morphometrically much closer to Rhipidomys nitela than to R. venezuelae. Voss et al. (2001) considered such an association implausible and suggested that this specimen represented another taxon, possibly allied to R. venezuelae. Further material will be needed to resolve this issue. There have been several reports that a distinct species of Rhipidomys inhabits the llanos (Eisenberg et al. 1979; Poulton 1982; O’Connell 1982, 1989; August 1984). Because the only material I have seen from the llanos consists of a possibly mismatched juvenile skull and skin, it is not clear whether these reports involve a new taxon or a geographical variant of R. venezuelae, R. couesi, or R. nitela.

Rhipidomys venustus Thomas, 1900 Mérida Highland Rhipidomys sy n o n y m s : Rhipidomys venustus Thomas, 1900a:152; type locality “Las Vegas del Chama, alt. 1400 m,” Mérida, Venezuela. Rhipidomys latimanus venustus: Cabrera, 1961:420; name combination.

616 Mammals of South America

d e s c r i p t i o n : Medium to large (head and body length 120–145 mm) with moderately long tail (120–140% of head and body length). Pelage soft and dense, bright chestnut brown on dorsum and white-tipped over dark slate hair bases below. Tail sometimes reddish rather than dark, terminating in pencil of hairs 10–15 mm in length. Ears large, well haired, and dark. Hindfeet range from 26– 30 mm in length and bear well-defined dark patches over metatarsals; sides of metatarsal portion and toes yellowish white. Skull has narrowed interorbital region with supraorbital ridges slightly more pronounced than in related species in “fulviventer” section; braincase rounded rather than angular; parapterygoid fossae often fenestrated; carotid circulation pattern primitive (large stapedial foramen, internal groove on squamosal and alisphenoid, and sphenofrontal foramen present). Maxillary toothrow averages 5 mm in length (range: 4.81–5.18 mm), average in comparison with skull length for genus. d i s t r i b u t i o n : Rhipidomys venustus is endemic to Venezuela, occurring in the Venezuelan Andes in the states of Mérida and Trujillo at elevations mostly above 2,000 m and potentially also in the adjoining, eastern part of Táchira state. Disjunct populations morphologically referable to this species have been found at elevations above 1,300 m in isolated mountain ranges farther northeast in Falcón and Yaracuy states, and in the Cordillera de la Costa in both Aragua and Vargas states and the Distrito Capital. s e l e c t e d l o c a l i t i e s (Map 322): VENEZUELA: Aragua, Monumento Natural Pico Codazzi (F. J. García and Sánchez-González 2013); Distrito Capital, Pico Ávila, near Hotel Humboldt (USNM 371236); Falcón, Serranía de San Luis, Parque Nacional Juan Crisóstomo Falcón, Sector Cumbres de Uria, ca. 9 km N of Cabure, ca. 1,320–1,370 m (R. P. Anderson et al. 2012); Mérida, La Coromoto, 7 km SE of Tabay (USNM 387909), Páramo de Mariño, Mérida/Táchira border (Durant and Díaz 1995); Trujillo, Hacienda Misisí (USNM 374528); Yaracuy, Sierra de Aroa, Parque Nacional Yurubí, Sector El Silencio, La Trampa del Tigre (F. J. García and SánchezGonzález 2013). s u b s p e c i e s : Rhipidomys venustus is monotypic. n a t u r a l h i s t o ry: Specimens of R. venustus and R. tenuicauda captured by the Smithsonian Venezuelan Project (N = 52) were collected in cloud forest (55%), evergreen forest (40%), and orchards (5%); most were found in trees and vines (68%), a few in houses (5%), and the remainder under bushes, on rock ledges, and in a log (Handley 1976; all identified as “Rhipidomys venustus”). Other specimens were taken in coffee plantations. Capture elevations were mostly between 2,000 and 3,350 m (specimen tag data), but the elevations of Salomón Briceño Gab-

aldón’s capture localities near Mérida as given on specimen tags (from 1,400 to 4,000 m) are questionable. Near Mérida, Aagaard (1982) found the species to be predominantly arboreal, with 80% of captures in trees. Individuals were more likely to come down to the ground in the wetter forests than at higher elevations. Aagaard (1982) also provided data on population ecology and reported that one female had two embryos in the wet season. One USNM specimen had one embryo in September (specimen tag). For parasites, see Ferris (1921), Furman (1972a), P. T. Johnson (1972), E. K. Jones et al. (1972), MachadoAllison and Barrera (1972), Tipton and Machado-Allison (1972), and Brennan and Reed (1974a). Guerrero (1985) listed the ectoparasites recorded from all species of Venezuelan Rhipidomys. r e m a r k s : Rhipidomys venustus is a moderately large species in the “fulviventer” section of the genus. The Táchira Depression (at roughly 1,000 m elevation) separates the range of this species from that of R. fulviventer to the southwest. The populations in the Cordillera de la Costa (Vargas to Aragua states) and in the Sierra de Aroá (Yaracuy state) and Sierra de San Luis (Falcón state) are isolated from the main species range in the Mérida-Trujillo Andes by dry lowlands. Further research, preferably using DNA sequences, is needed to determine how closely related these forms are to each other and to other members of the “fulviventer” group. Tribe (1996) treated the two forms in the Mérida-Trujillo Andes and in the Cordillera de la Costa as subspecies of R. fulviventer; see also the Remarks under both that species and R. tenuicauda.

Rhipidomys wetzeli A. L. Gardner, 1990 Wetzel’s Rhipidomys sy n o n y m s : Rhipidomys wetzeli A. L. Gardner, 1988:744; nomen nudum. Rhipidomys wetzeli A. L. Gardner, 1990:417; type locality “Camp VII (00°50′40′′N, 65°58′10′′W), 1800 m, Cerro de la Neblina, Territorio Federal Amazonas, Venezuela.” d e s c r i p t i o n : Very small (averaging 235 mm); adult upper molar row >9.9 mm; zygomatic notch very shallow; about a third of terminal tail whitish. . . . . . . . . . . . . . . . . . . . . . . . . .Thomasomys apeco 7′. Body size large or medium (adult head and body length 17 mm in length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dasyprocta

1′. Size smaller (470 mm); dorsal coloration rich brownish slate; mid-dorsal dark stripe weakly developed; ears short with black outer and lighter inner surfaces; distribution limited to southern Argentina and adjacent Chile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Lagidium wolffsohni 1′. Body size smaller (head and body length ranges from 360 to 425 mm); dorsal coloration highly variable, from creamy buff to dark gray; mid-dorsal dark stripe usually well developed; distribution from southern Ecuador to northern Argentina and Chile . . . . . . . . . . . . . . . . . . . 2 2. Dorsal color dark gray; dorsal surface of feet blackish; ears short (ca. 60 mm) and black on both surfaces; least interorbital breadth of skull narrow (ca. 16.5 mm); rostrum broad (ca. 16.2 mm); braincase flat; known only from southern Ecuador. . . . . . . . Lagidium ahuacaense 2′. Dorsal color highly variable, but typically buff to dark gray; dorsal surface of feet pale, not black; ears longer

Suborder Hystricomorpha: Family Chinchilloidea 773

(>65 mm, on average); broader interorbital breadth (>16.8 mm); narrower rostrum (100% of the combined length of the head and body (Voss 2011). The visible dorsal pelage is completely spiny in some species, but in other species the quills may be partially or completely concealed by long fur. Whether concealed by fur or not, the quills of Coendou are straight or gently curving, never wavy. At least on the rump, the quills of all species are defensive spines with hard, sharp, microscopically barbed points. The tail of most species is a robust, muscular organ with a welldeveloped dorsal prehensile surface. The skull lacks welldeveloped postorbital processes and bony auditory tubes. The usual sutures among adjacent cranial bones are visible in juvenile and in many subadult skulls, but most cranial sutures disappear with age (only the sutures surrounding

the premaxillae and the auditory bullae persist in old adult specimens). The frontal sinuses are conspicuously inflated in some species, but not in others. The roof of the external auditory meatus is smooth and featureless in some species, but in others it is provided with a transverse bony ridge (Voss et al. 2001:Fig. 70A) and is said to be keeled. The upper cheek teeth are low-crowned and wider than they are long; a median crest connecting the second and third transverse lophs is always present. Citations to published illustrations of external and craniodental morphology are provided in the species accounts that follow. Several long-furred species of Coendou were previously referred to the genus Sphiggurus (e.g., by Husson 1978; Woods and Kilpatrick 2005), and the short-tailed species C. rufescens was previously referred to the monotypic genus Echinoprocta. As traditionally recognized, however, these taxa are not reciprocally monophyletic, and allegedly diagnostic “generic” characters (e.g., size, long versus short fur, cranial sinus inflation) appear to have evolved homoplastically in the course of erethizontid phylogeny (Voss et al. 2013). Contradictory results (mtDNA sequence analyses interpreted as supporting the reciprocal monophyly of Sphiggurus and Coendou; Bonvicino, Penna-Firme, and Braggio 2002) were based on misidentified specimens (Voss 2011:9, footnote 2). sy n o n y m s : Coendou Lacépède, 1799:11; type species Hystrix prehensilis Linnaeus, by monotypy. Coendus E. Geoffroy, 1803:157; incorrect subsequent spelling of Coendou Lacépède. Coandu G. Fischer, 1814:102; incorrect subsequent spelling of Coendou Lacépède. Sinethere F. Cuvier, 1823a:427; type species S. prehensilis (Linnaeus), by original designation. Sphiggure F. Cuvier, 1823a:427; type species S. spinosa F. Cuvier, by original designation. Sinoetherus F. Cuvier, 1823c:256; incorrect subsequent spelling of Sinethere F. Cuvier. Sphiggurus F. Cuvier, 1823c:256; incorrect subsequent spelling of Sphiggure F. Cuvier (but to be maintained due to prevailing subsequent usage; Voss 2011:6). Coendu Lesson, 1827:290; incorrect subsequent spelling of Coendou Lacépède. Synethere Lesson, 1827:291; incorrect subsequent spelling of Sinethere F. Cuvier. Sinetheres J. B. Fischer, 1829:369; incorrect subsequent spelling of Sinethere F. Cuvier. Cercolabes Brandt, 1835:391; type species Hystrix prehensilis Linnaeus (proposed as a replacement name for Coendou Lacépède). Synoetheres Lund, 1839a:227; incorrect subsequent spelling of Sinethere F. Cuvier.

792 Mammals of South America

Sphingurus Tschudi, 1844:185; incorrect subsequent spelling of Sphiggure F. Cuvier. Echinoprocta Gray, 1865: 321; type species Erethizon (Echinoprocta) rufescens Gray, by monotypy. Cryptosphingurus Miranda-Ribeiro, 1936:975; type species C. villosus (F. Cuvier), by original designation. KEY TO THE SOUTH AMERICAN SPECIES OF COENDOU:

1. Size small (adult head and body length 400 mm; condylo incisive length of adult skull >77 mm; adult maxillary toothrow >18 mm); dorsal body pelage appears completely spiny (long fur absent); frontal sinuses inflated in most fully adult specimens . . . . . . . . . . . . . . . .7 6′. Usually smaller (combined length of adult head and body usually 30 mm; darker both dorsally and ventrally than other species in complex. Coloration uniformly brownish gray, back slightly darker than sides, venter grayish drab, with hairs dark grayish or slate for about three-fourths of their length and with pale drab tips. Hairs of sternal gland white to base, thus forming white patch contrasting strongly with surrounding ventral coloration; chin grayish white, underside of neck darker than other ventral areas; hairs surrounding perianal region with buffy or whitish tips. Like A. famatina, drab throat patch present. Forefeet and hindfeet covered dorsally with whitish hairs. Tail dark drab to grayish above contrasting with grayish white to whitish below. Cranially, nasals evenly narrow for about half to two-thirds of length, becoming markedly convergent posteriorly, ending in a point. Dorsal edge of zygoma slanted outward such that medial edge is visible from above; anterior ascending maxillary portion of zygoma thin. Zygomatic arches expanded laterally; frontals noticeably constricted. Ventrally, posterior border of palate pointed, mesopterygoid fossa wide, mastoid islands large, and bullae slightly inflated. Upper incisors broad, large, and opisthodont. Hypoflexus and metaflexus of upper molars about equal in size and positioned more or less horizontally. Major cusps of upper cheek teeth more rounded and less anteroposteriorly compressed then in other species; all teeth subequal in size and shape. The overall length of upper toothrow short in relation to length of skull, similar in proportional length to that of A. famatina and A. vaccarum, smaller than that of A. cinerea and A. schistacea, and much smaller than that of A. uspallata. In comparison to other species in complex, A. budini significantly larger in cranial length, diastema length, nasal length (except A. schistacea), and mandible length (except A. schistacea). Toothrows and palate significantly longer, and wider zygomatic arches, than A. famatina, but interorbital breadth significantly narrower than A. cinerea. d i s t r i b u t i o n : Abrocoma budini is known only from the Sierra de Ambato in Catamarcaprovince, Argentina. s e l e c t e d l o c a l i t i e s (Map 418): ARGENTINA: Catamarca, Cerro Ambato (Glanz and Anderson 1990), Otro Cerro (type locality of budini Thomas). s u b s p e c i e s : Abrocoma budini is monotypic. n a t u r a l h i s t o ry: No data on ecology, behavior, or any aspect of life history are known for this species, although Barquez et al. (1991) stated that the species (regarded as a subspecies of A. cinerea) lives in rocks and is apparently colonial. Thomas (1920b:476), in his description of this taxon, noted that the collector, Emilio Budin, found it “among rocks, in the clefts of which it lives.”

812 Mammals of South America

r e m a r k s : As with other species in the Abrocoma cinerea complex, A. budini is a geographic outlier to the broad range of A. cinerea and, as such, was considered only subspecifically distinct from that species by Ellerman (1940) and Cabrera (1961). Braun and Mares (2002) elevated A. budini to species status. The karyotype is unknown.

Abrocoma cinerea Thomas, 1919 Ashy Chinchilla Rat sy n o n y m s : Abrocoma cinerea Thomas, 1919f:132; type locality “Cerro Casabindo, 4800 m,” Jujuy, Argentina. Abrocoma cinerea cinerea: Ellerman, 1940:154; name combination. d e s c r i p t i o n : Medium sized, total length 64 mm); skull arched in dorsal profile; foramen magnum subcircular,

slightly higher than wide; premaxillae widening distinctly posteriorly; posterior loph of M3 directed posteriorly, posterior border strongly concave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cuscomys oblativus

Cuscomys ashaninka Emmons, 1999 Ashaninka Arboreal Chinchilla Rat sy n o n y m : Cuscomys ashaninka Emmons, 1999a:2; type locality “Peru: Departamento de Cusco, northern Cordillera de Vilcabamba, 11°39′36′′S; 73°40′02′′W (by GPS, map datum WGS-84); elevation 3370 m,” corrected to Junín department by Quintana Navarrete (2011). d e s c r i p t i o n : Large (mass >900 g; head and body length >300 mm), with long tail (tail length >200 mm), and long but wide hindfeet (length >60 mm). Fur dense and long, pale gray dorsally with abundant black guard hairs 40 mm long extending 20–25 mm beyond underfur in mid-dorsum, and giving blackish coloration along midback; sides paler, sprinkled with mixture of white and dusky overhairs; dorsal underfur pale gray, soft, and somewhat wavy. Head with narrow white blaze from nose to crown; lips and chin white. Venter gray, with lightly frosted hairs, and not contrasting with sides; midline of chest between forelegs with streak of short hairs, probably associated with a sternal gland. Mystacial vibrissae dense, stiff, and either white or dusky, and extend behind shoulder when flattened against body. Three supercilliary vibrissae present but no genal vibrissae evident; single vibrissa present on mid-forelimb of holotype, and only known specimen. Ear pinnae nearly naked, with fur at base sufficiently long to reach ear tips. Tail robust and long (76% of head and body length), clothed with stiff hairs that nearly hide underlying scales, and sharply bicolored dark for basal half and white for distal half. Forefeet have four toes, without evidence of a pollex; hindfeet with hallux without ungual tuft, other four digits with long, dusky tufts reaching beyond tips of stout, strongly curved claws. Feet thinly clothed with dusky hairs; broad with soles pigmented proximally but not distally (white in fresh specimen), covered with tiny tubercles; palmar and plantar pads soft and poorly defined. Only single pair of inguinal mammae was discovered, but specimen was primaparous, and its nipples small. Skull large and robust (greatest skull length >65 mm), dorsal profile flat, and rostrum deep and broad. Nasal bones broad and slightly inflated distally, two posterior tips meet in straight line with no intercalation of the frontals; premaxillary bones of rostrum do not widen posteriorly; frontals widest anterior to postorbital process and constricted posteriorly; dorsal projections of mastoid bones small and uninflated; parietal ridges and supraoccipital crest strongly developed. Incisors large and robust; upper incisors proodont. Maxillary toothrows slightly divergent posteriorly. Man-

Suborder Hystricomorpha: Family Abrocomidae 817

dible robust in comparison to species of Abrocoma, with angular and condyloid processes dorsoventrally deep; medial condyloid ridge passing midway up center of process, not approaching its posterior edge; external tip of condyloid process with well-defined, short medial crest; and low coronoid process. Occlusal pattern of cheek teeth similar to other species in family, but with lingual flexi at shallow angle and nearly equal in length with labial flexi such that mid-tooth mure short and nearly parallel to tooth axis. d i s t r i b u t i o n : Cuscomys ashaninka is known only from the type locality. s e l e c t e d l o c a l i t i e s (Map 420): PERU: Junín, Cordillera de Vilcabamba (type locality of Cuscomys ashaninka Emmons). s u b s p e c i e s : Cuscomys ashaninka is monotypic. n a t u r a l h i s t o ry: The holotype, and single known specimen, was found dead, probably killed by a long-tailed weasel (Mustela frenata). The specimen was found on a steep slope in tall, wet, mossy cloud forest dominated by Weinmannia fagaroides/microphylla (Cunoniaceae) and Polylepis cf. pauta (Rosaceae) trees with abundant Chusquea sp. scandent bamboo. Alonso et al. (1999) provided details of the vegetation and other fauna at the type locality. The stomach of the holotype was greatly expanded with 140 cc of finely triturated plant material, including fruit and unidentified plant tissue. When collected 15 June, it contained a single 8 × 5 mm embryo.

Map 420 Selected localities for species of Cuscomys ashaninka (●) and Cuscomys oblativus (ᇲ). Contour line = 2,000 m.

r e m a r k s : The type locality is the northernmost recorded for the family, about 200 km north of the Inca burials at Machu Picchu, where C. oblativus was found. Between these two localities are the deep canyons of the Urubamba and Apurimac rivers and the 5,000 m snow-capped peaks of the Nevado de Sacsarayoc. Upper elevations of the northern Vilcabamba ridge are essentially a habitat island. Other mammals collected at the type locality show relationships to those to the south from the Machu Picchu area, but the area is likely to have a high local mammalian endemism because of its size and degree of isolation (Emmons 1999a). Price and Timm (2002) described two genera of chewing lice (Phthripaptera, Gryopidae), one new, from the holotype of C. ashaninka.

Cuscomys oblativus (Eaton, 1916) Machu Picchu Arboreal Chinchilla Rat sy n o n y m s : Abrocoma oblativa Eaton, 1916:87; type locality “Machu Picchu,” Cusco, Peru. Cuscomys oblativus: Emmons, 1999a:2; first use of current name combination. d e s c r i p t i o n : See Emmons (1999a:6–8, Figs. 7–9, Table 1) for detailed descriptions and figures of two nearly complete skulls of C. oblativus recovered at Machu Picchu. Specimens slightly smaller than C. ashaninka in both cranial length and breadth, with much longer tympanic bullae; incisors slightly larger in width; toothrow length larger; interorbital constriction is broader. One specimens with M3 unerupted and is immature. Skull more strongly arched in dorsal profile, much like that of Abrocoma; upper incisors opisthodont rather than proodont; tympanic bullae much less inflated; bony auditory tubes are shorter, with their openings more laterally, as opposed to upwardly, directed. Maxillary process of superior zygomatic root broader anteroposteriorly, and canted such that superior root is anterior to inferior root. Narrower zygomatic process of C. ashaninka slants in opposite direction. Nasals also separated posteriorly by projection from frontal bones, and premaxillae of rostrum widen posteriorly when viewed dorsally. Foramen magnum subcircular and slightly higher than wide, contrasting with much wider than high condition of C. ashaninka. Finally, maxillary toothrows more nearly parallel for entire length, with less posterior divergence; posterior loph of M3 directed posteriorly rather than laterally, and with strongly concave posterior border in contrast to nearly flat border. Medial loph of M3 broad and square, not tapered as in C. ashaninka. A living specimen captured near Machu Picchu ( J. G. Ochoa E., pers. comm. to L. E. Emmons, with photographs) very like C. ashaninka, but with ears relatively

818 Mammals of South America

longer, paler, and more pointed than round ears of C. ashaninka; smaller area of pure white on upper lips and base of vibrissae, and much paler head, apparently lacking black guard hairs on crown that border white blaze of C. ashaninka. Sex and age of this individual undocumented, but it shows a molt-line on rump, suggesting that it is subadult. d i s t r i b u t i o n : Cuscomys oblativus is known only from the type locality. A living rat presumably of this species was recently found and photographed on the Inca Trail near Wiñay Huayna about 3 km (airline) south of Machu Picchu ( J. G. Ochoa E., pers. comm. to L. H. Emmons). s e l e c t e d l o c a l i t i e s (Map 420): PERU: Cusco, Machu Picchu (type locality of Abrocoma oblativus Eaton). s u b s p e c i e s : Cuscomys oblativus is monotypic. n a t u r a l h i s t o ry: No data on behavior, ecology, or reproductive biology are known for Cuscomys oblativus. r e m a r k s : For nearly a century this species was known only from the archaeological record at Machu Picchu, the famous Incan redoubt on the alto Río Urubamba. The tombs from which the original specimens were obtained date from between 1450 and 1532 ad (R. Burger, cited as pers. comm. in Emmons 1999a). Thomas (1920h:220) had concluded that the species was probably extinct “judging by the fact that . . . relatives are no longer found in this faunal area, but only far south in Chile and Argentina.” With the discovery of C. ashaninka, however, to the north in the Cordillera de Vilcabamba, Thomas’s statement regarding geographically distant relatives is no longer valid. A living individual was found and photographed near the type locality at Wiñay Huayna ( J. G. Ochoa E., pers. comm. to L. H. Emmons), but no recent specimen exists for further comparison with C. ashaninka. Emmons (1999a:13) surmised that individuals of this species might have been kept as pets, or even domesticated as food or amusement because parts of individuals were found alongside four human burials, including a complete animal in a ceramic pot. One had elongated incisors, as if it has been maintained in captivity.

Family Ctenomyidae Lesson, 1842 Claudio J. Bidau

The family Ctenomyidae consists of the single Recent genus Ctenomys and four to six extinct genera (McKenna and Bell 1997), including Actenomys Burmeister (Pliocene), Eucelophorus Ameghino (Pliocene- Pleistocene), Megactenomys Rusconi (Pliocene), Praectenomys Villarroel (Pliocene), Paractenomys Ameghino (Pliocene), and Xenodontomys Kraglievich (Late Miocene). Both Megactenomys and Paractenomys are now viewed as a either subgenera or synonyms of Ctenomys (Verzi and Lezcano

1996; Verzi 2002, 2008). Molecular phylogenetic analyses, both DNA sequences (e.g., A. H. Castillo et al. 2005; Cook and Lessa 1998; D’Elía et al. 1999; E. P. Lessa and Cook 1998; Opazo et al. 2005; Parada et al. 2011) and DNADNA hybridization (M. H. Gallardo and Kirsch 2001), strongly support a sister group relationship between the ctenomyids and the family Octodontidae. Authors, however, have differed as to whether these two taxa should be recognized at the level of the family (e.g., Simpson 1945; Woods and Kilpatrick 2005) or subfamily (e.g., McKenna and Bell 1997). The family is known only from southern South America, where much of its history has been arguably tied directly to the profound cooling and drying that began in the Miocene, especially with the Late Pliocene pulse detected worldwide at about 2.5 mya (Verzi 2002; Verzi and Quintana 2005). Earliest known fossils of Ctenomys date from the Late Miocene (Verzi 2002, 2008; Verzi and Quintana 2005; Reguero et al. 2007; Vieytes et al. 2007; Verzi et al. 2010). The differentiation of the ctenomyids involved diverse adaptations to open habitats, especially those related to digging and life underground (Reig and Quintana 1992; Verzi 2002; Verzi and Olivares 2006). These adaptations included (1) acquisition of molar euhypsodonty and associated changes (occlusal simplification, secondary acquisition of radial enamel on the molar leading edge), (2) acquisition of a crescent-shaped occlusal morphology adapted to an oblique mastication, and (3) subterranean specializations of the external body and limbs, skull, and skeleton (Verzi 2002). Verzi (2008) hypothesized phyletic relationships among fossil and extant ctenomyid genera based on cladistic analysis of craniodental characters. Unambiguous synapomorphies for a monophyletic Ctenomyidae include an anterior extension of the maxillary (maxillary extended anterodorsally with respect to premaxillary septum, constraining the incisive foramen posteriad), a dorsal position of the rostral masseteric fossa (which provides attachment for the origin of the M. masseter medialis anterior muscle; its depth indicates strong development of this muscle), a protruding external auditory meatus with the anterodorsal and anterior margin oriented anteriad, molars with flexi(id)s vestigial or absent, and a reduced M3, with the posterior or posterolingual face flat and anterior lobe protruding. Synapomorphies of the genus Ctenomys (including Paractenomys) include a rostral masseteric fossa positioned dorsal to the alveolar sheath of the upper incisor, deep, and ending in a curved crest slightly anterior to or level with the premaxillomaxillary suture; the bottom of the alveolar sheath of the upper incisor lodged in a cavity of the maxillary, positioned anterior to the alveolar sheath of M1; an external auditory meatus forming a protruding tube with its anterior wall moderately to very concave,

Suborder Hystricomorpha: Family Ctenomyidae 819

and with the ectotympanic recess forming a horizontal flat surface; a well-developed postcondyloid process, with a strong lateral apophysis on its ventral margin, and a crescent-shaped occlusal design of dpm4–m2 with a weak labial fold and a wider lingual concavity, with the posterior lobe of each molar more lingually oriented (Verzi 2008; Verzi et al. 2010).

Genus Ctenomys Blainville, 1826 The genus Ctenomys is the most speciose of any South American rodent with 63 species recognized herein ( J. R. Contreras et al. 2000; Azurduy 2005a). However, as noted by Woods and Kilpatrick (2005), some 85 names have been applied to this genus, and many taxa remain to be adequately delimited geographically or systematically. It is thus clear that the number of species will increase with the combination of much needed additional field collections and revisionary work. In fact, within the past 20 years alone, eight new Recent species have been described (summary in Reeder et al. 2007; T. R. O. Freitas et al. 2012) along with several known only from the fossil record (Verzi et al. 2004; Azurduy 2005a; S. O. Lucero et al. 2008; see also Mones 1986). Additional species await description (Montes et al. 2001; Parada et al. 2011). The earliest naturalists who explored southern South America made the initial observations and collections of Ctenomys. Rusconi (1931b) stated that Alcide d’Orbigny was the first one to collect a Ctenomys fossil, which formed the basis of C. bonariensis (= C. bonaerenses). Charles Darwin (1839, 1845) made observations on living tuco-tucos and also collected fossil mandibular fragments at Monte Hermoso in Buenos Aires province, Argentina, that Sir Richard Owen used to describe Ctenomys priscus, later transferred to the genus Actenomys (Villarroel 1975). Living Ctenomys have been divided into three subgenera, based on morphological criteria: Chacomys, to include the single species C. conoveri (Osgood 1946); Haptomys to include C. leucodon (Thomas 1916g); and the nominotypical Ctenomys for all other species (Rusconi 1928). However, molecular evidence fails to support the validity of these subgenera, as both C. conoveri and C. leucodon are either deeply nested with the complex of species comprising the nominotypical subgenus (Cook and Yates 1994) or form part of a large basal polytomy (E. P. Lessa and Cook 1998; A. H. Castillo et al. 2005; Parada et al. 2011). The genus is distributed from the Peruvian highlands, at approximately 15° south latitude, to Tierra del Fuego, with representative species in Bolivia, Chile, Argentina, Paraguay, Uruguay, and southwestern Brazil. The majority of species occur in Argentina where they are found in all provinces except Misiones (Bidau 2006), and where they occupy

a great diversity of habitats from sea level to an elevation of almost 5,000 m. Tuco-tucos are also one of the mammal groups with highest karyotypic diversification, including species with diploid numbers ranging from 2n = 10 to 2n = 70 (Bidau 2006). The oldest fossils of Ctenomys are from the Uquía Formation in northwestern Argentina, providing a minimum age for the genus at about 3.5 mya (Reguero et al. 2007; Verzi et al. 2010), with the central Andes suggested as the possible area of origin. The molecular estimate of the time to the most recent common ancestor of extant Ctenomys species is considerably older, estimated at 9.2 mya (range: 6.4–12.6 mya), although most species groups stem from within the past 3 mya (Parada et al. 2011). All species of tuco-tucos are of similar external morphology, each adapted for subterranean existence. However, there is considerable diversity in body size, ranging from the very small species such as C. pundti, C. talarum, or C. sericeus at less than 100 g and 140 mm head and body length (A. I. Medina et al. 2007) to very large ones, like the Chacoan species C. conoveri, where males can reach 1,200 g and 558 mm in head and body length (S. Anderson 1997). All species are sexually size dimorphic, with males the larger of the two sexes, but the degree of dimorphism increases with general body size (A. I. Medina and Bidau 2007; Bidau and Medina 2013; SteinerSouza et al. 2010). The pelage ranges from short to long, is typically very thick, and general color varies extensively from gray or creamy buff to black on the upper surface (Nowak 1999). As in the North American pocket gophers (Geomyidae), which tuco-tucos resemble in external appearance and habits, fringes of hair are present on both forefeet and hindfeet. In tuco-tucos, however, the hairs on the hindfeet are stiffened and form comb like bristles that are the origin of the generic (and familial) names Ctenomys and Ctenomyidae (Greek root ktenos = comb; Blainville 1826). The body is stout and cylindrical, the tail is short, and the limbs and neck are both short and very stout. All digits on both forefeet and hindfeet have very strong claws. The ears are very small, and the eyes are small but not as reduced as in other subterranean mammals. The incisors usually have bright orange enamel (except for C. leucodon, as per the name, where is it white or pale yellow). The molars are kidney-shaped, and the last one is reduced in size. Data on reproduction are available only for a few species. Females typically produce one litter per year but some species can produce two (i.e., C. talarum; Malizia and Busch 1991). Species may reproduce in the dry (C. opimus in Peru) or the wet season (C. torquatus in Uruguay; Nowak 1999). Average gestation is 120 days, and litter size varies between one and three young in C. opimus to one to seven in C. talarum. Bidau and Medina (2013)

820 Mammals of South America

investigated testis size allometry and its relationship to sperm competition. Males (and to a lesser degree, females) vocalize underground to mark territory, maintain social groups, or express fear. Burrow systems vary between species and type of soil but usually consist of a main tunnel up to 30 cm underground and of varying diameter, with several lateral ones with either blind ends or connecting to food sources on the surface, and a nest chamber. External openings are usually plugged when the burrow is occupied. Apparently, only C. sociabilis maintains burrows that are permanently open. Internal microclimatic conditions (temperature and humidity) are remarkably constant (20–22º C) in C. torquatus and C. talarum (A. I. Medina et al. 2007). Digging is typically a daylight activity. To dig, the substrate is loosened with the forefeet and removed with the hindfeet while incisors are used for cutting through roots (Weir 1974a). Tuco-tucos are completely herbivorous, eating roots and aerial parts of available plants, especially grasses (Barlow 1969). Vieytes et al. (2007; see also Justo et al. 1995) investigated the ultrastructure of the incisor enamel and delineated morphofunctional traits among octodontoid genera with disparate digging adaptations. Those taxa that use their teeth in digging have a higher inclination of the HunterSchreger bands, higher relative thickness of the external index, and a higher enamel zone, traits which uniquely or in combination provide for enamel reinforcement to withstand the higher tension forces encountered while digging in hard soils. Vassallo and Mora (2007) examined scaling and growth trajectories in craniomandibular traits relevant to tooth digging, including the development of the mandibular angle and masseteric crest and the robustness of the incisors, and documented significant shape differences between ctenomyid and octodontid genera. And SteinerSouza et al. (2010) documented shape diversity in the humerus with respect to digging adaptations. Within Ctenomys, these traits scale allometrically, such that large and small species do not differ in their respective ontogenetic trajectories. As a consequence, morphological diversification within this genus follows simple allometric scaling laws but changes in development resulting in departures from ontogenetic scaling underlie differentiation among genera within the superfamily. Similarly, Mora et al. (2003) examined cranial morphological attributes of tooth digging within Ctenomys and noted that incisor procumbency (a generalized character of tooth-digging) scales with rostral length but not overall size, but that incisor width and thickness do exhibit positive allometry such that larger species have proportionally more powerful incisors to resist greater bending forces. The phylogenetic relationships within Ctenomys using molecular markers have only recently begun (E. P. Lessa and

Cook 1998; J. R. Contreras and Bidau 1999; D’Elía et al. 1999; Mascheretti et al. 2000; Montes et al. 2001; Slamovits et al. 2001; Giménez et al. 2002; A. H. Castillo et al. 2005; Parada et al. 2011). Interestingly, the substitution rate in the mtDNA cytochrome-b gene, which is the most common gene examined today, is elevated in comparison to above-ground octodontid relatives (C. C. Da Silva et al. 2009). Although results of these studies tend to be concordant, especially when considered jointly with morphological, chromosomal, parasitological, and biogeographic data ( J. R. Contreras and Bidau 1999), species boundaries and phylogenetic relationships within the genus remain complex and incompletely understood. In this account, I recognize 64 species, 56 of which are monotypic and eight polytypic (with a combined 24 subspecies, including the nominotypical races of each). Two of these species (C. “yolandae” and C. “mariafarelli”) have yet to be properly described, but an account is provided for both because these names have been employed in the literature as though they were valid (e.g., Mascheretti et al. 2000; Woods and Kilpatrick 2005). Multiple other taxa defined by chromosomal or molecular sequences, each probably valid species, await formal description (see, for example, Parada et al. 2011). I include data on diploid number (2n), autosomal fundamental number (FN), presence of chromosomal polymorphism, and sperm morphology ( J. R. Contreras 1996; Bidau 2006) in each species account for which such data are available. sy n o n y m s : Orycteromys Blainville, 1826:63; used in the French form “Oryctéromes” for Ctenomys Blainville (see Palmer 1897b). Ctenomys Blainville, 1826:64; type species Ctenomys brasiliensis Blainville, by monotypy. Ratton Brants, 1827:187; part; inclusion of Ratton tucotuco Brants (1827:187), based on Azara’s (1802:69) “el tucotuco”; suppressed for the purpose of Principle of Priority (but not Homonomy) by the International Commission (ICZN 1982:Opinion 1232). Spalax: J. B. Fischer, 1829:300; part (listing of brasiliensis); not Spalax Gueldenstaedt, 1770. Georychus: Lichtenstein, 1830:plate 31; part; not Georychus Illiger, 1811. Haptomys Thomas, 1916g:305; as a subgenus of Ctenomys; type species Ctenomys leucodon Waterhouse, by original designation. Chacomys Osgood, 1946:47; as a subgenus of Ctenomys; type species Ctenomys conoveri Osgood, by original designation. Stenomys Avila-Pires, 1968:162; incorrect subsequent spelling of Ctenomys Blainville. Both Cook et al. (1990:4–5) and S. Anderson (1997:58– 59) provided illustrated keys to Bolivian species known

Suborder Hystricomorpha: Family Ctenomyidae 821

to them at that time, but, as documented in the accounts herein, I do not follow all of their taxonomic conclusions. Unfortunately, the production of a key for all 64 species herein covered is impossible at present. Species boundaries are both poorly defined morphologically and delimited geographically for too many taxa, 11 of which are known only from their type localities. The few specimens available preclude an adequate assessment of morphological variation and thus delineation of geographic trends for all but very few species. Moreover, while each species is described based on the available literature in the accounts here, these descriptions are uneven, incomplete, and all too often superficial in their coverage of the morphological characters provided. A thorough review of virtually every species, necessarily accompanied by widespread additional collecting, is critical to advance the current state of species-level systematics in the genus. Recently, Parada et al. (2011) recognized eight polytypic species groups of Ctenomys plus seven additional apparently monophyletic species lineages using mtDNA sequences. These groups are almost coincident with those proposed by J. R. Contreras and Bidau (1999) on the basis of morphological, biogeographic, chromosomal, and incipient molecular data. The polytypic groups include (from Parada et al. 2011, followed by that by J. R. Contreras and Bidau 1999): (1) “boliviensis” or Boliviano-Matogrossense, including C. boliviensis, C. goodfellowi, C. nattereri, C. robo, and C. steinbachi; (2) “frater” or Bolivian-Paraguayan, including C. conoveri, C. frater, C. lewisi, and an undescribed species from Llathu, Cochabamba, Bolivia; (3) “magellanicus” or Patagonian (in part), including C. colburni, C. coyhaiquensis, C. fodax, C. haigi, C. magellanicus, and C. sericeus; (4) “mendocinus” or C. mendocinus complex plus Eastern Lineage, including C. australis, C. flamarioni, C. mendocinus, C. porteousi, and C. rionegrensis; (5) “opimus” or Chacoan, including C. fulvus, C. opimus, C. saltarius, and C. scagliai; (6) “talarum” or Ancestral, including C. pundti and C. talarum; (7) “torquatus” or Corrientes and Eastern, including C. lami, C. minutus, C. pearsoni, C. perrensi, C. roigi, and C. torquatus; and (8) “tucumanus” or Chacoan, including C. argentinus, C. latro, C. occultus, and C. tucumanus. Single species lineages, those that lacked supported relationships to any other taxa, included C. maulinus, C. leucodon, C. tuconax, and C. sociabilis. J. R. Contreras and Bidau (1999) either regarded these unique, single species lineages as of uncertain position (C. leucodon and C. tuconax) or did not include them in their study (C. sociabilis). T. R. O. Freitas et al. (2012) placed their newly described species C. ibicuiensis within the “torquatus” clade, also based on mtDNA sequences. The phylogenetic hypothesis posited by Parada et al. (2011) and T. R. O. Freitas et al. (2012) is a remarkable

development, linking species that share biogeographic as well as biological characteristics. Unfortunately, however, these studies include only 40 of the 64 species recognized in the accounts that follow. Thus, the degree to which a relationship between clade membership and both distributional as well as other characters will remain robust must await the future inclusion of all known species into an enlarged analysis. Note added in proof: After this book went into production, S. L. Gardner et al. (2014) characterized each of the 12 Bolivian species they recognized, describing four as new (C. andersoni, C. erikacuellarae, C. lessai, and C. yatesi).

Ctenomys argentinus J. R. Contreras and Berry, 1982 Argentine Tuco-tuco sy n o n y m : Ctenomys argentinus J. R. Contreras and Berry, 1982b:166; type locality “Establecimiento Invernizzi, Campo Aráos, legua 2, 27 km norte de General San Martín, Departamento Libertador General San Martín, Provincia del Chaco, a 26°36′ de latitud sur y 59°15′ de longitud oeste,” Argentina. d e s c r i p t i o n : Medium sized (mean total length 257.5 mm in females and 260.5 mm in males; mean tail length 78.0 mm in females and 84.3 mm in males). Color very characteristic, as all specimens exhibit black dorsal band that starts on muzzle, passes between eyes to become enlarged on crown, and then narrower again to extend along dorsal surface onto tail; remainder dorsal region brown, becoming paler toward flanks where hair becomes yellowish brown and then pale grayish-brown ventrally. Light-colored collar between ears and throat another conspicuous character ( J. R. Contreras and Berry 1982b). Skull robust with strong crests in adult specimens and notably allometric in growth, resulting in “exaggerated” rostrum described by Thomas (1921a) for C. boliviensis. Tympanic bullae small and not very inflated; zygomatic arches strong with emergence of anterior apophysis of jugal, with greatest transverse width at junction of third and four sections; visible end of vomer well developed; interpremaxillary foramen, conspicuously separate in many species (Reig et al. 1966), not separable from incisive foramina; dorsal surface of nasals anteriorly flattened, much more than in C. validus; orbit relatively small but with postorbital apophysis of frontal and paraorbital apophysis of jugal, well developed; frontosquamosal suture coincides with internal margin of temporal crest; frontals become narrow behind postorbital apophyses; in old individuals, temporal crests increasingly closer to midline and may even make contact. Upper molariform teeth moderate to large. Upper incisors moderately proodont with anterior surface at about 105° relative to

822 Mammals of South America

horizontal plane. Baculum laminar and well ossified with enlarged proximal end and convex dorsal surface; length about 7 mm. d i s t r i b u t i o n : This species is known only from northern Argentina (Chaco, Formosa, Santiago del Estero, and possibly Santa Fe provinces; J. R. Contreras and Berry 1982b, 1985; Bidau et al. 2005; Bidau 2006). s e l e c t e d l o c a l i t i e s (Map 421; from J. R. Contreras and Berry 1982b, except as noted): ARGENTINA: Chaco, Campo Aráos (type locality of Ctenomys argentinus J. R. Contreras and Berry), Campo Bermejo, Colonia Benítez, General Pinedo, Las Breñas Pinedo, Pampa Chica, Presidencia Roca, Tres Isletas Pinedo; Formosa, Pozo del Tigre (Massoia 1970), San Martín Número Uno; Santa Fe, Tostado; Santiago del Estero, Bandera. s u b s p e c i e s : Ctenomys argentinus is monotypic. n a t u r a l h i s t o ry: Ctenomys argentinus is widely but sparsely distributed within its range, probably because it inhabits sandy soil patches separated by ample extensions of noncolonizable lands subjected to periodic floods that cause temporal cycles of contraction and expansion of tuco-tuco populations. Populations extend across the Chaco Húmedo and Chaco Seco ecoregions (Burkart et al. 1999). r e m a r k s : Previous to its formal description by J. R. Contreras and Berry (1982b) specimens of Formosa province had been assigned to C. boliviensis and C. conoveri

Map 421 2,000 m.

Selected localities for Ctenomys argentinus (●). Contour line =

(Massoia 1970, 1977). Ctenomys argentinus is closely allied to the species of the “Chacoan lineage” of J. R. Contreras and Bidau (1999) such as C. occultus, C. tucumanus, C. latro, and C. pilarensis of Paraguay. The karyotype is 2n = 44 with the FN = 50, 51, or 52, due to pericentric inversion polymorphism (Ortells et al. 1990; Ortells 1995; Bidau et al. 2005). Morphology of the sperm is simple symmetric (Bidau et al. 2005).

Ctenomys australis Rusconi, 1934 Dune Tuco-tuco sy n o n y m s : Ctenomys porteousi australis Rusconi, 1934b:108; type locality “Necochea (F.C.S.), Provincia de Buenos Aires,” Partido de Necochea, Buenos Aires, Argentina, 38°33′S, 58°45′ W, 10 m. Ctenomys australis: J. R. Contreras and Reig, 1965:165; first use of current name combination. d e s c r i p t i o n : Medium-sized to moderately large species with total length approximately 300 mm, mean range in head and body length 212–215 mm, tail length 96–103 mm, hind foot length 41–43 mm, and mass 349– 366 g ( J. R. Contreras and Reig 1965:175, 180). Skull longer and broader than that of C. brasiliensis but zygomatic and interorbital widths smaller; rostrum robust, especially transversally, and mandible very robust with very narrow incisors. d i s t r i b u t i o n : Ctenomys australis is distributed along the Atlantic coast of southern Buenos Aires province, Argentina, within the Pampa ecoregion. J. R. Contreras and Reig (1965:171) provided a detailed map of localities showing the juxtaposition of the range of this species with those of the adjacent C. talarum and C. porteousi. s e l e c t e d l o c a l i t i e s (Map 422): ARGENTINA: Buenos Aires, Claromecó (Slamovitz et al. 2001), Cristiano Muerto ( J. R. Contreras 1972), Monte Hermosa (A. I. Medina et al. 2007), Necochea (type locality of Ctenomys porteousi australis Rusconi), Punta Alta ( J. R. Contreras and Reig 1965), Río Quequén Salado ( J. R. Contreras and Reig 1965). s u b s p e c i e s : Ctenomys australis is monotypic. n a t u r a l h i s t o ry: Ctenomys australis is an exclusive inhabitant of the first line of vegetated dunes immediately behind the beach. In some parts of its range, this species is parapatric or sympatric with Ctenomys talarum recessus, which occupies the second line of dunes (see that account, and Comparatore et al. 1992). This is one of the more thoroughly studied species with regard to behavior, life history, and ecology of natural populations (Zenuto and Busch 1995; C. Busch et al. 2000). Mora, Kittlein et al. (2013) documented craniodental variation within and among populations, attributing interpopulation differences to demo-

Suborder Hystricomorpha: Family Ctenomyidae 823

Map 422

Selected localities for Ctenomys australis (●). Contour line = 2,000 m.

graphic characteristics delineated by phylogeographic analyses (see Mora et al. 2010) and local adaptation. r e m a r k s : Although it was initially described as a subspecies of C. porteousi, J. R. Contreras and Reig (1965) and Roig and Reig (1969) established the specific status of this taxon. The species is closely related to the Argentinean species of the “mendocinus” group, including C. azarae, C. mendocinus, and C. porteousi (Mascheretti et al. 2000), as well as to C. flamarioni, the most divergent “mendocinus” species from southern Brazil (Massarini, Barros, Ortells, and Reig 1991; D’Elía et al. 1999; J. R. Contreras et al. 2000; Parada et al. 2011). The karyotype is 2n = 48, FN = 80 (Massarini, Barros, Ortells, and Reig 1991), similar to that of other “mendocinus” group species, but especially to C. flamarioni (see Massarini and Freitas 2005). Sperm morphology is simple asymmetric (Vitullo et al. 1988). Mora et al. (2006) examined phylogeographic structure using mtDNA sequences and Apfelbaum et al. (1991) compared levels of electromorphic variation within and between C. australis and C. porteousi.

Ctenomys azarae Thomas, 1903 Azara’s Tuco-tuco sy n o n y m : Ctenomys azarae Thomas, 1903a:228; type locality “Sapucay, Paraguay”; corrected to “Province of Buenos Ayres, on the central pampas, lat. 37°45′, long. 65°W, 780 kilometers south-west of the Capital” by Thomas

(1903c), which now equals General Acha, Departamento Utracán, La Pampa, Argentina, 216 m. d e s c r i p t i o n : Relatively small species (external dimensions of holotype head and body length, 158 mm, tail length, 77 mm, hindfoot length (with claw), 35 mm). Dorsal color uniformly brown; venter pale buff, with darker markings on upper surface or white patches below; top of muzzle slightly darker than rest of body. Skull with same general shape as that of C. mendocinus, comparatively narrow and slender, not flattened and squared; nasals short and narrow; interorbital region ridged, with rudimentary postorbital processes; parietal ridges more marked than in similar species; zygomatic arches slope backward gradually to broadest point instead of being evenly rounded or square shouldered; mesopterygoid fossa penetrates to posterior edge of m2 instead of center of this tooth, as is more common in other species; bullae more swollen than those of C. mendocinus. Cheek teeth comparatively small, broad, and rounded in section, almost completely circumscribed by enamel and with only very small gap, at best, at their enteroexternal and posterointernal corners. d i s t r i b u t i o n : Ctenomys azarae inhabits central Argentinean provinces of La Pampa, Mendoza, and San Luis, within the Espinal, Monte de Llanuras, Mesetas, and Pampa ecoregions. s e l e c t e d l o c a l i t i e s (Map 423; from J. R. Contreras and Reig 1965, except as noted): ARGENTINA: La Pampa, Algarrobo del Aguila, Colonia 25 de Mayo, General Acha (type locality of Ctenomys azarae Thomas), 5 km S of Santa Rosa, Naicó, Utracán, Victorica; Mendoza, General Alvear (Braggio et al. 1999); San Luis, Arizona. s u b s p e c i e s : Ctenomys azarae is monotypic. n a t u r a l h i s t o ry: This species of tuco-tuco constructs burrows in sandy soils, in zones of low and open forest, and also on hills with psammophylic vegetation. Kin and Justo (1995) provided data on diet in natural and laboratory settings. r e m a r k s : Thomas (1903a:229) erroneously gave the type locality as “Sapucai, Paraguay” in his original description of this species, but corrected his mistake in a second publication that same year (Thomas 1903c:243) to “Province of Buenos Ayres, on the central pampas, lat. 37°45′S, long. 65°W, 780 kilometers south-west of the Capital, a region from which no examples of Ctenomys have been recorded.” This region is now recognized as General Acha in La Pampa Province. Ctenomys azarae is related to the “mendocinus-porteousi-australis” assemblage, and both Cabrera (1961) and J. R. Contreras and Reig (1965) regarded azarae as a subspecies of C. mendocinus. The karyotype is very similar to that of C. mendocinus (2n = 46, 47, 48), with the two species share the same chromosomal polymorphisms (Massarini, Barros, Ortells, and

824 Mammals of South America

Map 423

Selected localities for Ctenomys azarae (●). Contour line = 2,000 m.

Reig 1991; Massarini et al.1998; Braggio et al. 1999). The sperm is of the simple asymmetric type (M. H. Gallardo 1979; Vitullo et al. 1988). De Santis et al. (2001) described enamel microstructure.

Ctenomys bergi Thomas, 1902 Córdoba Tuco-tuco sy n o n y m s : Ctenomys bergi Thomas, 1902d:241; type locality “Cruz del Eje,” Departamento Cruz del Eje, Córdoba, Argentina, 30°44′S, 64°48′W, 449 m. Ctenomys mendocinus bergi: Cabrera, 1961:551; name combination. d e s c r i p t i o n : Small to medium-sized species; external dimensions of holotype, a male, head and body length 190 mm, tail length 74 mm; head and body ranges (from A. I. Medina et al. 2007) in males 157–163 mm and females 132–144 mm. General color above uniform sandy fawn while sides and ventral surfaces pale fawn; center of face from muzzle to between ears dark brown and conspicuously different from rest of body. Skull small, narrow, and not flattened in lateral profile but rather slightly and evenly convex; nasals parallel-sided or evenly narrowing posteriorly; posterior width across auditory meatus broader than zygomatic breadth; bullae large and inflated; mesopterygoid fossa extends to level of M2. d i s t r i b u t i o n : This species is restricted to the Chaco Seco ecoregion of Córdoba province, Argentina, extending northwest from the type locality along the course of the Río Cruz del Eje. Populations at Salinas Grandes reach almost 1,000 m. Contrary to Cabrera (1961), there are no confirmed records of this species from La Rioja Province.

Map 424

Selected localities for Ctenomys bergi (●). Contour line = 2,000 m.

s e l e c t e d l o c a l i t i e s (Map 424; from A. I. Medina et al. 2007, except as noted): ARGENTINA: Córdoba, Cruz del Eje (type locality of Ctenomys bergi Thomas, 1902), Guanaco Muerto, Las Toscas, Salinas Grandes. s u b s p e c i e s : Ctenomys bergi is monotypic. n a t u r a l h i s t o ry: This is a poorly known species sparsely distributed in low-density populations. r e m a r k s : Although Cabrera (1961:552) considered Ctenomys bergi a subspecies of C. mendocinus, the species is well differentiated from the latter by the possession of a unique karyotype (2n = 50, FN = 90; Giménez et al. 1999) and through mtDNA phylogenetic analyses (Mascheretti et al. 2000). The sperm has the simple asymmetric morphology (Giménez et al. 1999).

Ctenomys bicolor Miranda-Ribeiro, 1914 Bicolored Tuco-tuco sy n o n y m s : Ctenomys bicolor Miranda-Ribeiro, 1914:41, plates 20 and 23, Figs. 2–2a′, 4, and 6; type locality “Mato Grosso” (Avila-Pires 1968:182); restricted by Bidau and AvilaPires (2009) to Rôndonia (Brazil) between 11°50′10′′S and 12°00′00′′S, and 60°51′′35′′ W and 61°19′29′′W. Ctenomys minutus bicolor: Cabrera, 1961:553; name combination. d e s c r i p t i o n : The holotype and only known specimen (sex unknown) large; head and body length 230 mm, tail length 95 mm. Skull relatively short (length 46 mm) but wide (zygomatic breadth 31 mm). Miranda-Ribeiro (1914)

Suborder Hystricomorpha: Family Ctenomyidae 825

compared his single specimen to C. minutus and recorded a number of cranial differences, including zygomatic breadth and curvature, which are larger and more pronounced, respectively; presence of postocular process of frontals in C. bicolor but not in C. minutus; and general shape of cranium different. Dorsal color blackish gray flanks similar but hairs with ochraceous tips, limbs whitish-ochraceous, and tail whitish (Miranda-Ribeiro 1914; Avila-Pires 1968). d i s t r i b u t i o n : This species is known only from its rather ambiguous type locality. s e l e c t e d l o c a l i t i e s (Map 425): BRAZIL: Rondônia, no more precise locality is known (see above; type locality of Ctenomys bicolor Miranda-Ribeiro). s u b s p e c i e s : Ctenomys bicolor is monotypic. n a t u r a l h i s t o ry: No ecological or other biological data are known for Ctenomys bicolor. r e m a r k s : The only known specimen of C. bicolor was collected on October 9, 1912, by the Comissão Rondon although this information was not cited in the original description (Miranda-Ribeiro 1914). The specimen is deposited in the collection of the Museu Nacional (Rio de Janeiro) as MNRJ 2052 (Langguth et al. 1997), erroneously cited as MNRJ 2025 by João Moojen (in MirandaRibeiro 1955). The only information about the locality is “Matto Grosso,” which at the time of collection comprised vast territories in the present-day state of Rondônia, Brazil. Avila-Pires (1968: 182), who redescribed the holotype,

Map 425 Approximate position of the single known locality for Ctenomys bicolor (●) (see Remarks). Contour line = 2,000 m.

gave the same information. However, Bidau and AvilaPires (2009), based on the memoirs of Colonel Cândido Rondon who led the expedition during which the single specimen was collected (Viveiros 1958), restricted the type locality to a 1,000 km2 area of Rôndonia state between Primavera de Rondônia and the Rio Barão de Melgaçõ (possibly on the banks of Rio Pimenta Bueno) between the coordinates 11°50′10′′S and 12°00′00′′S, and 60°51′35′′W and 61°19′29′′ W. Cabrera (1961) listed C. bicolor as a valid subspecies of C. minutus, without justification.

Ctenomys boliviensis Waterhouse, 1848 Bolivian Tuco-tuco sy n o n y m s : Ctenomys boliviensis Waterhouse, 1848:278; type locality “Plains of Santa Cruz de la Sierra”; Thomas (1921a:136) selected as lectotype (BM 46.7.28.57, an adult male) the cotype of which the skull was figured by Waterhouse, and refined the type locality to “Santa Cruz de la Sierra,” Santa Cruz, Bolivia, 480 m, 17°48′S 63°10′W. Ctenomys boliviensis boliviensis: Cabrera, 1961:546; name combination. d e s c r i p t i o n : Large species, with total length of males reaching 356 mm, tail length 80 mm, and mass up to 650 g; females smaller, total length 316 mm, tail length 95 mm, and mass 420 g (S. Anderson et al. 1987; S. Anderson 1997). Fur soft, very glossy, and rather short; general hue bright, rufous brown; upper surface of head and muzzle blackish brown, with same color continuing as broad but poorly defined band along back of neck to fore part of back; under parts bright rusty yellow color, with exception of space between hind legs, and large patch covering fore part of abdomen, where hairs are entirely white; tail dark brown above, pale brown beneath; fur tinged gray next skin on under parts, but dark slate gray at base on upper parts; sides of body rufous brown; back darker shade of same color, becoming gradually deeper toward head, where dark color contracted into band which runs along neck, and joins black-brown color of upper surface of head; broad mark of somewhat paler hue descends from behind ears to sides of body. Vibrissae dirty white. Feet sparsely clothed with pale brown hairs, with whitish hairs on sides. Tail clothed with dirty white color, very short hairs, except at base where they may be 10 mm in length. Upper incisors notably very broad, proportionally more so than in C. brasiliensis. Skull remarkable for its narrowed middle part of rostrum; nasal bones broader at their extremities than in C. brasiliensis; auditory bullae narrow with portion that extends ontooccipital plane considerably less extended in vertical direction; ridge traversing outer surface of malar bone very well developed. Cheek teeth broader relative to

826 Mammals of South America

length, with length of first molar shorter than in C. brasiliensis. About 20% of adult specimens show an open frontoparietal fenestrae (S. L. Gardner and Anderson 2001). d i s t r i b u t i o n : Ctenomys boliviensis is distributed in south-central Santa Cruz, Bolivia. Massoia’s (1970) report of C. boliviensis for Argentina is in error; these specimens are C. argentinus ( J. R. Contreras, pers. comm.). s e l e c t e d l o c a l i t i e s (Map 426; from S. Anderson 1997, except as noted): BOLIVIA: Santa Cruz, 2 km SE of Cotoca, Escatia Cachuela Esperanza, 3.5 km W of Estación Pailón, 4 km SW of La Bélgica, 5 km S of Mineros, Palmar de Osorio, 1 km SE of Puerto Pacay, San Miguel Rincón, Santa Cruz de la Sierra (type locality of Ctenomys boliviensis Waterhouse), ca. 55 km SE of Santa Cruz at Brecha. s u b s p e c i e s : Cabrera (1961) recognized two subspecies, C. b. boliviensis and C. b. goodfellowi. The latter was originally described as a full species (Thomas 1921d) based on his comparisons with C. boliviensis that established many clear differences. S. Anderson et al. (1987) maintained the subspecific status of C. goodfellowi, but also cited a number of characters to suggest its specific condition, a position later taken formally by Cook and Yates (1994) and S. Anderson (1997). Anderson et al. (1987) also considered Ctenomys nattereri (from Mato Grosso, Brasil) to be a subspecies of C. boliviensis, although knowledge of this taxon is extremely limited. Thus, in this account, I treat C. boliviensis as monotypic and regard both C. goodfellowi and C. nattereri as full species. n a t u r a l h i s t o ry: Ctenomys boliviensis inhabits friable soils in areas not frequently flooded where food consists mainly of underground tubers and roots (S. Anderson 1997). As is characteristic of other species of tucotucos that have been studied in the field, this one eats primarily underground tubers and roots. Mean litter size is 1.7 (range: 1–5; N = 55; S. Anderson 1997). S. L. Gardner and Duszynski (1990) described eimerian parasites. r e m a r k s : Ctenomys boliviensis belongs to the Chacoan lineage of Ctenomys ( J. R. Contreras and Bidau 1999) along with C. argentinus, C. conoveri, C. latro, C. goodfellowi, C. steinbachi, C. pilarensis, and possibly C. nattereri ( J. R. Contreras and Berry 1982a; S. Anderson et al. 1987). This species exhibits substantial karyotypic diversity over its limited geographic range, with 2n ranging from 36 to 46 (S. Anderson et al. 1987; Cook et al. 1990). Vitullo and Cook (1991) described sperm morphology with a symmetric head; Biknevicius (1993) provided data on functional anatomy; Ruedas et al. (1993) gave data on genome size estimates; and Cook and Yates (1994) evaluated species boundaries and relationships based on electromorphic characters.

Map 426 2,000 m.

Selected localities for Ctenomys boliviensis (●). Contour line =

Ctenomys bonettoi J. R. Contreras and Berry, 1982 Bonetto’s Tuco-tuco sy n o n y m : Ctenomys bonettoi J. R. Contreras and Berry, 1982a: 123; type locality “7.5 kilómetros al sudeste de Capitán Solari, Departamento Sargento Cabral, Provincia del Chaco, a 26°48′ de latitud sur y a 59°33′ de longitude oeste,” = Colonia Elisa, Argentina. d e s c r i p t i o n : Moderate-sized tuco-tuco, with males reaching 183 mm in head and body length, 77 mm in tail length, 37 mm in hindfoot length, and 220 g in mass; equivalent female dimensions 171 mm, 61 mm, 33 mm, and 185 g, respectively. Dorsal color uniformly brown marbled with dark hairs with median black band, more noticeable on head and in specimens with worn pelage; flanks yellowish brown, becoming yellowish on venter; hands and hindfeet covered dorsally with silvery gray hairs; palmar and plantar surfaces pink in life; tail yellowish with slightly more darkened dorsal stripe. Skull moderately robust, but with gracile rostrum; broadest part of zygomatic arch at level of posterior part of orbital fossa; bullae large and easily visible from above; anterior notch of mesopterygoid fossa V-shaped and penetrates palate to level of middle of M2; orbit relatively well developed, with postorbital process of frontal blunt and poorly defined. Upper incisors nearly opisthodont, with anterior face at about a 98° angle relative to horizontal plane.

Suborder Hystricomorpha: Family Ctenomyidae 827

Map 427

Selected localities for Ctenomys bonettoi (●).

d i s t r i b u t i o n : Ctenomys bonettoi occurs only from a few populations around the type locality in Chaco province, Argentina, within the Chaco Húmedo ecoregion. The entire distribution of this species is contained within the range of C. argentinus. s e l e c t e d l o c a l i t i e s (Map 427; from J. R. Contreras and Berry 1982a): ARGENTINA: Chaco, Ciervo Petiso, Colonia Elisa (type locality of Ctenomys bonettoi J. R. Contreras and Berry), Laguna Limpia. s u b s p e c i e s : Ctenomys bonettoi is monotypic. n a t u r a l h i s t o ry: This is a poorly known species inhabiting sandy patches within periodically flooded humid Chaco areas. r e m a r k s : The karyotype of C. bonettoi is 2n = 50, FN = 70 (Bidau et al. 2005), one that shares many affinities to that of C. “yolandae” (Bidau et al. 2005; see that account, below), with which it appears closely related based on molecular sequences (Mascheretti et al. 2000). Ctenomys bonettoi has a simple asymmetric sperm (Bidau et al. 2005).

Ctenomys brasiliensis Blainville, 1826 Brazilian Tuco-tuco sy n o n y m s : Ctenomys Brasiliensis Blainville, 1826:64; type locality “des parties intérieures du Brésil, de la Province de

Las Minas,” Minas Gerais, Brazil; redefined herein as Minas, Lavalleja, Uruguay (see Remarks). Spalax Brasiliensis: J. B. Fischer, 1829:304; name combination. d e s c r i p t i o n : Blainville’s original description and measurements indicate relatively large body size. No other information on external characters, including color or craniodental attributes, have been published. Fernandes et al. (2012) compared skull of Blainville’s holotype with representatives of C. pearsoni and C. torquatus using geometric morphometrics but did not provide actual linear dimensions for any craniodental attribute. d i s t r i b u t i o n : The range of C. brasiliensis is uncertain; see Remarks. s e l e c t e d l o c a l i t i e s (Map 428): URUGUAY: Lavalleja, Minas (type locality of Ctenomys Brasiliensis Blainville). s u b s p e c i e s : Ctenomys brasiliensis is monotypic. n a t u r a l h i s t o ry: No data are available. r e m a r k s : The name C. brasiliensis cannot be applied with certainty to any geographic group of tuco-tucos because Blainville’s citation of Minas Gerais as the type locality is likely in error. Despite the frequent listing of this species as part of the fauna of Minas Gerais (e.g., J. A. Oliveira and Bonvicino 2006), there are no known specimens of any tuco-tuco collected from this part of Brazil, nor are subfossil specimens of the genus known from the famous Lagoa Santa caves studied by the Danish naturalist Peter Wilhelm Lund and others. It is possible that Blainville’s type locality actually corresponds to the locality of Minas in present-day Uruguay, which in the early 1800s was part of the Brazilian Empire (Reig et al. 1966). In this sense, C. minutus (Reig et al. 1966) and C. torquatus (C. O. da C. Vieira 1955) have been suggested as synonyms of C. brasiliensis. A second possibility is that C. brasiliensis is one of the forms of the “pearsoni” complex of Uruguay (including C. dorbignyi and C. pearsoni), the distribution of which includes the town of Minas. However, no detailed comparisons have been made to support either of these hypotheses. Recently, Fernandes et al. (2012) compared the skull of the holotype of Blainville’s C. brasiliensis (collected by M. Florent Prévost and currently in the Museum National d’Histore Naturelle, Paris; NMHNP 397) to several other species, especially those from Uruguay, with geometric morphometric methods. These data and rediscovered information on the accompanying label written as “St. Paul, prov. las Minas” support Minas, in the department of Lavalleja, Uruguay, as the type locality of C. brasiliensis. At the time the specimen was collected, the entire region of what is now Uruguay was dominated by the Portuguese Empire (“Provincia Cispaltina do Reino Unido de Portugal, Brasil e Algarves”), and after Brazilian independence

828 Mammals of South America

Map 428

Single known locality for Ctenomys brasiliensis (●).

in 1822, the Uruguayan territory was considered part of a new country, Brazil. It was not until after 1825 that the province that later became Uruguay gained independence. Today, the area along the southern coast of Uruguay contains only populations of C. pearsoni E. P. Lessa and Langguth (see that account). Although Blainville’s holotype falls within the morphospace of a large sample of C. pearsoni from southern Uruguay but not that of C. torquatus from northern Uruguay, Fernandes et al. (2012) argued that additional studies were required before the taxonomic relationship of C. brasiliensis—and thus the possible application of Blainville’s name—to the C. pearsoni complex of tuco-tucos can be established. Available evidence, however, supports the hypothesis that C. brasiliensis, the type species of Ctenomys, was collected in what is now Uruguay and never ranged into southeastern Brazil. Karyotype and sperm morphology are unknown. Gerard (1862) listed two Bolivian specimens at the British Museum without exact localities as C. brasiliensis, but these probably belong to C. boliviensis (S. Anderson 1997).

Ctenomys colburni J. A. Allen, 1903 White-bellied Tuco-tuco sy n o n y m : Ctenomys colburni J. A. Allen, 1903b:188; type locality “Arroyo Ayke, in the basalt canyons, 50 miles southeast of Lake Buenos Ayres, Patagonia,” = Cañones basálticos, Arroyo Aikén, 50 miles SE Lago Buenos Aires, De-

Map 429

Selected localities for Ctenomys colburni (●).

partamento Lago Buenos Aires, Santa Cruz, Argentina, 46°40′S, 70°30′ W, ca. 500 m. d e s c r i p t i o n : Small tuco-tuco, with mean head and body length 161 mm and tail length 71 mm for males, and 146 mm and 63 mm, respectively, for females ( J. A. Allen 1903b; Kelt and Gallardo 1994). Dorsal color yellowish gray strongly suffused with fulvous as opposed to black; color varies among individuals, especially with respect to distinctness of dorsal tail stripe that may be absent, present only as faint trace, or present with strongly developed black stripe. d i s t r i b u t i o n : This species is known only from a few localities in Santa Cruz and Río Negro provinces of Argentina. s e l e c t e d l o c a l i t i e s (Map 429): ARGENTINA: Río Negro, Estancia Huanuluan (Kelt and Gallardo 1994); Santa Cruz, Arroyo Aikén (type locality of Ctenomys colburni J. A. Allen), Casa de Piedra, Río Ecker (A. I. Medina et al. 2007), Estancia La Cantera (Kelt and Gallardo 1994), Río Deseado (Kelt and Gallardo 1994). s u b s p e c i e s : Ctenomys colburni is monotypic. n a t u r a l h i s t o ry: No data are available. r e m a r k s : Ctenomys colburni is morphologically similar to the neighboring Chilean species C. coyhaiquensis,

Suborder Hystricomorpha: Family Ctenomyidae 829

although the latter appears chromosomally more similar to the C. maulinus group (Kelt and Gallardo 1994). J. A. Allen (1903b) also pointed to similarity with C. sericeus from the Argentine Patagonia. The karyotype is 2n = 34 (M. H. Gallardo 1991). Morphology of the sperm is simple asymmetric (Kelt and Gallardo 1994).

Ctenomys coludo Thomas, 1920 Puntilla Tuco-tuco sy n o n y m s : Ctenomys coludo Thomas, 1920d:119; type locality “La Puntilla, near Tinogasta, Catamarca,” Argentina, 28°04′S, 67°34′ W, 1,000 m. Ctenomys coludo coludo: Tate, 1935:390; name combination. Ctenomys fulvus coludo: Cabrera, 1961:548; name combination. d e s c r i p t i o n : Relatively large species with total length of 302 mm and tail length of 97 mm in type specimen (a male), readily recognizable by uniformly pale color, long tail (>45% of head and body length), narrow skull, and large bullae; easily differentiated from two geographically nearest species: C. fochi, which is more than 20% smaller, and C. knighti, which is much darker, has shorter tail, larger teeth, and broader frontal region. d i s t r i b u t i o n : Ctenomys coludo is known only from the type locality, which is “a few miles out from Tinogasta toward Copacabana, at an altitude of about 1000 m above sea level” (Thomas 1920d:116).

Map 430

Selected localities for Ctenomys coludo (●). Contour line = 2,000 m.

s e l e c t e d l o c a l i t i e s (Map 430): ARGENTINA: Catamarca, La Puntilla (type locality of Ctenomys coludo Thomas), Portezuelo de Pasto Ventura (FMNH 46137). s u b s p e c i e s : Ctenomys coludo is monotypic. n a t u r a l h i s t o ry: No ecological or other biological data are available for this species. r e m a r k s : Ctenomys coludo is apparently related to C. fulvus from Chile. Karyotype and type of sperm are unknown.

Ctenomys conoveri Osgood, 1946 Chacoan Tuco-tuco sy n o n y m : Ctenomys (Chacomys) conoveri Osgood, 1946:47; type locality “Colonia Fernheim, 16 km. west of Filadelfia, Paraguayan Chaco. Approximately Long. 60°10′ W., Lat. 22°15′S.,” Boquerón, Paraguay. d e s c r i p t i o n : Largest species in genus, with males reaching 558 mm in head and body length, 122 mm in tail length, 60 mm in hindfoot length, and mass of 1,200 g (S. Anderson 1997). Pelage long and rather coarse, color nearly uniform cinnamon rufous with light mixture of dusky and scattered white hairs above and clear below. Tail heavily haired, rufous above and pale below, with median line of white toward tip. Skull massive and angular; jugal possesses unique cresentic excavation in front of high and broad dorsal process. Upper incisors very broad and heavy, slightly proodont, and grooved on anterior surface. Some adult specimens exhibit open frontoparietal fenestrae (S. L. Gardner and Anderson 2001). d i s t r i b u t i o n : This species occurs through the Chaco Boreal ecoregion of northwestern Paraguay and southern Bolivia. s e l e c t e d l o c a l i t i e s (Map 431; from S. Anderson 1997, except as noted): BOLIVIA: Chuquisaca, 9 km E of Carandaytí, 1.5 km NW of Povenir; Santa Cruz, 26 km E of Boyuibe; Tarija, 10 km S of Capirenda, Palo Marcado, Villa Montes. PARAGUAY: Boquerón, Colonia Fernheim (type locality of Ctenomys conoveri Osgood). s u b s p e c i e s : Ctenomys conoveri is monotypic. n a t u r a l h i s t o ry: No data are available on ecology, food habits, or reproduction. S. L. Gardner and Duszynski (1990) described eimerian oocysts in one specimen. r e m a r k s : Because Osgood (1946:47) believed that C. conoveri differed “widely from any previously described species,” he placed it as the sole member of his subgenus Chacomys. However, electrophoretic analyses do not support subgeneric rank but rather indicate a sister relationship between C. conoveri and both C. frater and C. lewisi, two species of the nominotypical subgenus, among those species examined (Cook and Yates 1994). A relationship to other species of a Chacoan group such as C. argentinus,

830 Mammals of South America

Map 431 2,000 m.

Selected localities for Ctenomys conoveri (●). Contour line =

C. boliviensis, and C. goodfellowi had been suggested earlier on morphological grounds ( J. R. Contreras and Berry 1982b). Osgood (1946) compared the skull of C. conoveri to that of C. robustus (now = C. fulvus Philippi), another large species, in his description. Eisentraut (1933) misidentified specimens of this species from Villa Montes, Palo Marcado, and near Samahuate in Bolivia as C. brasiliensis. Later, he (Eisentraut 1983) also referred specimens from the Chaco region of Bolivia to C. brasiliensis, considered by S. Anderson (1997:493) as “perhaps C. conoveri.” Krumbiegel (1941a) also misidentified specimens of C. conoveri from Villa Montes, Bolivia, as C. leucodon (see S. Anderson 1997). Reports of the presence of C. conoveri in Argentina (Massoia 1977) are based on misidentified specimens of C. argentinus ( J. R. Contreras and Berry 1982a). The karyotype for Bolivian specimens is 2n = 48 (S. Anderson et al. 1987:15), and for Paraguayan individuals is 2n = 50 (Ortells 1995). Sperm morphology is simple asymmetric ( J. R. Contreras 1996).

Ctenomys coyhaiquensis Kelt and Gallardo, 1994 Coyahique Tuco-tuco sy n o n y m : Ctenomys coyhaiquensis Kelt and Gallardo, 1994:344; type locality “2 km S Chile Chico and 1 km W Chile Chico aeródromo, Provincia General Carrera, XI Región de Aisén [= Aysén], Chile. 46°33′S, 71°46′W, 330 m.”

d e s c r i p t i o n : Small species of tuco-tuco, head and body length between 195–264 mm, tail length 60–81 mm, hindfoot length 28–34 mm, and mass 72–182 g. Pelage tawny brown washed with yellow and black. Dorsal pelage consists of two kinds of hairs, one long and black, scattered throughout, and other tricolored with dark gray base, buff median band, and black tips. Middorsal region darker, as typical of many other species of tuco-tucos; dorsal coloration fades laterally toward ventral region, where hairs are bicolored dark gray proximally and pale buff or ochraceous buff distally. Feet of adults covered dorsally with silvery-white hairs. Tail bicolored, with darker dorsal color extending ventrally along terminal one-third of tail. Skull with large orange and mildly proodont incisors; sturdy zygomatic arches; large auditory bullae; auditory meatus extending laterally just beyond zygomatic arches; nasals slightly flared anteriorly; bony capsule of incisor root protrudes from side of rostrum; pronounced lateral ridge separates dorsal and ventral zygomatic fossae; sphenoid bones large and extend posteriorly to occipital crest; infraorbital canal large and ovoid, with small dorsoposterior projection where zygomatic plate meets frontal bone; parietal bones possess small postorbital process, complementing similar process on jugal; incisive foramina never more than one-half length of diastema; alisphenoidpresphenoid bridge straight and runs perpendicular to sagittal plane; postalisphenoid canal oval; and generally single lateral foramen present in alisphenoid. Both M3 and m3 reduced. Combination of traits diagnostic for species. d i s t r i b u t i o n : Ctenomys coyhaiquensis is known only from two localities in Chile between 330 and 730 m. Kelt and Gallardo (1994) suggested that the species might extend into Argentina, because both collecting sites are within 1 km of the border between the two countries. s e l e c t e d l o c a l i t i e s (Map 432): CHILE: Aysén, 2 km S Chile Chico and 1 km W of Chile Chico Aeródromo (type locality of Ctenomys coyhaiquensis Kelt and Gallardo), Fundo Los Flamencos, 4.5 km SE of Coyhaique Alto (Kelt and Gallardo 1994). s u b s p e c i e s : Ctenomys coyhaiquensis is monotypic. n a t u r a l h i s t o ry: At the type locality (Kelt and Gallardo 1994), C. coyhhaiquensis occupied sandy or rocky soils that supported a sparse shrub and herbaceous community. Principal shrubs included Mullinum spinosum (Apiaceae), Colliguaya saliscifolia (Euphorbiaceae), Escallonia rubra (Escalloniaceae), and Berberis buxifolia (Berberidaceae). At the higher Coyhaique Alto site, these tucotucos inhabited a gravelly soil with bunchgrasses and a few shrubs (B. buxifolia and E. rubra; Kelt and Gallardo 1994). r e m a r k s : M. H. Gallardo et al. (1996) documented the loss of genetic (electromorphic protein) variation in a population following an eruption of Volcán Hudson in

Suborder Hystricomorpha: Family Ctenomyidae 831

Map 432 2,000 m.

Selected localities for Ctenomys coyhaiquensis (●). Contour line =

southern Chile in 1991. The karyotype consists of 2n = 28, FN = 44 (Kelt and Gallardo 1994), and the sperm is of the simple asymmetric type (Kelt and Gallardo 1994).

Ctenomys dorbignyi J. R. Contreras and Contreras, 1984 D’Orbigny’s Tuco-tuco sy n o n y m s : Ctenomys d’orbignyi J. R. Contreras and Contreras, 1984: 131; type locality “Paraje Mbarigüí, Departamento Berón de Astrada, Provincia de Corrientes, a 27°33′ de latitud Sur y a 57°31′ de longitud oeste,” Argentina, 54 m; note incorrect original spelling with apostrophe (ICZN 1999:Art. 32.5.2). Ctenomys dorbignyi: J. R. Contreras and Scolaro, 1986:21; corrected spelling of d’orbignyi J. R. Contreras and Contreras. d e s c r i p t i o n : Relatively large tuco-tuco, with average head and body length 206 mm (range: 190–224 mm), tail length 91 mm (range: 86–99 mm), hindfoot length (including claws) 40.4 mm (range: 38.7–43.0 mm), and mass 331 g (range: 269–376 g). Dorsal color fairly uniform brown tone overall; venter pale; there no collar of differentiated color; white postauricular spots as well as white areas in axilla and inguinal regions present, although extent of latter variable. Skull robust and relatively long, with broad and slightly expanded rostrum, and moderately proodont upper incisors; width of interorbital constriction

and zygomatic breadth proportionately smaller than species of Chaco region, and tympanic bullae more developed than in that species group; frontoparietal sutures gently curved forward; line through apex of spinous processes and postorbital process of jugal slants slightly forward; free end of vomer between premaxillaries well developed and clearly visible; no visible interpremaxillary foramen; orbital expansion of maxilla extends above jugal with crescent-shaped external depression extending onto adjacent bones, which not as deep as in C. argentinus or C. conoveri, but more marked than in C. perrensi, with vertical, thin but well-developed sickle-shaped blade. d i s t r i b u t i o n : Ctenomys dorbignyi occurs in a series of isolated areas in Corrientes and Entre Ríos provinces within the Esteros del Iberá and Pampa ecoregions of Argentina ( J. R. Contreras and Contreras 1984; J. R. Contreras and Scolaro 1986; see Remarks). s e l e c t e d l o c a l i t i e s (Map 433; from J. R. Contreras and Contreras 1984, except as noted): ARGENTINA: Corrientes, Costa Grande, Mbarigüí (type locality of Ctenomys dorbignyi J. R. Contreras and Contreras), Tres Bocas, Esquina, Los Angeles, Laguna Itá, Arerunguá, La Tilita, Ibahay, Paraje Yabyrahá, Caa Catí, Palmar Grande, Colonia Romero, Tacuaracuarendy Sarandicito (Argüelles et al. 2001); Entre Ríos, Paso Vera (Giménez et al. 2002), San Joaquín de Miraflores (Giménez et al. 2002), Tiro Federal (Giménez et al. 2002). s u b s p e c i e s : Ctenomys dorbignyi is monotypic. n a t u r a l h i s t o ry: Ctenomys dorbignyi inhabits sandy patches far from the forested islets that are frequent within the area of its distribution. Population size is strongly affected by the cycles of annual rainfall. Litter size averages 1.3 ± 0.58, N = 18 ( J. R. Contreras, pers. comm.). Population density is low in northern populations and much higher in the southern ones. J. R. Contreras and Contreras (1984) suggested that the species is at least semisocial, although this claim needs confirmation. r e m a r k s : Ctenomys dorbignyi is readily distinguished from neighboring species ( J. R. Contreras and Contreras 1984). From C. perrensi, C. dorbignyi differs in its color and color pattern, in less pronounced procumbency, by the reduction or obliteration of the interpremaxillary foramen, larger tympanic bullae, higher and wider rostrum, and a more convex cranium. From C. argentinus, C. dorbignyi differs in all diagnostic cranial characters. This species does show some superficial resemblance to C. minutus but differs in the morphology of the occipital foramen and relative zygomatic breadth. The karyotype of C. dorbignyi is 2n = 70 in all the populations with minor variation in FN (80 to 84). The karyotypic similarity to C. pearsoni (2n = 68–70) reinforces other commonalities between the two taxa (Argüelles et al. 2001).

832 Mammals of South America

Map 433

Selected localities for Ctenomys dorbignyi (●).

J. R. Contreras and Scolaro (1986) compared cranial measurements among four geographically partitioned samples covering the species range in Corrientes province, noting that the eastern sample (oriental nucleo), centered at the locality of Contreras Cué, was substantially divergent in multivariate morphospace relative to the other three samples. Interestingly, this same population does not share the typical 2n = 70 karyotype characteristic of C. dorbignyi but has diploid numbers ranging between 2n = 41 and 2n = 47 (Ortells et al. 1990; Giménez et al. 2002). Analyses of mtDNA suggest that this latter group is likely an undescribed species (informally called Ctenomys sp. by Giménez et al. 2002; see also Remarks for C. perrensi). Pending further field and laboratory analyses, the Contreras Cué sample is best considered as a taxon distinct from C. dorbignyi; it is not included in the mapped range. Sperm morphology is simple symmetric (Vitullo et al. 1988).

Ctenomys dorsalis Thomas, 1900 Black-backed Tuco-tuco sy n o n y m : Ctenomys dorsalis Thomas, 1900g:385; type locality “Northern Chaco of Paraguay”; a more specific locality is in-

determinable at present, but presumably either in Alto Paraguay or Boquerón departments. d e s c r i p t i o n : Small tuco-tuco, holotype (female) 156 mm in head and body length, 46 mm in tail length, and 30 mm in hindfoot length. Fur soft and fine. General dorsal color buffy fawn with marbled black dorsal line extending from nose to rump; line sharply defined on head, about 10 mm broad, but widens to more diffuse band on back; dark lateral face markings around eye or ear lacking, but well-marked light collar present behind cheeks and chin extending to each side of ear. Throat, chest, outer edges of belly, and narrow midline stripe pale buffy with slatecolored basal hairs; remaining ventral hairs self-colored white. Dorsal surfaces of both hands and feet dirty white. Tail hairs mixed black and white. Craniodental characters have not been described, except that incisors orange above and below. d i s t r i b u t i o n : The geographic distribution of C. dorsalis is unknown, but presumably encompasses the Chaco Boreal ecoregion of Paraguay and perhaps adjacent Bolivia and/or Brazil (see Remarks). s e l e c t e d l o c a l i t i e s (Map 434): PARAGUAY: Alto Paraguay or Boquerón, precise locality unknown. s u b s p e c i e s : Ctenomys dorsalis is monotypic. n a t u r a l h i s t o ry: No data are available. r e m a r k s : The type, and only known specimen, was collected in 1900 and presented to the Natural History Museum (London) by J. G. Kerr; it consists of a skin and upper incisors. Because of the uncertainty of its type locality, C. dorsalis is another of the problematic species of tuco-tucos, although various authors have provided arguments to restrict the type locality. For example, Rusconi (1928) proposed Resistencia (in Chaco province, Argentina) as the type locality. Moojen (1952b) suggested a distribution in present-day Chaco Boreal (which was part of Bolivia in 1900, the year the holotype was collected), perhaps extending into adjacent Brazil. Cabrera (1961), Mares and Ojeda (1982), Redford and Eisenberg (1992), and Woods and Kilpatrick (2005) give a variation on “northern Paraguayan Chaco.” Redford and Eisenberg (1992:map 11.129) map two localities without documentation. However, until additional specimens matching the details of the holotype are collected, the type locality of C. dorsalis will remain ambiguous. A useful hint for identifying at least the general Chacoan area where the type specimen was obtained might be in the local vernacular name Sumkum (Thomas 1900g), possibly sunkum. Careful examination of the vocabularies of the various indigenous tribes in the general Chaco region may help to pinpoint a more limited area of occurrence ( J. R. Contreras and Roig 1992). Karyology and sperm morphology are unknown.

Suborder Hystricomorpha: Family Ctenomyidae 833

Map 434

Possible range of Ctenomys dorsalis (") (see Remarks).

Ctenomys emilianus Thomas and St. Leger, 1926 Emily’s Tuco-tuco sy n o n y m : Ctenomys emilianus Thomas and St. Leger, 1926b:637; type locality “Chos Malal, Prov. Neuquén. Altitude 805 m,” Departamento Chos Malal, Neuquén, Argentina, 37°23′S, 70°16′W. d e s c r i p t i o n : Large, pale tuco-tuco, “readily distinguishable by its clear fawn color, contrasting with the whitish belly and sides, and its low flattish skull” (Thomas and St. Leger 1926b:638). External dimensions of holotype head and body length 211 mm, tail length 91 mm, and hindfoot length 39 mm. General color above pale glossy fawn, uniform on head and back, without frontal blackening; sides and venter, including chin and throat, buffy whitish, with this color extending further up sides and onto hips and thighs more than in most other species, and thus contrasting with brown color of rump. Hairs of forefeet and hindfeet and tail buffy whitish; tail lacks any blackening of its terminal tuft. Skull slender in build, flat, with zygomatic arches expanded but not convex; nasals narrow; interorbital region flattened; braincase low with masseteric ridge well defined; lambdoidal ridges well defined; vertical occipital central ridge absent; and bullae large and well inflated. d i s t r i b u t i o n : Ctenomys emilianus is only known from the type locality and neighboring areas in the Patagonian steppe of Neuquén province, Argentina.

Map 435 2,000 m.

Selected localities for Ctenomys emilianus (●). Contour line =

s e l e c t e d l o c a l i t i e s (Map 435): ARGENTINA: Neuquén, Chos Malal (holotype of Ctenomys emilianus Thomas and St. Leger), Río Quilquihue (Massoia 1988a). s u b s p e c i e s : Ctenomys emilianus is monotypic. n a t u r a l h i s t o ry: Ctenomys emilianus lives in sandy soils and dunes at elevations up to 800 m. It occurs parapatrically with a small and more darkly colored species (probably C. haigi) in the vicinity of the type locality of Chos Malal (Thomas and St. Leger 1926b; Pearson 1984). r e m a r k s : Neither karyotype nor sperm morphology have been described.

Ctenomys famosus Thomas, 1920 Famatina Tuco-tuco sy n o n y m s : Ctenomys famosus Thomas, 1920g:420; type locality “Potrerillo, at about 2600 m,” Sierra de Famatina, Departamento Famatina, La Rioja, Argentina, 25°50′S, 67°27′ W, 2,600 m. Ctenomys fulvus famosus: Cabrera, 1961:549; name combination. d e s c r i p t i o n : Relatively small tuco-tuco, with holotype (female) dimensions head and body length 160 mm, tail length 74 mm, and hindfoot length 31.5 mm. Color above and below uniformly pale, similar to that of C. coludo, but tail considerably shorter. Skull also similar to that of C. coludo but overall smaller, with smaller bullae,

834 Mammals of South America

Map 436 2,000 m.

Single known locality for Ctenomys famosus (●). Contour line =

with less widely expanded zygomatic arches, and less heavy cheek teeth; supraorbital region with small ledges. d i s t r i b u t i o n : Ctenomys famosus is known from the type locality and probably nearby areas within the Sierra de Famatina in La Rioja province, Argentina, at elevations to 3,800 m. s e l e c t e d l o c a l i t i e s (Map 436): ARGENTINA: La Rioja, Potrerillo (type locality of Ctenomys famosus Thomas). s u b s p e c i e s : Ctenomys famosus is monotypic. n a t u r a l h i s t o ry: No ecological data are available. r e m a r k s : Thomas (1920g) regarded C. famosus as morphologically similar to the geographically adjacent C. coludo, which he had named earlier in the same year, differing from the latter primarily by a relatively shorter tail and smaller bullae. A year later Thomas (1921g) suggested that famosus was only a subspecies of coludo. Cabrera (1961) treated famosus as a subspecies of C. fulvus. The karyotype and sperm morphology are unknown.

74 mm of tail length. Upper incisors orthodont (Travi 1981). Overall color sandy yellow, making C. flamarioni palest species of those inhabiting southern Brazil and adjacent Uruguay (Rebelato 2006). Baculum elongated (mean length 10.4 mm) and thin, with rounded tip. Glans penis with spines of various shapes (from sharp to rounded); spine density 12/mm2, mean spine length 226.26 ± 32.42 µm s.d. (Rocha-Barbosa et al. 2013). d i s t r i b u t i o n : Ctenomys flamarioni occurs within the coastal dunes in Santa Catarina and Rio Grande do Sul states, Brazil. s e l e c t e d l o c a l i t i e s (Map 437; from Travi 1981): BRAZIL: Rio Grande do Sul, Cidreira, Fazenda Caçapava (type locality of Ctenomys flamarioni Travi), Hermenegildo, Lagoa do Peixe, Tramandaí; Santa Catarina, Morro dos Conventos. s u b s p e c i e s : Ctenomys flamarioni is monotypic. n a t u r a l h i s t o ry: This is one of the best-known species of tuco-tucos with respect to ecology and behavior. Males occupy territories almost five times larger than females (G. P. Fernandez 2002). Tunnel systems are very long, especially in males, and constructed at a depth of about 30 cm (Bretschneider 1987). Food items are mainly species of Poaceae and Cyperaceae (Bretschneider 1987). The overall sex ratio does not differ from 1:1 in the gen-

Ctenomys flamarioni Travi, 1981 Flamarion’s Tuco-tuco sy n o n y m : Ctenomys flamarioni Travi, 1981:123; type locality “Fazenda Caçapava, Estação Ecológica do Taim, Rio Grande, Rio Grande do Sul, Brasil,” 32°52′S 52°32′W, 5–10 m. d e s c r i p t i o n : Medium to large-sized species, with holotype (female) measuring 289 mm in total length and

Map 437

Selected localities for Ctenomys flamarioni (●).

Suborder Hystricomorpha: Family Ctenomyidae 835

eral population, but in adults the ratio is biased toward females (2:1–2.7:1), and the species is polygynous in mating behavior (G. P. Fernandez 2002). Gestation is about 120 days long (Bretschneider 1987), and litter size ranges between two and three (Travi 1983). Fernandez-Stolz et al. (2007) described the role of dispersal in local population bottlenecks. r e m a r k s : Ctenomys flamarioni is distinguished from the neighboring species C. torquatus, C. minutus, and C. lami by its whitish-yellow color and zygomatic region. The karyotype of C. flamarioni is 2n = 48, FN = 50–78, partly associated with geographic variation in whole-arm constitutive heterochromatin. G-banding suggests a close cytogenetic relationship between C. flamarioni and species of the Argentinian “mendocinus-group,” such as C. australis, C. mendocinus, and C. porteousi (T. R. O. Freitas 1994; Massarini and Freitas 2005), a hypothesis strongly supported by mtDNA sequence analysis (Parada et al. 2011). Sperm morphology is the simple asymmetric type (T. R. O. Freitas 1995a).

Ctenomys fochi Thomas, 1919 Foch’s Tuco-tuco sy n o n y m s : Ctenomys fochi Thomas, 1919a:117; type locality “Chumbicha, Catamarca,” Departamento Capayán, Catamarca, Argentina, 28°52′S, 66°14′W, 415 m. Ctenomys mendocinus fochi: Cabrera, 1961:552; name combination; considered a valid subspecies of a polytypic C. mendocinus Philippi. C[tenomys]. fachi Redford and Eisenberg, 1992:374; incorrect subsequent spelling of Ctenomys fochi Thomas. d e s c r i p t i o n : Small species, with external dimensions of holotype (young adult male) head and body length 162 mm, tail length 76 mm, and hindfoot length 30 mm. General body color drab buffy brown with hairs of venter washed with paler tones; hairs throughout slaty at base; muzzle and crown nearly black. Skull similar to that of C. bergi, but with bullae uniformly more inflated and line connecting anterointernal angle with meatal tube more distinctly convex forward. d i s t r i b u t i o n : Ctenomys fochi is known only from the vicinity of the type locality in Catamarca province, Argentina. s e l e c t e d l o c a l i t i e s (Map 438): ARGENTINA: Catamarca, Chumbicha (type locality of Ctenomys fochi Thomas). s u b s p e c i e s : Ctenomys fochi is monotypic. n a t u r a l h i s t o ry: No ecological data are available. According to the collector, Emilio Budin, the species “lives in very dry red earth” (Thomas 1919a:119). r e m a r k s : Ctenomys fochi is apparently closely related to C. bergi from Córdoba province (Thomas 1919a),

Map 438

Single known locality Ctenomys fochi (●). Contour line = 2,000 m.

but is distinguishable in aspects of color, particularly the nearly black muzzle and crown, and by the more greatly inflated bullae. The karyotype and sperm morphology are unknown.

Ctenomys fodax Thomas, 1910 Lago Blanco Tuco-tuco sy n o n y m s : Ctenomys fodax Thomas, 1910a:243; type locality “Valle del Lago Blanco, Cordillera region of Southern Chubut, Patagonia (about 46°S., 71°W.)”; restricted to Estancia Valle Huemules, Departamento Río Senguerr, Chubut, Argentina (45°57′S, 71°31′ W, 575 m) by Pardiñas et al. (2007). Ctenomys talarum fodax: Rusconi, 1928:243; name combination. d e s c r i p t i o n : One of larger species in genus, with dimensions of holotype (adult male) head and body length 260 mm, tail length 98 mm, and hindfoot length (without claw) 40.4 mm. Fur soft; dorsal color generally cinnamon. Skull large and bowed, with nasals broad in front giving entire rostrum broad appearance; nasals extend posteriorly to frontopremaxillary processes; auditory bullae sufficiently expanded to be visible when braincase is viewed from above; interparietal longer than broad, commonly divided by median suture. d i s t r i b u t i o n : Ctenomys fodax is restricted to the vicinity of the type locality in the Patagonian steppe of Chubut province, Argentina.

836 Mammals of South America

Map 439

Selected localities for Ctenomys fodax (●).

s e l e c t e d l o c a l i t i e s (Map 439): ARGENTINA: Chubut, Estancia Valle Huemules, Lago Blanco (type locality of Ctenomys fodax Thomas, as restricted by Pardiñas et al. 2007), Lago Musters (A. I. Medina et al. 2007), Valle del Lago Blanco (FMNH 18191). s u b s p e c i e s : Ctenomys fodax is monotypic. n a t u r a l h i s t o ry: No ecological data are available. r e m a r k s : Considered by Thomas (1910a) to be most closely related to C. osgoodi J. A. Allen (now C. magellanicus osgoodi; see that account), but larger in body size and with distinctive cranial differences. Listed by Osgood (1943b) and Cabrera (1961) as a synonym of C. magellanicus osgoodi J. A. Allen. The karyotype is 2n = 28, FN = 38, and sperm morphology is of the simple asymmetric type (Montes et al. 2001).

Ctenomys frater Thomas, 1902 Forest Tuco-tuco, Red Tuco-tuco sy n o n y m s : Ctenomys frater Thomas, 1902c:228; type locality “Potosí, 4300 m,” Potosí, Bolivia, 19°35′S, 65°45′ W, ca. 4,300 m. Ctenomys budini Thomas, 1913a:141; type locality “Cerro de Lagunita, E. of Maimara. 4500m,” Jujuy, Argentina. Ctenomys sylvanus Thomas, 1919g:155; type locality “Tartagal, 600 m”; Salta, Argentina. Ctenomys sylvanus utibilis Thomas, 1920a:193: type locality “Yuto, Rio San Francisco. Alt. 500 m.”; about 70 km N Villa Carolina, Jujuy, Argentina.

Ctenomys budini barbarus Thomas, 1921d:185; type locality “Sierra Santa Barbara, S. E. Jujuy. Type from Sunchal, alt. 1200 m”; Jujuy, Argentina. Ctenomys budini budini: Thomas, 1921d:186; name combination. Ctenomys budini sylvanus: Thomas, 1921d:186; name combination. Ctenomys budini utibilis: Thomas, 1921d:186; name combination. Ctenomys sylvanus mordosus Thomas, 1926c:325; type locality “Tambo, 2200 m,” Tarija, Bolivia; considered by Cabrera (1961:548) to be a valid subspecies of a polytypic C. frater Thomas. [Ctenomys] sylvanus sylvanus: Tate, 1935:390; name combination. Ctenomys frater barbarus: Cabrera, 1961:547; name combination. Ctenomys frater budini: Cabrera, 1961:548; name combination. Ctenomys frater frater: Cabrera, 1961:548; name combination. Ctenomys frater mordosus: Cabrera, 1961:548; name combination. Ctenomys frater sylvanus: Cabrera, 1961:548; name combination. d e s c r i p t i o n : Small to medium-sized species; specimens of C. f. mordosus from Bolivia with total length 229–272 mm, tail length 55–76 mm (S. Anderson 1997); those from Jujuy, Argentina, larger, with total length 230– 300 mm, tail length 50–85 mm (M. M. Díaz and Barquez 2002). General color of nominotypical subspecies and C. f. mordosus brownish fawn with dull buffy undersurface without inguinal white patches (Thomas 1902c; S. Anderson 1997). Specimens from Salta province, Argentina, dark russet to black (M. M. Díaz et al. 1997), and those from Jujuy Province reddish or coppery (hence, common name “tuco colorado” [red tuco-tuco]; M. M. Díaz and Barquez 2002). Skull greatly vaulted. Thomas (1926c:325–326) characterized C. s. mordosus as having “size and general external appearance quite as in true sylvanus,” but with much broader and heavier incisors, “their combined breadth attaining 7 mm in old specimens as compared with 5.5 mm. in equally aged specimens of sylvanus.” Upper incisors nearly orthodont, with angle of anterior face 98° of horizontal plane. Rostrum of mordosus thickened, in a manner seen “to a still greater extent in C. boliviensis” and in C. steinbachi. “An allied species, with equally broad incisors, is the Ctenomys frater of Potosi, but that has peculiarly narrowed bullae and is of a decidedly lighter colour.” d i s t r i b u t i o n : Ctenomys frater occurs in southern Bolivia (Potosí and Tarija departments) and northwestern Argentina (Salta and Jujuy provinces).

Suborder Hystricomorpha: Family Ctenomyidae 837

s e l e c t e d l o c a l i t i e s (Map 440): ARGENTINA: Jujuy, Caimancito (FMNH 29048), Calilegua (FMNH 23235), Cerro de la Lagunita (type locality of Ctenomys budini Thomas), mountains W of Yala (FMNH 23241), San Rafael (FMNH 29053), Sunchal (type locality of Ctenomys budini barbarus Thomas), Yuto, Río San Francisco (type locality of Ctenomys sylvanus utibilis Thomas); Salta, Aguaray (CML 80), Tartagal (type locality of Ctenomys sylvanus Thomas). BOLIVIA: Potosí, Potosí (type locality of Ctenomys frater Thomas); Tarija, Caraparí (Anderson 1997), 3 km SE of Cuyambuyo (S. Anderson 1997), Tambo (type locality of Ctenomys sylvanus mordosus Thomas), Yacuiba (S. Anderson 1997). s u b s p e c i e s : Ctenomys frater currently includes five subspecies (synonymies listed here under the species): Ctenomys f. frater Thomas, an isolated population in eastern Potosí, Bolivia; Ctenomys f. barbarus Thomas, from the mountains in southern Jujuy and adjacent Salta, Argentina; Ctenomys f. budini Thomas, from the high elevations in Jujuy and adjacent west-central Salta, Argentina; Ctenomys f. mordosus Thomas, from southern Tarija, Bolivia, and perhaps extreme northern Jujuy, Argentina; and Ctenomys f. sylvanus Thomas, from the base of the Andes in eastern Jujuy and western Salta, Argentina. n a t u r a l h i s t o ry: In Argentina, Ctenomys frater has been captured in moist forests and grassy meadows between 2,000 and 4,500 m in Jujuy Province, and in flat areas with deep soils near creeks in Salta Province (Mares, Ojeda, and Kosco 1981; see also Thomas 1919g). In Bolivia, the subspecies C. f. mordosus occurs at elevations from 600 to 2,700 m, and C. f. frater at 4,300 m. No detailed data on habitat, habits, behavior, food, or reproduction is known for Bolivian populations (S. Anderson 1997). S. L. Gardner and Duszynski (1990) describe eimerian oocysts in the feces of three specimens of C. f. mordosus. r e m a r k s : Woods (1993) erroneously gave the type locality of C. frater Thomas as in Argentina. In 1921, Thomas (p. 186) argued that sylvanus Thomas and sylvanus utibilis Thomas, along with budini Thomas and a new form he described in that paper (budini barbarus) “should be united specifically, and be considered as four subspecies of one species” (i.e., C. b. budini, C. b. sylvanus, C. b. utibilis, and C. b. barbarus). In 1926, ignoring his earlier view that sylvanus was only a subspecies of budini, Thomas (p. 325) described Ctenomys sylvanus mordosus but noted that it was allied to Ctenomys frater. Cabrera (1961) grouped each of these names, in various combinations, into five subspecies of C. frater: C. f. barbarus, C. f. budini, C. f. frater, C. f. mordosus, and C. f. sylvanus (with utibilis Thomas as a synonym). Woods and Kilpatrick (2005:1562) listed budini Thomas as a

Map 440

Selected localities for Ctenomys frater (●). Contour line = 2,000 m.

species distinct from C. frater, with barbarus Thomas as a valid subspecies. These authors listed sylvanus Thomas both in the synonymy of C. frater (p. 1564, with an incorrect year of publication of 1925) and as a separate species, C. sylvanus (p. 1569, citing the correct publication year of 1919). Cook et al. (1990) compared C. f. frater and C. f. mordosus to other Bolivian species in external and craniodental characters. Cook and Yates (1994) regarded C. frater (as represented by C. f. mordosus) and C. lewisi to be more closely related to each other, based on electrophoretic analyses, than to any other Bolivian species these authors examined. Cook et al. (1990) described a karyotype consisting of 2n = 52, FN = 78 for C. f. mordosus, and Ruedas et al. (1993) reported on genome size and other karyological details of this same subspecies. The sperm is the simple symmetric morphological type (Vitullo and Cook 1991; Bidau 2006).

Ctenomys fulvus Philippi, 1860 Long-tailed Tuco-tuco sy n o n y m s : Ctenomys fulvus Philippi, 1860:157, Zool. tab. L; type locality “Reise durch die Wüste Atacama,” or vicinity of Pingo-Pingo, Atacama desert, Chile, 2,700 to 3,300 m, 24°00′S 69°00′ W (Osgood 1943b:127). Ctenomys atacamensis Philippi, 1860:158, Zool. Table II, Fig. 1; type locality “Reise durch die Wüste Atacama,”

838 Mammals of South America

or Tilopozo, about lat. 23°20′S, Atacama Desert, Chile (Osgood 1943b:127). Ctenomys robustus Philippi, 1896:11, plate 4, Fig. 2, and plate 5, Fig. 1a–d; type locality “la provincia de Tarapacá, cerca de Pica, en los lugares llamados ‘canchones’ en una elevacion de cerda de 12200 m,” Chile; Canchones (20°15′S 69°20′W) is on the open plain between Pica and Noria (Osgood 1943). Ctenomys pallidus Philippi, 1896:13:plate 4, Fig. 1 and plate 5, Fig. 3a–c; type locality “Breas, en el desierto de Atacama,” southwest of Antofagasta de la Sierra, about 26°3′S and 67°56′W, alt. 9,000–10,000 ft (Osgood 1943b:127; the coordinates, however, place the locality in Catamarca, Argentina). Ctenomys pernix Philippi, 1896:15, plate 5, Fig. 5 and plate 6, Fig. 2; type locality “Aguas Calientes,” near Socaire, east of Salar de Atacama, about lat. 23°S., long. 68°16′W., Chile (Osgood 1943b:127). Ctenomys chilensis Philippi, 1896:16, plate 6, Fig. 1; type locality “la cordillera de Linares” but probably from Atacama Desert (Osgood 1943b:127). Ctenomys fulvus robustus: Mann, 1978:292; name combination. d e s c r i p t i o n : Very large species, with total length 280–350 mm; samples assignable to robustus may exceed 350 mm (Mann 1978). Upper parts slightly grizzled clay color with sides considerably paler than back; forehead and narrow line around mouth darkened or even slightly blackish; under parts uniform, clear cinnamon buff; tail blackish brown above and terminates in light pencil; feet whitish buff with some darkening medially and proximally. Skull large and heavily ridged with swollen auditory bullae and broad, wedge-shaped nasals. d i s t r i b u t i o n : Ctenomys fulvus occurs in northern Chile at elevations above 2,700 m. s e l e c t e d l o c a l i t i e s (Map 441): CHILE: Antofagasta, Aguas Calientes (type locality of Ctenomys pernix Philippi), Pingo-Pingo; (type locality of Ctenomys fulvus Philippi), Salar de Atacama (Slamovitz et al. 2001), San Pedro de Atacama (Feito and Gallardo 1982), 20 mi E of San Pedro de Atacama (Osgood 1943b), Tilopozo (type locality of Ctenomys atacamensis Philippi); Tarapacá, Canchones, La Huayca (Feito and Gallardo 1982), near Pica (type locality of Ctenomys robustus Philippi). s u b s p e c i e s : Two subspecies of Ctenomys fulvus are currently recognized: C. f. fulvus (with atacamensis Philippi, pallidus Philippi, pernix Philippi, and chilensis Philippi as synonyms) and C. f. robustus Philippi (see Mann 1978; Woods and Kilpatrick 2005). The nominotypical form occurs in western Antofagasta and C. f. robustus is restricted to the Oasis de Pica in the desert of Tarapacá. The two ranges are separated by four degrees of latitude.

Map 441

Selected localities for Ctenomys fulvus (●). Contour line = 2,000 m.

n a t u r a l h i s t o ry: Ctenomys fulvus inhabits sandy soils in desert flats with creosote bush (Larrea, Zygophyllaceae) or other desert shrubs, and riparian forests along dry gullies. Burrow systems are deep (more than 25 cm below the surface), and burrow temperature is maintained between 19° and 25°C while the outside temperature may vary between 6° and 62°C. Individuals are active early in the morning (5:00 to 7:00 am) and especially in the dry season. They are known to eat Larrea leaves (Rosenmann 1959; Mann 1978). Hickman (1985, 1988) described mound-building behavior and swimming ability, and Cortés, Miranda et al. (2000) described thermal biology. r e m a r k s : Cabrera (1961) included both C. coludo Thomas and C. famosus Thomas as valid subspecies of C. fulvus. Both of these taxa are considered separate species herein. The two subspecies of C. fulvus share the same 2n = 26 karyotype (M. H. Gallardo 1979). Sperm morphology is symmetric in both subspecies (Feito and Gallardo 1982).

Ctenomys goodfellowi Thomas, 1921 Goodfellows’s Tuco-tuco sy n o n y m s : Ctenomys goodfellowi Thomas, 1921a:136; type locality “Esperanza, near Conception, Prov. Nuflo de Chaves, E. Bolivia,” Santa Cruz, Bolivia, 16°15′S 62°04′W, 400 m. Ctenomys boliviensis goodfellowi: Cabrera, 1961:546; name combination.

Suborder Hystricomorpha: Family Ctenomyidae 839

d e s c r i p t i o n : Large tuco-tuco, slightly smaller than related C. boliviensis; total length of females 257–288 mm, tail length 71–79 mm; for males, total length >330 mm and tail length >93 mm (S. Anderson 1997). Colors also very similar to those of C. boliviensis, although “the dark dorsal line is heavier and the white of the undersurface is reduced to inconspicuous axillary and inguinal patches” (Thomas 1921a:136). Broad, heavy orange incisors and very large premolars characteristics of both species. In general, cranium of C. goodfellowi smaller, less ridged, with less thickened zygomata, and smaller and less inflated bullae than C. boliviensis (Thomas 1921a). d i s t r i b u t i o n : Ctenomys goodfellowi is known only from two localities in north-central Santa Cruz department, Bolivia (see S. Anderson 1997). s e l e c t e d l o c a l i t i e s (Map 442): BOLIVIA: Santa Cruz, Esperanza (type locality of Ctenomys goodfellowi Thomas), 10 km N of San Ramón, La Laguna (S. Anderson 1997). s u b s p e c i e s : Ctenomys goodfellowi is monotypic. n a t u r a l h i s t o ry: No data are available on ecology, habitat, behavior, or food. A single pregnant female was trapped in June (S. Anderson 1997). S. L. Gardner and Duszynski (1990) report eimerian oocysts in the feces. r e m a r k s : Listed as a subspecies of C. boliviensis by Cabrera (1961) and S. Anderson et al. (1987), but electromorphic data (Cook and Yates 1994) support C. good-

Map 442 2,000 m.

Selected localities for Ctenomys goodfellowi (●). Contour line =

fellowi as a distinct species. Mitochondrial DNA sequence data (E. P. Lessa and Cook 1998), however indicate that C. boliviensis and C. goodfellowi are sister species, at least among the limited set of taxa these authors examined. The karyotype is 2n = 46, FN= 68 (S. Anderson et al. 1987), and the sperm is symmetric in its morphology.

Ctenomys haigi Thomas, 1919 Patagonian Tuco-tuco sy n o n y m s : Ctenomys haigi Thomas, 1919b:210; type locality “Maitén, W. Chubut. 700 m,” El Maitén, Departamento Cushamen, Chubut, Argentina, 42°03′S, 71°10′ W, 700 m. Ctenomys haigi lentulus Thomas, 1919b:211; type locality “Pilcañeu, Upper Rio Negro, 1400 m,” Pilcaniyeu, Departamento Pilcaniyeu, Provincia de Rio Negro, Argentina, 41°13′S, 70°61′ W. Ctenomys haigi haigi: Thomas, 1919b:211; name combination. Ctenomys mendocinus haigi: Thomas, 1927e:201; name combination. Ctenomys haigi luteolus Rusconi, 1928:245; incorrect subsequent spelling of lentulus Thomas; not luteolus Thomas. Ctenomys haigii: Pearson, 1995:116; inadvertent spelling error. d e s c r i p t i o n : Medium-sized and short-tailed species (mean body measurements from five specimens of females and males, respectively, in MVZ collection: head and body length, 172 and 194 mm; tail length, 81 and 88 mm; hindfoot length, 34 and 36 mm; mass, 152 and 229 g). Dorsal color grayish brown, without median line on crown or rump; top of nose dark brown; sides clearer gray and flanks and venter light to washed buffy. Mandible lacks deep channel. About 56% of adult specimens show open frontoparietal fenestrae (S. L. Gardner and Anderson 2001). d i s t r i b u t i o n : Ctenomys haigi occurs in the Neuquén, Rio Negro and Chubut provinces, Argentina in Patagonian steppe and the Monte de Llanuras y Mesetas ecoregions. s e l e c t e d l o c a l i t i e s (Map 443; from Pearson and Christie 1985, except as noted): ARGENTINA: Chubut, El Maitén (type locality of Ctenomys haigi Thomas); Neuquén, 37 km SW of Chos Malal, Collón Cura (Thomas 1927e), Collón Cura, 16 SE of La Rinconada, 1 km W of Confluencia, Estancia Alicurá, Parque Nacional Laguna Blanca, Paso del Cordoba (MVZ 183291); Río Negro, 10 km S of Comallo (MVZ 185053), 19 km SE of Bariloche, 43 km SSW of Bariloche, Campo Viejo, Estancia San Ramón (MVZ 186062), 7.5 km N and 8 km E of Cerro Ñireco (MVZ 183295), 5 km W of Comico, Lago Steffen (MVZ 162284), Laguna Tromen (MVZ 193693), Pilcaniyeu (type

840 Mammals of South America

locality of Ctenomys haigi lentulus Thomas), 5 km W of Sierra Grande. s u b s p e c i e s : Ctenomys haigi is monotypic. n a t u r a l h i s t o ry (from Pearson 1984, except as noted): As is characteristic of all tuco-tucos, C. haigi is restricted to self-dug underground burrows where it may be active day or night. It is rarely seen above ground, but occasional emergence is indicated by its frequent occurrence in owl pellets as well as the toothmarks on the small-sized, above-ground shrubs upon which it feeds. Individuals are vocal, uttering a single, short syllable and with as many as 30 such “calls” in a single bout. The species inhabits treeless steppe vegetation. Litter size ranges between two and four (mean 2.6). Lacey et al. (1998) described solitary burrow use by adults of both sexes. Hambuch and Lacey (2002) and Lacey (2001) contrasted patterns of variation at both MHC and microsatellite loci, respectively, between the asocial C. haigi and the geographically adjacent but social C. sociabilis. r e m a r k s : Thomas (1919b) considered C. haigi to be allied to C. colburni, although smaller and with less pronounced bullae. Subsequently, Thomas and St. Leger (1926b:639) thought that haigi “will be found to grade into” C. mendocinus. And, finally, Thomas (1927e) formalized this earlier suggestion by stating that his subspecies lentulus was indistinguishable from typical haigi, which he then placed as a subspecies of C. mendocinus.

Map 443

Selected localities for Ctenomys haigi (●). Contour line = 2,000 m.

Pearson (1984) argued that C. haigi was a species distinct from C. mendocinus on the basis of their different karyotypes, a position supported by substantial divergence in electromorphic and mtDNA sequence data (Sage et al. 1986; E. P. Lessa and Cook 1998). Pearson (1984) also regarded specimens from Chos Malal, Neuquén Province, Argentina, in the Natural History Museum, London, that Thomas identified as C. mendocinus were best assigned to C. haigi on the basis of size and coloration. The karyotype of C. haigi is 2n = 50, FN = 66 (Pearson 1984; M. H. Gallardo 1991). Sperm morphology is of the simple asymmetric type (M. H. Gallardo et al. 2002; Bidau 2006).

Ctenomys ibicuiensis T. R. O. Freitas, Fernandes, Fornel, and Roratto, 2012 Ibicuí Tuco-tuco sy n o n y m s : Ctenomys ibicuiensis T. R. O. Freitas, Fermandes, Fornel, and Roratto, 2012:1358: type locality “Manoel Viana, in central-western Rio Grande do Sul, southern Brazil, 29°23′37′′S, 55°25′43′′ W.” d e s c r i p t i o n : Species defined primarily by chromosomal and mtDNA cytochrome-b sequence differences relative to other species of “torquatus-group” from southwestern Brazil and adjacent parts of Argentina and Uruguay; few data available for external characteristics, including pelage color and color pattern, although species moderate in body size (head and body length 159 mm, tail length 75 mm, hindfoot length 37 mm, and mass 200 g; T. R. O. Freitas et al. 2012). Cranially, C. ibicuiensis most similar to geographically adjacent populations of C. torquatus, but differs with shorter skull, less robust zygomatic arches, and more compact cranium. Multivariate analyses of dorsal, ventral, and lateral landmarks of skull separate C. ibicuiensis from six other species, including C. lami, C. minutus, C. pearsoni, C. perrensi, C. roigi, and C. torquatus. d i s t r i b u t i o n : Ctenomys ibicuiensis is known from only six closely adjacent localities in the municipalities of Manoel Viana and Macambará in Rio Grande do Sul state, Brazil, at an elevation approximately 200 m. s e l e c t e d l o c a l i t i e s (Map 444; from T. R. O. Freitas et al. 2012): BRAZIL: Rio Grande do Sul, BR 176, Manoel Viana, Piraju, Manoel Viana (type locality of Ctenomys ibicuiensis T. R. O. Freitas et al.), Passo do Narciso, Maçambará. s u b s p e c i e s : Ctenomys ibicuiensis is monotypic. n a t u r a l h i s t o ry: No data ecology, reproduction, behavior, or other aspects of the population biology of this species have been reported. T. R. O. Freitas et al. (2012:1359) recorded the habitat as “sand dunes and grasslands, disturbed by agricultural activities and desertification.”

Suborder Hystricomorpha: Family Ctenomyidae 841

Map 444

Selected localities for Ctenomys ibicuiensis (●).

r e m a r k s : The karyotype consists of 2n = 50, FN = 68, with 10 biarmed and 14 acrocentric autosomal pairs and a biarmed X chromosome (T. R. O. Freitas et al. 2012). A distinctly large pair of biarmed autosomes is diagnostic. In their phylogenetic analysis of mtDNA cytochrome-b sequences (T. R. O. Freitas et al. 2012), C. ibicuiensis was sister to a clade comprised of C. lami, C. minutus, and C. torquatus.

Ctenomys johannis Thomas, 1921 San Juan Tuco-tuco sy n o n y m s : Ctenomys coludo johannis Thomas, 1921g:523; type locality “Department of San Juan. Type from Cañada Honda. Alt. 500 m,” Departamento Sarmiento, San Juan, Argentina, 31°59′S 68°33′W, 600 m. Ctenomys fulvus johannis: Cabrera, 1961:549; name combination. Ctenomys johanis: J. R. Contreras, Roig, and Suzarte, 1977: 162; first use of current name combination but inadvertent misspelling of johannis Thomas. d e s c r i p t i o n : Similar in body size and other characters to C. coludo from Catamarca province, Argentina, but color of C. johannis less strongly buffy (termed “drabgray”), with nape, foreback, and sides of head gray; nasal patch present, more strongly marked than in C. coludo. Ventral hairs with whitish tips, faintly tinged buffy. Caudal crest blackened terminally, darkening essentially absent in

Map 445 2,000 m.

Single known locality for Ctenomys johannis (●). Contour line =

C. coludo. Skull similar to that of C. coludo, but zygomatic arches less widely spread so that breadth across arches distinctly less than across opening of auditory tubes; interparietal sutures barely perceptible, or not at all. External dimension of holotype, head and body length 199 mm, tail length 97 mm, and hindfoot length 36 mm. d i s t r i b u t i o n : Ctenomys johannis is only known from the type locality in the Monte de Llanuras y Mesetas ecoregion of San Juan province, Argentina. s e l e c t e d l o c a l i t i e s (Map 445): ARGENTINA: San Juan, Cañada Honda (type locality of Ctenomys coludo johannis Thomas). s u b s p e c i e s : Ctenomys johannis is monotypic. n a t u r a l h i s t o ry: According to Emilio Budin, the collector, this species was found “under trees; holes made in naked soil” (Thomas 1921g:524). r e m a r k s : The karyotype and sperm morphology are unknown.

Ctenomys juris Thomas, 1920 Jujuy Tuco-tuco sy n o n y m s : Ctenomys juris Thomas, 1920a:194; type locality “El Chaguaral, between San Pedro and Villa Carolina. Alt. 500 m,” Departamento San Pedro, Jujuy, Argentina, 24°16′S, 64°48′W, 500 m (see J. R. Contreras 1984b:239). Ctenomys mendocinus juris: Cabrera, 1961:552; name combination.

842 Mammals of South America

d e s c r i p t i o n : Small species, resembling C. fochi but with much smaller bullae (Thomas 1920a; A. I. Medina et al. 2007). General color uniformly pale brown with buffy or whitish half-collar extending to ear on side of neck; as with C. fochi, marked darkening on top of muzzle; inner sides of forelimbs whitish, paler than venter; hands and feet white above; tail dull buffy whitish, with dark brown terminal crest. Skull with broad nasals, slightly narrowed posteriorly; zygomatic arches widely expanded, anterior breadth often greater than posterior; mesopterygoid fossa penetrates palate to level of middle of M2; bullae small and narrow but smoothly contoured, not compressed, and markedly smaller than those of C. fochi. Upper incisors particularly proodont, reaching angle of 108°, more so than either C. bergi (100°) or C. fochi (94°). External measurements of holotype, head and body length 177 mm, tail length 72 mm, and hindfoot length 29 mm. d i s t r i b u t i o n : Ctenomys juris is known only from the type locality in the Chaco Seco ecoregion of Jujuy province, Argentina. s e l e c t e d l o c a l i t i e s (Map 446): ARGENTINA: Jujuy, El Chaguaral (type locality of Ctenomys juris Thomas). s u b s p e c i e s : Ctenomys juris is monotypic. n a t u r a l h i s t o ry: According to Emilio Budin (Thomas 1920a:194), this tuco-tuco was found “in stony ground in ravines running down to the river.” r e m a r k s : Cabrera (1961) treated this species as a subspecies of C. mendocinus Philippi, a position main-

Map 446

Single known locality for Ctenomys juris (●). Contour line = 2,000 m.

tained by Redford and Eisenberg (1992) and Woods (1993). Galliari et al. (1996) listed C. juris as a species, without comment. The diploid number of C. juris is 2n = 26 (C. J. Bidau, unpubl. data). Sperm morphology is the simple asymmetric type (Bidau 2006).

Ctenomys knighti Thomas, 1919 Catamarca Tuco-tuco sy n o n y m s : Ctenomys knighti Thomas, 1919d:498; type locality “Otro Cerro, North-eastern Rioja”; an abandoned ranch at the southern end of Sierra de Ambato, NE Chumbicha, Departamento Capayán, Catamarca, Argentina, 28°45′S, 66°17′ W, 2,023 m (see Pardiñas et al. 2007). Ctenomys knighti knighti: Cabrera, 1961:549; name combination. d e s c r i p t i o n : Small to medium-sized species; dimensions of holotype (adult male) head and body length 203 mm, tail length 82 m, and hindfoot length 36 mm. Dorsal color dark brown; flanks, especially over thighs, buffy; venter uniformly ochraceous with cinnamon-buff hair tips; no collar present around the throat; muzzle, both on top and sides of mouth and tip of chin, distinctly blackish. Skull elongated with narrow nasals; parietal region lacks any trace of separate interparietal, even in the youngest specimens; incisive foramina elongated; bullae large and, when viewed from behind, have conspicuously smooth posterosuperior portion not covered by plastering bones of occipital series. d i s t r i b u t i o n : Ctenomys knighti is found in Catamarca and La Rioja provinces of Argentina within the Chaco Seco and Monte de Sierras y Bolsones ecoregions, at elevations from 770 to 2,025 m. s e l e c t e d l o c a l i t i e s (Map 447): ARGENTINA: Catamarca, Otro Cerro (type locality of Ctenomys knighti Thomas); La Rioja, Machigasta (Llanos 1947). s u b s p e c i e s : Ctenomys knighti is monotypic. n a t u r a l h i s t o ry: No ecological data are available. Emilio Budin, the collector, found the species “on stony ground” (Thomas 1919d: 499). r e m a r k s : The location of Otro Cerro has been debatable since Thomas (1919d) first described specimens from this locality (see Thomas 1920b; Pearson 1958; Cabrera 1961; and Myers et al. 1990 for varying opinions). Pardiñas et al. (2007:399–400 and Fig. 4, p. 403) reviewed this history and provided detailed information that placed this site at the southern end of the Sierra de Ambato in Catamarca, not Rioja, province. Fortunately, the resolution of this issue by Pardiñas et al. (2007) fixes the type locality for C. knighti and several other mammal species described by Thomas. Thomas (1919d) believed C. knighti allied to C. budini (= C. frater budini herein) from Jujuy Province, but distin-

Suborder Hystricomorpha: Family Ctenomyidae 843

Map 447

Selected localities for Ctenomys knighti (●). Contour line = 2,000 m. Map 448

guishable from that species by its dark muzzle, more buffy sides, absence of a collar, and cranially notably by the absence of a separate interparietal. Sperm morphology and karyotype are unknown.

Ctenomys lami T. R. O. Freitas, 2001 Lami Tuco-tuco sy n o n y m : Ctenomys lami T. R. O. Freitas, 2001:2; type locality “Beco dos Cegos, Lami Beach in the Guaiba river, near Porto Alegre, at 30°51′S, 51°10′W,” Rio Grande do Sul, Brazil. d e s c r i p t i o n : Quite variable in size, total length 231– 310 mm, tail length 67–92 mm, hindfoot length 31–42 mm, and mass 170–307 g. Dorsal color dark brownish, with each hair dark grayish basally and brownish near tip; ventral pelage paler. Cranially, nasal bones wide anteriorly and taper posteriorly; frontal region flat from interorbital region posteriorly; frontoparietal suture round; braincase oval-shaped, with length about one-third length of skull; zygomatic arches squared and robust; incisive foramina small; mesopterygoid fossa wide posteriorly and flared anteriorly; auditory bullae large and ventrally inflated. Mandible with long and narrow coronoid process, heavy condyloid process, and large angular process. All molariform teeth kidney-shaped, with M3 and m3 much reduced in size. Upper incisors large, orthodont, and faced with orange enamel. d i s t r i b u t i o n : Ctenomys lami is known from multiple localities in Rio Grande do Sul state, Brazil, in the

Selected localities for Ctenomys lami (●).

small area south and east of Porto Alegre between the Rio Guaiba and Lago Barros. s e l e c t e d l o c a l i t i e s (Map 448; from T. R. O. Freitas 2001): BRAZIL: Rio Grande do Sul, Beco dos Cegos (type locality of Ctenomys lami T. R. O. Freitas), Chico Lomã, Parque de Itapuã. s u b s p e c i e s : Ctenomys lami is monotypic. n a t u r a l h i s t o ry: T. R. O. Freitas (2001) recorded pregnant females of C. lami in the months of June and December. Litter size was one to three embryos (mean = 2.04 ± 0.73; N = 25). r e m a r k s : T. R. O. Freitas (2001) distinguished this species from the parapatric C. minutus primarily by its unique but highly variable karyotype. At least seven karyotypes are known, with diploid number ranging from 2n = 54 to 58 with fusion/fission and pericentric inversion systems described in detail (T. R. O. Freitas 2007). El Jundi and Freitas (2004) provided details on genetic and demographic structure.

Ctenomys latro Thomas, 1918 Mottled Tuco-tuco sy n o n y m : Ctenomys latro Thomas, 1918a:38; type locality “Tapia, about 20 miles north of Tucuman City. Alt. 600 m,” Departamento Trancas, Tucumán, Argentina, 26°36′ S, 65°18′ W, 689 m. d e s c r i p t i o n : Small to medium-sized species, head and body length 161–172 mm (A. I. Medina et al. 2007).

844 Mammals of South America

Overall color buffy fawn on sides of head, back, and flanks; crown and middle of face dark brown; venter pale buff with throat white and darker chest patch present; colors of the upper and under surfaces sharply differentiated; light buffy patch behind ear that runs downward and backward onto side of neck; tail dark brown along entire length of dorsal surface but pale buffy on sides and below. Skull low and flattened, with narrow braincase; rostrum unusually broadened, due to thickening of bone outside anterior half of incisor alveolus; nasals broad, abruptly and squarely truncated behind, considerably surpassed by premaxillary processes, and with sides forming straight converging lines; zygomatic arches widely expanded, but distinctly short anteroposteriorly; temporal ridges unite to form low median sagittal crest rather than remaining separated; supraoccipital smooth, without median ridge; bullae small but smooth and well inflated. Cheek teeth small and appear rather delicate; PM4 exceeds molars in diagonal diameter. d i s t r i b u t i o n : Ctenomys latro is known only from Tucumán province, Argentina, in the Chaco Seco ecoregion. s e l e c t e d l o c a l i t i e s (Map 449): ARGENTINA: Tucumán, Burruyacu, E Cerro Campo (Thomas 1926d), Río Choromoro (A. I. Medina et al. 2007), Tapia (type locality of Ctenomys latro Thomas), Ticucho (Ipucha et al. 2008). s u b s p e c i e s : Ctenomys latro is monotypic. n a t u r a l h i s t o ry: No data on ecology are available. Specimens have been collected in areas of open Chacoan forest with extremely stony soils.

Map 449

Selected localities for Ctenomys latro (●). Contour line = 2,000 m.

r e m a r k s : Cabrera (1961:553) synonymized C. latro with C. mendocinus, listing the name as a synonym under the subspecies C. m. tucumanus Thomas, part of his concept of a polytypic C. mendocinus. Reig and Kiblisky (1969) and Roig and Reig (1969) considered both C. latro and C. tucumanus to be distinct species based on karyotypic differences, a conclusion followed both by subsequent authors and as viewed herein. Ctenomys latro is closely allied to C. pilarensis, C. occultus, and C. argentinus in mtDNA sequence analyses, with this clade apparently sister to C. tucumanus (Mascheretti et al. 2000; Parada et al. 2011; see also J. R. Contreras and Bidau 1999). Contrary to Cabrera’s (1961) hypothesis, C. latro shares no molecular relationship with C. mendocinus (Parada et al. 2011). Several related karyotypes have been reported for the species, including 2n = 42, FN = 50 (Reig and Kiblisky 1968a), 2n = 40, FN = 44 (Ortells 1995) and 2n = 40–42, FN = 48 (Ipucha 2002; Ipucha et al. 2008).

Ctenomys leucodon Waterhouse, 1848 White-toothed Tuco-tuco sy n o n y m s : Ctenomys leucodon Waterhouse, 1848:281; type locality “San Andrés de Machaca, . . . south of the Lake Titicaca, Department of La Paz, Bolivia”; ca. 4,000 m, 16°44′S 69°01′W. Thomas, 1927b:552. Ctenomys (Haptomys) leucodon Thomas, 1916g:305; designation as type species of new subgenus Haptomys. d e s c r i p t i o n : Medium sized with total length of adults 200–278 mm, tail length 79–85 mm, and hindfoot length averaging 34 mm (Sanborn and Pearson 1947; S. Anderson 1997). Back clay colored with base of hairs slate gray followed by either broad or narrow clay band and tipped with black; head darker and sides of muzzle and cheeks buckthorn brown; undersurface near tawny-olive overall but with reddish tinge on chest; tail dark brown above and faintly lighter beneath, not dirty white as given in Waterhouse’s description, and without crest of long whitish hairs (Sanborn and Pearson 1947). Upper incisors strongly procumbent and almost unique within genus with white or pale yellowish white enamel (Waterhouse 1848; Pearson 1959). d i s t r i b u t i o n : Ctenomys leucodon occurs in the Altiplano highlands surrounding Lake Titicaca, extending from La Paz, Bolivia, to southern Puno, Peru (Pearson 1959). s e l e c t e d l o c a l i t i e s (Map 450): BOLIVIA: La Paz, Chilalaya (Cook et al. 1990), Comauchi (S. Anderson 1997), San Andrés de Machaca (type locality of Ctenomys leucodon Waterhouse). PERU: 10 km SW of Huacullani (Pearson 1959), Río Ccallacami, near Huacullani (Sanborn and Pearson 1947). s u b s p e c i e s : Ctenomys leucodon is monotypic.

Suborder Hystricomorpha: Family Ctenomyidae 845

Map 450 2,000 m.

Selected localities for Ctenomys leucodon (●). Contour line =

n a t u r a l h i s t o ry: Few data on ecology are available. A single pregnant female has been recorded in the month of August in Bolivia (S. Anderson 1997). In one local Peruvian population, Pearson (1959) noted that individuals were nonvocal, made large earthen mounds in sloping grassland, and occurred at slightly lower elevation than adjacent populations of C. opimus. S. L. Gardner and Duszynski (1990) examined feces of this species but found no eimerian oocysts. r e m a r k s : Thomas (1916g) placed C. leucodon into the monotypic subgenus Haptomys, a position that has mixed support from molecular markers. Cook et al. (1990) compared this species to others they recognized as occurring in Bolivia. Phylogenetic analyses of electromorphic allozymes (Cook and Yates 1994) placed C. leucodon in a near basal-polytomy with species of the nominotypical subgenus, whereas mtDNA sequences positioned C. leucodon in a near-basal polytomy, excluding C. sociabilis (Parada et al. 2011). Cook et al. (1990) described a karyotype with 2n = 36, FN = 68. Sperm morphology is unknown.

d e s c r i p t i o n : Relatively large, reddish-brown tucotuco with unusually procumbent incisors, similar to those of C. leucodon but more robust. Head and body length 204–219 mm, tail length 68–71 mm, and hindfoot length averages 37 mm. General color of upper parts uniform dark cinnamon brown without special markings; muzzle only slightly washed with black; under surfaces brighter cinnamon, often very bright, sometimes throughout but always in inguinal region; throat with slight, darker collar; forefeet and hindfeet dull whitish above; tail thinly haired, blackish above at base but whitish otherwise. Skull large, long, but neither broad nor robust; nasals rather short and broad; interorbital region broad, without projecting supraorbital ledges; lambdoidal crest strongly developed, with well-marked median forwardly directed angle; zygoma with simple angular projection above, not broadened at its tip; concave groove on outer upper side of malar absent; bullae appear somewhat compressed. Upper incisors very large and heavy, flattened and strongly pigmented orange in front, very proodont (incisive angle of holotype 117°), and readily visible in front of premaxilla when viewed from above. About 33% of adult specimens show open frontoparietal fenestrae (S. L. Gardner and Anderson 2001). d i s t r i b u t i o n : Ctenomys lewisi is known from two closely adjacent localities in northwestern Tarija, Bolivia (S. Anderson 1997:492, Fig. 770).

Ctenomys lewisi Thomas, 1926 Lewis’s Tuco-tuco sy n o n y m : Ctenomys lewisi Thomas, 1926c: 323; type locality “Sama, 4000 m,” 50 km W Tarija, Tarija, Bolivia, 21°3′S 65°10′ W.

Map 451

Selected localities for Ctenomys lewisi (●). Contour line = 2,000 m.

846 Mammals of South America

s e l e c t e d l o c a l i t i e s (Map 451): BOLIVIA: Tarija: 1 km E of Iscayachi, Río Tomayapo (S. Anderson 1997), Sama (type locality of Ctenomys lewisi Thomas). s u b s p e c i e s : Ctenomys lewisi is monotypic. n a t u r a l h i s t o ry: Ctenomys lewisi inhabits deep soils of the Tomayapo Valley and Sama between 3,450 and 4,000 m. Thomas (1926c) inferred a semiaquatic habit based on captures in holes in wet stream banks, but more recent captures have not confirmed this suggestion (S. Anderson 1997). Pregnant females have been recorded in the month of July. S. L. Gardner and Duszynski (1990) reported eimerian oocysts from feces. r e m a r k s : Both electromorphic (Cook and Yates 1994) and mtDNA sequence (E. P. Lessa and Cook 1998; Parada et al. 2011) analyses suggest a close sister relationship between C. lewisi and C. frater, and then with C. conoveri and an apparently undescribed species from Llathu, Cochabamba, Bolivia (Parada et al. 2011). Cook et al. (1990) described a karyotype with 2n = 56 and FN = 74; Ruedas et al. (1993) reported on genome size and other karyological attributes. Sperm morphology is the simple symmetric type (Vitullo and Cook 1991).

Ctenomys magellanicus Bennett, 1836 Magellanic Tuco-tuco sy n o n y m s : Ctenomys magellanicus Bennett, 1836:190, type locality “Port Gregory [= Bahía San Gregorio], near eastern end of north side of Straits of Magellan, Chile,” Aysén , 52°25′S, 69°45′ W, 0 m (see J. A. Allen 1905:35; Rusconi 1928:238; Osgood 1943b). Ctenomys fueginus Philippi, 1880:276, type locality “östlichen Insel,” eastern island or Isla Grande, Tierra del Fuego, Magallanes y Antártica Chilena, Chile (Osgood 1943b). Ctenomys neglectus Nehring, 1900b:535; type locality “Patagonien.” Ctenomys robustus J. A. Allen, 1903b:185; type locality “Rio Chico de Santa Cruz, near the Cordilleras,” Santa Cruz, Argentina; restricted by Pardiñas (2013) as “río Tucu Tucu, ca. 8 km aguas abajo desde su nacimiento (48.47ºS, 71.87ºW, departamento Río Chico, Santa Cruz, Argentina).” Preoccupied by Ctenomys robustus Philippi (1896), although not the same species (see account for C. fulvus). Ctenomys osgoodi J. A. Allen, 1905:191; substitute name for C. robustus J. A. Allen. Ctenomys magellanicus fueginus: Osgood, 1943b:119; name combination. Ctenomys magellanicus osgoodi: Osgood, 1943b:120; name combination. Ctenomys magellanicus dicki Osgood, 1943b:123; type locality “Estancia Ponsonby, east end of Riesco Island, Ma-

gallanes, Chile,” Isla de Riesco, Provincia de Magallanes, Magallanes y Antártica Chilena region, ca. 52°50′S 71°45′W. Ctenomys magellanicus obscurus Texera, 1975: 163; type locality “Estancia Lago Escondido, 20 km S de la Sección Rio Grande, cerca de Lago Blanco, Tierra Del Fuego, Magallanes y Antártica Chilena, Chile, ca. 500 m,” 53°53′S 68°52′W. d e s c r i p t i o n : Relatively large species with total length from 267 mm in C. m. magellanicus to 304 mm in C. m. fueginus. Generally pale-colored, with pale grizzled grayish buff upper parts and clear cinnamon buff under parts in C. m. magellanicus and C. m. fueginus; prevailing color of populations allocated to C. m. osgoodi; much darker, brownish ochraceous rather than grayish buff; color of C. m. dicki wholly mixed blackish and buffy smoke gray both above and below; that of C. m. obscurus homogeneously darker than other subspecies (Texera 1975). Skull notably angular with many sharp ridges and pointed processes, particularly so in specimens of nominotypical race. Skull of C. m. fueginus similar to that of C. m. magellanicus but with slightly more swollen and bulbous auditory bullae, broader interorbital region, and broader rostral or antemolar part. Skull of C. m. osgoodi also similar but with narrower and more laterally compressed auditory bullae. Skull of C. m. dicki essentially as that of C. m. fueginus, except that auditory bullae slightly smaller and shorter and interorbital region wide, as in C. m. magellanicus. d i s t r i b u t i o n : Ctenomys magellanicus is distributed in extreme southern Chile and southern Argentina, including Tierra del Fuego. s e l e c t e d l o c a l i t i e s (Map 452): ARGENTINA: Santa Cruz, Cordilleras, west of upper Río Chico (type locality of Ctenomys osgoodi J. A. Allen), 30 mi S of Santa Cruz (Osgood 1943b); Tierra del Fuego, Estancia San Martín, Bahía San Sebastián (MVZ 164145), Estancia Viamonte (Osgood 1943b), Lago Fagnano (Osgood 1943b), near east end of Lake Fagnano (Osgood 1943b). CHILE: Aysén, Río Ñirehuao (Osgood 1943b); Magallanes y Antártica Chilena, Bahía Felipe (USNM 398541), Estancia Lago Escondido (Ctenomys magellanicus obscurus Texera), Estancia Ponsonby, east end of Riesco Island (type locality of Ctenomys magellanicus dicki Osgood), La Cumbre, Baguales (Feito and Gallardo 1982), Port Gregory (type locality of Ctenomys magellanicus Bennett), Punta Arenas (AMNH 17444). s u b s p e c i e s : Both Osgood (1943b) and Cabrera (1961) considered C. magellanicus to be a polytypic species with four subspecies (dicki Osgood, magellanicus Bennett, fueginus Philippi, and osgoodi Allen). Texera (1975) later described a fifth subspecies (obscurus).

Suborder Hystricomorpha: Family Ctenomyidae 847

n a t u r a l h i s t o ry: An inhabitant of the Patagonian steppe, C. magellanicus lives usually in open meadows with dense grass cover. Burrow systems are constructed 30 cm or more below the surface. Individual feed on the roots of grasses and shrubs (Mann 1978). Native Americans from Tierra del Fuego called these tuco-tucos cururu, a name also applied to other medium-sized rodents in the area, and at least the indigenous Selk’nam included them in their diet (Pepa 2001; Pardo 2007). r e m a r k s : Thomas (1898h) recorded a specimen of this species from Tombo Point (Punta Tombo), Chubut, Argentina, without justification. This tuco-tuco is very likely not C. magellanicus, given the large expanse of Patagonian steppe separating this locality from the main distribution of the species. Osgood (1943b:122) referred a topotype of C. fodax in the Field Museum collection to C. m. osgoodi; C. fodax is herein considered a species distinct from C. magellanicus (see that account). The type locality of J. A. Allen’s C. robustus (subsequently renamed C. osgoodi) was given in the original description as “Rio Chico de Santa Cruz, near the Cordilleras ( J. A. Allen 1903b:185). Subsequently, Allen (1905:40) gave additional information to narrow the exact locality, stating first “in the alluvial river valley of the upper Rio Chico, at the eastern base of the Andes” and then a few sentences later “most specimens of this species appear to have been taken in Mayer Basin, at the edge of the Cordilleras.” Earlier in the same report, Allen (1905:2) had written about the route taken by the field party who “then followed a continuous journey of some 259 miles up the Rio Chico de Santa Cruz, to the mouth of the Rio Belgrano” with mammal specimens taken “north from the Rio Belgrado to the vicinity of Lake Buenos Aires.” Allen (1905:footnote 2) further wrote “most specimens are labeled ‘Arroyo Eche’ (= Aike).” Lago Buenos Aires (= Lago General Carrera) is about 180 km north of the mouth of the Río Belgrano where it joins the Río Chico (at about 48.24°S, 71.24°W). The type locality of osgoodi J. A. Allen is thus likely at a point between these two places. I have been unable to locate either “Mayer Basin” or “Arroyo Eche,” although present-day RN 40 crosses the Río Ecker about 60 km south of Perito Moreno, which is just east of Lago Buenos Aires. Ctenomys magellanicus is chromosomally polytypic. Reig and Kiblisky (1969) recorded diploid numbers of 36 and 38 for C. m. fueginus, and M. H. Gallardo (1979) described a diploid number of 34 for C. m. magellanicus. Lizarralde et al. (2003) examined telomeric sequence localization in the 2n = 34 and 2n = 36 cytotypes. Sperm morphology is the simple asymmetric type (Feito and Gallardo 1982). Fasanella et al. (2013) reported on historical demography and spatial structure in mtDNA sequences

Map 452

Selected localities for Ctenomys magellanicus (●).

and nuclear microsatellite loci for population samples on Tierra del Fuego that encompassed the two cytotypes.

Ctenomys “mariafarelli” Azurduy, 2005 Maria Farell’s Tuco-tuco sy n o n y m : Ctenomys mariafarelli Azurduy, 2005b:70; type locality “5.5 Km al noreste de la localidad de Vallegrande (18°28′S, 64°08′O; 1800 m), provincia Florida, del Departamento de Santa Cruz, Bolivia”; nomen nudum (see Remarks). d e s c r i p t i o n : Relatively large tuco-tuco, with total length of males (N = 2) 291–295 mm, tail length 74–85 mm, hindfoot length 39–41 mm, and mass 307–364 g; females (N = 3) smaller, total length 254–273 mm; tail length 73–81 mm; hindfoot length 33–38 mm, and mass 173–227g. Dorsal color brownish with poorly defined median blackish stripe, lacking half-collar typical of C. boliviensis, purportedly its closest relative; flanks paler brown or ochraceous; venter yellowish with white inguinal and axillary spots. Skull elongated and narrow with respect to expansion of zygomatic arches; nasal bones wide posteriorly and taper anteriorly; frontal region narrow; zygomatic arches slightly square; tympanic bullae moderately large and inflated. Upper incisors conspicuously proodont, large, and faced with orange enamel. d i s t r i b u t i o n : Ctenomys “mariafarelli” is known only from the type locality in Santa Cruz department, Bolivia.

848 Mammals of South America

Map 453 Single known locality for Ctenomys “mariafarelli” (●). Contour line = 2,000 m.

s e l e c t e d l o c a l i t i e s (Map 453): BOLIVIA: Santa Cruz: Vallegrande (type locality of Ctenomys mariafarelli Azurduy). s u b s p e c i e s : Ctenomys “mariafarelli” is monotypic. n a t u r a l h i s t o ry: No data are available on ecology, behavior, reproduction, or food preferences. r e m a r k s : According to Azurduy (2005b), the species is closely allied to C. boliviensis. Neither the karyotype nor sperm morphology is known. The name Ctenomys mariafarelli was published in the electronic journal Kempffiana, and thus at the time of publication did not meet the requirements of Article 8.6 of the International Code for Zoological Nomenclature (ICZN 1999). The recently amended Code (International Commission on Zoological Nomenclature 2012) accepts electronic publication of new names, but only if (a) the date of issue is subsequent to 2011, (b) the publication date is included in the work itself, and (c) the publication is registered in the Official Register of Zoological Nomenclature (ZooBank). Since none of these requirements apply to Azurduy’s name, mariafarelli Azurduy is a nomen nudum.

Ctenomys maulinus Philippi, 1872 Maule Tuco-tuco sy n o n y m s : Ctenomys maulinus Philippi, 1872: 442; type locality “D. Toribio Medina, hat diese Art im Januar und Februar d.J. in der hohen Cordillere der Prov. Maule gefunden und zwar in der Hähe des Sees laguna de Maule, aus

welchem der bie Talca vorbeifliessende und bei Constitucion Mündende Fluss gleichen Namens entspringt,” given as Laguna de Maule, Talca province, Chile, ca. 36°00′S, 70°30′ W” by Osgood (1943b:125). Ctenomys mendocinus maulinus: Thomas, 1927d:657; name combination. Ctenomys maulinus maulinus: Osgood, 1943b:24; name combination. Ctenomys maulinus brunneus Osgood, 1943b:125; type locality “Rio Colorado, Province of Malleco, Chile. Alt. 3,000 ft,” 38°27′S, 71°22′ W, 900 m. d e s c r i p t i o n : Medium sized, total length varying from 275 mm in nominotypical subspecies to 305 mm in C. m. brunneus. Dorsal color of C. m. maulinus uniformly light brown and tail typically with short, white pencil at tip. Color of C. m. brunneus richer and darker brown (Mann 1978); feet dull buffy white; tail brown above, pale buffy below with buffy white pencil at the tip. Skull with persistent frontoparietal fontanelle; wide flat interorbital space; imperceptible postorbital processes; auditory bullae relatively short and swollen in nominotypical subspecies but narrower and more elongate in C. m. brunneus. d i s t r i b u t i o n : The nominotypical subspecies C. m. maulinus occurs only in Talca province, Chile, whereas C. m. brunneus is distributed in the provinces of Cautín and Malleco between 1,000 and 2,000 m (Osgood 1943b; Greer 1965). Yepes (1935a) and Pearson (1984, 1995) extended the range of this species into Neuquén and Río Negro provinces of Argentina, but without comments on subspecies allocation. s e l e c t e d l o c a l i t i e s (Map 454): ARGENTINA: Neuquén, Aeropuerto Caviahue (MVZ 183299), 2 km E and 1 km N of Caviahue (MVZ 183298), Chapelco (MVZ 183304), 1 km E of Copahue, Las Maquinitas (MVZ 183310), Lago Epulafquen (MVZ 185055), Lago Lolog, NE coast, 5 km W of Rio Quilquihue (MVZ 183312), near Estancia Los Helechos, 2.5 km W and 5 km S of Cerro Colorado (MVZ 163462); Río Negro, ridge above Refugio Neumeyer (MVZ 163823). CHILE: Araucanía, Río Colorado (type locality of C. maulinus brunneus Osgood), Lonquimay, Río Colorado (MVZ 154132); Maule, Arroyo del Valle, Río Maule (FMNH 50731), Río Maule, 14 km above Curillanque (FMNH 50733), Laguna del Maule (type locality of Ctenomys maulinus Philippi). s u b s p e c i e s : Both Osgood (1943b) and Cabrera (1961) recognized two subspecies, the paler nominotypical form in Talca province, Chile, and the darker C. m. brunneus from Malleco and Cautín provinces, Chile. Specimens from Neuquén and Río Negro provinces in Argentina are, as yet, unassigned to subspecies (see Pearson and Christie 1985).

Suborder Hystricomorpha: Family Ctenomyidae 849

Map 454 2,000 m.

Selected localities for Ctenomys maulinus (●). Contour line =

n a t u r a l h i s t o ry: Ctenomys maulinus inhabits widely divergent habitats such as Nothophagus (Nothofagaceae) – Araucaria (Araucariaceae) woodlands and open volcanic sands from 900 to 2,000 m elevation (Redford and Eisenberg 1992). M. H. Gallardo and Anrique (1991) describe population parameters and burrow systems, and M. H. Gallardo and Kohler (1994) document demographic changes and loss of genetic variation in a local population following a volcanic eruption. r e m a r k s : Skins and skulls of Argentinean specimens are indistinguishable from C. m. maulinus from Chile (Pearson 1995). Numerous large tuco-tucos, probably C. maulinus, have been recovered from owl pellets more than 5,000 years old at Cueva Traful, near Confluencia, Neuquén province, Argentina (Pearson 1984). Both subspecies of C. maulinus share the same 2n = 26, FN = 48, karyotype (M. H. Gallardo 1979) and an asymmetrical simple sperm morphology (Feito and Gallardo 1976, 1982).

Ctenomys mendocinus Philippi, 1869 Mendoza Tuco-tuco sy n o n y m s : Ctenomys mendocina Philippi, 1869:38; type locality “Mendoza,” = Mendoza Province, Argentina, Departamento Capital, 32°53′S, 68°49′ W, 980 m. Ctenomys mendocinus: Philippi, 1896:17; correction of gender agreement. Ctenomys eremophilus J. R. Contreras and Roig, 1975:19; unavailable (ICZN 1999:Art. 13; see Parada et al. 2012).

Ctenomys eremicus J. R. Contreras, 1979a:45; nomen nudum. Ctenomys eremophilus J. R. Contreras, 1981:22; nomen nudum. d e s c r i p t i o n : Medium sized (mean total body length 247.3 mm in females and 262.12 mm in males; tail length 77.4 mm females and 82.2 mm males; Rosi et al. 2002, 2005; A. I. Medina et al. 2007). Dorsal pelage light brown to grayish red with transverse waves of blackish hair that disappear in paler ventral region; tail whitish with median dorsal stripe of longer hairs; feet covered with sparse white hair. Cranial features include broad rostrum, prominently ridged parietals without sagittal crest, well-developed lambdoid crest, jugals with prominent dorsally projected processes, enlarged infraorbital foramina with no canal for nerve transmission, and large bullae with flat and closely appressedparoccipital processes. Mandible with moderately developed coronoid process and wide angular process that flares outward. Upper and lower third molars vestigial. Upper incisors nearly orthodont, with roots extending to anterior edge of cheek teeth; enamel colored dark orange. d i s t r i b u t i o n : Ctenomys mendocinus is distributed along the eastern base of the Andes of west-central Argentinean provinces of Mendoza, San Luis, San Juan, and La Pampa provinces (Braggio et al. 1999; Rosi et al. 2002). Most populations occupy the Monte de Llanuras y Mesetas ecoregion between 174 and 3,400 m (Rosi et al. 2002; Bidau 2006). s e l e c t e d l o c a l i t i e s (Map 455): ARGENTINA: La Plata, Estancia la Pastoril (Braggio et al. 1999), LihuelCalel (Wilkins and Cunningham 1993), Naicó (Braggio et al. 1999), Río Salado (Braggio et al. 1999), Santa Rosa (Braggio et al. 1999); Mendoza, Desaguadero (Wilkins and Cunningham 1993), 3 km S of Laguna Diamante (Sage et al. 1986), La Paz (Wilkins and Cunningham 1993), Las Higueras (Rosi, Cona et al. 1996), Las lajas (Rosi, Cona et al. 1996), Lavalle (Wilkins and Cunningham 1993), Mendoza (type locality of Ctenomys mendocinus Philippi), Papagallos (Roig and Reig 1969), Tambillos (Rosi et al. 2002), Tupungato (Slamovitz et al. 2001), 25 de Mayo (Pearson and Lagiglia 1992); San Luís, Villa Mercedes (Rosi et al. 1992). s u b s p e c i e s : Ctenomys mendocinus today is considered monotypic. n a t u r a l h i s t o ry: Ctenomys mendocinus is one of the best-studied tuco-tuco species and one with the largest known geographic distribution (see Rosi et al. 2005). Albanese et al. (2010) described resource use and distribution and Camin (2010) reviewed gestation, maternal behavior, and growth and development. This species constructs burrows of the linear type with those of males significantly longer (mean 51 m) than those of females (22 m; Camin

850 Mammals of South America

et al. 1995; Rosi, Cona et al. 1996). As is true for most tuco-tucos, C. mendocinus has solitary habits even in the reproductive season and is strongly territorial (Puig et al. 1992; Rosi et al. 2000). Reproduction occurs from July to March; gonadal activity of females begins in the winter, but male testes seem to be active throughout the year (Dacar et al. 1998). Gestation lasts three months, and the annual mean litter size is 2.8 (range: 1–4; Rosi, Puig et al. 1996). Camin (1999) described mating behavior. Dietary habitats of C. mendocinus are also well known, with specialization primarily on the above ground parts of grasses and shrubs (Camin and Madoery 1994; Madoery et al. 1997; Puig et al. 1999; Tort et al. 2004). r e m a r k s : Cabrera (1961:551) included C. bergi, C. fochi, C. haigi, C. juris, C. occultus, C. recessus (= C. talarum recessus), and C. tucumanus as subspecies of C. mendocinus. He also included C. azarae and C. latro in the synonymy of C. m. mendocinus and C. m. tucumanus, respectively. Herein, each of these taxa is considered good species (Bidau 2006). M. M. Díaz et al. (2000) cited C. mendocinus for Salta province, Argentina, but those specimens are more appropriately assigned to C. fochi. Ctenomys mendocinus has its closest affinities (based on morphological, chromosomal, and molecular data) with other species in central Argentina that collectively comprise a “mendocinus” group, namely C. azarae, C. porteousi, and C. australis ( J. R. Contreras and Bidau 1999; Mascheretti et al. 2000), which has been expanded more recently to include C. flamarioni and C. rionegrensis (Parada et al. 2011) based on mtDNA sequences. J. R. Contreras and Roig (1975) coined the name Ctenomys eremophilus for a new species they proposed from the Ñacuñán Biosphere Reserve in Mendoza province, Argentina, in the abstracts of a scientific meeting. J. R. Contreras (1979a, 1981) subsequently referred to the same sample as C. eremicus or C. eremophilus, respectively. Parada et al. (2012), however, documented that eremophilus J. R. Contreras and Roig was unavailable, as it did not meet the requirements for publication (ICZN 1999:Art. 13). And, Galliari et al. (1996) concluded that both eremicus J. R. Contreras and eremophilus J. R. Contreras were nomina nuda as neither name was accompanied by a description, illustration, or reference to such (ICZN 1999:Art.12). Unfortunately, eremophilus has been used in the subsequent literature as though it were a valid species (Giannoni et al. 1996; Borruel et al. 1998; Rosi et al. 2009). Bidau (2006) regarded eremophilus as a synonym of C. pontifex Thomas, without comment (see Parada et al. 2012). The karyotype of C. mendocinus is polymorphic, with diploid numbers of 48 or 50 and number of autosomal arms varying between 68 and 80, mostly due to variation in short-arm heterochromatin (Massarini, Barros, Ortells,

Map 455 2,000 m.

Selected localities for Ctenomys mendocinus (●). Contour line =

and Reig 1991; Massarini, Barros, Roig, and Reig 1991; Braggio et al. 1999; Parada et al. 2012). Individuals with both 2n = 48 and 50 were present in the Ñacuñán Biosphere Reserve, with these samples sharing high similarity to other samples of C. mendocinus in mtDNA cytochromeb sequences (Parada et al. 2012). It has a simple asymmetrical type of sperm (Vitullo et al. 1988).

Ctenomys minutus Nehring, 1887 Minute Tuco-tuco sy n o n y m s : Ctenomys minutus Nehring, 1887:47; type locality “stammen aus den ‘Campos’, welche sich östlich von Mundo Novo (also ziemlich weit nördlich in der Provinz Rio Grando do Sul),” Brazil (= Taquara do Mundo Novo, Reig. et al. 1965; or = Taquara, Belton 1985), ca. 10 m, 29°39′S 50°47′ W; restricted by Langguth and Abella (1970:18), following Nehring (1900c:206), to the oceanic coast at a resort near the mouth of the Rio Tramandahy, 98 km E of Porto Alegre, Rio Grande do Sul, Brazil. Ctenomys minimus S. Anderson, 1985:14; incorrect subsequent spelling of Ctenomys minutus Nehring. d e s c r i p t i o n : Described from three skulls sent to Alfred Nehring by Th. Bischoff. Nehring’s original description included only a few dimensions of each skull (approximate total lengths 41.5, 39, and 35.5 mm, respectively; basilar lengths 34, 32.3, and 28.5 mm; widths of

Suborder Hystricomorpha: Family Ctenomyidae 851

upper incisors, 4.6, 4.0, and 3.8 mm; and lengths of upper toothrow, 31.5, 27.0 [?], and 27.6 mm). Nehring noted that all three skulls were of adult animals, because all teeth had erupted and were worn, although smallest of three was younger than largest. Other features apparent from illustrations provided in Nehring (1887, 1900c) include slightly proodont upper incisors, enlarged but anteriorposteriorly constricted auditory bullae, proportionally broad interorbital region, braincase with weakly developed parasagittal ridged, approximately equal distances across zygomatic arches and auditory tubes, and vertically directed postorbital spine of the jugal. Overall dimensions, contrary to implication of species epithet, place C. minutus among medium-sized species of tuco-tucos, with total length averaging 250 mm (Reig et al. 1966). Overall color medium to dark brown dorsally and light brown ventrally; young individuals usually paler than adults (Rebelato 2006). Baculum paddle shaped, mean length 9.34 mm, with V-shaped proximal tip. Glans penis with dense (12/mm2), single-tipped epidermal spines averaging 245.14 ± 49.81 µm s.d. in length (Rocha-Barbosa et al. 2013). d i s t r i b u t i o n : Ctenomys minutus is known from the southern Brazilian states of Santa Catarina and Rio Grande do Sul. s e l e c t e d l o c a l i t i e s (Map 456; from T. R. O. Freitas 1997, except as noted): BRAZIL: Rio Grande do Sul, Capão Novo, Cidreira, Mostardas, Osório, Palmares do Sul, Palmital, Passinhos, Taquara (type locality of Ctenomys minutus Nehring), Tavares, Tôrres; Santa Catarina, Jaguaruna, Morro dos Conventos. s u b s p e c i e s : Cabrera (1961:553) recognized two subspecies, C. m. minutus and C. m. bicolor, the latter corresponding to C. bicolor (Miranda-Ribeiro 1914), herein regarded as a separate species. Consequently, C. minutus is monotypic. n a t u r a l h i s t o ry: This species usually occupies the highest parts of sandy and dry fields and pastures not far from water bodies along the coastal plain of southern Brazil. This is a solitary and territorial species, with low vagility and sedentary behavior and sexual size dimorphism in favor of males (Marinho and Freitas 2006). Population densities may vary from 7 to 42 individuals per hectare (Gastal 1994; M. B. Fonseca 2003). Sex ratio is 1:1 in juveniles and subadults but biased toward females in adults, with 1.3 times more females in general and 1.26:1 females in the adult cohort (M. B. Fonseca 2003; Marinho and Freitas 2006). Gestation time is about 90 days, and sexual maturity is reached within 6–7 months (M. B. Fonseca 2003). r e m a r k s : Thomas (1898d:285) believed that the original series of three skulls upon which Nehring (1887)

based his C. minutus were immatures, “so much so, indeed, that I doubt if the full-grown animal is any smaller than the Uruguayan Ct. torquatus, Licht.” Nehring (1900a,c), however, rebutted Thomas’s assertion in great detail and provided line-drawings as well as a photograph of the largest of three skulls he used in his original description to emphasize its “adult” features, including well-developed ridging, broad zygomatic arches, and almost complete fusion of the sphenobasilar suture. S. Anderson (1997:497; see also S. Anderson et al. 1987) tentatively assigned Bolivian specimens from Santa Cruz department to C. minutus “on the basis of size and geographic occurrence.” This assignment, however, is probably in error. Anderson’s “geographic occurrence” rationale was based on Cabrera’s (1961) unjustified consideration of C. bicolor from Mato Grosso (or Rôndonia; see account of that species), Brazil, as a valid subspecies of C. minutus. Moreover, the holotype, and only known specimen of C. bicolor is large, not small in size, making the linkage of this taxon to either the Bolivian specimens or to true C. minutus from southeastern Brazil untenable, and thereby negating a geographic connection between the small Bolivian specimens and C. minutus. Indeed, E. P. Lessa and Cook (1998) referred to these Bolivian specimens as “Ctenomys sp. ‘minut,’ ” thus suggesting that

Map 456

Selected localities for Ctenomys minutus (●).

852 Mammals of South America

they had been incorrectly assigned to C. minutus. Whether or not these Bolivian specimens belong to another of those species that have been described or represent an as yet unnamed taxon must await further revisionary work on the genus. Populations of C. minutus from Brazil are very polymorphic for Robertsonian and tandem fusions, resulting in a variation of diploid number from 42 to 50 (T. R. O. Freitas 1997, 2005; Freygang et al. 2004). Marinho and Freitas (2000) and Gava and Freitas (2002, 2004) characterized contact zones between different cytotypes. The sperm has the symmetric morphology (T. R. O. Freitas 1995).

Ctenomys nattereri Wagner, 1848 Natterer’s Tuco-tuco sy n o n y m s : Ctenomys Nattereri Wagner, 1848:72; type locality “Caissora (Provinz Matogrosso)” (= Caiçara, Nehring 1990b: 537 and Cabrera 1961:553, or = Cáceres, S. Anderson et al. 1987:1), Mato Grosso, Brazil, ca. 200 m, 16°00′S 57°45′ W. Ctenomys boliviensis nattereri: S. Anderson et al., 1987:11; name combination. d e s c r i p t i o n : Moderately large, head and body length about 245 mm, tail length 71 mm, ear length 11 mm, and hindfoot length (including claw) 54 mm. Head and particularly muzzle very broad and flat, rhinarium nearly naked, eyes small, and incisors very broad and ungrooved; ear opening very small, within small pinna. Claws on forefeet especially long (medial claw about 16 mm), and typical tuco-tuco comb-like hairs extend from sides of hindfeet. Overall dorsal color uniform brownish and shiny, flecked with black that vaguely defines a dorsal stripe passing from middle of head along back, gradually disappearing toward rump. Under surface all black but with light shading, interrupted by white spotting, particularly in axillary and inguinal areas. Upper incisors faced with “vivid saffron-red” enamel. A third known specimen, from José Bonifácio, Rondônia state, Brazil, smaller, with head and body 218 mm and tail 72 mm ( J. A. Allen 1916d). d i s t r i b u t i o n : Ctenomys nattereri is known only from three localities, one each in Santa Cruz department, Bolivia, and both Mato Grosso and Rôndonia states in west-central Brazil. s e l e c t e d l o c a l i t i e s (Map 457): BOLIVIA: Santa Cruz, Santa Cruz de la Sierra (Parada et al. 2011). BRAZIL: Rondônia, José Bonifácio ( J. A. Allen 1916d); Mato Grosso, Cáceres (probable type locality of Ctenomys nattereri Wagner). s u b s p e c i e s : Ctenomys nattereri is monotypic.

n a t u r a l h i s t o ry: No data are available ecological characteristics of C. nattereri except for the account of the specimen that Leo E. Miller collected on February 24, 1914, during the Roosevelt-Rondon Expedition ( J. A. Allen 1916d; L. E. Miller 1918). According to L. E. Miller (1918:239), the single excavated burrow “measured fifteen feet [4.60 m] long, eight feet [2.45 m] deep and three feet [0.92 m] wide, and it required half a day for the Indians to complete the work.” This is a fairly deep system for tuco-tucos. The burrow, however, was simple because “at the end [of the 15 feet long tunnel] was a small cavity, but no nest. Small bunches of grass were found in the gallery which had been pulled down by the roots.” The local Nhambiquara, who helped Miller collect the specimen, were very fond of the animal’s flesh “and often dig them out to eat” (L. E. Miller 1918:238). Although “the animal seemed bewildered above ground and could not run fast” (L. E. Miller 1918:239), Theodore Roosevelt, who was watching the whole procedure, wrote that “the animal dug hard to escape, but when taken and put on the surface of the ground it moved slowly and awkwardly,” but “it showed vicious courage” (Roosevelt 1914:246). In his field notes, L. E. Miller (in J. A. Allen, 1916d:595) calls this tuco-tuco “cururu,” probably mistaking this with “curu-curu,” a common name given to tuco-tucos in parts of Brazil (A. B. de H. Ferreira 1986:513). Interestingly, cururu or cururú was the name given by indigenous Fueguians to C. magellanicus (see that account). r e m a r k s : The true geographic distribution of C. nattereri is almost completely unknown. Nehring (1900b) described and figured the skull upon which Wagner based his name C. nattereri, giving the locality as “Caiçara in Matto Grosso.” Cabrera (1961:553) also restated Wagner’s (1848) type locality of “Caissora” as “Caicara (= Caiçara).” S. Anderson et al. (1987:11), however, equated “Caissora” with “Cáceres” in the Brazilian state of Mato Grosso (16°00′S 57°45′ W). No locality named “Caissora” occurs in Brazil, and of the six Caiçara localities found in maps and gazetteers, none relates geographically to the probable type locality of C. nattereri. Thus, “Cáceres” is the most probable geographic location of the type of C. nattereri. J. A. Allen (1916d:569) reported finding one specimen of C. nattereri at 12°19′S 60°30′ W near the community of José Bonifácio (misspelled as José Bonefacio [pp. 560, 595] and José Bonesfascio [p. 569]) in the Brazilian state of Rondônia, although he gave no reason for this assignment. This locality is, however, quite distant from Cáceres, and separated from it by the high Chapada dos Parecís, suggesting an atypically (for a tuco-tuco) large distribution. Moreover, L. E. Miller (in J. A. Allen 1916d:595)

Suborder Hystricomorpha: Family Ctenomyidae 853

detected the sporadic presence of Ctenomys mounds from “Tapiropoan” (= Tapirapoãn or Tapirapuã) at 14°51′S and 57°45′ W, up to José Bonifácio. S. Anderson et al. (1987) compared the skull of this specimen with those of C. boliviensis and found a number of small but insignificant differences. These authors thus concluded that nattereri Wagner was a subspecies of C. boliviensis Waterhouse, which they (as first reviewers) selected as having date priority. Their action thus expanded the range of this tuco-tuco species even more. A further complication is the description of C. rondoni by Miranda-Ribeiro (1914), also from Mato Grosso but with the imprecise locality of Maria de Molina and Rio Juruena (see the account of C. rondoni). Again without justification, Cabrera (1961:553) synonymized C. rondoni with C. nattereri, a decision followed most recently by Woods and Kilpatrick (2005:1561). Herein, these two are treated as separate species. Clearly, detailed surveys for tuco-tucos in the Brazilian states of Mato Grosso and Rôndonia and the adjacent Bolivian province of Santa Cruz are required to determine the current biological boundaries of these various “species” and map their distributions correctly. Both karyotype and sperm morphology is unknown. MtDNA cytochrome-b sequence analysis (Parada et al. 2011) places C. nattereri as a member of the “boliviensis” group, along with C. boliviensis and C. goodfellowi, a well-supported monophyletic clade identified as the

Map 457 2,000 m.

Selected localities for Ctenomys nattereri (●). Contour line =

“Boliviano-Matogrossense” group by J. R. Contreras and Bidau (1999).

Ctenomys occultus Thomas, 1920 Furtive Tuco-tuco, Oculto sy n o n y m s : Ctenomys occultus Thomas, 1920e:243; type locality “Monteagudo, about 80 km. S.E. of Tucuman City,” San Miguel de Tucumán, Departamento Simoca, Tucumán, Argentina, 27°31′S, 65°17′ W, 296 m. Ctenomys mendocinus occultus: Cabrera, 1961:552; name combination. d e s c r i p t i o n : Small species, head and body length 1380–151 mm (A. I. Medina et al. 2007). Overall color warm brown, with upper surfaces glossy cinnamon brown with some vague darkening on crown, but without blackish forehead; under surfaces washed with pale drabby, chin and throat more sharply drab. Specimens range from whitish to drab below. Skull similar to that of C. juris with small bullae, proodont incisors, and presence of small sharp-edged ledges projecting over orbital fossae, which are short and more abruptly cut; zygomata widely spaced with middle region markedly convex outward; often small medial additional foramen present anterior to incisive foramina; mesopterygoid fossa extends forward to middle of M2. Anterior face of the proodont incisors angled at 102° to 104° of horizontal plane. d i s t r i b u t i o n : Ctenomys occultus is known from only a few localities in Tucumán province in the Chaco Seco ecoregion. s e l e c t e d l o c a l i t i e s (Map 458): ARGENTINA: Tucumán, Alberdi ( J. R. Contreras, pers. comm.), La Cocha ( J. R. Contreras, pers. comm.), Lamadrid (Thomas 1920e), Monteagudo (type locality of Ctenomys occultus Thomas), Simoca (Parada et al. 2011). s u b s p e c i e s : Ctenomys occultus is monotypic. n a t u r a l h i s t o ry: No data on ecology are available; Redford and Eisenberg (1992) stated that individuals live in areas of xeric vegetation, but without documentation. r e m a r k s : Thomas (1920e:244) regarded C. occultus to be closely allied to C. juris from Jujuy province, differing from it “by so many little characters that it seems to deserve a special name, and also to C. latro from Tucumán province, despite their differences in size.” Reig and Kiblisky (1968a) used the unique karyotype of 2n = 20, FN = 40, of C. occultus to validate it as a species distinct from C. mendocinus. This species belongs to the “tucumanus group,” along with C. argentinus, C. latro, and C. tucumanus, based on mtDNA sequence analyses (Parada et al. 2011). The sperm is the simple asymmetric type (Bidau 2006).

854 Mammals of South America

Map 458 2,000 m.

Selected localities for Ctenomys occultus (●). Contour line =

Ctenomys opimus Wagner, 1848 Andean Tuco-tuco sy n o n y m s : Ctenomys opimus Wagner, 1848:75; type locality: “Bolivia,” restricted by Thomas (1900g:383) to “Sahama,” Mount Sahama, Oruro, Bolivia, ca. 17°49′S, 67°28′ W, 3,000–4,000 m. Ctenomys opimus nigriceps Thomas, 1900g:383; type locality “Tetiri, about 40 miles [64 km] W. of Puno, on the Puno-Moquegua road. Altitude 16,000 feet [4,880 m],” Pampa de Titiré, Puno, Peru. Ctenomys opimus luteolus Thomas, 1900g:384; type locality “Cordilleras of Jujuy, [Jujuy,] Argentina Republic.” Ctenomys opimus opimus: Yepes, 1930:325; name combination. Ctenomys luteolus: Yepes, 1935a:252; name combination. Ctenomys optimus S. L. Gardner and Anderson, 2001:12; incorrect subsequent spelling of Ctenomys opimus Wagner. d e s c r i p t i o n : Large, total length of Bolivian and Peruvian specimens 270–340 mm and those from Argentina (Salta and Jujuy provinces) 275–300 mm (Pearson 1959; Cook et al. 1990; S. Anderson 1997; M. M. Díaz and Barquez 2002; A. I. Medina et al. 2007). Pelage long, lax, and soft in texture, with dorsal color uniformly pale yellowish, tending to become darker as tips of hairs wear, sometimes in patches, as on top of head. Majority of adult specimens show open frontoparietal fenestrae (S. L. Gardner and Anderson 2001).

d i s t r i b u t i o n : Ctenomys opimus occurs widely across the Altiplano from southern Peru to northwestern Argentina, northern Chile, and southwestern Bolivia, all at elevations above 3,200 m. s e l e c t e d l o c a l i t i e s (Map 459): ARGENTINA: Catamarca, Antofagasta de la Sierra (R. A. Ojeda 1985); Jujuy, Tres Cruces (A. I. Medina et al. 2007); Salta, Chorrillos (Yepes 1930), La Poma (Mares, Ojeda, and Barquez 1989), Los Cardones (Ipucha et al. 2008), Salar Pastos Grandes (M. M. Díaz et al. 2000), Tolar Grande (M. M. Díaz et al. 2000), Vega Cortadera (M. M. Díaz et al. 2000). BOLIVIA: La Paz, Esperanza, near Mount Sahama (Cook et al. 1990), Huaraco-Antipampa (Cook et al. 1990); Oruro, Challapata (Thomas 1902c), Cruce Ventilla (Cook et al. 1990), Huancaroma (Cook et al. 1990), Mount Sajama (type locality of Ctenomys opimus Wagner), Oruro (Cook et al. 1990); Potosí, Livichuco (Thomas 1902c), Potosí (Thomas 1902c), Uyuni (Cook et al. 1990). CHILE: Arica y Parinacota, Choquelimpie (Sanborn and Pearson 1947), Lagho Chungara (Feito and Gallardo 1982). PERU: Puno, Caccachara (Sanborn and Pearson 1947; Pearson 1951), Lago Loriscota (MVZ 139609), Pampa de Ancomarca (MVZ 115976), Pampa de Tetirí (type locality of Ctenomys opimus nigriceps Thomas), 25 km SW of Pisacoma (MVZ 115981), Río Santa Rosa, 8 mi W of Mazocruz (MVZ 115982); Tacna, Lago Suche (Pearson 1959). s u b s p e c i e s : Three subspecies are recognized in the current literature (e.g., Cabrera 1961; Woods and Kilpatrick 2005): nigriceps Thomas, from Moquegua, Tacna, and Puno departments in southern Peru; opimus Wagner, from northern Chile and throughout the highlands of Bolivia; and luteolus Thomas, from the mountains of northwestern Argentina in Jujuy, Catamarca, and Salta provinces. These taxa differ primarily by differences in color pattern. n a t u r a l h i s t o ry: This species occurs at elevations up to 5,000 m, where it can be very abundant in areas of sparse vegetation and loose sandy, gravely, or cindery soils. Pearson (1951, 1959) described burrow systems, food habits, digging behavior, parasites and associates, reproductive biology, sexual dimorphism, and population densities at several study sites in southern Peru. Bennett (1846:8) found animals on sandy slopes and valleys “at no great distance from water” where “large patches of land were completely undermined by its workings.” He believed that animals ate below ground bulbs and grass roots, rarely leaving their burrows to feet on grass stems. Their burrowing activity was heightened in the morning. S. Anderson (1997) recorded reproduction season in Bolivia. C. R. Lambert et al. (1988) and S. L. Gardner and Duszynski (1990) reported on eimerian oocysts in the feces of Bolivian specimens. This species is

Suborder Hystricomorpha: Family Ctenomyidae 855

Map 460 2,000 m.

Map 459

Selected localities for Ctenomys opimus (●). Contour line = 2,000 m.

the type host of a species of sucking louse (Durden and Musser 1994). r e m a r k s : George R. Waterhouse (in Bennett 1846:8) referred to specimens from Potosí, Bolivia recorded by Bennett (1946:8–9) as C. brasiliensis; these, however, most likely represent C. opimus. Feito and Gallardo 1982) regarded C. opimus to be closely allied to C. fulvus based on sperm morphology; molecular analyses either place C. opimus in a basal position (electrophoretic characters; Cook and Yates 1994), within a group of Bolivian species with respect to those from geopolitical areas outside of Bolivia (mtDNA sequences; E. P. Lessa and Cook 1998), or within a “opimus group” that also included C. fulvus, C. scagliai, and C. saltarius (mtDNA sequences; Parada et al. 2011). All analyzed subspecies have the same karyotype of 2n = 26 metacentric chromosomes, or FN= 48 (M. H. Gallardo 1979; Cook et al. 1990; Toloza et al. 2004; Ipucha et al. 2008). Ruedas et al. (1993) provided data on genome size. The sperm type is simple symmetric (Feito and Gallardo 1982; Vitullo and Cook 1991).

Ctenomys osvaldoreigi J. R. Contreras, 1995 Osvaldo Reig’s Tuco-tuco sy n o n y m : Ctenomys osvaldoreigi J. R. Contreras, 1995a:1; type locality “Estancia San Luis, Ruta Provincial 20, 10 kiló-

Single known locality for Ctenomys osvaldoreigi (●). Contour line =

metros al oeste del Río Yuspe, en el extremo sudeste del Departamento Cruz del Eje, Provincia de Córdoba, 31°24′S, 64°48′ W, aproximadamente a 2000 metros,” Argentina. d e s c r i p t i o n : Medium sized, total body length of male holotype 275 mm with mass, 244 g; equivalent data for female paratype 254 mm and 203.2 g, respectively; and for female topotypic series, body length 235– 254 mm, mass 176–279 g ( J. R. Contreras 1995a; A. I. Medina et al. 2007). General color uniformly ochraceous brown dorsally (corresponding to “antique brown” in Smithe’s [1975] atlas) with tawny tips to hairs; venter ochraceous (“cinnamon”) and lacking inguinal and axillary white spots common in many species in genus; white collar that characterizes most Bolivian and Chacoan species is lacking; tail bicolored, brown above and cream below; dorsal surfaces of feet same general color as body. Skull gracile with elongated rostrum that exhibits little evidence of lateral widening; weakly developed temporal crests; slender zygomatic arches, with breath across them significantly greater than that across external auditory tubes; interparietalscarcely visible or fused with parietal and squamosal bones; bregmatic fontanelles lacking in adults; auditory bullae small and uninflated. Small fossa that characterizes most Chacoan species absent. d i s t r i b u t i o n : Ctenomys osvaldoreigi is only known from its type locality in Córdoba province, Argentina.

856 Mammals of South America

s e l e c t e d l o c a l i t i e s (Map 460): ARGENTINA: Córdoba, Estancia San Luis (type locality of Ctenomys osvaldoreigi J. R. Contreras). s u b s p e c i e s : Ctenomys osvaldoreigi is monotypic. n a t u r a l h i s t o ry: No data on behavior, ecology, reproduction, or food preferences are available. r e m a r k s : Giménez et al. (1999) described a karyotype with 2n = 52, FN = 56 (see also Ipucha et al. 2008), and simple, asymmetric sperm morphology.

Ctenomys paraguayensis J. R. Contreras, 2000 Paraguayan Tuco-tuco sy n o n y m : Ctenomys paraguayensis J. R. Contreras, 2000:62; type locality “Corate-í, 12 kilómetros al oeste de la ciudad de Ayolas, departamento Misiones, República del Paraguay, aproximadamente en las coordenadas: 27°24′S–57°01′ W.” d e s c r i p t i o n : Medium sized with head and body length of three known specimens 166–174 mm, tail length 73–80 mm, hindfoot (with claw) 34.8–37 mm, and mass 146–187 g. General color very similar to that of C. pilarensis, the other tuco-tuco species from eastern Paraguay, including presence of prominent, pale semicollar that passes obliquely from below ear around back of head, reaching base of neck; cheeks of C. paraguayensis, however, paler with face lacking any blackish coloration. Ventral coloration clear creamy gray without white spots in inguinal or axillary regions; tail only slightly bicolored. Skull graceful in overall appearance; width across zygomatic arches always greater than width across auditory tubes; postorbital spine of jugal rises almost perpendicular to occlusal plane of cheek teeth rather than obliquely; rim of zygomatic arch lacks foramen that may be present in other species; superior placement of auditory meatus relative to cheek teeth, a characteristic shared with species in northeastern Argentina and adjacent Uruguay, one of most notable features; two lateral openings through which alisphenoid-presphenoid bridge is visible present both sides of mesopterygoid fossa; this bridge is thin, with medial posterolateral expansion shaped like sharp stylus about 4 mm in length. J. R. Contreras (2000) provided detailed comparisons, particularly of cranial features, between C. paraguayensis, C. dorbignyi, and C. pilarensis, and somewhat less so to C. argentinus. d i s t r i b u t i o n : Ctenomys paraguayensis is known only from the type locality in Misiones department, Paraguay. s e l e c t e d l o c a l i t i e s (Map 461): PARAGUAY: Misiones: Corate-í (type locality of Ctenomys paraguayensis J. R. Contreras). s u b s p e c i e s : Ctenomys paraguayensis is monotypic. n a t u r a l h i s t o ry: No ecological data are available.

r e m a r k s : Ctenomys paraguayensis was described based on three specimens secured at the type locality. The species is distinct in both cytogenetic and morphological characters relative to all other known species in the genus. The karyotype is 2n = 52 ( J. R. Contreras 2000), more similar to species occurrying in northern Corrientes province, Argentina (see accounts of C. perrensi and allies), and not to the neighboring C. pilarensis from Ñeembucú department, Paraguay. Comparative analysis of morphometric, osteological, and general somatic characteristics indicated a clear differentiation of this species with C. pilarensis as well as no close affinity with those species from the northeastern Argentinean provinces of Corrientes and Entre Ríos, such as C. dorbignyi. Ctenomys paraguayensis may represent Brants (1827) Ratton tucotuco Brants, a bibliographical species based on Azara’s (1802) “el tucutuco” from Paraguay, but definitive evidence for this hypothesis is lacking (see Langguth 1966, 1978). Brant’s tucotuco, however, was ruled (ICZN 1982:Opinion 1232) to be a vernacular name and unavailable for use in zoological nomenclature. Because of the great environmental change resulting from the construction of the Yacyretá dam, C. paraguayensis is very likely reduced in numbers if it has not already vanished from its very restricted geographic range in extreme eastern Paraguay. Sperm morphology is unknown.

Map 461

Single known locality for Ctenomys paraguayensis (●).

Suborder Hystricomorpha: Family Ctenomyidae 857

Ctenomys pearsoni E. P. Lessa and Langguth, 1983 Pearson’s Tuco-tuco sy n o n y m : Ctenomys pearsoni E. P. Lessa and Langguth, 1983:86; type locality “Arroyo Limetas, 25 km SE de Carmelo, Dep. Colonia, Uruguay.” d e s c r i p t i o n : Medium sized, total length 245– 277 mm, tail length 72–82 mm, and mass 165–300 g (E. P. Lessa and Langguth 1983; E. M. González 2001). Body color similar to that of C. torquatus, and both species possess same clear half-collar. Skull depressed and elongated; dorsal surface of frontals almost flat from level of interorbital constriction toward rear; frontoparietal sutures straight and almost transverse; parietals show anterior medial elongated zone limited by temporal crests, in same plane as frontals; rostrum narrow and elongated, with markedly proodont incisors; frontals narrowed because of very limited interorbital constriction; braincase relatively narrow; interpremaxillary and incisive foramina enlarged and highly visible; palate narrow and excavated between molariform teeth, with thin bony septum present in sagittal plane; auditory bullae elongated and project from behind occipital condyles; paroccipital processes well developed; preorbital foramina high and elongated; mandibular apophyses of jugals triangular and moderately robust. Coronoid process of mandible subtriangular, with wide base; posterior border elevated toward front relative to plane of molariform teeth. E. P. Lessa and Langguth (1983) detailed number of small but clear cranial differences that distinguish this taxon from both geographically neighboring (such as C. torquatus, which it strongly resembles) and distant species. Penile morphology distinctive feature of C. pearsoni, with paddle-shaped, single-tipped baculum wider, shorter, and better defined than in other tuco-tucos (Altuna and Lessa 1985). d i s t r i b u t i o n : Ctenomys pearsoni occurs along the coast of Uruguay from Rocha department in the east to Colonia in the west, and in adjacent Entre Ríos province in Argentina. s e l e c t e d l o c a l i t i e s (Map 462): ARGENTINA: Entre Ríos, Médanos (Reig et al. 1966). URUGUAY: Canelones, Cuchilla Alta (Tomasco and Lessa 2007); Colonia Arroyo Limetas (type locality of Ctenomys pearsoni E. P. Lessa and Langguth), Estanzuela (E. P. Lessa and Langguth 1983); Maldonado, Chihuahua (Tomasco and Lessa 2007), José Ignacio (Tomasco and Lessa 2007), Solís (Tomasco and Lessa 2007); Montevideo, Carrasco (Tomasco and Lessa 2007); Rocha, Laguna de Rocha (Tomasco and Lessa 2007), Laguna Negra (Tomasco and Lessa 2007), Valizas (Tomasco and Lessa 2007); San José, Arazatí (E. P. Lessa and Langguth 1983), Río Santa Lucía (E. P. Lessa and Langguth 1983); Soriano, 1 km N of Nueva Palmira (E. P. Lessa and Langguth 1983).

s u b s p e c i e s : Ctenomys pearsoni is monotypic. n a t u r a l h i s t o ry: Ctenomys pearsoni inhabits coastal sandy soils along the edge or near river mouths (Altuna et al. 1999). Altuna (1985) described details of the burrow microclimate. This is a solitary, highly territorial, and aggressive species, typical of most tuco-tucos. Females are sexually mature and mate within their first year, but males do not. The baculum and other reproductive structures of males are not fully developed until an age of one year (Altuna and Lessa 1985). The mating system is polygynous. Reproduction occurs during the winter months, and litter sizes range between two and four. As in other tucotucos, young are weaned after 30–40 days and are fully independent at about 2 months’ age. Maternal behavior is highly developed in this species, as is probably true for most other tuco-tucos (Altuna et al. 1999). Vocal signals in pups and geographic variation in vocalizations have been studied by Francescoli (2001, 2002). As for other wellstudied tuco-tucos, C. pearsoni is an herbivorous generalist preferring grasses such as Cynodon dactylon and Panicum racemosum, the more abundant species in its habitat (Altuna et al. 1999). Feeding behavior of these tuco-tucos has been well studied; individuals are autocoprophagic (Altuna et al. 1998, 1999). The caecum is unique, weighing 30% of total mass, thus making it the (relatively) largest among all hystricognaths for which this feature has been measured (Altuna et al. 1998). r e m a r k s : Ctenomys pearsoni shares a pair of spiny bulbs on the male phallus with C. dorbignyi, C. perrensi, and C. roigi from Argentina (Altuna and Lessa 1985). The karyotype of C. pearsoni is distinctive but highly variable, with diploid numbers ranging from 56 and 70 in Uruguayan populations (A. Novello and Altuna 2002; A. F. Novello and Lessa 1986) with the chromosome morphology of the 2n = 70 form almost the same as the karyotype of C. dorbignyi (Argüelles et al. 2001). In Uruguay, a series of chromosomally differentiated populations extending from Montevideo to Punta del Este (east of the Santa Lucia river in the departments of Carrasco, Salinas, and Maldonado) are included in the “pearsoni complex” (E. P. Lessa and Langguth 1983; E. M. González 2001; A. Novello and Altuna 2002). The Argentinean Médanos population of C. pearsoni has 2n = 68 (Reig et al. 1966; originally assigned to C. torquatus), but differences from the 2n = 70 pearsoni-dorbignyi pattern are minimal. The morphologically very similar C. torquatus has a completely different karyotype (see below). However, populations of the “pearsonicomplex,” that is, those populations morphologically close to typical C. pearsoni, are karyotypically distinct (2n = 56–64; A. F. Novello and Lessa 1986). Sperm type is symmetrical. Tomasco and Lessa (2007) described the molecular phylogeography of the chromosomally variable

858 Mammals of South America

Map 462

Selected localities for Ctenomys pearsoni (●).

populations (2n = 56, 58, 64, 66, and 70) along the coast of Uruguay and discussed the role of chromosomal diversification in speciation within with species and tuco-tucos more generally. D’Anatro and D’Elía (2011) detailed morphometric variation among populations representing all karyotypic forms. With a single exception, all populations were indistinguishable, supporting their view that not all fixations of chromosomal rearrangements define independent evolutionary units that would warrant species recognition.

Ctenomys perrensi Thomas, 1896 Perrens’s Tuco-tuco sy n o n y m s : Ctenomys Perrensi Thomas, 1896:311; type locality “Goya, Corrientes, Argentina,” Departamento Goya, Corrientes, Argentina, 29°08′S, 59°16′ W, 37 m. Ctenomys perrensis Cabrera, 1961:554; incorrect subsequent spelling of Ctenomys perrensi Thomas repeated by several subsequent authors (e.g., Redford and Eisenberg 1992; Woods 1993; Nowak 1999). d e s c r i p t i o n : Medium sized, total length 230– 270 mm (A. I. Medina et al. 2007). General color dark buff or clay, heavily mixed with black along median line from face extending down back; eye to ear and below is lighter patch; cheeks brownish. Under surfaces from throat to belly rich buff, but patches of pure and sharply

contrasting white occur in axillary and inguinal regions. Upper surfaces of hands and feet thinly haired white. Skull short, broad, and rounded, not heavily ridged; zygomatic arches broader than breadth across posterior skull as measured at auditory meatus; nasals short, tapering backward, unusually broad and truncated behind; interorbital region short and very broad, postorbital process and ledges of limited development; frontoparietal suture almost directly transverse, little bowed backward; bullae small and little inflated, especially anteriorly. Upper incisors distinctly opisthodont, forming arc of smaller circle than in most tuco-tucos. d i s t r i b u t i o n : Ctenomys perrensi occurs in westcentral Corrientes province, Argentina (see detailed map in J. R. Contreras et al. 1985, and Remarks). s e l e c t e d l o c a l i t i e s (Map 463; from Giménez et al. 2002, except as noted): Ctenomys perrensi (sensu stricto): ARGENTINA: Corrientes, Colonia 3 de Abril, Goya (type locality of Ctenomys perrensi Thomas). Ctenomys perrensi complex: ARGENTINA: Corrientes, Arroyo Peguajó (Mirol et al. 2010), Chavarría, Contreras Cué, Curuzú Laurel, Estancia Tacuarita (Mirol et al. 2010), Loma Alta, Loreto, Manantiales, Pago Alegre, Paraje Angostura (Mirol et al. 2010), Paraje Caiman, Saladas, San Miguel (Parada et al. 2011). s u b s p e c i e s : Ctenomys perrensi is monotypic. n a t u r a l h i s t o ry: Very little ecological data are available. Mean litter size is 2.45 ± 0.89 s.d. (N = 11; J. R. Contreras, pers. comm.). r e m a r k s : Both Cabrera (1961:554) and Woods and Kilpatrick (2005:1567) incorrectly cited the year of publication of Thomas’s description as 1898. However, the issue of the Annals and Magazine of Natural History in which Thomas proposed Ctenomys perrensi (series 6, volume 18) appeared in 1896. Ctenomys perrensi is closely allied at the molecular level to all other Ctenomys inhabiting Corrientes Province, including C. roigi, C. dorbignyi, and unnamed chromosomally distinct taxa inhabiting central and northwestern Corrientes (referred to as Ctenomys sp. and Ctenomys sp. in Giménez et al. 2002), and also to C. pearsoni from Entre Ríos province, Argentina, and Uruguay ( J. R. Contreras and Bidau 1999; Mascheretti et al. 2000; Giménez et al. 2002). Parada et al. (2011) have named this assemblage of species the “torquatus” group (equivalent to the “Corrientes” group of J. R. Contreras and Bidau, 1999) on molecular evidence. However, none of the five taxa from Corrientes form reciprocally monophyletic groups in either allozyme or mtDNA or microsatellite analyses (Ortells and Barrantes 1994; Giménez et al. 2002; Mirol et al. 2010), al-

Suborder Hystricomorpha: Family Ctenomyidae 859

of C. perrensi in Entre Ríos province (Woods 1993; Redford and Eisenberg 1992), but these records actually correspond to C. pearsoni.

Ctenomys peruanus Sanborn and Pearson, 1947

Map 463 Selected localities for Ctenomys perrensi (●) and those of the Ctenomys “perrensi-complex” (ᇲ; see Remarks).

though each is well differentiated chromosomally, suggesting that the origin of the whole assemblage has been recent and that collectively they form a “superspecies” complex (Giménez et al. 2002; Mirol et al. 2010; Gómez Fernández et al. 2012). The karyotype of C. perrensi (sensu stricto) is 2n = 50; however, the “perrensicomplex” (C. perrensi + Ctenomys sp. α + Ctenomys sp. β) members range in diploid number from 2n = 41 to 2n = 66 (Ortells 1995; Giménez et al. 2002). This species has a simple symmetric type of sperm (Vitullo et al. 1988). The map of localities (Map 463) separates those records for C. perrensi sensu stricto from the karyotypically differentiated forms referred to as the “perrensicomplex,” which extend toward central Corrientes province. Additional karyotypically distinct populations occur in northeastern Corrientes province, but these seem more related at the molecular level to C. dorbignyi, despite their low chromosome numbers. All references to the presence of C. perrensi in Misiones province are erroneous (Yepes 1935a; Honacki et al. 1982; Redford and Eisenberg 1992; Woods 1993). Misiones is the only Argentinean province where no Ctenomys populations are known to exist. There are also references to the presence

Peruvian Tuco-tuco sy n o n y m : Ctenomys peruanus Sanborn and Pearson, 1947: 135; type locality “Pisacoma, alt. 14,000 ft., Department of Puno, southern Peru,” 16°55′S 69°22′ W, 3,965 m. d e s c r i p t i o n : Large, pale, dark-footed species, with broadly expanded zygomatic arches, sagittal crest, and reduced last molar. Mean head and body length 220 mm, mean tail length 88 mm, and mean hindfoot length 41 mm (A. I. Medina et al. 2007). Back, sides, and belly colored creamybuff, heavily lined in black to give overall brown tone; nose, lips, ears, and surrounding fur dark brown; hindfeet brown above, forefeet the same color as body; tail tawny. Skull with broadened zygoma expanded anteriorly so much so that zygomatic width greater than distance between outer edges of bony auditory meatus; sagittal crest present, even in smaller females; top of skull moderately arched. Last molar above and below about one quarter size of other molars. d i s t r i b u t i o n : Ctenomys peruanus is limited to Puno department in southern Peru. s e l e c t e d l o c a l i t i e s (Map 464): PERU: Puno, Pampa de Quellecota (Pearson 1959), Hacienda Pichupichuni, Río Callacame, 8 km NW of Huacullani (Pearson 1959), Quellecota (MVZ 114767), Mazocruz (Sanborn and Pearson 1947), Pisacoma (type locality of Ctenomys peruanus Sanborn and Pearson). s u b s p e c i e s : Ctenomys peruanus is monotypic. n a t u r a l h i s t o ry (from Pearson 1951, 1959): This species inhabits open, often heavily grazed pampa shrub steppe composed of thorn bushes, closely cropped grass, dwarf flowers, and occasional tufts of taller grasses in southern Peru, where its range meets that of C. opimus. In the sandy and gravelly soils these tuco-tucos likely compete seriously with domesticated livestock (alpaca, llama, and sheep). This is the only Peruvian species that vocalizes conspicuously, with an alarm call described as “a musical bubbling” (p. 157). They are active during the day, will sit motionless with their heads at the entrance to their tunnels, and forage above ground to a meter or more from their burrow opening. Stomach contents contained coarse vegetable matter. The breeding season begins in November and lasts at least through April, with a gestation period approximating 4 months. There is likely only one litter produced by each female in a year. Litter size varied from 1 to 5, with a mean of 3.5, although resorption rates reduce the mean litter to about three young. Young

860 Mammals of South America

Map 464 2,000 m.

Selected localities for Ctenomys peruanus (●). Contour line =

are precocial, with late-term embryos well furred and neonates well developed at birth. Sex ratio may slightly favor females (Pearson 1951) or be strongly skewed to females (Pearson 1959). Several other vertebrates (mammals, birds, reptiles, and amphibians) use abandoned burrow systems. Pearson (1959) estimated density by counting active burrow opening and observing, with binoculars, the heads of active tuco-tucos at their entrances. He also suggested that C. peruanus was social, living in colonies, a behavior that contrasts with other tuco-tucos except C. sociabilis. r e m a r k s : Sanborn and Pearson (1947) believed that C. peruanus was closely related to C. fulvus from northern Chile. The karyotype and sperm type of C. peruanus have not been reported.

Ctenomys pilarensis J. R. Contreras, 1993 Pilar Tuco-tuco sy n o n y m : Ctenomys pilarensis J. R. Contreras, 1993:44; type locality “Pilar, [Ñeembucú,] Paraguay.” d e s c r i p t i o n : Medium sized, head and body length of males 189–209 mm and that of females 169–177 mm (A. I. Medina et al. 2007). No other details published. d i s t r i b u t i o n : Ctenomys pilarensis occurs in extreme southern Paraguay. s e l e c t e d l o c a l i t i e s (Map 465; from Giménez et al. 1997, except as noted): PARAGUAY: Ñeembucú, Des-

Map 465

Selected localities for Ctenomys pilarensis (●).

mochado, Mayor Martínez, Paso Pucú, Pilar (type locality of Ctenomys pilarensis J. R. Contreras). s u b s p e c i e s : Ctenomys pilarensis is monotypic. n a t u r a l h i s t o ry: Ctenomys pilarensis inhabits fine sandy soils and is often found in manioc plantations. No specific data on behavior, reproduction, or ecology are known. r e m a r k s : I have been unable to locate the original description of this species, which was apparently published in the abstracts and proceedings of a scholarly meeting. If the rules of the Code were followed in this brief presentation, then the name pilarensis J. R. Contreras is valid. However, if eventual access to these proceedings shows that the Code requirements were not followed, then pilarensis J. R. Contreras will become a nomen nudum, and this taxon will require a new name. Mascheretti et al. (2000) included C. pilarensis in a group of Chacoan species that otherwise included C. argentines, C. latro, C. occultus, and C. tucumanus, which Parada et al. (2011) called the “tucumanus group.” Both studies were based on mtDNA sequences. This species is chromosomally polytypic with the few populations sampled either 2n = 48 or 2n = 50. Each karyotype, however, has an FN = 50, supporting differentiation through Robertsonian changes (Giménez et al.

Suborder Hystricomorpha: Family Ctenomyidae 861

1997). The sperm is the simple asymmetric morphology (Giménez et al. 1997).

Ctenomys pontifex Thomas, 1918 Brown Tuco-tuco sy n o n y m : Ctenomys pontifex Thomas, 1918a:39; type locality “East side of the Andes near Fort San Rafael, Province of Mendoza,” Argentina; restricted to Volcán Peteroa, Malargüe department, ca. 35°26′S, 70°20′ W by Pearson and Lagiglia (1992). d e s c r i p t i o n : Medium sized; external dimensions of holotype (adult female) head and body length 183 mm, tail length 77 mm, and hindfoot length 34 mm. Color above uniform drab-brown without darker markings; under parts paler and buffier; tail brown above, whitish below. Skull rather narrow; zygomatic arches not expanded widely and with median ascending process placed posteriorly, making orbit proportionally large compared with temporal fossa; nasals long and nearly parallel sided, slightly surpassed behind by premaxillary processes; braincase lacks strong ridges; mesopterygoid fossa narrow; bullae long and narrow, in marked contrast with those of nearby C. mendocinus. d i s t r i b u t i o n : Ctenomys pontifex is known only from Mendoza province, Argentina. s e l e c t e d l o c a l i t i e s (Map 466): ARGENTINA: Mendoza, Ñacuñán ( J. R. Contreras 1979a), Volcán Peteroa (type locality of Ctenomys pontifex Thomas). s u b s p e c i e s : Ctenomys pontifex is monotypic. n a t u r a l h i s t o ry: Giannoni et al. (1996) described the burrowing behavior of C. pontifex (under the nomen nudum C. eremophilus; see Remarks). No other ecological data are available. r e m a r k s : Ctenomys pontifex is another tuco-tuco species for which the type locality is uncertain and (as in the case of C. knighti discussed previously) where other rodent species share the same type locality. Thomas (1918a:40) gave this locality as “East side of the Andes near Fort San Rafael, Province of Mendoza”; Cabrera (1961:555) listed it simply as “San Rafael, Mendoza” and not, as Rusconi (1928:244) had thought, to “Fuerte de San Rafael, Provincia de Mendoza.” This locality is within the Department of 25 de Mayo of Mendoza province. Pearson and Lagiglia (1992:35) assigned to C. mendocinus tucotucos collected in the vicinity of the presumed type locality of C. pontifex, and suggested that Thomas Bridges had likely collected the type specimen of pontifex in the neighbourhood of the Peteroa volcano, near the border between Argentina and Chile. This locality is in the Department of Malargüe, Mendoza, about 200 km WSW of San Rafael

Map 466 2,000 m.

Selected localities for Ctenomys pontifex (●). Contour line =

between 2,400 and 3,000 m elevation (Pearson and Lagiglia 1992). Bidau (2006) regarded eremophilus J. R. Contreras and Roig as a synonym of C. pontifex, but Parada et al. (2012) clearly linked this unavailable name to C. mendocinus (see that account). The diploid number is 50 (M. O. Ortells, pers. comm.), but the sperm type is unknown.

Ctenomys porteousi Thomas, 1916 Cinnamon Tuco-tuco sy n o n y m s : Ctenomys porteousi Thomas, 1916g:304; type locality “Bonifacio, S.W. Buenos Ayres Province, about 36°40′S, 62°W,” Departamento Guaminí, Buenos Aires, Argentina, 36°49′S, 62°13′ W, 100 m. Ctenomys porteousi porteousi: Yepes, 1935a:252; name combination. d e s c r i p t i o n : Medium sized with mean head and body length 186 mm (range: 174–205), tail length 77 mm (range: 68–89), hindfoot 30 mm (range: 28–33), and mass 192 g (range: 115–240; J. R. Contreras and Reig 1965). General color above cinnamon-brown lined with black; mid-dorsal area darkened, sometimes black, but dark area not sharply defined; top of muzzle and crown also blackish; under parts near vinaceous buff or drabby, bases of hairs

862 Mammals of South America

dark slaty; upper surfaces of hands and feet buffy whitish; tail dull whitish or pale brown, with darker, often blackish, terminal crest. Skull large but with smooth crown, parietal ridges imperceptible even in oldest individuals; incisive foramina medium in size; foramen magnum placed unusually high, with either one or two projections downward on its upper edge; bullae large. Upper incisors proodont, angled in comparison to toothrows between 97° and 100°; their enameled surfaces dark orange. d i s t r i b u t i o n : Ctenomys porteousi is found in the Pampas ecoregion of southeastern Buenos Aires province, Argentina. s e l e c t e d l o c a l i t i e s (Map 467; J. R. Contreras and Reig 1965, except as noted): ARGENTINA: Buenos Aires, Álamos, Bonifacio (type locality of Ctenomys porteousi Thomas), Daireaux, Papín (Thomas 1916g), Pirovano. s u b s p e c i e s : Ctenomys porteousi is monotypic. n a t u r a l h i s t o ry: No information on ecology is available. r e m a r k : Ctenomys porteousi is a member of the “mendocinus” group based on mtDNA sequences, along with C. australis, C. flamarioni, C. mendocinus, and C. rionegrensis (Parada et al. 2011). It has the typical “mendocinus” karyotype of 2n = 46, 47, or 48 (Massarini, Barros, Ortells, and Reig 1991). Massarini et al. (1992) described the genetic structure of populations of this species based on electromorphic markers. The sperm is sim-

Map 467 2,000 m.

Selected localities for Ctenomys porteousi (●). Contour line =

ple asymmetric in morphology (Vitullo et al. 1988). Apfelbaum et al. (1991) compared levels of electromorphic variation within and between C. porteousi and C. australis, and Mapelli et al. (2012) detailed phylogeography and posited Late and post-Pleistocene population history based on mtDNA sequences.

Ctenomys pundti Nehring, 1900 Pundt’s Tuco-tuco, Small Tuco-tuco sy n o n y m s : Ctenomys Pundti Nehring, 1900a:420; type locality “Alejo Ledesma im Süden der Provinz Cordoba,” Departamento Marcos Juárez, Córdoba, Argentina, 33°38′S, 62°37′ W, 113 m. Ctenomys mendocinus pundti: Cabrera, 1961:553; name combination. d e s c r i p t i o n : One of smallest species; overall head and body length of specimen used by Nehring in his description 170 mm, tail 43 mm, and hindfoot (including claws) only 20 mm. Color of upper parts yellowish-brown; under parts whitish-gray; both forefeet and hindfeet whitish above; tail bicolored, blackish above and whitish below. Dorsal hairs with yellow-brown tips and dark blue-gray bases. A. I. Medina et al. (2007) collected fully mature specimens with head and body length ranging between 133 and 138 mm in females, and 144 and 157 mm in males; some specimens weighed less than 100 g. Skull likewise small, with dimensions given by Nehring of total length 31.3 mm, basilar length 25.5 mm, zygomatic breadth 19.5 mm, width across auditory meatus 19.6 mm, least interorbital constriction 6.6 mm, nasal length 10.2 mm, diastema length 8.0 mm, upper toothrow length 6.9 mm, and width across both lower incisors 3.2 mm. Nehring noted, in particular, that occiput was not sharpedged but founded, reflecting weakly developed lambdoidal crest. Other cranial features apparent in illustrations provided by Nehring (1900a,c) include proodont upper incisors, greatly expanded and ventrally rounded auditory bullae, auditory meatus set on same plane as upper cheek teeth, and weakly developed but verticalpostorbital process of jugal. Many of these characters are attributes of small size. d i s t r i b u t i o n : Ctenomys pundti occurs in the provinces of Córdoba and San Luis in north-central Argentina within the Pampa and Espinal ecoregions. s e l e c t e d l o c a l i t i e s (Map 468, from A. I. Medina et al. 2007, except as noted): ARGENTINA: Córdoba, Alejo Ledesma (type locality of Ctenomys pundti Nehring), La Carlota, Manantiales, Puente Olmos; San Luis, Eleodoro Lobos ( J. R. Contreras, pers. comm.) s u b s p e c i e s : Ctenomys pundti is monotypic. n a t u r a l h i s t o ry: No ecological data are available.

Suborder Hystricomorpha: Family Ctenomyidae 863

Map 468

Selected localities for Ctenomys pundti (●). Contour line = 2,000 m.

r e m a r k s : The karyotype of C. pundti includes a 2n = 50 and FN = 84 (Ipucha et al. 2008). Tiranti et al. (2005) discussed the morphological and karyological relationships of this species to other tuco-tucos, concluding that C. pundit is closest to C. talarum. The sperm morphology is the simple symmetric type (Bidau 2006).

Ctenomys rionegrensis Langguth and Abella, 1970 Rio Negro Tuco-tuco sy n o n y m s : Ctenomys minutus rionegrensis Langguth and Abella, 1970: 13; type locality “Balneario Las Cañas, boca del Arroyo Las Cañas, 7 km al Sudoeste de Fray Bentos, Río Negro, Uruguay,” ca. 100 m, 33°06′S 58°20′ W. Ctenomys rionegrensis: Altuna and Lessa, 1985:483; first use of current name combination. d e s c r i p t i o n : Relatively small tuco-tuco; external and cranial measurements for both sexes separately: males, head and body length 178–190 mm, tail length 71–83 mm, hindfoot length 30–33 mm, greatest skull length 45.9– 47.9 mm, condylobasilar length 41–42.8 mm; females, head and body length 162–190 mm, tail length 65–83 mm, hindfoot length 29–33 mm, greatest skull length 41–44.6 mm, condylobasilar length 37.1–40.0 mm. Dorsal color varies extensively, with individuals either clear brownish-orange, dark-backed, or melanic (D’Elía et al. 1998; Wlasiuk et al. 2003); “agouti” individuals with small, yellow parauricular spots and yellowish venters; no inguinal or axillary

spots present; base of all body hairs, above and below, dark gray; tail bicolored with dorsal dark brown line along length. Skull with sides of rostrum parallel when viewed from above; temporal crests of parietal run almost parallel getting more near posteriorly; dorsal face of frontals and parietals flat. In comparison with C. torquatus, skull more rectilinear in shape; nasals flat or slightly convex longitudinally; dorsal border of foramen magnum with wide medial indentation; lateral processes seen in C. torquatus barely conspicuous; dorsal radius of upper incisors shorter such that incisors more opisthodont; most external point of zygomatic arch near its posterior end; zygoma dorsoventrally narrow with respect to C. torquatus; vertex of mandibular process of zygoma more rostral with respect to vertex of frontal process; longitudinal crest running along the external surface of the zygomatic bone is almost straight. The ventral root of zygomatic process of maxillary, at its origin, projected backward forming open angle; rostral edge of dorsal root of zygomatic arch projected forward and upward with respect to plane that passes to masticatory surface; Hill’s (1935) interpremaxillary foramen very small. d i s t r i b u t i o n : Ctenomys rionegrensis inhabits the southeastern most part of the Río Negro department in Uruguay, between the Río Negro and Río Uruguay, and the coast of the Río Uruguay in Entre Ríos province, Argentina. s e l e c t e d l o c a l i t i e s (Map 469): ARGENTINA: Entre Ríos, Concordia (Langguth and Abella 1970), Colonia Yerua (Langguth and Abella 1970), Paranacito (Reig et al. 1966), Parque Nacional El Palmar (Reig et al. 1966), Ubajay (Reig et al. 1966), Victoria (Reig et al. 1966). URUGUAY: Río Negro, Arrayanes (Wlasiuk et al. 2003), Balneario Las Cañas (type locality of Ctenomys minutus rionegrensis Langguth and Abella), La Guarida (Wlasiuk et al. 2003), La Tabaré (Wlasiuk et al. 2003), Mafalda (Wlasiuk et al. 2003). s u b s p e c i e s : Ctenomys rionegrensis is monotypic. n a t u r a l h i s t o ry: Ctenomys rionegrensis inhabits sand dunes between the Río Negro and Río Uruguay in Uruguay and in adjacent Argentina, where it has undergone recent demographic expansion (E. P. Lessa et al. 2005). Population densities are high, up to 40 adults per hectare (Tassino 2006), with multiple animals, including multiple adults, sometimes captured at the same burrow entrance (E. P. Lessa et al. 2005). These data suggested that C. rionegrensis might exhibit a level of sociality beyond that of the typical tuco-tuco solitary habits. However, ratio telemetric studies (Tassino et al. 2011) documented that C. rionegrensis is not social, as individuals neither exhibited the extensive spatial overlap nor sharing of nest sites characteristic of the group-living C. sociabilis (Lacey et al. 1997; Lacey 2000). Nevertheless, overlap in areas occupied

864 Mammals of South America

Map 469

Selected localities for Ctenomys rionegrensis (●).

by adults was detected, suggesting an intermediate pattern of space use between the extremes of complete solitariness and group living. Breeding is highly seasonal, with activity beginning in the late austral autumn with initial births occurring in the early spring (Tassino and Passos 2010). r e m a r k s : Ctenomys rionegrensis shows a remarkable variation in pelage color with three primary morphs: melanic, agouti, and dark-backed (D’Elía et al. 1998; Wlasiuk et al. 2003). These authors also described population genetic structure and gene flow rates using molecular markers (see also E. P. Lessa et al. 2005). Altuna and Lessa (1985) established that C. rionegrensis is a species distinct from C. minutus from nearby Rio Grande do Sul in Brazil based on characters of the male phallus. The karyotype of this species is both polymorphic with populations and polytypic among them. At the type locality, specimens show 2n = 50 (Kiblisky et al. 1977), but diploid numbers ranging from 48 to 56 have been reported for other Argentinean and Uruguayan populations (Bidau 2006). Sperm morphology is the simple asymmetric type (Altuna et al. 1985).

Ctenomys roigi J. R. Contreras, 1988 Roig’s Tuco-tuco sy n o n y m : Ctenomys roigi J. R. Contreras, 1988:53; type locality “Procedente de Costa Mansión, 10 km. al sur de Em-

pedrado, Departamento Empedrado, Provincia de Corrientes, a 28°02′S, 58°49′ W, 60 m,” Argentina. d e s c r i p t i o n : Relatively large tuco-tuco, mean total length 277.8 mm (range: 260–299 mm), head and body length 198.1 mm (176–200 mm), tail length 88.7 mm (76– 99 mm), hindfoot (with claw) length 38.6 mm (34.5–43.8), and mass 231.1 g (175.5–278.8 g). Sexually dimorphic, with males averaging 105% larger in head and body length and 131% heavier than females. Dorsal color brownish hues, more tawny on back, clay on flanks, and lightening progressively from head to rump; head in particular with dark area extending from nose to neck, more accentuated in worn than newly molted pelage; many specimens with small tufts of white hairs on head dispersed within normal coat; light collar typical of other species distributed nearby (C. argentinus, C. pearsoni, C. torquatus, or C. validus) not present; pale zone surrounds pinna and area of white rostral vibrissae. Ventral color cinnamon with pale creamy wash; ventral white spots present in majority of specimens in both axillary and inguinal regions. Legs and feet pale, with hair almost white, even ungual combs. Tail sparsely covered with hair, moderately bicolored in fresh specimens, but blackens evenly after skin dries in preserved material; tip with short pencil of hairs. Skull robust, solid, and strong, endowed with only moderately expanded tympanic bullae not visible in dorsal view; zygomatic arch strong with greatest breadth across arches wider than that across external auditory canals; rostrum short, robust, and with very broad nasal bones anteriorly that taper and truncate before leading edge of orbit; premaxillary bones extend to posterior limit of nasals or only slightly beyond; frontal bones slightly concave above; interorbital constriction broad, terminating in well-marked postorbital process; bregmatic fenestra, conspicuous in C. dorbignyi and C. perrensi, is rarely present; temporal crests well developed, so squamosal does not extend onto dorsal surface of skull, although degree of development is both age and sex dependent; well-developed lambdoidal crests present, with interparietal barely developed or not apparent at all. Ventrally, paroccipital processes broad, covering nearly half of posterolateral surface of auditory bullae, greater extent then in other species (such as C. argentinus and C. bonettoi); fossa for insertion of masseter superficialis muscle shallow, appearing in some older specimens simply as an ossification of terminal tendon of insertion; mesopterygoid fossa V-shaped notch. Upper incisors distinctly proodont, with their anterior face at angle of 109° relative to horizontal plane formed by upper cheek teeth, much more so than other closely adjacent species, such as C. dorbignyi, C. bonettoi, C. perrensi, or C. argentinus. Upper molariform teeth medium in size; the anterior prism of PM4 very enlarged and with

Suborder Hystricomorpha: Family Ctenomyidae 865

visible inner groove; M3 small and either circular or subcircular in shape. Baculum small, spatulate-shaped bone, with ventral face flattened and more rugose and slightly convex dorsal face, usually with slight depression of varying length along median axis. Average bacular length 6.74 mm (range: 5.7–7.6 mm), average maximum width 1.85 mm (range: 1.4–2.4 mm). d i s t r i b u t i o n : Ctenomys roigi inhabits a very limited area no more than 12 km long and 3 km wide along the coast of the Río Paraná in Corrientes province, Argentina. s e l e c t e d l o c a l i t i e s (Map 470): ARGENTINA: Corrientes, Colonia Brougnes (Giménez et al. 2002), Costa Mansión (type locality of Ctenomys roigi J. R. Contreras), Empedrado (Parada et al. 2011), Estancia Yacyretá (A. I. Medina et al. 2007). s u b s p e c i e s : Ctenomys roigi is monotypic. n a t u r a l h i s t o ry: Little is known about the population biology or ecology of this species. As summarized by J. R. Contreras (1988), individuals are solitary living in individually exclusive but closely adjacent burrow systems. Breeding takes place during the spring-summer. Fully 50% of females were either obviously pregnant or lactating in October, with 11% young of the year, while two months later, in December, 40% of the population were young of the year with pregnant and lactating individuals comprising only

Map 470

Selected localities for Ctenomys roigi (●).

10% and 30%, respectively. Litter size is low, with seven of eight females with a single fetus, and one female with two, for an overall average of 1.124 young per pregnancy. This species occupies sandy loam soils in prairie habitats covered by herbaceous plants, particularly invasive Solanaceae, in areas strongly subject to overgrazing by cattle. These areas are not seasonally inundated. Individuals feed from within their burrows, either harvesting tubers and roots of plants such as Rhunchosia pallida, Ipomoea bonariensis, Senecio grisebachi, or Byptia mutabilis, or the basal stems of the dominant grasses. Individuals also access above-ground plant materials by pulling whole plant into their tunnels from below rather than by venturing onto the ground surface. r e m a r k s : The karyotype of C. roigi is 2n = 48, FN = 76 (Giménez et al. 2001, 2002), and the sperm is the simple symmetric type (Bidau 2006). Ortells et al. (1990) reported the FN as 80 (and cited as such by Woods and Kilpatrick 2005:1568), but their calculation included the sex chromosomes. In C. roigi, both X and Y chromosomes are biarmed, thus increasing the autosomal FN by four.

Ctenomys rondoni Miranda-Ribeiro, 1914 Rondon’s Tuco-tuco sy n o n y m s : Ctenomys rondoni Miranda-Ribeiro, 1914:39, plates 20 and 23, Figs. 1–1a′, 3, and 5; type locality (based on the lectotype chosen by Moojen, in Miranda-Ribeiro 1955:415) “Maria de Molina,” = Campos dos Palmares de Maria de Molina, Vilhena, Rondônia, Brazil, 12°07′12′′ S 60°28′56′′ W. Stenomys rondoni: Avila-Pires, 1968:162; inadvertent misspelling of genus name. d e s c r i p t i o n : Medium sized with head and body length about 230 mm and tail length 80 mm. Dorsal pelage comprises pale hairs at base but turning to sepia at tips; head and especially venter slightly rufous; tail uniformly brownish. Skull robust and depressed, approximately 54 mm in total length and 34 mm across zygomatic arches (MirandaRibeiro 1914). Intermaxillaries robust with lateral protruding expansion that decreases toward front and projects past incisors; supraorbital process protrudes; interparietal contacts frontals along narrow zone; transverse occipitaltemporal crest straight; tympanic bullae inflated; occipital foramen round anteriorly and square posteriorly; maxillaries narrow; body of ethmoid bones very narrow, pterygoids small but thick. Mandible particularly strong and wide. d i s t r i b u t i o n : Ctenomys rondoni is known only from two specimens, one each from localities in Mato Grosso and Rondônia states in western Brazil. s e l e c t e d l o c a l i t i e s (Map 471): BRAZIL: Mato Grosso, Juruena (Miranda-Ribeiro 1914); Rondônia,

866 Mammals of South America

Campos dos Palmares de Maria de Molina (type locality of Ctenomys rondoni Miranda-Ribeiro). s u b s p e c i e s : Ctenomys rondoni is monotypic. n a t u r a l h i s t o ry: No ecological data are available. r e m a r k s : The type locality of C. rondoni has been varyingly given as Rio Juruena (S. Anderson et al. 1987) or Juruena (Avila-Pires 1968). Miranda-Ribeiro (1914) did not select a holotype and based his description on both the skin and partial cranium of the single specimen from Juruena as well as on the more complete cranium of the specimen from Maria de Molina. João Moojen (in Miranda-Ribeiro 1955:415) designated the Maria de Molina specimen as lectotype (MNRJ 2051) while MNRJ 2050 from Juruena remained as paralectotype. However, in a catalog of type specimens at the Museo Nacional, Avila-Pires (1968:183) incorrectly switched the specimen numbers. Thus, Maria de Molina and not Juruena should be considered the type locality of Ctenomys rondoni. Subsequently, MNRJ 2051 was corrected in the museum records, and the cranium received the same number as the skin, MNRJ 2048 (see Langguth et al. 1997). Despite clarification of the locality and catalog number of the lectotype, both known localities remain troublesome. Maria de Molina does not exist on maps or in gazetteers of Brazil, either old or new. In fact, the 1909 expedition led

Map 471

Selected localities for Ctenomys rondoni (●). Contour line = 2,000 m.

by Coronel Cándido Rondon (when the specimens of C. rondoni [as well as those of C. bicolor] were collected) established camp in an unpopulated site near José Bonifácio. Rondon (in Viveiros 1958:298) named the place “Campos dos Palmares de Maria de Molina,” which establishes the coordinates given herein. Although all recent authors have regarded C. rondoni as a synonym of C. nattereri (e.g., Cabrera 1961:553) or as a valid subspecies of C. boliviensis (e.g., Woods and Kilpatrick 2005:1561), I believe these decisions are unjustified given theambiguous geographic status of both boliviensis and nattereri. No data are available on either karyotype or sperm morphology.

Ctenomys rosendopascuali J. R. Contreras, 1995 Rosendo Pascual’s Tuco-tuco sy n o n y m : Ctenomys rosendopascuali J. R. Contreras, 1995b:1; type locality “Mar Chiquita, Departamento San Justo, provincia de Córdoba, Argentina, 30°48′S, 62°53′ W, 65 m”; nomen nudum? (see Remarks). d e s c r i p t i o n : Relatively small with head and body length of males ranging from 160–177 mm, and 159– 166 mm for females (A. I. Medina et al. 2007). Few other character data published. d i s t r i b u t i o n : Ctenomys rosendopascuali is only known from a few localities in Córdoba province, Argentina, in the Chaco Seco ecoregion. s e l e c t e d l o c a l i t i e s (Map 472): ARGENTINA: Córdoba, Candelaria (Giménez et al. 1999), Los Mistoles (Mascheretti et al. 2000), Mar Chiquita (type locality of Ctenomys rosendopascuali J. R. Contreras). s u b s p e c i e s : Ctenomys rosendopascuali is monotypic. n a t u r a l h i s t o ry: No data on ecology, behavior, or reproduction are available. r e m a r k s : Giménez et al. (1999:91) described a polytypic chromosome complement of 2n = 52 with a variable FN of 62, 64, and 66 (see also Ipucha et al. 2008). The sperm is the simple asymmetric type (Giménez et al. 1999). Mascheretti et al. (2000) concluded that C. rosendopascuali was part of a lineage that also included C. azarae, C. bergi, C. bonettoi, C. mendocinus, and C. “yolandae” based on mtDNA sequences. It is unclear whether the issue of Nótulas Faunísticas (volume 86, pp. 1–6) in which J. R. Contreras (1995b) described C. rosendopascuali was actually published (Yolanda Davies, daughter of Julio R. Contreras, pers. comm. to U. F. J. Pardiñas, Oct. 25, 2012). If not, then the taxon to which subsequent authors have referred under this name will require a formal description.

Suborder Hystricomorpha: Family Ctenomyidae 867

Selected localities for Ctenomys saltarius (●). Contour line = 2,000 m.

Map 472 Selected localities for Ctenomys rosendopascuali (●). Contour line = 2,000 m.

Map 473

Ctenomys saltarius Thomas, 1912

s u b s p e c i e s : Ctenomys saltarius is monotypic. n a t u r a l h i s t o ry: Ctenomys saltarius inhabits hillsides and valleys of the Monte Desert, and is especially common in Larrea (Zygophyllaceae) flats and areas with Prosopis (Fabaceae) where it feeds on creosote and other shrubs (Mares, Ojeda, and Kosco 1981). r e m a r k s : Both karyotype and sperm are unknown.

Salta Tuco-tuco sy n o n y m s : Ctenomys saltarius Thomas, 1912c:639; type locality “Salta, [Salta,] N Argentina.” Ctenomys talarum saltarius: Yepes, 1935a:252; name combination. d e s c r i p t i o n : Fairly large with head and body length (of holotype, adult female) 200 mm, tail length 90 mm, and hindfoot length 33 mm. Fur short and overall dull in tone, having neither length nor glossiness of neighboring species (e.g., C. opimus luteolus Thomas and C. tucumanus Thomas). Upper parts dull raw umber, browner along dorsal midline, paler on sides; under parts dull buffy whitish; area around snout whitish with inconspicuous dark collar further behind; feet dull white above; tail markedly bicolored, blackish above and dull white below. Skull very narrow, with zygomatic arches less spread than distance from front of incisors to back of toothrow, a condition that contrasts with other species; frontal region also very narrow, with interorbital breadth less than length of molar series; postorbital processes practically absent. d i s t r i b u t i o n : Ctenomys saltarius is known only from a few localities in Salta province, Argentina, all within either the Yungas or Chaco Seco ecoregions ( J. R. Contreras 1984a). s e l e c t e d l o c a l i t i e s (Map 473): ARGENTINA: Salta, Cafayate (CML 854), Salta (holotype of Ctenomys saltarius Thomas), Tolombón (A. I. Medina et al. 2007).

Ctenomys scagliai J. R. Contreras, 1999 Scaglia’s Tuco-tuco sy n o n y m s : C[tenomys]. scagliai J. R. Contreras and Bidau, 1999:3; nomen nudum. C[tenomys]. scagliai J. R. Contreras, Castro, and Cicchino, 1999:5; nomen nudum. Ctenomys scagliai J. R. Contreras, 1999:10; type locality: “Los Cardones, sobre la Ruta Nacional No 307, Kilómetro 101, entre las localidades tucumanas de El Infiernillo y Amaicha del Valley, aproximadamente a 2.500 metros sobre el nivel del mar (26°38′S–65°49′ W),” Tucumán, Argentina. d e s c r i p t i o n : Medium sized with external measurements of holotype including head and body length 195 mm, tail length 85 mm, hindfoot length (with claw) 37.0 mm, ear length 10 mm, and mass 270 g. General color clear ochraceous brown on back to yellow-brown (straw) on flanks and venter; hairs long, silky, and strongly bicolored, with black basal part for two-fifths length of dorsal hairs and about half the length of ventral hairs; top of

868 Mammals of South America

muzzle and head black, extending back as dorsal stripe; both vibrissae and supra-ungual combs white; area surrounding vibrissae same color as rest of face; tail covered by short and sparsely distributed hairs, bicolored, with proximal part dirty white becoming progressively darker until distal third, which is black; ears very small, with creamy white subauricular areas that suggest pale collar; no white spots in either axillary or inguinal regions; legs covered with sparse coat of fur colored similar to that of belly. Skull robust but looks more delicate than those of many other species; nasal bones short and relatively narrow, tapering only slightly posteriorly, with premaxilla and incisors in clear view from above and broadened premaxillary and maxillary wings on either side; posterior border of frontal bones convex; interorbital region relatively broad with weakly developed postorbital processes; frontals extend laterally to form part of overhanging roof that forms part of orbit; squamosal forms part of dorsal roof of skull, with well-developed post-tympanic projections; pair of sesamoid bones in front of lambdoidal crest between parietals and post-tympanic process of squamosal gives latter spatulate shape; interparietal enlarged and V-shaped, both uncommon features for genus; distance across external meatus on both sides typically greater than greatest width across zygomatic arches; laterally, alveoli of upper incisors positioned in common depression located posterior to proximal edge of vomer; no interpremaxillary opening, which is apomorphic condition for species; external auditory meatus positioned high on side of skull, with its lower border above plane formed by occlusal surface of upper toothrow; zygomatic arch relatively delicate, with zygomatic process of maxilla forming moderately obtuse angle; bullae appear inflated and evenly rounded in lateral view, but transversely compressed in ventral view, with expanded paroccipital process appressed only to very posterior margins; palate relatively short, with acutely V-shaped mesopterygoid fossa extending anteriorly to middle of M2; openings in alisphenoid asymmetrical, with one on right side and two on left; foramen ovale wide and within it alisphenoidpresphenoid bridge runs anteromedially from alisphenoid to become trapezoidal plate linked by short isthmus to presphenoid. Upper incisors orthodont. d i s t r i b u t i o n : Ctenomys scagliai is only known from the vicinity of the type locality in Tucumán province, Argentina. s e l e c t e d l o c a l i t i e s (Map 474): ARGENTINA: Tucumán, Los Cardones (type locality of Ctenomys scagliai J. R. Contreras), Km 95 of Hwy 307 near Tafí del Valle (A. I. Medina et al. 2007). s u b s p e c i e s : Ctenomys scagliai is monotypic.

Map 474

Selected localities for Ctenomys scagliai (●). Contour line = 2,000 m.

n a t u r a l h i s t o ry: Ecology, reproduction, behavior, or other aspects of the population biology are unknown. r e m a r k s : The karyotype is 2n = 36, FN = 64 (Ortells 1995, as C. knighti; see J. R. Contreras 1999). Sperm morphology is symmetrical, the plesiomorphic condition for the genus ( J. R. Contreras 1999).

Ctenomys sericeus J. A. Allen, 1903 Silky Tuco-tuco sy n o n y m s : Ctenomys sericeus J. A. Allen, 1903b:187; type locality “Cordilleras, upper Rio Chico de Santa Cruz, Patagonia”; restricted to “confluencia de los ríos Belgrano y Chico (~48.26°S, 71.20°W, departamento Río Chico, Santa Cruz, Argentina” (Pardiñas 2013). Ctenomys seriseus Rusconi, 1928:243; incorrect subsequent spelling of sericeus J. A. Allen. d e s c r i p t i o n : Small with total length of males averaging 200 mm (range: 195–208 mm), tail length 56.6 mm (51–62 mm), and hindfoot length 26.2 mm (25–28 mm; A. I. Medina et al. 2007). Pelage short, soft, and glossy. General color above yellowish-gray strongly varied with black, hairs being plumbeous on basal three-fourths, then banded narrowly with pale yellowish brown, and tipped with black; flanks and ventral surface buff; sides of nose yellowish-brown; top of nose and top of head like midback; ears small and blackish, upper surfaces of feet dingy gray with slight yellowish cast; tail pale yellowish, with

Suborder Hystricomorpha: Family Ctenomyidae 869

Map 475

Selected localities for Ctenomys sericeus (●).

median dusky stripe along apical half of upper surface. Skull with interparietal either lacking or greatly reduced in size. d i s t r i b u t i o n : Ctenomys sericeus is only known from two localities in Santa Cruz province, Argentina. s e l e c t e d l o c a l i t i e s (Map 475): ARGENTINA: Santa Cruz, La Porteña, Río Vista (Parada et al. 2011), confluence of Río Chico and Río Belgrano ( J. A. Allen 1905). s u b s p e c i e s : Ctenomys sericeus is monotypic. n a t u r a l h i s t o ry: J. A. Allen (1905:41) stated that Ctenomys sericeus was parapatric to C. osgoodi. No other data are available. r e m a r k s : J. A. Allen (1903b) compared C. sericeus to both C. pundti Nehring and C. bergi Thomas, two species from nearby Córdoba province and from both of which it differs in coloration. Subsequently, J. A. Allen (1095:40) narrowed the type locality of the confluence of the Chico and Belgrano rivers in Santa Cruz province. This species has a karyotype of 2n = 28–30 chromosomes and a simple asymmetric sperm type (Montes et al. 2001; Bidau 2006).

Ctenomys sociabilis Pearson and Christie, 1985 Colonial Tuco-tuco sy n o n y m : Ctenomys sociabilis Pearson and Christie, 1985:338; type locality “Estancia Fortín Chacabuco, 1075 m, 3 km S y 2 km W Cerro Puntudo, 71°11′40′′ W, 40°58′00′′S,” Departamento Los Lagos, Neuquén, Argentina.

d e s c r i p t i o n : Medium sized with head and body length averaging 192 mm (range: 168–247 mm), tail 68 mm (range: 67–80) mm, hindfoot length 34 mm (range: 32– 36 mm), and mass 182 g (range: 180–234 g). Color overall ochraceous-tawny above mottled with black hairs, especially in frontal region of head; ventral color similar, but lacks black hairs; diagnostic ochraceous-orange spot on both sides of nose and conspicuous black and white moustache uniformly present. Claws large, relatively narrow, and only slightly curved. Cranially, rostrum elongated, arc of upper incisors wide, and auditory bullae uninflated and exceptionally narrow. d i s t r i b u t i o n : Ctenomys sociabilis has a narrow range between the Río Traful and Lago Nahuel Huapi, west of the Río Limay in the Reserva Nacional Nahuel Huapi in Neuquén province, Argentina (Pearson 1995). s e l e c t e d l o c a l i t i e s (Map 476): ARGENTINA: Neuquén, Estancia Fortín Chacabuco (type locality of Ctenomys sociabilis Pearson and Christie); Estancia La Primavera, 11 km NW of Confluencia (MVZ 179310), 4 km N and 4 km E of Estancia Paso Coihue (MVZ 184869), Estancia Rincon Grande (MVZ 186111). s u b s p e c i e s : Ctenomys sociabilis is monotypic. n a t u r a l h i s t o ry: Ctenomys sociabilis is one of the more thoroughly studied tuco-tuco species in the field. It is the only clearly documented social tuco-tuco (although C. peruanus is suspected to be social; see Pearson 1959). Their populations consist of aggregates of collective burrows at the margins of mallines, the local name for the moist meadows in the Andean-Patagonian steppe, where somewhat lush vegetation grows (Pearson and Christie 1985). The majority of active burrow systems surveyed across the species range, however, were in non-mallín habitats (Tammone et al. 2012). It inhabits black, wet, and fine soils. It is also the only tuco-tuco that does not maintain a burrow with the mouth permanently closed and exhibits a substantial level of above-ground activity. The grass Poa is a main food item. Reproduction occurs in the winter, with young typically born in November. Gestation is about three months, and litter size varies from two to six young. Populations of this species may contact those of C. haigi and C. maulinus (Pearson and Christie 1985). Lacey et al. (1997) studied burrow sharing by multiple individuals; Lacey and Wieczorek (2004) described kinship patterns and group composition; Lacey (2004) documented that sociality reduces direct individual fitness; Woodruff et al. (2010) examined stress physiology and social biology in wild and captive populations; and Schwanz and Lacey (2003) showed that individuals have the capacity to discriminate gender by olfactory cues. Hambuch and Lacey (2002) and Lacey (2001) contrasted patterns of variation at both MHC and microsatellite loci, respectively, between the colonial C. sociabilis

870 Mammals of South America

Map 476 2,000 m.

Selected localities for Ctenomys sociabilis (●). Contour line =

and the geographically adjacent but asocial C. haigi. Chan et al. (2005) and Chan and Hadly (2011) documented a substantial loss of genetic diversity in modern population samples of C. sociabilis over the past 10,000 years. r e m a r k s : The chromosome complement of C. sociabilis has 2n = 56, FN = 72 (M. H. Gallardo 1991); its sperm is the simple asymmetric type (Pearson and Christie 1985; M. H. Gallardo et al. 2002). Mason (2004) described the middle ear apparatus.

on sides sharply defined; vibrissae white; chin and band across lower neck in front of arms brown, separated by broad whitish patch running across interramal region and narrowing on sides to point below ear; arms and legs pale-colored, except for narrow band running down front of forelimbs; hands and feet almost naked above, pale brown, with lateral fringes whitish; tail very thinly clothed, with dull white, sparse hairs. d i s t r i b u t i o n : Ctenomys steinbachi occurs in westcentral Santa Cruz province, Bolivia. s e l e c t e d l o c a l i t i e s (Map 477, from S. Anderson 1997, except as noted): BOLIVIA: Santa Cruz, 6 km N of Buen Retiro (type locality of Ctenomys steinbachi Thomas), 2 mi S of Caranda, Río Surutó, San Rafael de Amboró, 10 km S of Zanja Honda. s u b s p e c i e s : Ctenomys steinbachi is monotypic. n a t u r a l h i s t o ry: No published data on the autecology available. A pregnant female was collected in August with a single embryo (S. Anderson 1997). r e m a r k s : Molecular analyses support a close phylogenetic relationship with the geographically adjacent C. boliviensis and C. goodfellowi (Cook and Yates 1994; E. P. Lessa and Cook 1998). Parada et al. (2011) placed this species in their “boliviensis” group, along with C. boliviensis, C. goodfellowi, C. nattereri, and C. robo, based on mtDNA sequences. Ctenomys steinbachi has a karyotype with 2n = 10 and FN = 18 (S. Anderson et al. 1987), the lowest chromosome number known for a rodent, shared

Ctenomys steinbachi Thomas, 1907 Steinbach’s Tuco-tuco sy n o n y m : Ctenomys Steinbachi Thomas, 1907b:164; type locality “Campo of Province Sara, near Santa Cruz de la Sierra, Bolivia”; restricted to 6 km N of Buen Retiro, 17°13′S 63°38′ W by S. Anderson et al. (1987:13). d e s c r i p t i o n : Very large with males reaching at least 350 mm in body length, and with males and females of equivalent size (S. Anderson et al. 1987). Measurements of holotype (an adult male) head and body length 245 mm, tail length 86 mm; hindfoot length (with claw) 45 mm. Fur straight, fine, and glossy, with hairs of back about 13 mm in length. General color unusual dark drabby-gray-brown or coppery, quite unlike that of any other Ctenomys known to Thomas when he described this species. Color uniform over entire head, upper surface, and sides; under surface creamy white, hairs dull slaty for their basal two-thirds; line of demarcation

Map 477 2,000 m.

Selected localities for Ctenomys steinbachi (●). Contour line =

Suborder Hystricomorpha: Family Ctenomyidae 871

only with the grass mouse Akodon sp. 2n = 10. Vitullo and Cook (1991) described a simple symmetric type of sperm morphology.

Ctenomys talarum Thomas, 1898 Talas Tuco-tuco sy n o n y m s : Ctenomys talarum Thomas, 1898d:285; type locality “ ‘Las Talas,’ Ensenada, La Plata,” on the Río de la Plata, east of La Plata, Partido de Berisso, Buenos Aires, Argentina, 34°52′S, 57°53′ W, 10 m. Ctenomys talarum antonii Thomas, 1910a:240; type locality “Los Yngleses, in the eastern part of the Province of Buenos Ayres,” Argentina. Ctenomys talarum recessus Thomas, 1912a:241; type locality “Bahía Blanca,” Buenos Aires, Argentina. Ctenomys talarum anthonii: Rusconi, 1928:243; inadvertent misspelling of antonii Thomas. Ctenomys mendocinus talarum: Thomas, 1929:44; name combination. Ctenomys mendocinus recessus: Thomas, 1929:44; name combination. Ctenomys talarum talarum: Tate, 1935:391; name combination. Ctenomys talarum occidentalis Justo, 1992:35; type locality “Luan Toro [= Luán Toro],” La Pampa, Argentina. d e s c r i p t i o n : Small with three subspecies currently recognized similar in size and degree of sexual dimorphism (A. I. Medina et al. 2007). Mean body length (both sexes combined) of nominotypical subspecies 233.4 mm, range: 212–254 mm, and tail 66.7 mm, range: 56.0–75.0 mm (Reig et al. 1966). Tail short (5 kg); hindfeet with interdigital webbing; pelage with long, coarse guard hairs over thick, soft underfur; maxillary teeth with two to three labial and three lingual flexi; teeth increasing in size from front to back; paroccipital process greatly elongated, vertical, and completely free from bulla . . . . . . . Myocastorinae 1′. Smaller (mass 30 mm; minimum interorbital breadth >16 mm; found on east slope of central Andes, Amazon Basin, and gallery forests of Cerrado. . . . . . . . . . .Dactylomys 2′. Digits 3 and 4 of forefeet and hindfeet not especially elongated, with claws on all digits; greatest breadth across zygomatic arches 60 mm), and short ears (about 20 mm). Dorsal color tones more muted than in D. dactylinus; grizzled grayish-olivaceous streaked with black, becoming paler on sides, and gradually merging with sparsely furred, pure white venter; face distinctly grizzled gray with white banded hairs above and below eyes and with olivaceous black stripe bordered by pale-tipped hairs extends on midline from nose posteriorly between ears to nape, darkening progressively to blackish brown from above eyes to neck, but in some samples black not pronounced. Mystacial vibrissae in some samples short, extending only to one-half length of superciliary vibrissae, in contrast to much longer mystacial vibrissae of D. dactylinus. Tail with well-furred base that extends for about 65 mm; it is heavily scaled and naked in appearance from furred base to tip, but scales appear finer, averaging six annuli per cm near tail base and 7.5 per cm near tip, and less distinctly pentagonal than those of D. dactylinus; each caudal scale-hair distinctly dark brown or black over basal half, becoming completely colorless along terminal half to third of tail; median hair extends 1.5–2.0 scale rows. Tail bicolored, especially over anterior two-thirds of its length, but with broad, dark dorsal surface becoming gradually paler toward tip. Skull large, rostrum short and broad, and supraorbital ledges proportionally broader than in other species but, with these others, form subtriangular postorbital processes. Skull differs from that of D. dactylinus in that paroccipital processes more anteriorly directed, following curvature of tympanic bullae, and postorbital process of zygomatic arch composed primarily of jugal. Cheek teeth of both upper and lower jaws are as in the other species. d i s t r i b u t i o n : Southwestern margins of the Amazon Basin, from central Peru south to central Bolivia, and east as far as the central Rio Juruá in western Brazil. This range is largely, but not exclusively, coincidental with the large area of bamboo (primarily Guadua spp.) dominated forest in the western Amazon (see J. M. Jacobs and von May 2012). In general, this species seems to occur at higher elevations than D. dactylinus or is restricted to the headwaters where the two species co-occur in the same river basin. s e l e c t e d l o c a l i t i e s (Map 486): BOLIVIA: Cochabamba, Mission San Antonio, Rio Chimoré; La Paz, La Reserva (AMNH 264884). BRAZIL: Acre, Fazenda Santa Fé (= Flora), left bank Rio Juruá (Patton et al. 2000). PERU: Ayacucho, Hda. Luisiana (LSUMZ 16761); Cusco, Consuelo, 15.9 km SW of Pilcopata (FMNH 175250), Quincemil (FMNH 65680), 2 km SW of Tangoshiari (USNM 588070); Madre de Dios, Tambopata (Emmons

1981); Ucayali, Balta, Río Curanja (LSUMZ 12422), Sepahua (MVZ 173099). s u b s p e c i e s : Dactylomys boliviensis is monotypic. n a t u r a l h i s t o ry: Summaries of reproduction, ecology, and behavior of D. boliviensis are given in Emmons (1981; Peruvian animals mentioned are now assigned to this species) and Dunnum and Salazar-Bravo (2004). Habitat includes bamboo and cane thickets typically along river margins (Salazar-Bravo et al. 1994; Patton et al. 2000). Adaptations for arboreal browsing are detailed by Emmons (1981). High pulse number that ranges from a mean of 20 to 44 characterize staccato vocalizations (Emmons 1981; M. N. F. da Silva and Patton 1993). Pregnant females were recorded in July at La Reserva in Bolivia (Salazar-Bravo et al. 1994). r e m a r k s : Calouro (1999) reported bamboo rats from four localities on the Brazilian side of the Serra do Divisor in the upper Rio Juruá basin of Acre state, assigning these sightings to D. dactylinus. These records most likely represent D. boliviensis, given the analyses presented by Patton et al. (2000) which were also based on specimens from the upper Rio Juruá. Dunnum et al. (2001) described a chromosome complement with 2n = 118 and FN = 168, the highest diploid number known for any mammal. Didier (1962) figured and described the baculum of a specimen from southeastern Peru, which averaged 3 mm longer than that of a specimen of D. dactylinus from northern Peru.

Map 486 2,000 m.

Selected localities for Dactylomys boliviensis (●). Contour line =

Suborder Hystricomorpha: Family Echimyidae 883

Dactylomys dactylinus (Desmarest, 1817) Amazon Bamboo Rat sy n o n y m s : Echimys dactylinus Desmarest, 1817b:54; type locality not given; restricted to “Upper Amazon area” (Thomas 1912d:88); see Remarks. Dactylomys dactylinus: I. Geoffroy St.-Hilaire, 1838a:888; first use of current name combination. Dactylomys typus I. Geoffroy St.-Hilaire, 1838a:888; type locality “l’Amérique méridionale, probablement le Brésil”; a renaming of Echimys dactylinus Desmarest, 1817. D[actylomys]. dactylinus: J. A. Allen, 1900a:221; name combination. Dactylomys dactylinus canescens Thomas, 1912d:87; type locality “Itacoatiara, below Manaos [=Manaus], Middle Amazons,” Amazonas, Brazil. D[actylomys]. dactylomys J. A. Allen, 1914c:389; incorrect subsequent spelling of dactylinus Desmarest. Dactylomys dactylinus dactylinus: J. A. Allen, 1916b:208; name combination. Dactylomys dactylinus modestus Lönnberg, 1921:38; type locality “on the banks of the river Curaray, El Oriente, Ecuador, 1,000 ft,” presumably Pastaza. d e s c r i p t i o n : Large olivaceous to yellowish rat; head and body length about 315 mm, with long tail (about 125% head and body length), long hindfeet (>60 mm), and short ears (about 20 mm). Face pale tancinnamon or umber-brown, without white bands on hairs above eyes; self-colored hairs extend above and below eyes, nose, and over rostrum, gradually darkening to blackish, red, or chestnut between ears and posteriorly onto neck. This stripe contrasts sharply with grizzled yellowish to blackish dorsum, which is streaked with black hairs (see Patton et al. 2000:177, Fig. 116). Dorsal hairs chestnut or black at their bases, with subterminal black band and yellow or pale yellow tips. Sides become progressively more fulvous, with posterior thighs and sides of tail base bright burnt orange. Mid-dorsal hairs are of two types: Heavier and longer hairs bicolored, black basally with short pale yellow tip; more abundant thinner hairs blackish or reddish basally with short dark tips. Venter sparsely covered with completely white hairs. Tail base fully haired for about 60 mm, then appears naked to tip; not bicolored at base. Scales large, prominent, pentagonal, and coarse in appearance; average about five annuli per cm near base to six per cm at tip; scale hairs appear correspondingly shorter, extending less than 1.5 scale rows. All scale hairs colorless along entire length of tail distal to furred base. Skull large, with short rostrum and broad, well-developed supraorbital ledges that form subtriangular postorbital processes; paroccipital processes more vertically oriented than

in D. boliviensis, and thus not following contour of bullae as closely. d i s t r i b u t i o n : Dactylomys dactylinus is distributed in the Amazon Basin from eastern Colombia south through eastern Ecuador, northern and central Peru to northeastern Bolivia and east along the Amazon River to its mouth in Brazil, extending north into the headwaters of the Río Orinoco in Venezuela and south through gallery forests along Amazonian tributaries into the eastern Cerrado of Brazil. s e l e c t e d l o c a l i t i e s (Map 487): BOLIVIA: El Beni, 4 km S of Guayaramerin (AMNH 210356); Pando, Ingavi, N bank of Río Orton (USNM 579620). BRAZIL: Amazonas, Borba (AMNH 91865); Colocação Vira-Volta, left bank Rio Juruá (Patton et al. 2000), Ilha das Onças (Patton et al.2000), right bank Rio Purus (Patton et al. 2000); Pará, 52 km SSW of Altamira, right bank Rio Xingu (USNM 549596), Fazenda Santana, Ilha Mexiana (SilvaJúnior and Nuñes 2000), Fordlândia (FMNH 92916), Reserva Biológica de Trombetas (H. Sick 31573), Serra dos Carajás (Moraes-Santos et al. 1999); Goias, Usina Hidroelétrica Serra da Mesa (Bezerra Silva, and Marinho-Filho 2007); Maranhão, Palmeiral, Matöes (Silva-Júnior and Nunes 2000); Roraima, Caracaraí (MPEG 6766). COLOMBIA: Meta, Serranía de La Macarena (ICN 2013), Villavicencio ( J. A. Allen 1916b). ECUADOR: Pastaza, Montalvo (FMNH 41471); Sucumbios, Limoncocha (USNM 528370). PERU: Loreto, Orosa (AMNH 73771), Sarayacu (AMNH 76427); Ucayali, Yarinacocha (FMNH 55501). VENEZUELA: Amazonas, Coyowateri (C. Molina et al. 1995), Río Siapa (Ojasti et al. 1992; C. Molina et al. 1995). s u b s p e c i e s : Whether both modestus Lönnberg and canescens Thomas represent valid geographic variants of D. dactylinus or whether other species should be segregated from the genus must await confirmation of the true locality of Desmarest’s holotype and an appropriate analysis of geographic variation in both morphology, call structure, and molecules over the known range of this species. We, therefore, treat D. dactylinus as monotypic and list both canescens Thomas and modestus Lönnberg as synonyms. n a t u r a l h i s t o ry: This species typically inhabits bamboo and cane thickets on the margins of seasonally inundated and upland rainforest, or in Ecuador only, the canopy of tall forests (LaVal 1976; Emmons 1981 [Ecuador material only]). Few data are available on reproductive biology, although pregnant females have been reported at the end of the rainy season in June, in the central Amazon (Patton et al. 2000). These are vocal rats, with calls composed of staccato pulses in series of 5 to 10 notes in the southwestern and central Amazon (mean = 7; Patton et al. 2000), but in Ecuador of a mean of 42 pulses was emitted

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during 14-second calls (Emmons 1981). Calls of D. boliviensis from Peru (Manu) had longer individual pulses with longer interpulse intervals than those of D. dactylinus from Ecuador, but without much difference in pulse numbers (Emmons 1981). An adequate understanding of geographic variation in call structure is needed for both species. r e m a r k s : Thomas’s (1912d) restriction of the type locality to the upper Amazon is probably in error. Lönnberg (1921) suggested that Desmarest’s holotype in the Muséum National d’Histoire Naturelle in Paris came from somewhere downriver from Iquitos in northwestern Peru. When Deville (1852) named the genus, he used both Desmarest’s holotype in Paris and three additional specimens (male, female, and young) collected by the Castelnau expedition, of which Deville was a part, at “La Mission de Sarayacu, rivière de l’Ucayale, Pampa del Sacramento.” He noted that the holotype was in very poor condition, and he described it as having fur varying red-brown, black, and fawn (fauve) above, with a small crest of reddish brown on the head. He described the Ucayali specimens as red, brown, and black above, tawny (fauve) red on the flanks, clear red on the outer hind thighs, and with a small crest of stiff reddish hairs on the head and nose. These specimens clearly differ in coloration from both modestus Lönnberg and boliviensis Anthony as detailed in the original descriptions of each of these taxa. We assign specimens from Limoncocha on the Río Napo in Ecuador to D. dactylinus, as these correspond to the description of D. d. modestus (Lönnberg 1921). Specimens from the Napo have black underfur and a short self-colored brown crown patch that ends at the level of the ears, with some black hairs above the ears. However, other specimens from further east along the Rio Xingu in Brazil also have

Map 487 2,000 m.

Selected localities for Dactylomys dactylinus (●). Contour line =

similar coloration. Aniskin (1993) described a chromosome complement of 2n = 94, FN = 144, for specimens assigned to this species from the Loreto in northern Peru. As we have not seen these specimens, nor are they described in Aniskin’s report, we cannot verify their identification. Didier (1962) described and figured the baculum based on a specimen from northern Peru. O. J. Linares (1998) tentatively assigned specimens from southern Venezuela to the subspecies canescens Thomas.

Dactylomys peruanus J. A. Allen, 1900 Montane Bamboo Rat sy n o n y m s : Dactylomys peruanus J. A. Allen, 1900a:220; type locality “Juliaca, Peru, altitude 6000 feet,” corrected to “Inca Mines [= Santo Domingo Mine], about 200 miles northeast of Juliaca, on the east side of the Andes, on the Inambary [Inambarí] River,” Puno, Peru by J. A. Allen (1901b:41). Dactylomys [Lachnomys] peruanus: Thomas, 1927f:604; name combination. description: Smallest species ingenus; head and body length of holotype 240 mm, tail length 320 mm, hindfoot length 51 mm, and ear length 14 mm. Fur distinctly soft to touch, lacking the strong bristles characteristic of both D. boliviensis and D. dactylinus. Tail longer than head and body length (about 130%); unique in being heavily furred along basal one-fifth of its length and lightly furred along distal four-fifths, instead of naked; tail hairs long, brownish-black in color; tail terminates in dark tufted tip; scale annuli remain visible even though tail is hairy. Dorsal color uniformly warm yellowish brown (olivaceous), slightly more gray-brown to clear gray on muzzle and forehead, but without stripe on top of head. Dorsal hairs bicolored, grayish black beneath and buffy at tip, with distal light band increasing in length over rump and flanks. Ventral hairs white to base, with some tipped in gray; overall ventral color whitish, or midventer may be dusky washed with some buff. Forelegs and hindlegs thickly furred with long hair to wrists and heels. Color of thighs and adjacent lateral tail base ranges from indistinct to bright orange. Vibrissae long, when appressed extending back to shoulders, predominantly black in color with pale tips. Ears small and do not protrude above hair on top of head. Skull smaller than that of other species in genus, but conforms to them in most details of cranium and teeth; paroccipital processes curve forward following bullar contour, as in D. boliviensis. Species distinguishable primarily by its uniform olivaceous coloration, dense and softer pelage, and furry tail, rather than by cranial characters.

Suborder Hystricomorpha: Family Echimyidae 885

d i s t r i b u t i o n : Dactylomys peruanus occurs in the middle elevations of the eastern Andean slopes of southern Peru and northern Bolivia. s e l e c t e d l o c a l i t i e s (Map 488): BOLIVIA: La Paz, Cotapata (Salazar-Bravo et al. 2003), La Paz, Astillero (BM 1.6.7.57). PERU: Cusco, Amaybamba (MVZ 173100); Junín, Acobamba (BM 27.11.1.221), Cordillera Vilcabamba (USNM 582148); Puno, Inca Mines (type locality of Dactylomys peruanus J. A. Allen), San Juan (FMNH 71131). s u b s p e c i e s : Dactylomys peruanus is monotypic. n a t u r a l h i s t o ry: Little is known about the natural history of this rarely encountered species. The holotype was collected on the ground by a stream bank; the specimen from Amaybamba, Peru, was taken at night in a clump of bamboo about 2 m above ground; and the Bolivian specimens were taken in a bamboo thicket in wet mossy cloud forest at 2,000 m. Emmons found them to be common in the canopy of bamboo thickets at 2,000 m in wet cloud forest of the Vilcabamba region in Peru, where they vocalized with distinctive birdlike calls, unlike those known for any of its congeners. The species was also photo-documented in wet Chusquea bamboo forest at 2,600 m in the Machu Picchu Sanctuary, Peru (R. Williams, pers. comm. to L. H. Emmons), where Dactylomys sp. remains were found with a pre-Colombian Inca burial (Yale Peabody Mus. osteo. 3322, Ant. 196396).

Map 488 2,000 m.

Selected localities for Dactylomys peruanus (●). Contour line =

r e m a r k s : This species differs from both D. dactylinus and D. boliviensis in its softer and longer dorsal pelage and in its furred tail, the basis for Thomas’s (1916e) assignment to the monotypic subgenus Lachnomys. Tate (1935) gave generic rank to Lachnomys, but Ellerman (1940:136) wrote “it scarcely seems even a valid subgenus.” Upham et al. (2013) found D. peruanus basal to the sister-pair of D. boliviensis and D. dactylinus in DNA sequence analyses. The karyotype is unknown. Alberico et al. (2000) record the species in the Cundinamarca, Colombia, at an elevation of 1,700 m in the Andes Biogeographical Region, but without reference to a museum voucher. Given the documented distribution, this assignment seems likely in error, perhaps due to confusion with the externally somewhat similar Olallamys.

Genus Kannabateomys Jentink, 1891 Kannabateomys is a monotypic genus closely allied to, and strongly resembling, Dactylomys (Y. L. R. Leite and Patton 2002; Emmons 2005), but restricted in distribution to the Atlantic rainforest of Brazil, Uruguay, Argentina, and Paraguay (Emmons and Feer 1997). It is smaller than Dactylomys (head and body length 230–347 mm; mass up to 570 g) with a similarly long tail (tail length 300–420 mm; >120% of head and body length), moderately long hindfeet (45–57 mm), and relatively short ears (16–27 mm). The upper parts are uniform glossy olivaceous to fulvous, finely streaked with black, and the sides of the body and tail are sometimes fulvous. The fur is long and soft, the hairs blackish with buffy tips. The head is large with a square muzzle; vibrissae are long, dense, and coarse, with the mystacial vibrissae reaching the shoulder; the cheeks are grayish. The tail is much longer than the head and body, robust, furred to the tip, and tapering from thick body hair on the base to sparse hair distally, bicolored pale below, dark brown above at the base paling through dusky to white or buff near the tip. The tip sometimes has a tuft of dark brown hairs. The hands and feet have long, grasping toes; the hands have four long fingers, the center two of which are separated by a wide gap. Nails, not claws, are present on all digits. The under parts are orange with variable amounts of white on the throat and chest. The lips around the mouth are white. The skull resembles that of other genera in the subfamily, except that the maxillary toothrows are nearly parallel and labial and lingual flexi of the cheek teeth remain separate, with the mesoflexus and hypoflexus not coalescing to divide the tooth into two Y- or V-shaped lophs. sy n o n y m s : Dactylomys: Wagner, 1845a:146; part (description of amblyonyx); not Dactylomys I. Geoffroy St.-Hilaire.

886 Mammals of South America

Kannabateomys Jentink, 1891:109; type species Dactylomys amblyonyx Wagner, by original designation. Cannabateomys Lydekker, 1896:91; incorrect subsequent spelling of Kannabateomys Jentink.

Kannabateomys amblyonyx (Wagner, 1845) Atlantic Bamboo Rat sy n o n y m s : Dactylomys amblyonyx Wagner, 1845a:146; type locality “Ypanema” (= Floresta Nacional de Ipanema, 20 km NW Sorocaba, São Paulo, Brazil, 23°26′7′′S 47°37′41′′W, 701 m; L. P. Costa et al. 2003). Kannabateomys amblyonyx: Jentink, 1891:109; first use of current name combination. Kannabateomys amblyonyx pallidior Thomas, 1903b:489; type locality “Sapucay,” Paraguarí, Paraguay. Kannabateomys amblyonyx amblyonyx: Tate, 1935 435; name combination. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : Kannabateomys amblyonyx occurs along the Atlantic coast of Brazil south to Uruguay and inland to northeastern Argentina and eastern Paraguay (Emmons and Feer 1997). s e l e c t e d l o c a l i t i e s (Map 489): ARGENTINA: Misiones, Parque Nacional Iguazú (Crespo 1982b). BRAZIL: Paraná, Usina Hidroelétrica Salta Caixas (Y. L. R. Leite and Patton 2002); Rio de Janeiro, Reserva Biológica de Poço das Antas (Y. L. R. Leite and Patton 2002); Rio Grande do Sul, Parque Estadual do Itapuã (R. B. Silva et al. 2008); Santa Catarina, Theresopolis (NMW 1691); São Paulo, Ipanema (type locality of Dactylomys amblyonyx Wagner). PARAGUAY: Paraguaí, Sapucay (type locality of Kannabateomys amblyonyx pallidior Thomas). s u b s p e c i e s : Specimens from the southern part of the range in Argentina and Paraguay are notably dull, buff yellowish with the venter and tail almost white (Emmons and Feer 1997). Thomas (1903b) gave these southern populations the formal subspecies name pallidior, but an appropriate analysis of geographic variation and thus the validity of subspecies designations remains to be accomplished. n a t u r a l h i s t o ry: This is an arboreal rat typically living singly or in pairs. The combination of paternal care of young, delayed juvenile dispersal, a reduced degree of sexual dimorphism, and exclusive home ranges for members of the same sex but with male and female ranges overlapping are attributes that suggest social monogamy as the basic mating system (R. B. Silva et al. 2008). Individuals feed on the young shoots and leaves of bamboo and other plants, and inhabit bamboo thickets, especially at watersides, and dense thickets without bamboo in swamps, in Atlantic coastal

Map 489 Selected localities for Kannabateomys amblyonyx (●). Contour line = 2,000 m.

forests, inland rainforest, wet gallery forest, and bamboo patches such as planted bamboo hedgerows between agricultural fields (Hensel 1872a; Kierulff et al. 1992; Olmos et al. 1993; Stallings et al. 1994). Paresque et al. (2004) described a karyotype with 2n = 98 and FN = 126.

Genus Olallamys Emmons, 1988 This is a poorly known genus whose distribution is limited to the Andes of northern Colombia and northwestern Venezuela, at elevations generally above 2,000 m and in association with moist bamboo thickets. The smallest genus among the dactylomyines, with head and body varying between 150–225 mm, also with a long tail (>140% of head and body length). The tail is sparsely haired, faintly to strongly bicolored, and with the distal half paler than the proximal part. The fur is soft, without spines or bristles. Upper parts are a shade of reddish brown and the under parts are white to yellow. The genus is characterized by claws on all digits of forefeet and hindfeet, except d2 of the hindfoot that bears an oblique, asymmetrical nail. Two species are usually recognized, although the differences between them, beyond size, are slight, and it is possible that these represent a single, geographically differentiated species with subpopulations in the separate Andean cordilleras of northwestern South America. sy n o n y m s : Thrinacodus Günther, 1879; type species Thrinacodus albicauda Günther, 1879:144, by original designation; pre-

Suborder Hystricomorpha: Family Echimyidae 887

occupied by Thrinacodus St. John and Worthen, 1875 (Chondrichthyes: Elasmobranchii). Olallamys Emmons, 1988:241; replacement name for Thrinacodus Günther, with the same type species, Thrinacodus albicauda Günther. KEY TO THE SPECIES OF OLALLAMYS:

1. Maximum zygomatic breadth 15 mm . . . . . . . . . . . . . . . . . Olallamys edax

Olallamys albicaudus (Günther, 1879) White-tailed Olalla Rat sy n o n y m s : Thrinacodus albicauda Günther, 1879:145; type locality “the vicinity of Medellin, Columbian Confederation,” Antioquia, Colombia. Thrinacodus apolinari J. A. Allen, 1914c:387; type locality “Tomeque [= Fómeque ], (altitude 6500 feet), Bogotá district,” Cundinamarca, Colombia. Thrinacodus albicauda apolinari: Cabrera, 1961:545; name combination. Olallamys albicauda: Woods, 1993:790; first use of current name combination, but incorrect gender of specific epithet. d e s c r i p t i o n : As for the genus; distinguishable from O. edax (below) primarily by tail color, for which proximal half is reddish-brown and terminal half white, with grayish tinge toward tip. Smaller than O. edax; head and body length 150 and 180 mm, respectively for holotypes of albicaudus Günther and apolinari J. A. Allen, respective tail lengths 255 and 260 mm. d i s t r i b u t i o n : Known only from the Andes of Colombia. Alberico et al. (2000) indicated that this species ranged in elevation from 2,000–3,200 m in the Andes Biogeographical Region in the departments of Antioquia, Cundinamarca, Nariño, and Quindío. These authors listed specimens from three Colombian collections (IAvH, ICN, and UV) without reference to the vouchers or specific localities. s e l e c t e d l o c a l i t i e s (Map 490): COLOMBIA: Antioquia, Páramo de Belmira (Delgado and Zurc 2005), Reserva San Sebastián-La Castellana (Delgado and Zurc 2005); Cundinamarca, Reserve Biológica Carpanta (ICN 17047), San Cristobal (FMNH 71128); Nariño, Laguna de La Cocha (UV [RBM 4143]). s u b s p e c i e s : Cabrera (1961) recognized two subspecies, the nominotypical form from the Cordillera Oriental near Medellín and apolinari J. A. Allen, from the Cordillera Central near Bogotá. No analysis of geographic variation in character traits has been done to validate this hypothesis.

Map 490 Selected localities for Olallamys albicaudus (●) and Olallamys edax (䢘). Contour line = 2,000 m.

n a t u r a l h i s t o ry: Little is known about the ecology of this species. Recent records (Delgado and Zurc 2005) are from disturbed primary forest containing homogeneous patches of dense bamboo at or near tree line. r e m a r k s : Didier (1962) described and figured the baculum. J. A. Allen (1914c:387) defined apolinari as a species separate from Günther’s albicauda primarily on the basis of uniform pale brown color along the length of the tail as opposed to the terminal white present in the latter. Cabrera (1961) assigned apolinari J. A. Allen as a subspecies of Thrinacodus (= Olallamys) albicauda without comment.

Olallamys edax (Thomas, 1916) Greedy Olalla Rat sy n o n y m s : Thrinacodus edax Thomas, 1916e:299; type locality “Sierra de Mérida. Alt. 2800 m.,” Mérida, Venezuela. Olallamys edax: Woods, 1993:791; first use of current name combination. d e s c r i p t i o n : Similar in color and other external characters to O. albicaudus, but tail completely white along its ventral surface and distal half white above. Larger than O. albicaudus, with head and body length of holotype 225 mm, tail length 345 mm, and skull length 57 mm.

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d i s t r i b u t i o n : Known only from the vicinity of the type locality in the Mérida Andes (O. J. Linares 1998). s e l e c t e d l o c a l i t i e s (Map 490): VENEZUELA: Mérida, Sierra de Mérida (type locality of Thrinacodus edax Thomas). s u b s p e c i e s : Olallamys edax is monotypic. n a t u r a l h i s t o ry: This species is known from highelevation bamboo thickets; its ecology and reproduction are undescribed. r e m a r k s : Olallamys edax was separated from O. albicauda on the basis of tail color, skull size, and tooth size, characters that vary among specimens of the latter species from the Central Cordillera in Colombia. For example, the tail of the holotype of apolinari J. A. Allen is pale brown above and paler below ( J. A. 1914c:388), and the terminal half of the tail of the holotype of albicauda Günther is white. Future studies may well show that O. edax is not a valid species, but too few specimens are currently available in museum collections for a proper analysis.

Subfamily Echimyinae Gray, 1825 Louise H. Emmons, Yuri L. R. Leite, and James L. Patton

All genera in this subfamily are arboreal rodents with a pelage that may be spiny, bristly, or soft, and a tail that is typically as long as or longer than the head and body length. The feet are short and broad, and possess raised, smooth plantar pads developed under the joints. Molars are brachydont, with four roots (except in Callistomys), but crowns are often high (hypselodont or coronal hypsodont). The occlusal plane is angled away from plane of the palate, achieved by tipping otherwise straight-sided teeth so that the labial gumline is higher than the lingual (except in Callistomys). The cheek teeth have deep reentrant flexi(id)s that may split teeth into separate, parallel laminae. One to three deep flexi are present on the labial side of the maxillary cheek teeth. The posterior tip of the lower incisor root terminates anterior to m3. Both the maxillary zygomatic process and the jugal are usually slender. Toothrows are long, over 25% of basilar length of the skull. G. A. S. Carvalho and Salles (2004) assigned six genera to this subfamily, and Emmons (2005:299; Table 3) included eight. Five genera (Callistomys, Diplomys, Echimys, Makalata, and Phyllomys) are in common between these two recent reviews, but Emmons (2005) described two as new (Pattonomys and Santamartomys). She placed three genera as incertae sedis within the subfamily because of their individually unique sets of attributes. One of these, Isothrix, has been consistently included within the subfamily by earlier authors (e.g., McKenna and Bell 1997; Woods and Kilpatrick 2005; G. A. S. Carvalho and Salles

2004)), and two, Lonchothrix and Mesomys, have usually been included within the Eumosopinae (McKenna and Bell 1997; Woods and Kilpatrick 2005), despite sharing some characters with echimyine genera (see discussion in Patton and Reig 1990). Iack-Ximenes et al. (2005a) have recently added a ninth genus (Toromys). Phylogenetic analyses of taxon-limited mitochondrial and nuclear DNA sequence data (Y. L. R. Leite and Patton 2002; Galewski et al. 2005; B. D. Patterson and Velazco 2008; Upham and Patterson 2012; P.-H. Fabre et al. 2012; Upham et al. 2013) consistently recover a well-supported clade consisting of (Makalata (Echimys + Phyllomys)), (Makalata, (Echimys + Toromys)), or (Makalata, Echimys (Phyllomys + Toromys)), depending upon the genera included in the respective analyses. All molecular studies indicate that Isothrix groups at the base of this clade of three or four genera. Furthermore, the recent analysis by P.-H. Fabre et al. (2012) and Upham et al. (2013) supported Emmon’s contention that Lonchothrix and Mesomys, long recognized as sister taxa, also group with these echimyine genera. In the expanded morphological analysis of G. A. S. Carvalho and Salles (2004), Isothrix is contained within a clade otherwise composed of (Pattonomys (Echimys (Isothrix, Makalata, Toromys, (Phyllomys + Diplomys)))). Callistomys was placed outside this clade in their analysis, as were both Lonchothrix and Mesomys. The rarely collected Callistomys, Diplomys, Pattonomys, and Santamartamys, have not been included as yet in molecular phylogenetic studies. sy n o n y m s : Echimyinae Gill, 1872:22; a subset of the genera contained within the Echimyina of Waterhouse (1848:286–359). Echinomyinae Alston, 1876a:92; name attributed to Waterhouse (1848) on p. 72. Loncherinae Thomas, 1897a:1024. KEY TO THE GENERA OF ECHIMYINAE (SEE EMMONS 2005 FOR DESCRIPTIONS AND ILLUSTRATIONS OF CHARACTERS):

1. Occlusal surface of maxillary cheek teeth with one lingual and three labial flexi/fossettes . . . . . . . . . . . . . . . 2 1′. Occlusal surface of maxillary cheek teeth with pattern other than one lingual and three labial flexi/fossettes. . . 4 2. Pelage of lower back soft. . . . . . . . . . . . . . . . . . . . . . . 3 2′. Pelage of lower back spiny . . . . . . . . . . . . . . . Echimys 3. Maxillary cheek teeth hypselodont with three roots; occlusal plane strongly angled labially . . . . . . Callistomys 3′. Maxillary cheek teeth brachydont with four roots; occlusal plane weakly angled labially . . . . . . . . . . Isothrix 4. Occlusal surface of maxillary cheek teeth with four separate and parallel laminae. . . . . . . . . . . . . . . . . . . . . . 5 4′. Occlusal surface of maxillary cheek teeth with two labial and two lingual flexi (or fossettes) . . . . . . . . . . . . 6

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5. Lower molars with three separate lophs; auditory meatus close to squamosal suture; guard hairs unbanded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Diplomys 5′. Lower molars with anteroloph separate; auditory meatus well separated from squamosal suture; guard hairs banded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Phyllomys 6. Anteroloph of lower premolar lacks fossetid; upper incisor root at level of or outside zygoma; maxillary and premaxillary portions of incisive foramina septum separate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6′. Anteroloph of lower premolar with central fossetid or with flexid opening lingually; upper incisor root within maxillary root of zygoma; maxillary and premaxillary portions of incisive foramina septum broadly fused . . 8 7. Dorsal pelage stiff; mesoloph of third upper molar approximate in size to protoloph; metalophid of lower premolar and anterolophid of lower molars separate; auditory tube directed forward; inferior jugal process inconspicuous . . . . . . . . . . . . . . . . . . . . Santamartamys 7′. Dorsal pelage spiny; mesoloph of third upper molar much smaller than protoloph; metalophid of lower premolar and anterolophid of lower molars not separate; auditory tube directed laterally; inferior jugal process elongate . . . . . . . . . . . . . . . . . . . . . . . . . . .Pattonomys 8. Dorsal pelage spiny; plantar surface of hindfeet without tubercles; third upper molar with four or more welldeveloped lophs . . . . . . . . . . . . . . . . . . . . . . .Makalata 8′ Dorsal pelage bristly; plantar surface of hindfeet with ‘ tubercles between pads; posteroloph of third upper molar reduced, or M3 with 3 lophs only . . . . . . . Toromys

Genus Callistomys Emmons and Vucetich, 1998 Louise H. Emmons and Yuri L. R. Leite

Callistomys can be diagnosed by the following set of characters (taken from Emmons and Vucetich 1998:3; Emmons 2005): cheek teeth have three roots; both upper and lower cheek teeth are high crowned; PM4 and M1 are unilaterally hypsodont (lingual side of crown higher than labial side, crown curved outward); PM4–M3 are tetralophodont, with three labial flexi and one lingual flexus; hypoflexi and mesoflexi are deep, with PM4 completely divided by the joined hypoflexus-metaflexus into two U-shaped lophs with no mure; M1–3 have a narrow mure connecting protocone and hypocone. The hypoflexids of pm4–m3 are set at a strong oblique angle; the medial end of the flexid extends farther anterior then the labial end. Lower premolars are tetralophodont; the anteroconid and protoconid are united, enclosing the anteroexternal flexid as a slit-like fossetid; the anterior half

of the tooth approximates a triangle with its axis slightly tipped anterolabially; and the hypoflexids and metaflexids do not join (pm4 is not divided by a continuous flexid). The lower incisors are robust and strongly curved. Cranially, the jugals are expanded dorsoventrally; the lateral jugal fossa is wide and diffuse anteriorly, not coming to a sharp point, with the anterior edge of the fossa positioned above PM4, anterior to a line extended from the posterior border of the ascending maxillary process of the zygomatic arch. The superior zygomatic root of the maxillary is expanded posteriorly. The tympanic auditory bullae are inflated, with a large auditory meatus at the end of a strongly developed auditory tube. The angular process of the mandible is strongly projected ventrally with respect to the inferior projection of the symphysis such that an angle drawn between the ventral posterior tip of the angular process and the occlusal plane of the toothrow, with the apex at the anterior edge of the occlusal surface of pm4, is greater than 30°. The single living species is a moderate-sized (head and body length 250–295 mm, tail length 273–325 mm, hindfoot length 43–47 mm, and ear length 16 mm) and arboreally adapted rat with a striking black (or brown) and white patterned pelage. The fur is long and dense, with hairs of uneven lengths; overhairs are slender and soft, lacking spines or bristles, and the underfur is dense, long, and wavy. Dorsal hairs are brown at their base with tips black or white such that color is entirely whitish except for the sharply defined glossy black saddle (fading to brown in old museum specimens) covering the dorsum from shoulders to tail, and across upper forelegs. A wide, black diamondshaped patch extends over the nape and crown to between the eyes. The tail is black at its base, with the distal part silky white above, golden yellow below; it is thickly covered with short, dense, flat-lying hairs. Ear pinnae are small and inconspicuous. Vibrissae are slender; longest mystacial vibrissae reaches to shoulder when flattened back; superciliary vibrissae reach to ear tip. Lower legs and feet are stout and broad, toes are long. There are two pairs of lateral mammae. sy n o n y m s : Nelomys: Pictet, 1843a:205; part (description of pictus). Loncheres (Isothrix): Waterhouse, 1848:327; part (listing of picta); neither Loncheres Illiger nor Isothrix Wagner. Echimys: Tate, 1935:414; part (listing of pictus); not Echimys F. Cuvier. Callistomys Emmons and Vucetich, 1998:3; type species Nelomys pictus Pictet, by original designation. r e m a r k s : This genus was erected to include two species from coastal Brazil. One of these is known only from a mandibular fragment collected by Lund at Lagoa Santa, Minas Gerais, and described by Winge (1887:71), who referred it to

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“Lasiuromys villosus Dev. ? 1852),” a subjective synonym of Isothrix bistriata. This species is apparently without a name, and is listed by Emmons and Vucetich (1998:7) as Callistomys sp. The second species is Callistomys pictus (Pictet 1843a), which was originally placed in the genus Nelomys (= Phyllomys; see that account), an action continued by Emmons and Feer (1990 1997), but which has been varyingly assigned also to Isothrix (E.-L. Trouessart 1880; Ellerman 1940; Cabrera 1961; Patton and Emmons 1985; Eisenberg and Redford 1999) or Echimys (Tate 1935; Moojen 1952b; Woods 1993). These different assignments highlight the overall uniqueness of this taxon. Indeed, several features distinguish Callistomys from other genera in the subfamily Echimyinae and raise questions about whether it belongs in the subfamily: The possession of the eumysopine cheek tooth root pattern and hypselodonty, and the dorsoventrally expanded jugals and anterior zygomatic arch, likewise features common with the Eumysopinae (especially Euryzygomatomys and Clyomys) and not shared by any other living echimyine. The phylogenetic analysis of G. A. S. Carvalho and Salles (2004) place the genus as sister to a clade otherwise containing the dactylomyines and all other genera of echimyines. Leite’s preliminary molecular sequence data suggest that Callistomys has no close relative among all living echimyid genera.

Callistomys pictus (Pictet, 1843) Painted Tree Rat sy n o n y m s : Nelomys pictus Pictet, 1841a:29; nomen nudum. Nelomys pictus Pictet, 1843a:205; type locality “Bahia”; probably from Fazenda Almada in the region north of the city of Ilhéus, Bahia, Brazil (Moojen 1952b). Loncheres (Isothrix) picta: Waterhouse, 1848:327; name combination. Loncheres (Isothrix) pictus: E.-L. Trouessart, 1897:606; name combination. [Isothrix] picta: Thomas, 1916e:295; name combination. [Echimys] pictus: Tate, 1935:414; name combination. Echimys pictus: Moojen, 1952b:133; name combination. Isothrix picta: Cabrera, 1961:537; name combination. Callistomys pictus: Emmons and Vucetich, 1998:3; first use of current name combination. d e s c r i p t i o n : As for the genus. d i s t r i b u t i o n : Callistomys pictus is endemic to the Atlantic Forest with known localities limited to three adjacent municipalities near Ilhéus and Itabuna, in coastal Bahia, Brazil (Vaz 2002). Eisenberg and Redford (1999) list a specimen from the Rio de Birasa without documentation. Peter W. Lund collected subfossil remains from Lagoa Santa, Minas Gerais, but the species is unknown from the modern fauna of this region (Emmons and Vucetich 1998).

Map 491:

Selected localities for Callistomys pictus (●).

s e l e c t e d l o c a l i t i e s (Map 491): BRAZIL: Bahia, Fazenda Almada (probable type locality of Nelomys pictus Pictet; Moojen 1952b), Reserva Particular do Patrimônio Natural Jequitibá (Vaz 2002), Rio do Braço (MNRJ 11207). s u b s p e c i e s : Callistomys pictus is monotypic. n a t u r a l h i s t o ry: An apparent inhabitant of evergreen lowland rainforest, but only 13 specimens are known. Recent fieldwork (Vaz 2002) found this species in cocoa plantations, but substantial habitat loss and modification has likely led to severe restriction in the number of extant populations. The species is locally hunted for food (Vaz 2002). Valim and Linardi (2008) described the host association of ectoparasitic lice in the genus Gyropus. r e m a r k s : The first use of the name stems from Pictet (1841a:29), in a list of new species obtained by the Musé de Genève. Pictet (1843a:203) later provided the description of his new taxon. K. Ventura et al. (2008) described a karyotype with 2n = 42, FN = 76.

Genus Diplomys Thomas, 1916 Louise H. Emmons and James L. Patton

These are moderate-sized arboreal rats without spines but with guard hairs flattened and slightly stiff, each with a

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deep dorsal sulcus. The dorsal guard hairs are 1.8–2.0 cm long; underhairs are few, fine, and inconspicuous. The dorsal body fur extends from 1.5–5.0 cm onto base of the tail, and the distal part is fully but moderately clothed with stiff, bristle-like, brown hairs, and with scales visible beneath. The feet are without tiny tubercles between pads. The skull is long and narrow, with the dorsal surface is curved throughout its length from nasals to occiput when viewed laterally. The jugal is narrow below the postorbital process, with an inconspicuous ventral process positioned well forward of the dorsal process. The tympanic bullae are not inflated, the auditory meatus is positioned close to the squamosal, and auditory tubes are well developed and directed strongly forward such that the middle ear bones are not visible in lateral view. The distance between the foramen ovale and the masticatory foramen of the alisphenoid is typically very short, and the ventral roof of the canal formed by these foramina is often nearly obsolete. The hamular process of the pterygoid has a prominent, anteriorly directed spur. A large, oval sphenopalatine vacuity is present anterior to the presphenoid-basisphenoid suture. The squamosotympanic fenestra is tube-like, opens forward, and is without a depression on squamosal below. The angle of the sigmoid notch, between angular and condyloid processes of the mandible, is shallow, and the mandibular foramen on the side of ramus is positioned well anterior to the condyloid ridge, not in a fossa. The masseteric crest is large. Maxillary cheek teeth are large and the toothrow is relatively long. Morphology of the upper teeth resembles that of Phyllomys spp. (see below), with the occlusal surface divided by three flexi into four laminae. These laminae are parallel in M1–3, but in PM4 the labial ends of the two anterior lophs are bent forward. The flexi are of even depth, such that with wear, three straight fossettes are centered on the molars. In the mandibular cheek teeth, all flexids may traverse all lophs in unworn teeth, but with wear the metaflexid divides m1–3 into a free posterolophid. The middle loph (entoconid + hypoconid) is usually connected to the anterolophid at near its midpoint by a short mure, forming a highly distinctive pattern of two crescent-shaped lophids connected by a central stem. The hypoflexids are positioned at an oblique angle. The lower premolar is split into three or four parts by two or three flexids; the anterior loph forms a rounded triangle enclosing a flattened oval transverse fossette, metalophid is a separate lamina, and the entoconid and posterolophid are either joined labially or divided into separate parts by the metaflexid. The lower incisors are strongly curved. There are two pairs of lateral mammae. The phallus lacks deep lateral ridges, but the ventral surface has a long,

longitudinal slit distal to a short transverse fold. The dorsal tip possesses a long, slender, bacular papilla, and an inconspicuous urethral lappet is present. Two species are now recognized within the genus, subsequent to Emmons’s (2005) removal of rufodorsalis J. A. Allen to her new genus Santamartamys: D. caniceps (Günther) from Colombia and D. labilis (Bangs, 1901, with darlingi Goldman, 1912b, a synonym) from Panama south along the Pacific coast of Colombia to Ecuador. Hall (1981:874–875) provided a taxonomic summary for and mapped the distribution of D. labilis in Panama. Few specimens are available from either species, and given the lack of more than cursory comparisons in the literature, the number of species and their range(s) remain questions for the future to address. Largely by virtue of its relatively soft pelage and well-haired tail, Diplomys has often been associated with Amazonian and Guianan genus Isothrix (e.g., E.-L. Trouessart 1880; Goldman 1912b) or the Atlantic Forest Phyllomys (Goldman 1916). The phylogenetic analyses of G. A. S. Carvalho and Salles (2004) supported a sister relationship to the Atlantic Forest Phyllomys. Molecular data are as yet unavailable to test any phyletic hypothesis. sy n o n y m s : Loncheres: Günther, 1876:745; part (description of caniceps); not Loncheres Illiger. Loncheres (Isothrix): E.-L. Trouessart, 1880b:178; part (listing of caniceps); neither Loncheres Illiger nor Isothrix Wagner. Echimys (Isothrix): E.-L. Trouessart, 1904:504; part (listing of caniceps); neither Echimys F. Cuvier nor Isothrix Wagner. Phyllomys: Goldman, 1916a:126; part (listing of caniceps); not Phyllomys Lund. Diplomys Thomas, 1916d:240; type species Loncheres caniceps Günther, by original designation. KEY TO THE SPECIES OF DIPLOMYS:

1. Range restricted to Cauca Valley, Colombia; maxillary and mandibular molar toothrows divergent, with ends curved outward such that a straight edge held against the first and last tooth shows a gap between them and the middle teeth . . . . . . . . . . . . . . . Diplomys caniceps 1′. Range (in South America) restricted to western Colombia and northwestern Ecuador; both maxillary and mandibular toothrows nearly straight . . . . . . Diplomys labilis

Diplomys caniceps (Günther, 1876) Colombian Rufous Tree Rat sy n o n y m s : Loncheres caniceps Günther, 1876:745; type locality “Medellin,” Antioquia, Colombia.

892 Mammals of South America

Loncheres (Isothrix) caniceps: E.-L. Trouessart, 1880b:178; name combination. Echimys (Isothrix) caniceps: E.-L. Trouessart, 1904:504; name combination. Phyllomys caniceps: Goldman, 1916a:126; name combination. Diplomys caniceps: Thomas, 1916d:240; first use of current name combination. d e s c r i p t i o n : Larger of two species; head and body length 212–320 mm, tail length 178–267 mm; hindfoot length 40–48 mm, ear length 12–20 mm, and mass 360– 430 g. Upper parts dull or bright rusty red-brown faintly streaked with dark brown hairs, reddish brightest on rear half of body, and forequarters sometimes fulvous. Fur stiff and dense but lacks spines. Nose brown; head forward of the ears is gray streaked with black, face marked with small whitish spots over the eye and at base of vibrissae, and pale yellow spot present behind and below the ears. Ears short and generally do not protrude above crown. Vibrissae coarse and long, reaching to shoulder. Chin often white, throat whitish or orange, and remainder of the under parts range from pale to rich orange, often dark rustorange along the midline of the abdomen and underside and sides of the tail base. Tail robust, subequal in length to body length (90–105%), and moderately but completely covered with dark brown hairs that stand outward to give bristly appearance; scales of tail just visible beneath the hair. Hindfeet broad, yellow-brown to gray or brown above. Cranial and dental characters as for the genus. d i s t r i b u t i o n : Diplomys caniceps is apparently limited to the Caribe Biogeographical Region (Alberico et al. 2000) in northwestern Colombia, in the Cauca Valley in the vicinity of Medellín (Emmons and Feer 1997). Cuervo Díaz et al. (1986) extended the range to the Serranía de San Lucas in the state of Bolívar, but without documentation. Eisenberg (1989: map 13.73) reversed the ranges of D. caniceps and D. rufodorsalis (= Santamartamys rufodorsalis), incorrectly mapping the former to northeastern Colombia. s e l e c t e d l o c a l i t i e s (Map 492): COLOMBIA: Antioquia, Finca Katiri (CTUA, C. Delgado-V., pers. comm.), vicinity of Medellín (type locality of Loncheres caniceps Günther); Bolívar, Corregimiento de Ventura (INDERENA 3856). s u b s p e c i e s : Diplomys caniceps is monotypic. n a t u r a l h i s t o ry: This species has not been studied in its natural habitat. r e m a r k s : Diplomys caniceps is superficially similar to D. labilis (below) in external characters, but the two species seem to differ in cranial characters. The exact type locality is unknown. The collector, T. K. Salmon, shipped

Map 492 Selected localities for Diplomys caniceps (䢘) and Diplomys labilis (●). Range of D. labilis in Panama from Hall (1981). Contour line = 2,000 m.

specimens from Medellín to England, but worked in the Magdalena, Neche, Pocuné, Río Sucio, and Cauca valleys in all directions from that city (Sclater and Salvin 1879). It is unclear if D. caniceps is geographically isolated from coastal D. labilis. This species is represented only by specimens in the Natural History Museum in London, the Instituto de Investigación de Recursos Biológicos Alexander von Humboldt in Bogotá, Colombia (Alberico et al. 2000), and Colección Teriológica Universidad de Antioquia (CTUA), Medellín, Colombia (C. Delgado-V., pers. comm.).

Diplomys labilis (Bangs, 1901) Central American Rufous Tree Rat sy n o n y m s : Loncheres labilis Bangs, 1901:638; type locality “San Miguel Island, [Archipiélago de las Perlas], Panama.” Isothrix darlingi Goldman, 1912b:12; type locality “Marrangantí (near Real de Santa María), on the Rio Tuyra, eastern Panama.” Echimys (Isothrix) labilis: E.-L. Trouessart, 1904:504; name combination. Phyllomys labilis: Goldman, 1916:126; name combination. Phyllomys darlingi: Goldman, 1916:126; name combination.

Suborder Hystricomorpha: Family Echimyidae 893

Diplomys labilis: Thomas, 1916d:240; first use of current name combination. Diplomys darlingi: Thomas, 1916d:240; name combination. D[iplomys]. l[abilis]. darlingi: Handley, 1966:787; name combination. d e s c r i p t i o n : Externally similar to D. caniceps but somewhat smaller (head and body length about 190 mm, tail length 267 mm, hindfoot 40 mm, and ear length 12 mm). Upper parts ochraceous buff to bright rusty, slightly darkened by admixture of black-tipped hairs, becoming grayish brown on middle of face and cheeks; nose, lips, and muzzle gray, with white vertical streak at base of vibrissae (see photograph in Tesh 1970a); wrists, ankles, and chin gray; feet silvery white above. A small pale spot present above eyes, contrasting with a black eye-ring; ears dark, with marginal fringe of longer hairs; narrow strip of white encircles the pinnae. Tail generally proportionally shorter than that of D. caniceps, 70–100% of the head and body length; unicolored brownish, tapering evenly to tip; thinly clothed with short hairs, which become somewhat longer although not denser or forming a distinct brush near tip. Dentition is similar to that of D. caniceps. Cranially, palate narrower and premaxillae sometimes extend posterior to nasals in D. labilis in comparison with conditions in D. caniceps. There is considerable variation of ventral color from dark to paler rufous, of the rostrum from broad to quite narrow, and of the premaxillary bones either even with, or extending posterior to nasals. Verification of current species boundaries, and therefore their geographic ranges, awaits analyses of existing specimens and further collecting. d i s t r i b u t i o n : Diplomys labilis occurs from central Panama, including Isla San Miguel in the Gulf of Panama, south along the Pacific coast of Colombia (Pacífico Biogeographic Region; Alberico et al. 2000) and extends into northwestern Ecuador. Specimens and localities from western Colombia were listed as “probably D. labilis” by Emmons and Feer (1997), and those in the collections of Museo de Historia Natural de la Universidad del Cauca and Universidad del Valle in Colombia from Cauca, Chocó, and Nariño departments were assigned to D. labilis by Alberico et al. (2000). Specific localities for these latter specimens, however, were not provided. We assign specimens in the Field Museum from western Colombia to D. labilis. Tirira (2007:223) mapped the range of this species as extending into northwestern Ecuador but records no specific localities. A subadult specimen collected in 1901 from “Bayone, N. Ecuador” exists in the collections of the Natural History Museum, London (BM). We have been unable to locate this locality, although it may be on the Río Borbón in Esmeraldas province as specimens of other species in the BM were collected there on the same date (Paynter 1993).

s e l e c t e d l o c a l i t i e s (Map 492; South America only): COLOMBIA: Antioquia, Turbo (FMNH 70101); Cauca, Río Saija, La Boca (FMNH 90109); Córdoba, Socorre, upper Río Sinu (FMNH 69119). ECUADOR: Esmeraldas, Bayone (BM 2.7.26.2). s u b s p e c i e s : Two subspecies occur in Panama, the insular nominotypical form and darlingi Thomas on the mainland (Hall 1981). There has been no evaluation of variation in populations from Colombia or Ecuador. n a t u r a l h i s t o ry (from Tesh 1970a, based on studies in Panama): This is a nocturnal, solitary, arboreal species that feeds on both fruits and leaves. Individuals nest in tree holes, usually in trees near the water, and can be seen sticking their heads out of the entrance if disturbed. They are agile climbers and aggressive when captured. Their habitat includes both mature and secondary rainforest and deciduous forest, including lowland and montane, mangroves, and plantations with trees. Litter size is one or two. r e m a r k s : Both Thomas (1916d, e) and Goldman (1916) suggested that labilis Bangs and darlingi Goldman were allied, but retained each as separate species. Handley (1966:787) listed the mainland darlingi as a subspecies of the insular labilis, a conclusion followed by Hall (1981:874). Valim and Linardi (2008) described the host association of ectoparasitic lice in the genus Gyropus.

Genus Echimys F. Cuvier, 1809 Louise H. Emmons, Yuri L. R. Leite, and James L. Patton

Members of this genus are moderate-sized arboreal rats with the pelage including stout spines. The tail is longer than the head and body, completely covered with dense hair that forms a pencil at tip. Four pairs of mammae are present, three laterals and one inguinal. The phallus of E. chrysurus (Emmons 2005) is stout, strongly ridged on its sides, with a short, triangular bacular papilla at the dorsal tip; the ventral lip of urethral crater forms a short, U-shaped fold above a straight-line lip. The skull has small to medium-sized auditory bullae with a small meatus on a short auditory tube directed laterally at nearly a right angle to the cranial axis; the meatus is positioned near (less than half its diameter) to the squamosal suture. The lateral process of the supraoccipital (erroneously termed mastoid process by Emmons et al. 2002 and Y. L. R. Leite 2003; see Verzi et al. 2013 for anatomical details) is short. The squamosotympanic fenestra is small and subcircular, with no raised ventral lip, and is entirely anterior to the auditory meatus. The premaxillary part of the septum of the incisive foramina is free posteriorly. The jugal is deep below the postorbital process, and the jugal

894 Mammals of South America

fossa is very broad, forming an angle of at least 40°. The postorbital process of the zygoma is formed only by the jugal. The mandibular foramen is anterior to the condyloid ridge, not in a fossa with base in ridge; the masseteric crest is weakly developed. Maxillary toothrows are parallel, not converging anteriorly. The cheek teeth are rectangular, longer than wide, and with tall crowns. Only one lingual flexus is present (the hypoflexus), which usually joins with mesoflexus to completely divide tooth into two U-shaped lophs (that is, there is no mure connecting the protoloph and mesoloph); three labial flexi are present. The four lophs of PM4–M2 are subequal in length and width and nearly parallel. The paraflexus and metaflexus are long, about two-thirds or more of the width of the tooth, and parallel; the hypoflexus or its trace is short, about one quarter to one-third of the width of the tooth. Hypoflexids of the lower molars reach less than half way across tooth, open at a wide angle, and are scarcely, if at all angled forward, such that lophids adjoining the tip of the hypoflexid are about equal in width. The metaflexids of m1 and more prominently, m2, have an angled internal tip with two points (perhaps outlining a mesoconid) that bends slightly posteriorly; the mesoflexid has an internal tip that bends slightly anteriorly. The lower premolar is pentalophodont, completely divided by two flexids into three parts: a symmetrical triangular anterior loph, rounded at its anterior tip and enclosing a subcircular fossetid; a single, laminar, central metalophid bar; and posterolophid and entoconids of posterior third of tooth united labially into a single, V-shaped loph that opens lingually. The lower incisors are not strongly curved. sy n o n y m s : Myoxus: Zimmermann, 1780:352; part (description of chrysurus); not Myoxus Zimmermann. Hystrix: Schreiber, 1792: table 170B; part (description of chrysuros); not Hystrix Linnaeus. Glis: Treviranus, 1803:182: part (listing of chrysurus); not Glis Brisson. Echimys F. Cuvier, 1809:394; based on Allamand’s (1778) “lérot a queue dorée” and Azara’s (1801:73) “rat épineux”; type species Echimys cristatus Desmarest (= Myoxus chrysurus Zimmermann) by subsequent designation (Tate 1935:430). Loncheres Illiger, 1811:90; type species Myoxus chrysurus Zimmermann, by original designation. Echimys Desmarest, 1817b:54; type species Echimys cristatus Desmarest, by original designation (see Remarks). Loncheris Olfers, 1818; incorrect subsequent spelling of Loncheres Illiger. Nelomys Jourdan, 1837:522; type species Echimys cristatus Desmarest (see Remarks).

Echinomys Wagner, 1840:199; unjustified emendation of Echimys F. Cuvier (same unjustified emendation cited by I. Geoffroy St.-Hilaire 1840:1); see Remarks. Echimys I. Geoffroy St.-Hilaire, 1840:30; not Echimys F. Cuvier (see Remarks). Enchomys Gloger, 1841 (1842):100; replacement name for Echimys Desmarest, and thus an objective synonym (see Thomas 1895a:190). Echmiys Miranda-Ribeiro, 1914:48; incorrect subsequent spelling of Echimys F. Cuvier. r e m a r k s : J. A. Allen (1899c), Thomas (1916e), and Tate (1935) outlined the convoluted and intertwined taxonomic history of Echimys and Loncheres, two generic names that have been commonly applied to the arboreal spiny rats, including Echimys as we envision this genus herein. Echimys was first used by É. Geoffroy St.-Hilaire in a manuscript apparently written in either 1808 or 1809 but never published (I. Geoffroy St-Hilaire 1838, 1840). F. Cuvier (1809) first published the name basing it on the “lérot à queue dorée” (from Allamand’s [1778] supplements to Buffon’s Histoire Naturelle, which was also the basis of Myoxus chrysurus by Zimmermann [1780]), and the “rat épineux”of Azara (1801). F. Cuvier (1812) described and figured the dentition of the only two species mentioned by him as belonging to this genus, namely the same “le lérot à queue dorée” (plate xv, Fig. 15) and “rat épineux” (plate xv, Fig. 14). Illiger (1811) described Loncheres, referring to it two species: Loncheres paleacea, a nomen nudum first made available by Olfers (1818:212; also see Hershkovitz 1959b) and Myoxus chrysurus Zimmermann. Because an undescribed species cannot be taken as the type of a genus, Myoxus chrysurus Zimmermann becomes the type of Illiger’s Loncheres. The seven species of spiny rats that É. Geoffroy St.-Hilaire referred to the genus Echimys in his unpublished manuscript were then described by Desmarest (1817b), who specifically equated the “rat épineux de d’Azara” to Echimys spinosus (a Euryzygomatomys) and É. Geoffroy St.-Hilaire’s “lérot à queue dorée” to Echimys cristatus, a renaming of Myoxus [= Loncheres] chrysurus. Desmarest wrote explicitly of Echimys “Le lérot à queue dorée d’Allamand et de Buffon en est le type” (1817b:54) and thus designated Echimys cristatus, which he equated with “lérot à queue dorée,” as the type species of the genus Echimys. Tate (1935:418) considered this “clearly a designation of the type of Echimys,” as do we. Many authors have overlooked Desmarest’s designation, however, and since Cuvier’s description and figures clearly indicated that his two species are not congeneric, J. A. Allen (1899c:262–263) argued that one of these needed to be selected as the type of his Echimys and further argued that the erection of Loncheres Illiger, with its type M. chrysurus (= E. cristatus Desmarest), automatically made Echimys

Suborder Hystricomorpha: Family Echimyidae 895

spinosus Desmarest (or “rat épineux de d’Azara”) the type of Echimys F. Cuvier. Thomas (1916c:71) disagreed, pointing out that J. Fleming (1822:191) had much earlier selected “Hystrix chrysurus Lin Gmel” (= Myoxus chrysurus Zimmermann) as the type of Echimys. Finally, Tate (1935:430) stated that J. Fleming had merely listed the name Hystrix chrysurus without clearly and unambiguously selecting it as the type to F. Cuvier’s Echimys. He then (p. 430) designated “as the type species of Echimys F. Cuvier, 1809, the “lérot à queue dorée” (= Myoxus chrysurus Zimmermann, 1780, = Echimys cristatus Desmarest, 1817).” É. Geoffroy St.-Hilaire, followed by F. Cuvier and Desmarest, may have originally named the taxon because the Paris Museum had earlier acquired a specimen from French Guiana that is noted in É. Geoffroy St.-Hilaire’s 1803 catalogue as the basis for the description of the “lérot à queue dorée” (MHN A-7694 old no. 403), although Allamand stated that his (1778) description is of a Surinam specimen, which was sent to him by Klockner. It is not clear what became of the holotype from Surinam or if É. Geoffroy St.-Hilaire ever saw it. The lovely figure in Allamand (1778) was clearly drawn from the specimen he described in great detail, but subsequent figures in later editions of Buffon were progressively poorer copies. Zimmermann (1780) condensed his description of Myoxus chrysurus from Allamand’s more detailed one, and translated its name directly into Latin, without evidence that he ever saw a specimen. In his 1899 paper, J. A. Allen also removed the terrestrial spiny rats from Echimys (and Loncheres) to his new genus Proechimys (p. 264), a broad concept in which he included species now grouped into four genera within the subfamily Eumysopinae (Proechimys proper, Trinomys, Hoplomys, and Mesomys). Many subsequent researchers have shared Allen’s narrowed view of the genera of arboreal spiny rats (Thomas 1928c, d; Tate 1935; Ellerman 1940; Cabrera 1961). Moojen (1952b), however, was the first to recognize further groups in the traditional Echimys, elevating the Atlantic Forest arboreal spiny rats to the genus Phyllomys Lund. Husson (1978) erected the genus Makalata to include Nelomys armatus I. Geoffroy St.-Hilaire, and more recently Emmons and Vucetich (1998) created Callistomys to include Nelomys pictus Pictet. Emmons, Leite et al. (2002; see also Y. L. R. Leite 2003) confirmed Moojen’s separation of Phyllomys. Most recently, Iack-Ximenes et al. (2005a) placed Echimys grandis Wagner in the new genus Toromys, and Emmons (2005) removed Echimys semivillosus I. Geoffroy St.-Hilaire to her new genus Pattonomys. What remains of Echimys F. Cuvier, therefore, is only a remnant of the large number of species once, and varyingly, included within the genus. Echinomys has been commonly listed as a synonym of Echimys F. Cuvier, with the author given as either I. Geof-

froy St.-Hilaire, 1840 (e.g., Tate 1935) or Wagner, 1840 (Simpson 1945; Cabrera 1961; Woods 1993; McKenna and Bell 1997; Woods and Kilpatrick 2005). It is unclear which of these two publications has date priority. Echinomys is, however, an unjustified emendation of Echimys F. Cuvier (rationale for name modification given by Wagner [1840:199; 1843a:339]). Moreover, all species listed by Wagner (1843a:339) under his Echinomys belong not to Echimys but to other genera of echimyids, notably Euryzygomatomys, Mesomys, Proechimys, or Trinomys (see those accounts). Cabrera (1961) included 19 valid species or subspecies in his concept of the genus Echimys. Most of these are now placed in other genera, three of which have been described subsequent to his work. Herein, we follow the recent revisionary analyses noted immediately above in the allocation of the names Cabrera listed within Echimys as follows: Makalata Husson (including armatus I. Geoffroy St.-Hilaire and macrura Wagner), Pattonomys Emmons (carrikeri J. A. Allen, occasius Thomas, punctatus Thomas, and semivillosus I. Geoffroy St.-Hilaire), Phyllomys Lund (blainvillei Jourdan, braziliensis Lund, dasythrix Hensel, lamarum Thomas, medius Thomas, nigrispinus Wagner, thomasi Ihering, and unicolor Wagner), and Toromys Iack-Ximenes, de Vivo, and Percequillo (grandis Wagner and rhipidurus Thomas). With the removal of these names to other genera, Echimys as currently understood comprises three species, one of which was only recently described. KEY TO THE SPECIES OF ECHIMYS:

1. Distributed in eastern Amazonia and Guianan region ..........................................2 1′. Distributed in western Amazonia; head glossy black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Echimys saturnus 2. Wide to narrow white blaze from nose to crown, may be reduced to white tuft on top of head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Echimys chrysurus 2′. Top of head dark maroon. . . . . . . . . . . Echimys vieirai

Echimys chrysurus (Zimmermann, 1780) White-faced Tree Rat sy n o n y m s : Myoxus chrysurus Zimmermann, 1780:352; type locality “Surinam,” based on Allamand’s (1778) “lérot à queue dorée” with a nearly verbatim translation of Allamand’s description. Hystrix chrysuros Schreiber, 1792:Table 170B; see also Schreiber, 1843:333; incorrect subsequent spelling of chrysurus Zimmermann. M[yoxus]. chrysuros: H. F. Link, 1795:77; name combination.

896 Mammals of South America

Glis chrysurus: Treviranus, 1803:182; name combination. Loncheres chrysurus: Illiger, 1811:90; name combination. Loncheres paleacea Illiger, 1811:90; nomen nudum. [Loncheres] chrysura: Illiger, 1815:108, lapsus to be ignored. Echimys cristatus Desmarest, 1817b:54; a renaming of Allamand’s “lérot à queue dorée”; attributed the name to É. Geoffroy St.-Hilaire, not to Zimmermann. Loncheres paleacea Olfers, 1818:212; type locality “Brazilien”; renaming of Loncheres paleacea Illiger, a nomen nudum; antedates Lichtenstein (1820) and Kuhl (1820), who both redescribed the same Berlin specimen seen by Olfers and Illiger. Nelomys paleaceus: I. Geoffroy St.-Hilaire, 1838a:887; name combination. Nelomys cristatus: I. Geoffroy St.-Hilaire, 1838a:887; name combination. Loncheres cristata: Wagner, 1843a:332; name combination. Echimys chrysurus: E.-L. Trouessart, 1904:503; first use of current name combination. E[chimys]. paleaceus: Thomas, 1916e:295; reference to Lichtenstein’s name. [Echimys] paleacea: Tate, 1935: 431; name combination and incorrect gender concordance. Echimys paleacea: Ellerman, 1940:113; incorrect gender concordance, following Tate (1935). d e s c r i p t i o n : A relatively large species, mean head and body length 277.3 mm (range: 242–300 mm, N = 11), tail length 336.8.0 mm (range: 305–370 mm), hindfoot length 50.8 mm (range: 42–54 mm), and ear length 19.5 mm (range: 19–20 mm). Upper parts colored dark to pale graybrown, pelage of upper parts densely covered with wide, flat spines from neck to rump with remainder of pelage composed of stiff bristles. A pale-colored (whitish to yellowish) blaze occurs down center of head, from crown to nose, either completely covering face between the eyes or only as narrow stripe or small white tuft on crown; remainder of crown usually dark brown; cheeks and sides of neck sometimes reddish. Ears small, thinly haired, and brown. Eyes dark brown, with weak, dull red eyeshine. Tail longer than the head and body (mean 120%), fully haired, dusky basally with distal half to two-thirds white, yellow, or chestnut. Chin, throat, inguinal region, and a band across chest behind the elbows white; remainder of under parts graybrown, not sharply differentiated from sides. Considerable individual variation present in color, particularly in extent of white on head, under parts, and tail. Feet large, broad, with strong claws on all toes; colored gray-brown above. d i s t r i b u t i o n : Echimys chrysurus is known from the eastern Amazon Basin and Guianan region of Brazil, Guyana, Surinam, and French Guiana, east of the Rio Negro north of the Rio Solimões and east of the Rio Xingu south of the Rio Solimões.

selected localities (Map 493): BRAZIL: Amapá, Serra do Navio (Iack-Ximenes et al. 2005b); Amazonas, Rio Pitinga (M. N. F. da Silva and Patton 1993); Maranhão, Vargem Grande (T. G. Oliveira and Mesquita 1998); Pará, 52 km SSW of Altamira, right bank Rio Xingu (Y. L. R. Leite and Patton 2002), Baião (Iack-Ximenes et al. 2005b), Peixe-Boi (Iack-Ximenes et al. 2005b), São Domingo do Capim (Iack-Ximenes et al. 2005b). FRENCH GUIANA: Cayenne (Iack-Ximenes et al. 2005b). GUYANA: East Berbice-Corentyne, Potaro Highlands (Iack-Ximenes et al. 2005b), Essequibo Islands–West Demerara, Supinaam River (Iack-Ximenes et al. 2005b); Upper Takutu–Upper Essequibo, Tamton (ROM 36840). SURINAM: Nickerie, Polder, near Nieuw Nickerie (Husson 1978), Paramaribo, near Paramaribo (Husson 1978). s u b s p e c i e s : Echimys chrysurus is monotypic. n a t u r a l h i s t o ry: Nocturnal, arboreal, and usually solitary, E. chrysurus occurs in mature lowland rainforest where it feeds on fruit and probably leaves. Individuals use the middle and upper levels of the forest, especially in viney areas, but are also present in open forest (Miles et al. 1981). They may run quickly through the branches but are more typically slow and methodical in their movements, making them difficult to spot. When disturbed they creep quietly into thick vegetation and sit motionless for many minutes, then sneak away silently (Emmons and Feer 1997). They make nests of leaves in tree holes. Known predators include the Spectacled Owl (Haverschmidt 1968). r e m a r k s : Cuvier’s (1809) Echimys included several species now classified in different genera, but Desmarest (1817b) clearly fixed the type species of Echimys by writing “Le lérot à queue dorée d’Allamand et de Buffon en est le type” (p. 54), which is Myoxus chrysurus Zimmermann. Iack-Ximenes et al. (2005b:57) followed Tate (1935:430) in considering E. cristatus Desmarest as a junior synonym of Echimys chrysurus Zimmermann. Lichtenstein (1820) has been generally regarded as the author of Loncheres paleacea (e.g., Thomas 1916e; Ellerman 1940; Cabrera 1961; Woods 1993; Woods and Kilpatrick 2005), with Illiger’s (1811) first use of the name considered a nomen nudum. Iack-Ximenes et al. (2005b) suggested that E. paleaceus is a valid species, a conclusion that followed Moojen’s (1952b) earlier opinion. Cabrera (1961:541) listed paleaceus as a valid subspecies of E. chrysurus, but cited Kuhl (1820) as the author of the name because his work apparently appeared earlier in 1820 than did Lichtenstein’s description. However, both Iack-Ximenes et al. (2005b) and Cabrera (1961) overlooked Olfers’ 1818 description of Loncheris [sic] paleacea (see Hershkovitz 1959b, for discussion), which was based on the same specimen in the Berlin Museum described later by both Kuhl and Lichtenstein. Thus, Kuhl and Lichtenstein only redescribed Olfer’s paleacea.

Suborder Hystricomorpha: Family Echimyidae 897

Map 493

Selected localities for Echimys chrysurus (●) and Echimys vieirai (䢘).

d e s c r i p t i o n : Also moderately large arboreal rat, head and body length 272–335 mm (N = 2), tail length 295–383 mm, hindfoot length 50–51, ear length 17– 18 mm. Upper parts generally glossy brown and head, mid-back, and tail base deep glossy black; sides chestnut or coppery in color. Dorsal pelage composed of stiff bristles and mid-back has wide, flat spines that do not extend onto rump; spines slaty with black tips. Ears short, buried in hair of head. Under parts white, white-spotted, or whitish with buff tinge; chin dark. Tail much longer than the head and body (140% in one individual); densely haired; black at base with variable length of white on or near tip. Hindfeet broad and strong, with strong claws on each toe. Some melanistic individuals known. d i s t r i b u t i o n : Echimys saturnus is known from the eastern Andean foothills and adjacent lowlands of Ecuador and northern Peru; all records are below 1,000 m. s e l e c t e d l o c a l i t i e s (Map 494): ECUADOR: Napo, Cerro Galeras (AMNH 71903), Río Pucuno (MCZ 41569); Orellana, Río Cotapino (KU 68093), Tiputini Biodiversity Station (Blake et al. 2010). PERU: Amazonas,

Hershkovitz (1959b) argued that Illiger’s (1811:90) L. paleacea is actually valid, as it is contained within his diagnosis of the genus Loncheres. However, because Illiger (1811) listed two species under his new genus, one of which was a valid taxon at the time (chrysurus), the nonspecific description of the genus cannot be said to diagnose his new species (paleacea). Thus, paleacea Illiger remains as a nomen nudum, as thought by J. A. Allen (1899c). Lichtenstein (1820) redescribed the same Berlin specimen that formed the basis for Illiger’s paleacea as like a porcupine with a white stripe on the head and a tail with a scaly base and tufted tip, features that clearly link paleaceus to E. chrysurus. Finally, Iack-Ximenes et al. (2005b:58) assigned a specimen from Peixe-Boi, Pará state, Brazil in the Natural History Museum of London (BM 14.6.10.1) to E. chrysurus, the same specimen which Thomas (1916e:295) remarked was “the closely allied but smaller Amazonian species E. paleaceus, Licht., [which] has been received from the Goeldi Museum, Para (locality, Peixe-Boi).” We have examined this specimen and agree that it represents E. chrysurus. Therefore, pending further field and museum work, we regard paleaceus as a synonym of E. chrysurus and accept Olfers as the valid author of the name.

Echimys saturnus Thomas, 1928 Dark Tree Rat sy n o n y m : Echimys saturnus Thomas, 1928d:409, type locality “Rio Napo, Oriente of Ecuador. Alt. 3300′,” probably Napo province.

Map 494

Selected localities for Echimys saturnus (●). Contour line = 2,000 m.

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mouth of Río Santiago (AMNH 98262); Ucayali, Río Pisqui (AMNH 98261). s u b s p e c i e s : Echimys saturnus is monotypic. n a t u r a l h i s t o ry: This species has not been studied in the field. Blake et al. (2010) obtained nine cameratrap photographs of this rare species on the ground at night beside a stream by a mineral lick. One photo included an apparent adult pair and one young traveling together in a tight group (color photo in Blake et al. 2010). Repeated presence at a lick suggests an herbivorous diet (Emmons and Stark 1979). r e m a r k s : Virtually nothing is known about this very infrequently seen or collected species. Thomas (1928d:409) considered E. saturnus closely related to E. chrysurus, but “distinguishable by the absence of a white crown-patch, by its deep black head and centre area of the back, its coppercoloured sides, white middle line below, and nearly wholly black tail.” Iack-Ximenes et al. (2005b: table 1) provided comparative measurements for a single specimen of E. saturnus and a sample of similar aged (by tooth wear categories) E. chrysurus. The former species is slightly larger in all dimensions of the skull with the exception that it has smaller bullae. Emmons (2005:286, Fig. 14) provided dorsal, ventral, and lateral photographic views of the cranium and a lateral view of the left mandible of the holotype (BM 34.9.10.182).

Echimys vieirai Iack-Ximenes, de Vivo, and Percequillo, 2005 Vieira’s Tree Rat sy n o n y m : Echimys vieirai Iack-Ximenes, de Vivo, and Percequillo, 2005b:52; type locality “Barreirinha, right bank of the Tapajós River, near São Luis do Tapajós, Pará State, Brazil; geographic coordinates 04°25′S, 56°13′ W.” d e s c r i p t i o n : Smallest species in genus, but only known from young individuals; head and body length of one specimen 245 mm, tail length 340 mm, hindfoot length 50 mm, and ear length 15 mm. Upper parts generally dark brown and head from muzzle to crown, midback, and tail base black; head with dark maroon medial stripe from rostrum to crown; sides dull brown only slightly distinct from back. Dorsal pelage composed of stiff bristles and mid-back has wide, flat spines that do not extend onto rump. Ears short, buried in hair of head. Under parts light brown. Tail long (139% of head and body length), densely haired, brown at base with terminal third white. Hindfeet broad and strong, with strong claws on each toe. d i s t r i b u t i o n : Echimys vieirai is known only from two localities south of the Rio Amazon in Amazonas and Pará states, Brazil (Iack-Ximenes et al. 2005b).

s e l e c t e d l o c a l i t i e s (Map 493): BRAZIL: Amazonas, Virgen Guajará (Iack-Ximenes et al. 2005b); Pará, Barreirinha (type locality of Echimys vieirai Iack-Ximenes, de Vivo, and Percequillo). s u b s p e c i e s : Echimys vieirai is monotypic. n a t u r a l h i s t o ry: This species has not been studied in the field. r e m a r k s : Known from only two juvenile specimens, this species is distinguished from E. chrysurus primarily by the lack of the white blaze on the top of the head that is so characteristic of the latter throughout its broad range. In this respect, E. vieirai is similar to E. saturnus from the northwestern Amazon, but other features of the pelage and cranium, as well as the large hiatus between the known ranges, make it unlikely that they represent only geographic variants of the same taxon.

Genus Isothrix Wagner, 1845 Louise H. Emmons and James L. Patton

These are medium to relatively large arboreal rats with soft fur, and a tail covered with long, unbanded hair that curls outward like a bottlebrush but may not completely hide the underlying scales. The tail of both I. pagurus and I. sinnamariensis has the tendency to coil at the tip into a tight downward spiral of loops (Patton and Emmons 1985; Vié et al. 1996). The cranium is broad, with a short and broad rostrum; zygomatic arches are strongly bowed outward anterior to squamosal. The tympanic bullae are moderately inflated, and the auditory meatus is medium-sized, positioned near the squamosal, and with a short auditory tube strongly slanted forward. The squamosotympanic fenestra is a long, open slit that reaches posteriorly to the base of the lateral process of the supraoccipital. The postpalatal notch is deep, extending to the middle of M2; the incisive foramina are large and wide. In the pterygoid region, there is no shelf of bone behind the base of parapterygoid (hamular) processes on the wall of the buccinator foramen. Anterior to the presphenoid-basisphenoid suture is a round vacuity connected to a slit-like vacuity along the side of the presphenoid that is shaped like a written musical note. The base of the mandible has strongly developed masseteric and pterygoid crests; the mandibular foramen is anterior to the condyloid ridge and not in a fossa. The maxillary toothrows are short, ≤26.8% of basilar length of Hensel. Maxillary cheek teeth are small and short, with a somewhat subcircular shape in occlusal view. The plane of the maxillary teeth is not strongly tipped laterally as in other echimyines; rather, the occlusal surface is nearly on a plane parallel to the palate (see Em-

Suborder Hystricomorpha: Family Echimyidae 899

mons 2005:258, Fig. 2). All hypoflexi(id)s of both upper and lower premolars and molars are oval to subcircular with a mure; the adjacent lophs curve around the hypoflexi to nearly close at the rim of the tooth. Hypoflexids of the mandibular cheek teeth slant slightly backward, with the internal end of the flexid slightly posterior to the external end. The lower premolar is pentalophodont, hypoflexid is short, with a mure, and other flexids are close to parallel, and all are open lingually when unworn. This tooth quickly wears to a pointed oval, with three parallel lingual fossettes and a round labial fossette derived from the hypoflexid. Mammae range in number from three to five lateral pairs with usually one inguinal pair. The phallus of I. bistriata is short and blunt, with deep longitudinal grooves on sides, the lappet above urethra is not salient from the crater (figured in Emmons 2005), and the baculum is long and narrow (Patton and Emmons 1985). We recognize six species, which fall into two readily separable groups based on body size and pelage color and color pattern. The species within each group, however, lack easily observable morphological differences. The three species of the “bistriata” group (I. bistriata, I. negrensis, and I orinoci) are all large, but separable from one another only by multivariate analyses of cranial mensural variables and, in the case of two of them, by molecular data (data for I. orinoci are lacking). The other three species (I. barbarabrownae, I. pagurus, and I. sinnamariensis) are all smaller; the latter two of this triad are largely distinguishable by karyotype as they share similar but reciprocally monophyletic mitochondrial sequences. Adult specimens documenting overall size and color pattern are unknown for the recently described I. barbarabrownae. Each of the six species has allopatric ranges, so species assignments of museum specimens can be confidently made by a combination of morphology coupled with distributional data. sy n o n y m s : Isothrix Wagner, 1845a:145; type species Isothrix bistriata Wagner, by subsequent designation (Goldman, 1916:125.) Loncheres (Isothrix): Waterhouse, 1848:327; part, as subgenus (listing of bistriata and pagurus). Lasiuromys Deville, 1852:557; type species Lasiuromys villosus Deville, by monotypy. Echimys (Isothrix): E.-L. Trouessart, 1904:504; part, as subgenus (listing of bistriata, pagurus, and villosus); not Echimys F. Cuvier. r e m a r k s : Members of this genus, like Callistomys spp., have some characters shared with eumysopines and not with other echimyines. These include small and somewhat rounded cheek teeth with only the hypoflexi(id)s open (other flexi(id)s appearing as closed enamel folds), and an open squamosotympanic fenestra. Some molecular se-

quence analyses (Lara et al. 1996; Y. L. R. Leite and Patton 2002; Galewski et al. 2005; B. D. Patterson and Velazco 2008; Upham and Patterson 2012) failed to firmly support inclusion of Isothrix within the Echimyinae, although other studies did (P.-H. Fabre et al. 2012). Phylogenetic analyses of morphological characters (G. A. S. Carvalho and Salles 2004; B. D. Patterson and Velazco 2006) do place Isothrix within a group of echimyine genera. As mentioned previously, Emmons (2005) regarded the phylogenetic position to be sufficiently equivocal to list Isothrix as Echimyinae incertae sedis. The two most recent and comprehensive molecular analyses both place Isothrix as basal to other echimyine plus the dactylomyine genera (P.-H. Fabre et al. 2012; Upham et al. 2013). The genus was reviewed by Patton and Emmons (1985), who included Callistomys pictus, following previous authors and without any character evaluation or other justification. Exclusive of pictus, these authors recognized two species: Isothrix bistriata, a wide-ranging western Amazonian taxon (in which they included the named forms pachyura Wagner, villosa Deville, orinoci Thomas, negrensis Thomas, molliae Thomas, and boliviensis Petter and Cuenca Aguirre) varyingly characterized by black or dark-brown supraorbital stripes extending onto the nape of the neck; and Isothrix pagurus, a smaller species with a reddish nose that lacks stripes on the head and that is limited to both sides of the lower Amazon River east of the Rio Negro-Madeira axis. Patton and Emmons (1985), however, documented that populations of I. bistriata from the Venezuelan Amazon (including the holotype of orinoci Thomas 1899) were separable from those of the western Amazon of Peru and Bolivia in multivariate morphometric characters as well as in color pattern. They lacked samples from the central Amazon of Brazil, except the holotype of negrensis Thomas, which by itself fell within a western Amazon morphometric group. Based on similar color and color patterns, Patton and Emmons (2005:12) treated orinoci Thomas as a valid subspecies of a polytypic Isothrix bistriata, and listed negrensis Thomas as a junior synonym of the nominotypical subspecies. Subsequently, based on newly collected materials and expanded analyses, Patton et al. (2000; see also M. N. F. da Silva and Patton 1993) showed that samples from the central Amazon of Brazil, including the geographic area from which the holotype of negrensis was obtained, were phyletically separable from those of western Amazonia in mtDNA sequences, and that these former samples were also different in a multivariate morphometric analysis from both western Amazonian samples and those from southern Venezuela. Bonvicino, Menezes, and Oliveira (2003) documented chromosomal differences between populations from the western and central Amazon and expanded on the molecular divergence

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analysis of Patton et al. (2000). These authors concluded that negrensis Thomas was a valid species, diagnosable by morphometric, chromosomal, and molecular characters, a conclusion followed by Emmons (2005), Woods and Kilpatrick (2005), B. D. Patterson and Velazco (2006, 2008), and Lim et al. (2006). Emmons (2005) listed orinoci Thomas as a valid species but without comment, and B. D. Patterson and Velazco (2006) provided a thorough rationale for the species status of this taxon. Herein, we follow these recent trends and divide Isothrix bistriata (sensu Patton and Emmons 1985) into three species: bistriata Wagner, negrensis Thomas, and orinoci Thomas. Additionally, two newly recognized species have been discovered in the past two decades. Vié et al. (1996) described I. sinnamariensis from French Guiana, closely related to I. pagurus but with a radically different chromosome complement. And, B. D. Patterson and Velazco (2006) described I. barbarabrownae from the eastern Andean slope in southern Peru. Finally, pachyura Wagner, 1845 has been commonly referred to Isothrix as a valid species or subspecies (Palmer 1904; Tate 1935; Ellerman 1940; Cabrera 1961) or simply arranged as a junior synonym of I. bistriata (Patton and Emmons 1985). However, Wagner (1848) himself, while renaming I. pachyura as I. crassicaudus, stated that it was probably the same as Lund’s Nelomys antricola, to which E.-L. Trouessart (1880b:179, as Echimys [Thrichomys] antricola) agreed. Thomas (1916e) also correctly allocated pachyura Wagner to Cercomys (= Thrichomys, see that account), and Moojen (1952b:172) regarded it as a valid subspecies of C. cunicularis (a composite taxon [see Remarks in the Thrichomys account] but as understood by Moojen would equal Thrichomys apereoides of today). KEY TO THE SPECIES OF ISOTHRIX:

1. Size large (mean head and body length >235 mm; mean condyloincisive length of skull >49 mm); black stripes on top of head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1′. Size smaller (mean head and body length 40 mm. . . . . . . . . . . . . . . . . . . . . . . Phyllomys medius 6′. Aristiforms on rump