The Amphibamidae (Amphibia: Temnospondyli), with a description of a new genus from the Upper Pennsylvanian of Kansas 0893380466

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THE UNIVERSITY OF KANSAS MUSEUM OF NATURAL HISTORY

MI

^j^aton No. 85

The Amphibamidae (Amphibia: Temnospondyli), with a Description of a

New Genus from the Upper

Pennsylvanian of Kansas

Eleanor Daly

LAWRENCE

17 February 1994

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The University of Kansas

Museum

of

Natural History

Miscellaneous Publication No. 85 17 February 1994

The Amphibamidae (Amphibia: Temnospondyli), with a Description of a New Genus from the Upper Pennsylvanian of Kansas

Eleanor Daly Museum of Natural Science 111 North Jefferson Street Jackson, Mississippi 39201

Mississippi

USA

Museum

of Natural History

Dyche Hall The University of Kansas Lawrence, Kansas

MISCELLANEOUS PUBLICATIONS

M. Mengel, Richard F. Johnston, and Larry D. Martin Managing Editor: Joseph T. Collins Assistant Managing Editor: Kate Shaw

Editors for this issue: Robert

Miscellaneous Publication No. 85 Pp. iv

+ 1-59; 40

figures; 4 tables

Published 17 February 1994

ISBN: 0-89338-046-6

©

1994 by Museum of Natural History

Dyche Hall The University of Kansas Lawrence, Kansas 66045-2454,

USA

Printed by University of Kansas Printing Service

Lawrence, Kansas

CONTENTS

INTRODUCTION

1

THE HAMILTON LAB YRINTHODONT.....

1

ACKNOWLEDGMENTS

2

ABBREVIATIONS

-.,

SYSTEMATIC PALEONTOLOGY Class Amphibia

.,

3

3 3

Order Temnospondyli

3

Superfamily Dissorophoidea

3

Family Amphibamidae

3

Type genus

3

Revised diagnosis

3

Taxonomic note

3

Eoscopus, new genus

3

Etymology

3

Diagnosis

3

Eoscopus lockardi, new species

4

Taxonomic note

4

Holotype

4

Paratypes

4

Description

5

General features

5

Skull

5

Lower jaw

10

Vertebrae

11

Ribs

14

Pectoral girdle

15

Pelvic girdle

17

Forelimb

19

Hindlimb

20

Amphibamus Cope 1865 Skull

24 25

Vertebrae

Ribs

27

30

,

Girdles

32

Limbs

32

Dermal

33

structures

Tersomius Case 1910 Skull

35

Lower jaw

39

Axial skeleton Girdles and limbs

The Family Amphibamidae The Dissorophoidea

34

Now

:

39

42 45

47

DISCUSSION

52

SUMMARY

55

LITERATURE CITED

55

INTRODUCTION A

previously

unknown Pennsylvanian

dis-

1972). In 1976, the fauna and flora of the quarry

al.,

Hamilton

were the subject of a symposium at the 108th annual

Quarry, eastern Kansas (University of Kansas Verte-

meeting of the Kansas Academy of Science (Trans.

sorophoid

is

part of the fossil fauna of

brate Paleontology

County,

ca.

2 mi

E

KU-GRN-01); Greenwood of Hamilton, (Sec.

R12E). The fossil-bearing limestone

5,

T24S,

Kansas Acad.

Sci.

79:99-102). In 1988, another

Hamilton Quarry symposium was held

at the

22nd

a channel

annual meeting of the south-central section of the

deposit in or has been eroded into the Topeka Lime-

Geological Society of America, with a day-long

stone of the

Shawnee Group,

is

Virgilian Stage. Its

relative time relations with other

well-known Penn-

sylvanian vertebrate fossil localities are Figure

shown

in

(compiled from: Bell, 1944; Branson, 1962a,

1

1962b, 1962c; Carroll, 1967a, 1967b, 1969; Copeland, 1957; DeMar, 1970; Eagar, 1964;

J.

field trip to the trip

quarry area. The comprehensive field

guidebook (Mapes and Mapes, 1988)

is

the best

source of information on Hamilton Quarry and includes a complete history of

work

quarry

at the

(Bridge and Mapes, 1988).

The fauna reported from Hamilton Quarry

T.

Gregory, 1950; Moran, 1952; Olson, 1946; Panchen

cludes tetrapods, acanthodian

fish,

in-

sharks, lungfish,

and Walker, 1961; Peabody, 1952; Reisz, 1972;

eurypterids, arachnids, insects, myriapods, crusta-

Romer, 1952; Vaughn, 1969, 1972; and Wanless,

ceans, bivalves, crinoids, bryozoans and fusilinids.

1962).

By

Walter Lockard discovered the specimen, an acanthodian

fish, at

vertebrate

the quarry site in

E. Bridge (Department of

far the

most common vertebrates

are an

acanthodian, Acanthodes bridgei (Zidek, 1976), and the labyrinthodont described herein.

The

fish re-

1969,

mains often are whole bodies, and the tetrapods

Geology of Em-

often are found as articulated groups of bones,

1964 while looking for invertebrate

Thomas

first

fossils. In

poria State University) began to take field parties to

sometimes as nearly complete skeletons. These speci-

the quarry. Since then, fossil material from Hamilton

mens

Quarry has become more widely studied. The

first

layered brownish-gray to buff limestone, or pre-

a

served three dimensionally in a massive gray lime-

published report was an abstract of a paper read

at

Geological Society of America meeting (Bridge

et

are either flattened onto a bedding plane in a

stone.

THE HAMILTON LABYRINTHODONT phoidea, a group of rhachitomous temnospondyls

of this family name, Trematopsidae, is not properly formed (from the genitive singular of the Greek ops,

known mainly from the Lower Permian of the south-

opos) and should be corrected according to the Code

This labyrinthodont belongs to the Dissoro-

central

and southwestern United

family

is

fairly well

States. This super-

known, with more than 20

named genera. In general, dissorophoids are small to medium in size and their skeletons are well ossified overall with relatively long slim limbs and short

vertebral columns.

The

interclavicles

and clavicles

(Milner, 1978)). The Trematopidae are distinguished

by

antorbital openings that

communicate with

the

by a somewhat squared snout (Berman et al., 1985). The Hamilton dissorophoid does not show these features. The best match was external nares and

with the characters of the family Dissorophidae.

of dissorophoids are small and their femora bear

Most

large adductor flanges.. Typically, their skulls are

rinthodont bears a semilunar flange that projects

short-faced with large orbits and high otic notches.

ventrally into the otic notch

Distinguishing marks of smaller scale are not lack-

The dissorophids are best known for their dorsal dermal armor plates. Their skulls usually are ornamented with characteristic superficial ridges and exostoses. The Hamilton dissorophoid lacks these

ing. Initial

assignment of the Hamilton labyrinth-

odont to a dissorophoid family did not present any

notably, the squamosal of the Hamilton laby-

(DeMar, 1968).

problem. The gilled Micromelerpetontidae and Bran-

striking features, but they are lacking also in

chiosauridae (Boy, 1972) were clearly not nearest

phibamus of the Pennsylvanian. Tersomius of the Lower Permian and Micropholis of the Lower Trias-

relatives.

Of the

terrestrial families, the

Trematopi-

dae were easily dismissed also. (The usual spelling

sic, all

.4/;/-

heretofore considered dissorophids. These

-

UNIV.

KANSAS MUS. NAT.

PENNSYLVANIAN

UPPER CARBONIFEROUS EUROPEAN COAL MEA. NOVA SCOT.

LOCALITIES

ILLINOISAN MIDCONTIN. APPAL ACH. VIRGILIAN

HIST. MISC. PUB. No. 85

Kounova-

MONONGAHELAN -Hamilton

§§§§

-Pittsburgh

McLEANSMISSOURIAN

BOROAN

CONEMAUGHIAN

WEST-

I

PHAL-

PICTOUAN

STE-

-Falmouth -Garnett,

PHANIAN

Howard

UPPER

-Pitcairn

-Oakwood

DES-

MOINESAN alleghen" -Linton -Mazon K

.

n Creek

KEEWA-

D

NyranyFlorence-

C

Fenton-

NEEAN

IAN

B

Newsham-

McCOR-

ATOKAN

MICKIAN

Airdrie-

POTTS VILLEAN

MID-

.

DLE

CUMBERLANDIAN

JogginsPirnie-

A

Jarrow. SwanwickColne-

WM.

.

.LOW

-ER RIVERSDAL

MORROWAN CANSOAN

NAM' IRIAN

v//////// Fi?.

1

Time relations chart of well-known fossil vertebrate localities of the Pennsy vanian and Upper Carboniferous. 1

.

To

test the idea that these

unarmored, normal-skulled genera have always been

definition of the family.

placed at the base of proposed dissorophid phytoge-

unspecialized dissorophoids and the Hamilton

nies because of their apparently unspecialized na-

dissorophoid are

ture

D

and the great age of Amphibamus (Westphalian

equivalent).

Boy

(

1 985 recommended removal of these atypi-

cal genera

)

from the Dissorophidae, and suspicion is

growing among other recent workers (Berman et al., 1

987

)

that they

members of

a long-lived distinct

group, specimens of the North American A mphiba-

mus and Tersomius species were assembled for reconsideration. As a result of this study and an extensive literature survey, this hypothesis

is

sup-

ported and familial reassignments are proposed.

cannot be included in any reasonable

ACKNOWLEDGMENTS my gratitude to Larry D.

O. Wiley, The University of Kansas, and Donald

Martin, William E. Duellman and Hans-Peter

Baird of Princeton University made a cast of the type

Schultze of The University of Kansas for their

of Amphibamus

advice and criticism during the production of this

electron microscope) photomicrographs were

I

would

paper.

like to express

Thanks

are also

due

to those institutions that

lent their specimens for study.

The author has profited

from conversations with Andrew R. and Angela C. Milner.

The holotype was acid-prepared by Edward

lyelli for

me. The

SEM

(scanning

made

by Lorraine Hammer of The University of Kansas. This paper was improved by the comments of two

anonymous reviewers.

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI)

ABBREVIATIONS Used

S

in figures:

F

frontal

jugal

J

L

lacrimal

MX N

nasal parietal

squamosal

ST T

supratemporal tabular

V

maxilla

P

septomaxilla

SQ

vomer

Institutional

acronyms

are the following:

Ameri-

Museum of Natural History (AMNH), Field Museum of Natural History, University of Chicago

can

PA

palatine

PF

postfrontal

(FMNH UC or UR), Emporia State University (HQ),

PM

premaxilla

Museum of Natural History, The University of Kansas (KUVP), Museum of Comparative Zoology

PO

postorbital

PP

postparietal

PR

prefrontal

Q

(MCZ), University of California

(UCLA

quadrate

QJ

at

VP), United States National

Natural History

Los Angeles

Museum

of

(USNM), and Yale Peabody Mu-

seum (YPM).

quadratojugal

SYSTEMATIC PALEONTOLOGY Class Amphibia

Order Temnospondyli Superfamily Dissorophoidea

Family Amphibamidae

—Amphibamus Cope 1865. diagnosis. — Dissorophoid temno-

Type genus. Revised

spondyls, distinguished as follows: 1.

Pleurocentra extend ventrally to meet, or almost meet,

2.

Wyman's (1858) Raniceps lyelli because the name was preoccupied, and he created the family name soon after. Pelion Cope 1 868 is a junior for

generic

homonym

below the notochord;

Ribs short posterior to the shoulder

combination Pelion lyelli was created by Cope ( 1 868)

ticle

re-

of Pelion Kirby 1858. According to Ar-

39 of the Code, a family name

name

of

its

type genus

is

is

invalid

if

the

homonym, so The family name

a junior

gion, such that the rib series lacks a

Peliontidae should be replaced.

thoracic basket.

Amphibamidae Moodie 1910

is

used instead.

In addition to these apomorphic characters, a constellation of primitive ones

is

moveable basal

Eoscopus,

usually present, as

follows: small external nares, stapedial foramen,

—From Greek eo "dawn" and Diagnosis. — Amphibamid dissorophoid with

articulation of the braincase, iliac

Etymology.

blades curving posteriorly, overlapping bony scales.

pos "watcher."

The

short ribs of

amphibamids

are distinct

from

those of trematopids in that they are not flattened or

new genus

relatively

narrow

sko-

overlapping in the thoracic region (Williston, 1909;

shoulder ribs that begin on the axis, with the

Case, 1911). The reduced axial rib pair of bran-

pairs

chiosaurs (Boy, 1978)

is

—

absent in amphibamids.

Taxonomic note. Peliontidae Cope 1 875 is the oldest family name attached to the type genus. The

more

ribs; a

first five

robust; a single spatulate pair of sacral

deep contact between pelvis halves for

anterior

a

interorbital bridge; eight pairs of

two

thirds of their length, followed

interdigitation; terminal phalanges

knobbed.

the

by an

KANSAS MUS. NAT.

UNIV.

HIST. MISC. PUB. No. 85

Eoscopus lockardi, new species

Named

in

honor of Walter Lockard.

Diagnosis as above.

Taxonomic

note.

—This

name was

published in Daly (1976) without a taxo-

nomic description, thereby creating a nomen nudum. The correct date of publication

is

therefore that of this paper.

Holotype

—KUVP 80408.

anterior vertebrae, part (Fig. 2).

Paratypes.

Skull and

and counterpart

—Listed below.

are dorsoventrally flattened

All skulls

and

split

through the dorsal bones unless otherwise indicated.

KUVP 47270. skull

Posterior dorsal part of a

and a long

series of vertebrae.

KUVP 47272. Skull fragment, including a set of circumorbital bones and a

palpebral cup.

KUVP

49491. Presacral vertebral col-

umn,

pelvis,

and femur.

KUVP 50000. Premaxilla and maxilla. KUVP 80409. Skull and anterior vertebrae.

KUVP 8041

1

.

Skull, presacral vertebral

column, girdles, and femora.

KUVP

80412. Posterior part of whole

animal, with

tail

and lower part of one

leg missing.

KUVP

80413. Skull, part and counter-

part.

HQ

14. Partial skull, including orbits

and

anterior portion.

HQ 15. Partial skull, lacking part of right side.

HQ

122A-B. Skull and

brae, part

HQ

anterior verte-

and counterpart.

123A-B. Pelvis and one hind

part

leg,

and counterpart.

HQ 127. Half pelvis and one hind leg. HQ 247. Pelvis of young individual (pubes lacking).

HQ

250A-B, D-I.

A

largely complete

specimen, preserved in the round.

Most of the

skull

and

tail

are missing,

as well as the distal part of leg, the interclavicle,

one hind

and cleithrum.

HQ 252. This specimen is the counterpart of KUVP 80412.

Fig. 2.

Eoscopus lockardi, gen.

and counterpart, x

80408B

is at

1.5.

the bottom.

KUVP

et sp. nov.

80408A

is

The holotype,

at the

top and

part

KUVP

.

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI)

HQ 254A-B. Partial foot, part and counterpart. HQ 255B. Partial skull, posterior half. HQ 258 A-B. Skull, part and counterpart. HQ 260. Skull. HQ 424A-B, HQ 428. Partial skull, some vertebrae and limb bones.

HQ 43 HQ 55

1

HQ

551.

Apparently Eoscopus was completely covered in overlapping, rounded scales, arranged in vertical

rows around the body. They are clearest at the wrists and ankles, which are unossified

Vertebrae, ribs, femur, tibia, and fibula.

.

Scale impressions are faintly visible in the dark-

ened areas around some of the bones of

in this individual.

No dermal armor or ossicles have been found asso-

A-C. Nearly complete skeleton with partial body shadow, some scale impressions, and dark

ciated with any specimen, except in the eyelids and

eyeball remains; part and counterpart.

palate.

HQ

1

598A-D;

HQ

599A-D.

cluding a laterally compressed skull, vertebrae in line,

Some

Partial skeleton, in-

and scattered limb bones.

HQ 641. Scapulocoracoid and humerus. HQ 716A-B. Partial skull, part and counterpart. HQ 720. Disrupted skull and complete vertebral

of the specimens were prepared for study

by embedding them ment,

it

was possible

the round bones tubules.

Skull.

Description

—

C

remains of a nearly

(the poorly preserved

whole animal). The head of HQ 55 1

is

nearly half as

long as the trunk (3.5-7.5 cm). The head of

and 599

is

HQ 598

two-fifths the length of the trunk (3.5 to

8.5-9.0 cm). This

is

also the proportion of

KUVP

80411 (3.3-7.5 cm).

The

tail

of

HQ

551 can be seen on part

impression on the stone,

cm

of

to see the internal structure of

were cartilaginous. The is filled

—Nearly

all

interior of

with a meshwork of bony

of the skull specimens are

the round are fragmentary. is

shown

when

It is

the light

B

is

as an

almost

estimated to have been

when complete, about

The dermal bone pattern

in the reconstruction (Fig. 3).

Measure-

ments were made of the distance from the ventral edge of the quadratojugal

to the lateral

edge of the

supratemporal to approximate the greatest height of the skull. This distance

is

about one fourth to one

third of the midline length, indicating a rather skull. Skull

parallel to the surface.

all

flattened dorsoventrally; those that are preserved in

General features. The size and proportions of Eoscopus are easily observed in specimen HQ 55 1 A, B, and

and removing

acetic acid. After this treat-

the long bones and the neural arches, because the articular surfaces

column.

in plastic

10%

the matrix with

measurements are presented

Because the bones are

split in

in

low

Table

1

most Hamilton

specimens, the outer surfaces must be observed on the acid-prepared skulls

KUVP

80408 and

KUVP

three fourths as

47270. Eoscopus possesses the usual ridge-and-pit

HQ 252KUVP 80412 has both trunk and tail; the tail is about

Lateral line canals are absent, as are the ridges and

four

exostoses seen on the skulls of most dissorophids.

5.7

long

long as head and body together. Individual fifths as

long as the trunk (6.3-7.5 cm).

The hindlimb of HQ 55 1 long (three

252-KUVP 80412 is longer

tail

It

approximately 4.5

of trunk length), and that of

fifths

trunk length).

is

about 5

seems

cm

HQ

cm long (two thirds of

that the individual with a

also has longer limbs.

animal with a trunk 12-13

HQ

cm long,

that is three fifths of trunk length.

250, a larger

has a hindlimb

The humerus of

HQ 250 is essentially the same length as the femora (2.6, 2.7

tibia (1.6

cm), and

its

ulna

is

cm), but the radius

the is

same length

as the

shorter (1.4 cm). In

general the proportions of the limb segments are primitive; thus the distal parts are shorter than the

proximal ones and the radius the

humerus (Hotton, 1970).

is

0.54 of the length of

surface ornamentation of the outer skull bones.

The sutures are unfused. The most noticeable feature of these relatively large size of the orbits,

skulls

is

the

and the accompa-

nying narrowness of the interorbital bridge. Orbit length varies from 0.30-0.42 of the total length in the midline of the skull. There does not

any associated trend with increase

seem

in size.

to be

A ridge,

borne on the prefrontal, frontal, postfrontal. and postorbital bones borders each orbit around the

medial half of

its

circumference.

The eyes of Eoscopus were covered with large palpebral cups, composed of a mosaic of small, cornered pieces of bone (KUVP 80413). The intact cups closely approximate the prefrontals, frontals,

UNIV.

KANSAS MUS. NAT.

HIST. MISC. PUB. No. 85

3

I

.

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI) Table

1

.

Selected skull measurements of Eoscopus lockardi in cm. Skull

Muzzle

Orbit

Table

Bridge

Table

length

length

length

length

width

width

1.41

3.35

2.0

3.35

1.0

1.2

1.35

1.85

0.42

—

0.28

1.4

—

0.75

1.4

—

1.05

3.8

—

0.65

3.3

1.06

1.3

0.85

0.54

1.93

0.95

0.45

0.29

KUVP 80413 HQ 14 HQ 15 HQ 122

3.65

—

1.1

1.45

0.6

—

0.29

1.6

—

1.05

1.2

5.55

2.0

2.0

1.8

1.25

1.5 est

1.0

0.27

3.8

1.1

1.6

1.2

0.62

1.0

0.7

0.26

HQ258 HQ260

3.5

1.1

1.0

1.25

0.5

3.85

1.15

1.45

1.15

0.6

3.4

1.35

0.95

0.95

0.45

Specimen number

KUVP 47270 KUVP 80408 KUVP 80409 KUVP 80411

598-599

0.65

1.1

and postfrontals and leave a crescentic area uncov-

2.05

— — 2.25 — 2.05 —

0.57

— —

—

0.26

0.7

0.65

0.21

whereas

in others

122A, and

specimens have partially preserved cups, and

in all

other visible cornering usually

and shape.

anterior apex of the otic notch,

size

Ocular plates were present in the eyeballs (KUVP

47272 and

HQ

551).

It is

many made up a complete minimum (KUVP 47272).

not possible to say

14,

table

how

it is

—

0.65

HQ

same

—

1.0

other

cases the bony pieces have the

length

0.75

Many

ered on the lateral side of each orbit.

Height/

Postorb.

2.42

1.28

HQ

Skull

height bar length

cupped.

KUVP

It is

best observed on

80408 and 80413. Anis

present at the

between the

skull

and the cheek.

The

external nares are observable only on

HQ

the

25 8B. They are small and anterolateral in position.

The infilling of the canal is a prominent marker of the lacrimal bone in many specimens. The foramina of the orbital surface are preserved only on KUVP 80408. This acid-prepared specimen shows three foramina in each orbit, arranged linearly on the left lacrimal and triangularly on the right. The contact

by displacement of the surrounding bones. The septomaxilla is not observable on any specimen. A

ring but 15 plates

is

On all other skulls they are concealed or obliterated

between the prefrontal and the palatine expected

in

a dissorophoid is internal to the orbital surface of the lacrimal.

For confirmation of

this,

possible to

it is

observe the size and shape of the disarticulated palatine in the right orbit of

KUVP

80408. The

from a short

dorsal part of the palatine extends

rostral process of the prefrontal to contact the jugal at the

midventral border of the

orbit.

exposure of the palatine probably

is

25 8B have the bones of

HQ

external

confined to the

anteroventral rim of the orbit. There

exposure of the ectopterygoid.

The is

14,

no external 122 A, and

In the intact skull there

is

sometimes a

maxillae, is

definite

is

The

the nasals

and pre-

present between the nares. This feature

HQ

best viewed on

14, 15,

and 260.

dorsal processes of the premaxillae are long

and close

to the nares.

They

fit

into notches in the

which are floored with bone. As a result, the dorsal processes cannot be viewed without removnasals,

ing

some of the

nasal bone ventral to them.

and 260 were prepared

to

and

is

exposed on

outline on

HQ

HQ

14

expose the processes. The

notch medial to each naris

KUVP

is

a feature of the nasal

80408.

It

can be seen

in

14 and 55 1C.

An internal nasal

flange

was discovered

other dissorophoids (Bolt. 1974a).

It is

in a

few

present in

Eoscopus and is partially preserved on KUVP 80408 where

this area in articulation.

bounded by

rostral fontanelle,

it

can be seen through a gap

portion of the palate.

On

in the anterior

the ventral surface of the 4

cornering anterodorsal to each orbit, as the roof

nasal bone, the long flange extends anteromedian )

passes from top to side. This, together with

from

its

the apex of the prefrontal.

A posterior part of

inturning into the front wall of the orbit, gives the

the flange extends along the anteroventral edge o\

some cases. In some specimens the prefrontal is only slightly curved,

the prefrontal

prefrontal an inflated appearance in

near the

from the anterior corner

orbit.

The

flange

may

to the

curve

include a lacrimal

KANSAS MUS. NAT.

UNIV.

contribution, but the ventral surface of the lacrimal

bone

is

not preserved on

The

KUVP 80408.

anterior apex. is

notch

is

as

large,

A supratympanic flange is present, but

preserved only on KUVP 47270 and

HQ 598 A. Its

ventral edge has a squamosal semilunar flange,

(DeMar, 1968). A supratym-

typical of dissorophids

occurs in each bone. The holes

may represent rugose

HQ 250 was split into its parts. The marginal teeth are large and curve inward at the tips. Broken teeth have thin walls and large pulp attachment areas that were pulled off when

expected for dissorophoids, curving concavely ventrally from an otic

HIST. MISC. PUB. No. 85

panic shelf (Bolt, 1974c) extends from the skull

spaces. Externally, labyrinthine grooving seldom visible, but

when

is

larger teeth are chipped, ridges on

their inner walls leave vertical stripes of dentine

on

and spacing of teeth

is

the matrix infilling. Size

The area

similar in upper and lower jaws. Counts of teeth and

ventral to the shelf is unsculptured, as in trematopids

tooth spaces of selected upper jaws are presented in

above the supratympanic

table

(Berman

et al.,

flange.

1985) and (apparently) Iratusaurus

Table

40-65

the skull table, the supratemporal bears a ventral

bones.

is

teeth; the

The

projection, a semilunar flange (Bolt, 1974c). There

Countable upper jaws of Eoscopus possess

2.

(Gubin, 1980). Ventral to the shelf, near the end of

palatal

number varies with the length of the

view of the

skull

is

dominated by the

a tabular contribution to the supratympanic flange

large interpterygoidal vacuities. Braincase bones

determine whether the squamo-

cannot be seen through them, or posterior to the

also. sal

It is

difficult to

has a small contact with

it

parasphenoid; these bones were unossified in

or not.

all

Only KUVP 80408 shows the condylar area well. The subotic parts of the squamosal and quadratojugal

covered with large curved denticles, and the vacu-

completely cover the posterior portion of the quad-

ities

specimens. The bones surrounding the vacuities are

themselves were covered with denticulated

rate.

They

lateral sculptured

skin.

The

parts

by a definite rim. The posteromedial process of

bony

platelets

are delimited

from the

the quadratojugal nearly encircles the dorsal process

denticles are borne in small groups on

(HQ

15).

The palpebral cup

ossicles

can be distinguished from the palatal platelets by

of the quadrate. The lateral portion of the condylar

shape: palpebral cup bones are cornered, whereas

Eo-

palatal platelets usually are larger and more rounded.

surface

is

borne by the quadratojugal cover

scopus. The dorsal process of the quadrate

is

in

a strong

knob, wider than long, with a rounded top.

Eoscopus possesses short tabular horns, which vary somewhat in shape and angle and can be seen

on KUVP 47270, 80408, and 80413, and HQ 15 and 598A. The horns turn slightly ventrally from the plane of the skull table. has a light pitting on

On KUVP 80408 its

A

similar covering for the vacuities has been re-

ported for the dissorophids Broiliellus hektotopos

(Berman and Berman, 1975) and Kamacopsacen'alis (Gubin, 1980). Steen (1931) found them on Am-

phibamus

the horn

outer side, rather than

lyelli

and Stegops divaricata, and Romer

(1930) described them on Erpetosaurus, acolosteid. Fang-and-pit pairs are present in the positions

The best prepared vomers,

typical of temnospondyls.

KUVP

normal sculpturing. This is not true of KUVP 47270,

on

another acid-prepared specimen.

curved denticles, which point toward the postero-

The round

parietal

foramen

is

always present a

short distance behind the orbits. This opening lacks

The posterior border of the skull table is marked by a grooved ridge running from side to side. The occipital cover is not well preserved on any specimen. Some of it seems to be present on KUVP 80413 and HQ 15. A sheet of dermal bone probably extends to the foramen magnum and ventrally on both sides as two lobes, and then shortens laterally a raised rim.

until

it

disappears into the skull table again at about

the middle of the tabulars.

The ventral surface of the

dorsal part of the postparietals are exposed on

250A.

A

round hole, located somewhat

HQ

laterally,

80408, are patchily

set

with strong re-

medial corners of the bones. There are three pairs of fangs-and-pits on the right left.

The

largest fang

is

vomer and four on

the

located at the anterior end of

the internal naris. Its recurved tip points posteriorly.

Another occurs on the medial border of the naris. the left vomer, another smaller fang

border just posterior to

it.

is

On

located on the

The remaining fang lies in

the middle of each vomer,

between the

naris

and the

midline of the palate. The smaller fangs are not as erect as the slightly

one

at the

end of the

more curved and point

naris,

and they are

strongly in the

same

direction as the denticles.

The

palatal pattern of

KUVP

80409. a second

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI) Table

2.

Measurements

Specimen number

in

KUVP HQ 14

Premaxilla

Maxilla

Maxilla

length

count

length

count

4.89

80409 80413

HQ 15 HQ122A

acid-prepared specimen, 4).

Only the fangs

nares are present.

cm and tooth counts of upper jaw bones of Eoscopus lockardi. Left above, right below.

Premaxilla

KUVP 50000 KUVP 80408 KUVP

44

1.32

21

0.71

11

0.79

12

0.80

12

not

0.81

12

measurable

0.74

12

2.62

0.70

10

2.85

30

0.76

10

incomplete

30

44 34 36

— —

1.13

16

4.23

0.70

10

2.86

0.75

13

2.82

is

somewhat different (Fig.

at the anterior

ends of the internal

The remainder of

the

vomers

covered with a uniform carpet of denticles, so that

is it

were absent. Either there

It is

'

— — 35

33?

32

possible that this specimen might represent

another amphibamid taxon; however,

it

differs

from

KUVP 80408 only in this character. A large palatine fang-and-pit present at the posend of each naris

is

certain that other fangs

is

a great deal of individual variation in vomerine

anterior set.

The

some kind of polymorphism is present.

teromedially.

On KUVP

dentition, or

9

terior

is

comparable

in size to the

of this fang points pos-

tip

80408, a small fang

is

located medial to this larger one, but this is

not the case with

KUVP

80409. Like

the palatine, the ectopterygoid bears a

fang, the tip of which points posteromedially.

The exact shape of

the

vomers

is

not

preserved because of breakage anteriorly

and posteriorly. Nevertheless, most of the

vomer

is visible.

Posterior to the trans-

verse posterior borders of the premaxillae is

a rounded, denticle-free space. This

probably

is

the internarial pit found in

some other dissorophoids and which

is

flattened into the plane of the rest of the

palate in both of these acid-prepared speci-

mens.

No

internarial

foramen has been

observed on these specimens.

Both the upper and lower sides of the ectopterygoid are observable on

KUVP

80408. The contacts of its anterior end are visible

on

KUVP

80413.

On

the palatal

surface a wide smooth groove extends anteriorly

an Eoscopus lockardi, gen. 80409, x 2.

Fig. 4.

KUVP

et sp. nov.

The palate as seen on

from the posterior edge and

to

elongate foramen. In dorsal view, the

foramen

is

larger

and rounder than

in

ventral view, and an anteroposterior in-

UNIV.

10

ternal divider

pterygoid vacuity

is

is

visible.

The medial border of

a prominent heavily den-

ticulated ridge for about half its length.

low

the

thickened, so that the interpterygoidal

rimmed with

is

KANSAS MUS. NAT.

The ridge is

anteriorly, but enlarges posteriorly

and

finally

transforms into the round, hollow projection of the internal process of the pterygoid.

cover the ridge continue onto

The denticles that process for most

On KUVP

also.

80408, denticles exist only

near the internal process, but on 80409, they extend

halfway

The

to the

squamosal contact.

internal processes of the pterygoid are pre-

KUVP

served on

80408, 80409 and 80413. Their

open ends are confluent with V-shaped openings

in

The two foramina

uniformly.

for the internal ca-

rotid arteries are in the lateral faces of the denticle

platform.

They

are invisible ventrally because the

edges of the triangular area are laterally produced.

On KUVP

80409, shallow grooves can be seen at a 45°

curving medially to approach the foramina angle.

Most of

this

of its length and pass posteriorly onto the quadrate

ramus

HIST. MISC. PUB. No. 85

present on

the slender parasphenoidal rostrum

KUVP

80409. As

vomers, two narrow ridges

it

rise

is

approaches the along

its

sides,

The rostrum probably widens where it contacts the vomers. The creating a shallow ventral trough.

anterior corners of the posterior plate are everted

and convex, while the transverse anterior edge remains

straight.

Each protrusion once covered

the

the

posterior and ventral sides of a cartilaginous basi-

pterygoid shells covered cores of palatoquadrate

pterygoid process. Unfortunately the posterior parts

the posteroventral sides of each process. In

cartilage.

life,

A similar morphology was described for

the dissorophid Ecolsonia

(Berman

which has an ossified braincase.

In this animal, a

triangular posteroventral part of the basipterygoid

process

fits

into the V-slot of the internal process of

the pterygoid.

For the

lateral half

of

process of the pterygoid

its

is

of the parasphenoid are not well preserved.

A

et al., 1985),

length, each internal

attached to the convex

compressed

anterior portion of a dorsoventrally

is

now

normally

due

to flattening of the skull. Laterally

is

oriented vertically,

is

it

a

little

its

free

KUVP

on the

80408.

It

mal portion. A second stapes lies inside the curve of the lamina ascendens on the left. Its unfinished footplate shows its tubular interior structure. KUVP 80409 has one stapes preserved, lying behind the skull (Fig. 4).

Lower

jaw.

—

Skulls of Eoscopus usually are

preserved with the lower jaw. In spite of the num-

merges

ber of jaws in the collection, the only adequate

end extends

further medially than the process.

An epipterygoid is present in the left interpterygoidal vacuity of

in position

curled

with the quadrate ramus just above the internal process of the pterygoid, while

approximately

is

a robust, perforated rod with an enlarged proxi-

lamina ascendens. This transverse sheet of bone, that

stapes

right side of the parasphenoid of

KUVP 80408, lying lengthwise.

examples for description are the acid-prepared

KUVP 80408

and 80409.

The symphyseal region of both mandibles is entirely visible. The expected fang-and-pit pairs at the anterior ends of the bones are present. At the

consists of a conical base, unossified ventrally,

symphysis, the dentaries enlarge to double the

and a strong ascending process. The epipterygoid

contact area, resulting in a projection into the angle

It

ossification could not

have participated

eral side of the basal articulation,

in the lat-

because the

of the jaw. This strengthening must exist because

jaw

the

is

slender at the symphysis.

The inner end

hollowed ventromedially by the

pterygoid completely surrounds that part of the

of each dentary

palatoquadrate.

meckelian sulcus. The anterior splenial follows the

The most prominent feature of the parasphenoid is its

elevated, triangular denticle patch at the base

of the rostrum. This area

80408 and rostrum. projects

KUVP

is

preserved on

KUVP

80409, along with most of the

The apex of the triangular denticle patch well below the palate. From there the

surface slopes posteriorly and at

its

base, bends to

the level of the rest of the parasphenoid.

Recurved and

denticles carpet this triangular area closely

is

sulcus and most likely participated in the symphysis,

although

all

four of the preserved splenials are

broken before reaching

this point (Fig. 5).

The posterior ends of

the

jaw

are not as well

preserved as the anterior ends and nothing can be said about the articulation or the adductor fossa.

A

on the right side of KUVP 80408. It is a small, oval opening between the prearticular, angular, and postsplenial. single meckelian fenestra can be seen

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI)

bone

is

jaw is visible, and more heavily sculptured than

the dentary. This

is

also true of Dissorophus

The

exterior surface of the left

the angular

BroilieUiis

and

(DeMar, 1968). The angular in Eoscopus

lacks the ventral keel present in Dissorophus, ever. Sharp, recurved denticles

how-

cover the dorsomedial

jaw and extend from the region of the symphysis to the presumed position of the adductor fossa. The coronoid bones that bear the denticles cannot be described because of their position. The contact between the two splenials is well preserved on KUVP 80409.

part of the

Vertebrae. ries

—Six specimens have complete

se-

of presacral vertebrae, lying in line and with the

arches

more or

Despite their

unobscured

These are

less in position.

47270 and 80412. completeness, none of these is

in all parts

of

its

column, and only

KUVP 47270 can provide a vertebral count. Most likely, KUVP 47270 has 24 presacral vertebrae (Fig. 6). It is

impossible to count the postsacral vertebrae

of either

KUVP

have been

80412 or

at least 50.

HQ

rapidly in size posterior to the ribs.

The presacral neural arches the acid-prepared

HQ

551, but there must

Caudal vertebrae diminish

on 47270 and on

are best observed

KUVP

specimen

250F. In lateral view, the neural arch of each

middorsal vertebra shows a long posterior sweep

behind the pedicel. The neural spine surmounts

this

unsupported posterior region. The shapes of the neural spines vary regionally; on the

seven

first

arches, the spines are square in profile, whereas for a typical middorsal arch each spine,

arched

hump

(Fig. 7).

The

face anteriorly by 30^-0° . ossified in the midline,

is

a smoothly

anterior zygapophyses

The arches

and the

right

are not co-

and

left

halves

are often shifted relative to each other.

HQ 551,

KUVP

598-599, and 720, and

11

Internal views of the neural arches are available

on

KUVP

47270 and 49491. The vertebrae

are

exposed in ventral view, and the inside of the slightly spread arches are visible between intercentra.

On

the inner surface of each neural arch pedicel, Eosco-

pus bears a

pit,

spinal cord in

men, the

pits

which must have

life.

lain opposite the

On KUVP 47270,

a large speci-

shown on arches 10-15

open, except on the

1

1th arch, in

are

deep and

which the opening

by bone so that it faces posteriorly. KUVP 4949 1 a much smaller specimen, has shallower pits surrounded by half covered

is

.

thin rims restricting the opening.

The arch pedicels

rest

on triangular para-

chordal processes, the apices of which

halfway down centra

(HQ

lie

the sides of the vertebral

250F). The posterior edge of

each triangle

is

noticeably longer than the

anterior one. Elongated transverse processes,

corresponding to the joined rib heads,

in-

cline anteroventrally, parallel to the poste-

rior edges.

The

articular surfaces face

posteroventrally and

They were

laterally.

finished in cartilage rather than bone, like the

zygapophyses. Preservation of transverse processes depends greatly on the extent of ossification at death. In

upper borders of the

KUVP

rib facets

47270, the

appear to be

the lower edges of the parachordal processes,

while on

KUVP 80408 transverse processes

are not visible at

Fig. 5.

Eoscopus lockardi, gen.

of the lower jaw in ventral view, x the anterior

end of a half jaw.

et sp. nov.

2. Inset,

Reconstruction

an enlarged view of

all.

Although many specimens have vertebrae, few have centra well-enough presen ed to

be readily interpretable. The intercentra

are

much more commonlv observed

than

12

UNIV.

KANSAS MUS.

NAT. HIST. MISC. PUB. No. 85

.

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI)

Eoscopus lockardi, gen.

Fig. 7. in lateral

et. sp.

and ventral views. Based on

13

nov. Reconstruction of a middorsal vertebra

HQ 250F, x 7.

pleurocentra, which are less ossified, especially in

served in the round. These do not conform entirely

younger individuals. The central elements are well

with the pleurocentra described from

displayed on

HQ 250F, where a short segment of the

middorsal column

is

preserved with

all

the elements

HQ 250F; they

lack the dorsal development that allows a long

contact above the notochord.

The pleurocentra

are

well ossified and lying almost in their original posi-

roughly rhombic with the anterior corner slightly

tions.

ventral to the middle of their height.

The height of the intercentra is not great when compared to their other dimensions. Their posterior edges are angled where they lose contact with the

rounded corner

pleurocentra and contact the neural arches.

complete, well-ossified specimen,

it is

On

a

possible to

distinguish the posterior face by the presence of this angle.

None of the intercentra in the collection bears

visible rib facets, with the single exception of one

HQ

250F. In this case, the facet

is

just

on

above the

have had

is

The

posterior,

high and the pleurocentra

slight contact

may

above the notochord. The

difference between these pleurocentra and those of

HQ

250F may reasonably be ascribed

variation, because

KUVP 49491

is

to ontologic

a smaller indi-

vidual.

KUVP

Pleurocentra are observable on also.

The vertebrae of

this

specimen are

80408

laterally

compressed, and only the pointed dorsal halves of the pleurocentra of one side are preserved as impres-

posterior corner.

The well-ossified dorsal pleurocentra of HQ 250F

sions.

There

is

less dorsal

development than

in

are large in lateral view. Their long dorsal contact

KUVP 49491. There is no dorsal, posterior corner,

may have been

and the pleurocentra

co-ossified above the notochord.

Like the intercentra, the pleurocentra have corners at the level

of the ventral apices of the parachordal

processes. However, the pleurocentra have corners

on the anterior edges rather than the trally,

posterior.

Ven-

the pointed tips of the pleurocentra approach

each other closely, usually preventing contact be-

tween adjacent

intercentra.

The

centra of Eoscopus

the notochord.

The

may

not have touched above

position of these vertebrae

farther anterior in the column,

and

this

may

is

influ-

ence the size and shape of pleurocentra.

KUVP

49491 affords a view of the inner or

notochordal surfaces of the central elements.

Andrews and Westall (1970:272) published

a de-

scription of this part of the osteolepiform fish

KUVP 4949

resemble those of Micropholis in this respect (Broili

Eusthenopteron that also applies to

and Schroder, 1937). Specimen KUVP 49491, which has been partially uncovered by acid treatment, re-

The inner surfaces of the central elements are made

vealed a damaged presacral column in ventral view,

are covered with irregular vertical ridging.

where the pleurocentra are clearly visible (Fig. 8). On KUVP 4949 1 pleurocentra are well pre-

the atlantal neural arch. This arch

,

1

of unfinished bone of an unusually close texture, and

KUVP 80409 and 47270 provide lateral views of is

two

thirds as

KANSAS MUS. NAT.

UNIV.

14

HIST. MISC. PUB. No. 85 vertical

grooving that fans onto the

anterior

zygapophyses and the base

of the neural spine. The neural spine is

it seems probwas higher and more

not preserved but

able that

it

square than those of

neighbors.

its

Eight rib-bearing vertebrae fol-

low

the sacral.

bears the

first

The

last

of these

haemal arch,

as in

Eryops (Moulton. 1974). KUVP 80412 shows an array of haemal arches in lateral view. Unfortunately, the central elements are unossified.

The haemal spines diminish

are robust

and

in length posteriorly in a

regular fashion. Four vertebrae with

haemal arches terminate the preserved on

KUVP

series

47270. The

haemal canal occupies about half

whole

the height of the

The

(Fig. 9).

legs

structure

on either side of

compressed

the canal are laterally

and are narrow when viewed from the anterior or posterior. itself is

Eoscopus lockardi, gen. x 2.5.

Fig. 8.

vertebrae,

et sp. nov.

two

it,

and

it

half-arches, unfused to any central

zygapophyses face anteriorly

The neural spine

at

The

ante-

about a 45°

The neural arches do not have tail. The five anteriormost caudal arches have spines with a low square profile. More posteriorly, the anterior corner disappears and the spines slope toward the highest point at the rear of each arch.

the posterior zygapophyses.

parachordal parts than

rises

The axis is nowhere well preserved, but what can be seen of

it

on

indicates that to

it,

KUVP 47270 and other specimens

it is

similar to the vertebrae posterior

except that the neural spine

enlarged.

It

The

is

anteroposteriorly

bears transverse processes and ribs, as

can be verified from

KUVP 80408.

sacral arch can be seen

on

with an associated sacral rib (Fig.

can be readily identified by

its

was

lengthened neural spines in the

on a slope, so that its posterior corner lies just above the hindmost point of angle.

it

continued by a cartilaginous segment.

element. Transverse processes are absent. rior

eted at the end. indicating that

KUVP 49491,

long anteroposteriorly as those following exists as

Femur, pelvis and lumbar

The spine

round and heavy, and sock-

each caudal neural arch

KUVP

47270,

In isolation,

it

enlarged transverse

The

dorsal portion of

smaller relative to the

true of the dorsal vertebrae,

and the caudal neural arches are not lengthened behind the pedicels. Ribs.

—All

the ribs of

Eoscopus

are double-

headed, with the heads conjoined with bone. They

show two

often

meeting

6).

is

is

distal

at a

articulating faces

on the heads, The

projecting apex at about 140° .

segments of the ribs are dorsoventrally flattened

and have square ends. Regionalism

is

evident (Fig. 10).

The first pair of

processes and anterior zygapophyses. The arch

ribs

immediately preceding the sacral arch

fourth pair, then diminishes through the eighth pair.

is

corre-

is

borne by the

spondingly marked by enlarged posterior zygapo-

Behind the shoulder

physes. The pedicels of the sacral arch are

ribs extends to the

somewhat larger than those of other vertebrae, and show heavy

axis.

Length increases

ribs, a series

to the

of similar dorsal

sacrum; thus, there

is

no pectoral

region in the rib series of Eoscopus. There

is

a single

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI)

15

only slightly turned with

respect to each other.

Grooving similar

to that

on the arch pedicel runs longitudinally on the waist

of the

spreading onto

rib,

The

the blade.

The

to end.

rib

is

arched from end

slightly

sacral rib of

HQ 250H differs from the others

is

that

from edge Eoscopus lockardi, gen.

Fig. 9.

et sp. nov.

Reconstruction

of a haemal arch in lateral and ventral views, based on

47270, x

vex dorsally)

KUVP

it is

to

curved

edge (conalso.

A series of caudal ribs is visible on KUVP 47270,

6.

and three pairs are partly sacral pair,

and eight pairs of caudal

ribs follow the

sacrum.

exposed on

HQ

250H. The two

anterior pairs are straight, strong,

A complete series of shoulder ribs is displayed on KUVP 8041 and 80412. The anterior five pairs are preserved on one side of KUVP 80408, and a few lie near the disarticulated anterior vertebrae on HQ

and square-ended; they are nearly

122B. The shoulder ribs curve gently; the longest of

pairs are thick, square-ended,

them is about half again as long as the ribs following. They are narrowest about one third of their length from the proximal end. The ribs vary regionally, in

extend two vertebrae posteriorly.

1

that the sixth, seventh,

and eighth pairs are shorter

The fourth pair, or the third and fourth pairs are the longest. The larger ribs sometimes are visibly angled where the than the four preceding ones (Table

3).

shaft rotates to the plane of the distal end.

On KUVP

The

as long as the sacral rib.

remaining six pairs curve posteriorly.

Of these,

the middle four

and

Their two heads are delimited by

an indentation in the bone bridging them.

The two

ribs are short

their

last pairs

of

and pointed, and

heads cannot be distin-

guished.

Pectoral girdle.

—Four

speci-

80412, the five anterior pairs are markedly more

mens possess

robust than the three following, and the second pair

ral girdle.

has very wide distal ends. The third rib pair has the

a scapular blade, possibly part of

second largest

The

distal

ends on

dorsal ribs are

all

this

shaped

like isosceles triangles.

est diameter, the dorsal ribs

HQ 250E has most of

specimen.

another scapulo-coracoid, and

They heads, which are

most of a clavicle.

about equal in

are narrowest just distal to their

parts of the pecto-

From

size.

their

expand evenly

narrowto their

HQ 55

1

has a

pair of scapulocoracoids, a pair

of clavicles, and a bone that

may

be the interclavicle. The third

HQ 64

square distal ends, which are narrower than the

specimen,

joined heads.

ulocoracoid with the scapular part

Examples of the massive

sacral rib are available

on KUVP 47270, and HQ 250H, and 252. The sacral rib has a large oval head, a thick waist located at a

third of

its

length,

and a wide-bladed

distal portion.

That of KUVP 47270, the most complete available, is

about 13

mm

mm long, 5 mm wide at the head, and 9

The sacral arch bearing it is The head and the flat blade are

at the distal end.

about 7

mm

long.

1

,

bears a scap-

preserved as an impression.

KUVP

80411 has the interclavicle and possibly both clavicles.

The scapula of

HQ

gen. et sp. nov.

Reconstruction

250E

is

short and broad, and has superficial sculpturing consisting

vertical

Fig. 10. Eo-

scopus lockardi.

of fine

grooves, each with a

of the rib scries. based on

KUVP

80412AandKU VP 47270.x 2.

Table

Measurements of anterior

3.

KUVP

Rib

left

Eoscopus lockardi

KUVP

in

cm.

KUVP

80411 right

left

80412

left

right

0.67

—

0.70

0.72

0.73

0.74

0.80

0.73

0.74

0.83

0.77

0.78

1st

0.70

2nd

0.80

3rd

0.88

4th

0.88

— — — —

5th

0.73

0.77

0.80

0.74

0.72

0.72

0.72

0.68

0.64

0.72

0.70

0.66

0.69

0.70

0.69

0.50

0.50

0.55

— — — — — —

7th 8th

9th 10th 11th

small pit or foramen at

much

its

ventral end.

symmetrical on either side, scapulocoracoid

bone

They

—

0.49

0.47

HQ 55 A is 1

that of

is

HQ

and

are waisted

bow

like

641

crescentic, but the lower

is

rather than pointed.

The

best

(Fig. 11).

The

ties.

arm

at

half bears grooves,

— — —

which radiate anteriorly from the

center of the bone. Thirteen of them can be counted as matrix stripes. Originally the anterior border of

truncated

is

At the transition from the scapu-

portion to the coracoid portion of the bone,

bends

0.54

smaller animal, and the scapulocoracoids

are quite different in shape.

lar

ribs of

NAT. HIST. MISC. PUB. No. 85

80408

pair

6th

a

KANSAS MUS.

UNIV.

16

it

an angle slightly more than 90 degrees.

Because the edge of the angle

is

not parallel to a line

bisecting the crescent, but rises anteriorly, the cora-

coid portion has more area than the scapular.

A deep

impression in the stone preserves clearly the thick, robust area of the supraglenoid buttress.

The bone is

much thickened below and behind the buttress, until near the posterodorsal corner. Although the coracoidal portion

is

preserved as bone, this lateral

was removed in order to demonstrate its thickness. The glenoid fossa is not preserved, nor are area

there any traces of foramina; however, a

deep

pit is

present on the inner surface just below the glenoid area.

Evidence for

its

existence was a smooth-

topped stone projection, uncovered while removing the lateral part of the coracoidal plate. tion has

been accidently removed. The

The pit

projec-

may

be

which ought to be present in this position. However, the pit is narrow and no foramina appear to open into it. the subscapular fossa,

The

split interclavicle

of

KUVP 8041

presents the medial side of silhouette

is

its

1

(Fig. 12)

exterior half.

Its

approximately hexagonal, with the two

anterolateral faces concave.

The

exterior anterior

Fig.

1 1

.

Eoscopus lockardi, gen.

scapulocoracoid and humerus of

HQ

et sp. nov. the

641.

x

2.5.

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI) the interclavicle tate.

The

may have been

exterior surface

is

scalloped or den-

ornamented where

it

is

( 1

978) much resembles a rotated Eoscopus clavicle,

but note that in Branchiosaurus the triangular pro-

not grooved or overlapped by the clavicles, as can be

jection

seen from the irregular appearance of the postero-

stem.

rounds the anterior edge of the scapula (and presumably the ventral end of a cleithrum). arises near the ventral

is

on the opposite

Pelvic girdle.

medial portion of the bone.

The clavicle of Eoscopus (Fig. 12) is longstemmed and lacks surface ornament on its ventral expanded portion. The dorsal portion is well preserved on HQ 250E and is as tall as the scapula lying slightly posterior to it. It curves smoothly where it

A

low keel

end of the stem, becoming

counterpart of this specimen, and silastic casts made,

which display the internal and exterior surfaces of most of a whole pelvis (Fig. 13). In the next best specimen, HQ 250H, there is an impression of the interior surface of a half-pelvis.

toward the point of the leaf-shaped ventral

plate.

HQ

about

suture line

1

35° ; in addition, the plate

is

rotated clockwise with

clavicle of

Eoscopus

is

An enigmatic feature of the the

flat

triangular process

projecting from the anterior border of the stem, at

about a third of its length. This process both the clavicles of

HQ

551 A, and

larger in this smaller individual.

on

is

visible

is

relatively

A possibly homolo-

gous anterior process was described for the clavicle of Dissorophus multicinctus by DeMar ( 1 968).

The

cleithrum described for Branchiosaurus by

Boy

Fig. 12.

(KUVP

127, 247, 252, and 551 A). visible

is

No

puboischial

on the two with complete

Both acetabula can be seen on the cast of 123B, and the upper part of another

KUVP 4949

1

.

The

is

articulation surface

HQ

exposed on is distinct,

and has the expected posterodorsal indentation. Another, smaller scallop is present anterodorsally, that the surface has an

such

upper lobe. The acetabulum

has projecting rims dorsally and ventrally, but there is

no supra-acetabular

The

iliac

blade

is

buttress.

straplike with a squared end,

and curves posteriorly.

Its

anterior edge bears a

Eoscopus lockardi, gen. et sp. nov. Reconstructions of the interclavicle and on KUVP 8041 1. Right: the clavicle, based on HQ 250E.

the interclavicle, based

in smaller

49491, 80411, and 80412, and

ventral plates.

respect to the slanting stem, so that it lay more or less horizontally in the body.

Both of these pelves

have the pubes, which were unossified

The angle between

is

are eight pelves preserved

which is HQ 123 A and removed from the part and

B. All of the bone was

specimens

and the plate

—There

(articular) side of the

in the collection, the best of

most prominent just below the angle and descending the stem

17

clavicle,

x

5. Left:

UNIV.

18

prominent hump, such

pronged

in silhouette.

KANSAS MUS.

that the ilium

is

NAT. HIST. MISC. PUB. No. 85

almost two-

At the hump, the dorsal edge

of the iliac blade bends and then runs straight posteri-

more robust edge curves more is well shown on acid-prepared specimen HQ 252. The internal

orly.

The

ventral,

gradually. This feature of the ilium

the

is

sacral attachment.

The

cast of

HQ

is

two becomes

a peg-and-socket arrangement.

The right plate bears

a rounded projection, which originally fitted into a

matching indentation on the

left

plate,

at

the

areas immediately anterior and posterior to the "peg"

from the

interior to

ately posterior to the

groove

thirds of the plates. Posteriorly, the contact

123 bears an

The groove pierces the crest immedibend in the iliac blade. The

the exterior.

halves was deep and indicated by a

left

posteriormost point of the- midline contact. The

additional deep groove through the dorsal edge of the iliac blade, running obliquely

and

ridge on the interior midline along the anterior

marking the

faintly undulated,

surface of the blade

right

also interlock slightly.

It is

similar arrangement

is

Ecolsonia; Figure 12B

possible that a

somewhat

present in the pelvis of

Berman,

in

et al.,

(1985)

is

suggestive.

On HQ

continued by three ripples in the internal

123, the pubes are sharply everted or

On

surface.

downturned along

The suture line between the ilium and the ischium is marked on the internal surface of the pelvis by a slight ridge, accompanied by faint grooving perpen-

tral

On the external edge of the puboischiadic plate, a hump opposite the acetabulum marks

passing in a slight arc across to the other acetabulum.

where the bones meet. The suture

angle anteriorly, but this

dicular to

it.

ilium and the pubis

is

line

between the

their anterior edges.

(HQ 123B)

this

eversion

is

the ven-

apparent as a

ridge running between the acetabula. starting just posterior to the anterior corner on one side and

In the interior

view of the pelvis the pubes meet at an is

not reflected in the edge

not well marked; the ridge and

of the deflected portion. The everted anterior portion

and disappear as they pass

of the pubis must be the area of origin of the

the grooving diminish

puboischiofemoralis internus muscle in Eoscopus.

anteriorly.

The midline joint is best observed on HQ 123 A, in which the contact is exposed. The halves of the puboischiadic plate originally met at an angle slightly greater than a right angle. The union between the

Fig. 13.

half

Eoscopus lockardi, gen.

et sp. nov.

internal surface. Right: the left external surface.

The

The

cast of

HQ

123B, showing the external side

of the pelvis, has two large, round obturator fo-

ramina in the expected position. They are not visible on

HQ

123 A in a position opposite that of the outer

pelvic girdle, from casts of

HQ

123 A and B, x

3. Left:

the right

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI)

19

Ap-

HQ 250G and H. The wrists and ankles are unossified on HQ 55 A. The nine bones probably do not make

parently the canals run anterodorsally to open ante-

up the complete carpus, because Olson ( 1 94 1 ) found

openings. Instead, two large foramina are visible on the downturned, anterior borders of the pubes.

riorly.

The pubes of Eoscopus

are similar to those

1

eleven in the carpus of Acheloma cumminsi (as

The element

described for Eiy ops (Case, 1911), considering their

Trematops

difference in width.

metacarpal most likely

Forelimb.

—The

humerus

ends and has a

is

moderately ex-

milleri).

humerus can be seen on HQ 250H (Fig. 14) and 641 (Fig. 11). Poor ones are present on HQ 551 A. The plane of the distal end of the humerus is

and

rotated about 45° with respect to the plane of the

ing.

proximal end of

HQ

rotation in the

humerus of

250H. There seems

to

be

less

lying with the first

first

distal carpal, last

two

may be the fourth. The three bones just distal to the radius may be the ulnare, fourth centrale,

panded with a round cross-section. Good examples of the

definite, if short, shaft

the

whereas the small nubbin between the metacarpals

at its

is

radiale, with the small

missing. distals

The other four

intermedium considered

carpals are interpreted as

and centralia, with one of their number miss-

The four metacarpals can be observed on both

HQ 641, but this may be the result of flattening.

The ends

of both bones are smoothly

rounded without processes or

A

deltopectoral

crest projects

from the ante-

condyles.

rior edge of the at right

humeral head

angles to the axis of

the bone. This feature

is

a

more prominent on the smaller humerus (HQ 641)

little

than the larger

The bone

is

(HQ

250H).

otherwise fea-

tureless except for fine lon-

on the

gitudinal grooves

sur-

face of the head.

The

distal portion

forelimb

is

of the

present on

250H and 551 A. The

HQ ulna

bears an olecranon on the

HQ

250H;

this is uncertain in the

case of

proximal end of

HQ

551 A. The radius and

ulna are equally thick and

long

if

the olecranon

considered.

is

not

The radius and

ulna bow slightly toward each other as they lie on

HQ 250H.

A keel runs down

the poste-

rior face

of the ulna, from the

proximal end of the olecra-

non

to the distal end.

Nine wrist bones are present on casts made from

Eoscopus lockardi, gen. et sp. nov. The forelimb. from HQ 250G and Above: humerus, ulna and position of natural molds. Below: radius, and metacarpals, from casts.

Fig. 14.

H, x

3.

carpals,

KANSAS MUS. NAT.

UNIV.

20

HQ 250G and H and 551 A. The and

the thickest

is

is

intertrochanteric fossa, in passing from the internal

about two thirds as long as the

trochanter to a terminus slightly closer to the poste-

others. Metacarpals

more

gressively

third.

The

first

metacarpal

two through four become pro-

They

slender.

which bends

for the fourth,

are straight, except

towards the

slightly

third metacarpal has a smaller distal

end

HQ 55 is

finally

flange diminishes in height dis-

blends into the shaft

the triangular popliteal concavity.

A, both front feet are superimposed. Thus

more rounded, except

1

it

appears to have a rather blunt forefoot, with short

A It

terminal phalanx

unobscured on

is

narrows abruptly from

its

Hindlimb.

—Good examples of

with specimens

250H and

KUVP 4949

1

,

HQ

articulation, as if

form a claw, but instead ends with a and

slight bulb.

femur are

the

HQ

1

apex of

at the

On the dorsal side

of the distal end, the intercondylar fossa extends the posterior condyle

not possible to count the phalanges, but Eoscopus

55 1 A.

and

tally,

HQ 250, only one phalanx is present, and on

digits.

to

The

rior condyle.

about a fourth of the length of the bone. In end view,

than the others. All the metacarpals are short.

On

HIST. MISC. PUB. No. 85

23 A and B,

is

square and the anterior one

for a projection

femur

the

straight

is

on the

marking the

The distal end of

anterior side of the popliteal space.

shaft, or nearly so,

Eoscopus was probably able

to

and

completely extend

its leg.

Good specimens

HQ

of the tibia and fibula exist on

123 A and B, 252, and 431. Both bones have

widely expanded ends, except for the

end of

distal

the tibia,

which

been prepared with acetic acid and the other two

more modestly enlarged with a flat oval cross-section. As is typical in lower tetrapods,

have had the damaged bones removed from the

the tibia

and fibula

fibula

shorter than the tibia in

matrix and

I,

252, and 43

1

.

Three specimens have

made of the

silastic casts

spaces where

they lay to allow observations of their intact sides.

The

Perhaps the best femur

three

is

that of the casts of the part

is

fibula

is

bow toward

measured specimens; however,

(HQ

of the bone (Fig. 15). Hindlimbs exist on specimens

bones, the distal end of the bone

127, 253, and 551, but these are not well pre-

The proximal end of

the femur,

viewed end-on,

has approximately the shape of a curved teardrop, the posterior side of the head. Appar-

tail at

ently there are

no

distinctive features of the upper,

convex surface of the femoral head; the rugosities

on the femoral

cast of

HQ

2501 are

artifacts

preparation and the groove on the cast of is

absent from other specimens. There

internal trochanter distal to the

is

HQ

of

123B

a prominent

end of the femoral

head, projecting at almost right angles to the plane of the head. In well-ossified specimens, such as 1

HQ

23 and 250, the internal trochanter is stepped below

the proximal

end and separated by a notch. This

morphology was described (Holmes and

Carroll, 1977)

Cardiocephalus in Gregory

for Caerorhachis

and Doleserpeton et al.,

(as

1956; fide Bolt,

The adductor

flange continues the projection of

the trochanter distally along the shaft of the bone.

On

one case

is

On both

rotated about 45°

with respect to the proximal end. This feature supanteriorad. The expanded ends of the bones leave room for each other by lying at right angles; that is, the proximal end of the tibia is extended

anteroposteriorly and that of the fibula mediolaterally,

whereas the

no posterior ridge and no fourth trochanter. the two larger femoral specimens, the is

ends have the opposite relation.

distal

The proximal end of

the tibia

is

bilobed in end

view, with the posterior lobe smoothly rounded and the anterior lobe sharply angulated

cnemial

crest.

The

by a prominent

crest extends distally along the

proximal expansion of the bone, which third of

its

the tibial

An

length.

about a

head bear grooving radiating proximally.

crest running

down

the shaft. This

specimen

is

Both inner and outer surfaces of

unexpected feature of the

1

tibia is a

second

the posterior or internal side of

revealed on the acid-prepared

is

HQ 43

part of the head,

1969).

There

in

123 A and B) they are the same length.

plies half the torsion necessary to point the pes

served.

with the

most specimens.

nine tenths the length of the tibia in

is

and counterpart of HQ 123, which show both sides

HQ

each other and the

.

The

crest arises

and disappears

from the

at the distal

distal

expan-

sion of the bone. Aposterior crest has been described for the tibia of Cacops (Williston, 1910), but

it

may

not be homologous. The crest of Cacops begins at the proximal

end toward one side and has a small

fifths

hump at its midlength. Possibly these crests increase

of the length of the bone. The adductor flange

attachment area for the interosseus cruris. In modern

crosses the long axis of the bone distal to the

salamanders

intertrochanteric fossa extends for about

two

this

muscle holds the

tibia

and fibula

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI)

Fig. 15.

Eoscopus lockardi, gen.

anterior view,

HQ

et sp. nov.

123B. Right: posterior view,

The hindlimb, from

HQ

123 A.

casts of

HQ 23A and 1

21

B.

x

3. Left:

UNIV.

22

KANSAS MUS.

NAT. HIST. MISC. PUB. No. 85

together and assists in transfer of weight between

tarsus of

them (Schaeffer, 1941). The wide, flattened ends of the

little

equal areas in lateral view.

observe them end-on the fibula

is flat

in

fibula

It is

have about

not possible to

any specimen. The head of

or slightly convex in profile.

end describes an S-curve, very noticeable

distal

Its

in

(HQ 1 23 A), but more gentle in lateral view (HQ 252). This curved surface

123 A and B.

specimen provides a view of the dorsal surface only. In that

view

it is

not obvioiis that the tarsus of

or anterior

rather broad foot.

articulates with

one side of the intermedium.

A

broad groove passes distally across the high corner

(HQ

123 A), possibly marking the passage of an

to side in

for the tarsus of Trematops, perhaps because his

123 was originally arched;

and fibulare. The high medial corner of the distal end

elements are a

Schaeffer ( 1 94 1 ) did not mention such a feature

posterior view

conforms to the articular surfaces on the intermedium

Its tarsal

their ventral surfaces, indicating

whole complex arched from side

that the life.

HQ

hollowed on

it

seems only

to

HQ

have a

Individual tarsal elements differ in the details of their outlines

true for

from one surface to the other. This was

Trematops

also,

and

it

occasioned some of

Schaeffer's corrections of Williston's (1909) original description.

The type specimen affords

a view of

passes through the tarsus immediately distal to this

A good example of the resulting disagreements is the case of

point.

the intermedium.

artery connecting with the perforating artery

An

ossified ankle with the

available in the collection.

HQ

bones

which

in position is

123 A and

B

are part

and counterpart bearing a pelvis with the right hind

The incomplete bone have been removed and silastic

the plantar side rather than the dorsal.

The intermedium of Eoscopus and Trematops

is

a large bone between the tibia and the fibula, with a

toward the high

free proximal border that rises

limb, lacking only part of the foot.

medial corner of the

remains of the

the fibula, tibia, fibulare, and fourth centrale.

made

casts

two

sides.

for study

The

from the impressions on the

posterior side of the tarsus

played on the cast of HQ

on the cast of HQ 123B

1

is

dis-

23 A, and the anterior side

(Fig. 15). Part of

also bears an ossified tarsus,

HQ 250H

which was prepared

in

fibula. Its other

Williston (1909) described the intermedium of

Trematops without mentioning the with a large facet contacting the

tibia is plain in anterior

Eoscopus resembles

that of

tibia, to

when both

specimens available. tarsus of

but

which it was

apparently ligamentously attached. The source of the error

The

tibia,

Schaeffer (1941) described and figured the bone

same way, but it is disarranged and incomplete. The tarsus was unossified in all other hindlimb the

borders contact

is

revealed

sides of a similar

ankle are examined. The facet for attachment to the ible in posterior

view (HQ 123B) but

view (HQ 1 23B ).

invis-

In both views, the

Trematops, as described by Schaeffer (1941). The

intermedium has a

name Trematops is now considered synonymous with Acheloma (Dilkes and Reisz, 1987) but it is convenient for Williston's and Schaeffer's name to be used in this section. The tarsus specimen was

perforating artery in the border toward the fibulare.

provided by E. C. Olson, then of the University of

thought that there was a gap between the intermedium

Chicago;

and the

it

is

not further identified.

Apparently the pretarsale present on the medial side of the ankle of

Trematops

is

lacking in Eosco-

pus. This bone cannot be seen and there for

it

to articulate

centrale.

is

no space

with the distal end of the

On the whole however,

first

rounded notch for the

This must be a real difference between Eoscopus

and Trematops, because neither Williston nor Schaeffer found

it

in the latter,

although Williston

fibulare.

In plantar view, the fibulare of

rowest

at its distal

end rather than

the fibula, as reported

view

in

Eoscopus

at its

is

nar-

contact with

by Schaeffer for the dorsal

Trematops. Otherwise

it

conforms

to the

(1923) described the carpus of

same exception as that noted for the intermedium. The proximal end in posterior view has a marked step cut into the medial corner. When the fibula, fibulare, and

as being originally arched, but flattened

intermedium were naturally aligned a gap existed

it is

appropriate to

describe the tarsus of Eoscopus by comparing

it

with

Schaeffer's account.

Gregory

Eryops

definite

et al.,

before fossilization; this also

is

the situation with the

description of Trematops, with the

between them

at this corner,

such that

it

continued

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI) by the notch

the space enclosed

On

in the

intermedium.

the dorsal side of the fibulare, a notch cut in the

third tarsale,

23

whereas the ventral surface

is

a

little

hollowed proximodistally.

border matches that in the intermedium, such that

Largest of the tarsalia is the fourth, as in Trematops.

the fibula does not participate in the rim of the

Unlike the relations described for Trematops, the fourth tarsale of Eoscopus does not contact the fifth

passage on the dorsal side of the ankle.

The it

is

tibiale is like that

much

narrower.

It

of Trematops, except that

metatarsal, or any metatarsal other than the fourth.

articulates with the

Its

first,

greater width overlaps toward the third metatar-

second, and fourth centralia.

sal,

The fourth centrale, the widest bone in the tarsus, most clearly shows the arch of the ankle in plantar

contact.

view. An end view of this bone

centrale,

of

HQ

250H,

in

which the

thickness of the bone, and

The fourth

evident.

is

possible on the cast

axis of the arch, the

its

articular surfaces are

centrale resembles that of

Trematops. Ventrally, the centrale gular, but larger

on the

Williston; dorsally,

its

is

nearly rectan-

edge

is

The

of the fourth tarsale

tibial side

convex curve

a long

is

that borders the third tarsale, third

and fourth

centrale. Contact with the fifth

and

tarsale is short

The proximolateral

straight.

corner of the fourth tarsale appears truncate, bestraight and two slanting fibulare. The line of

cause the articulation with the fibulare

is

diagonal, matching the inner of the

shown

in

faces on the distal end of the

V-shaped

to

contact on the tarsale

tibial side, as

distal

but the distal corner of the third tarsale prevents

everted, so that the edge

is

is

provide two articulation surfaces, as described in

raised and the articular surface faces slightly dor-

Schaeffer. In Eoscopus, the fourth centrale contacts

sally (covered in life

by the

fibulare). Inspection

Schaeffer 's Figure

shows

that Trematops' fourth

the tibia, as Schaeffer said

probably did in

it

1

When

Trematops.

tarsale

The other three centralia differ in details of shape from the descriptions of'Trematops. The first centrale

the lateral side

of Eoscopus

is

portion near the fibulare

between the

tibiale

centrale

is

narrow and elongated to fill the space

and the

first tarsale.

narrower mediolaterally

in posterior view, to

form with the curve of the ankle. The

con-

third

and

smallest centrale deviates from a square only in that its

proximal edge rises toward the fibular side in

The

is

fifth tarsale is

narrow-headed

seen in plantar view,

quite different: the distolateral

is

corner of the tarsale

The second

almost square in anterior view, but a little

also like this.

is

fifth

rounded and everted, and the is

slightly cornered.

narrow

match the becomes wider

distally, to

metatarsal.

It

proximally by enlarging laterally until

remaining half of the

slants ventromedially, along with the lateral sloping

facet of the distal

end of the

everted on the

fibulare.

contact

centrale.

fourth. In plantar view, the fifth tarsale

The shapes of the first two tarsalia of Eoscopus closely match those depicted for Trematops by Schaeffer. The first tarsale is a little squarer than in Trematops. It is slightly hollowed dorsally, proximodistally rather than from side to side. Its ventral surface is not preserved. The second tarsale is shorter than that depicted for Trematops, and the

dorsally, everted, or hollowed.

The third tarsale of Eoscopus is more complex in shape.

Its

edge

fibular

is

strongly concave, en-

croached upon by the fourth with the second tarsale

border

is

centrale.

centrale

concave rises

but the proximal

to articulate with the

The proximal edge and

tarsale. Articulation

is straight,

toward the

is

second

distal to the third

tibial side.

There

is

a

slight central depression in the dorsal surface of the

covers the

it

proximal face

fibulare. Its

dorsal view, to follow the lower edge of the fourth

smallest of the series in Eoscopus.

of

is

Consideration of

all

The

fifth tarsale, as it is is

line

not wider

the tarsalia leads one to

believe that the shape of the tarsus of Eoscopus

more complex than ity

must

exist at

of

on the

a simple arch.

is

A dorsal concav-

each side of the more

distal part

of

the ankle. This interpretation accounts for the dorsal

hollowing of the

first tarsale,

and the everted proxi-

mal articular surfaces of the fourth and fifth tarsalia. The physical traces are considerably more marked laterally on the ankle because the long straight fibulare concentrates the curvature. The peculiarities

of the plantar surfaces of the tarsalia are not

readily explained.

The metatarsals casts of

HQ

dorsal and

are best observed

on

the silastic

123 A and B, which display them

ventral views.

KUVP 804

1

2

and

in

HQ 232

UNIV.

24

KANSAS MUS. NAT.

provide another view of the first two metatarsals, not

HQ

wholly preserved on the

metatarsal

first

is

123.

thickest

On

these specimens

and about two

the length of the others, the fourth metatarsal

thirds is

the

longest, and the fifth has smaller ends than the others.

The metacarpals

are

metatarsals, as can be verified

ments of

HQ

250.

As

is

70%

as long as the

HIST. MISC. PUB. No. 85 delicate ends.

langes of Branchiosaurus

cf.

Micromelerpeton are known

to

the hindfeet of Escopus are longer than

its

skewed medially,

as if the twist neces-

sary to point the foot anteriorad could not be pro-

vided entirely by the ankle.

The phalangeal formula of the pes of Eoscopus is 2-2-3-4-3. This was determined by inspection of the acid-prepared

specimen

HQ

252

same formula has been reported (Broili and Schroder, 1937)

(Fig. 16).

The

for Micropholis

and f"or Micromelerpeton

and Branchiosaurus (Boy, 1972).

DeMar

(1968)

was 2-3 4 4 influenced by Trematops. The pes of

said that the formula for Dissowphus 2,

but his judgment

may have been

that given by Schaeffer for Dissowphus, shown in DeMar 's Figure 17, can be interpreted more plausibly as 2-2-3-4—3. The pha-

langeal formula of Escopus appears to be

among temnospondyls. As

common

with the front toes, the

terminal phalanges of the hind toes have slender.

Fig. 16.

Eoscopus lockardi, gen.

et sp. nov.

may

be

A

reconstruction of the possible appearance of

Eoscopus

in life is

presented in Figure 17.

forefeet.

123, the metatarsals are not quite straight, but

are slightly

slightly en-

widespread.

The heads of the metatarsals are marked on both sides with a few short longitudinal grooves of varying depth. As can be seen from either of the casts of

HQ

straight

B. petrol ei and

have

larged ends (Boy. 1972). This toe form

by making measure-

typical of temnospondyls,

These are not clawlike, but are

and knobbed rather than pointed. The terminal pha-

Amphibamus Cope 1865

is

The coal-swamp amphibian genus Amphibamus composed of three known species from three

different Westphalian

D localities (see Fig.

1 ).

Speci-

mens of A. /vW//(Wyman, 1858) from Linton. Ohio, and A. grandiceps Cope 1865 from Mazon Creek Illinois,

were examined.

Amphibamus has been

carefully described from

detailed, articulated specimens.

Wyman

published a preliminary note on this

chian" found

at

with the genus

Linton.

Many

Amphibamus

856)

( 1

new

first

"batra-

authors have dealt

subsequently, includ-

ing Cope, Moodie. Romer. Steen.

J.

Gregory.

T.

Watson, Carroll, Bolt, and A. R. Milner. Modern descriptions are

Watson ( 1940, ,4. grandiceps). Gre-

gory (1950; A. grandiceps), Carroll (1964,

A

lyelli).

Bolt (1979. A. grandiceps), Milner (1982. A.

and A. grandiceps) and Hook and Baird

(

lyelli

1984. A.

lyelli).

The two American species were studied from

The ilium and hindlimb.

HQ 252, x 2.5.

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI)

Eoscopus lockardi, gen.

Fig. 17.

et sp. nov.

Reconstruction of appearance in

The holotype of A.

casts of natural molds.

lyelli,

25

HQ 551, x 0.875.

based on

life,

taxonomic importance. However, a number of inter-

AMNH 6841, was made available as a plaster cast

esting features, previously

from the original coal block, showing the dorsal side

ered and the following description has therefore

of the animal. lateral

A latex cast of AMNH 2002 shows a

been broadened.

view of the posterior body and anterior tail of

a larger individual.

USNM

4461, a block of coal

bearing an impression of the posterior trunk and a leg, was loaned for study. The A. grandiceps specimens examined were

hind

three split Mazon Creek concretions, each showing most of a small individual in part and counterpart. They include YPM 794, the neotype (Fig. 18); YPM

795, the type of Mazonerpeton; and

FMNH UC

unknown, were discov-

Skull. is

much

—The quadrate

of Amphibamus grandiceps

like that of Doleserpeton (Bolt, 1968).

best viewed

on the

UC 2000, where the lower jaw does not cover 19). its

It is

FMNH

right side of the skull of

it

(Fig.

The quadrate has a prominent dorsal process on

exposed medial corner, with a groove running up

the posterior side

may be

and over the end (Bolt, 1979). This

YPM 794 also. The

seen on the right side of

medial condyle

is

almost a mirror image of the

2000, the type of Miobatrachus. The two Yale nod-

dorsal process. In posterior view the quadrate

ules were prepared for silastic casting

shaped, with the arms facing medially, such that the

removal of

their mineral infilling,

by complete

exposing clear

Amphibamus specimens fall into The largest A. grandiceps (YPM 794) the size of the smallest A. lyelli

size classes. is

about half

(AMNH 6841). All

the nodule skeletons are of juveniles, although

postmetamorphic (Carroll, 1964; Bolt, 1979). Despite their

age difference and their great similarity,

the specimens represent

ing features include the

two species. Differentiatnumber of teeth and the

vertebral count (Carroll, 1964). Milner (1982) adds that A.

grandiceps

that A. lyelli has a

skull of a

articular surfaces face slightly outward.

quadratojugals of

impressions.

is

smaller at metamorphosis, and

wider

young A.

skull.

lyelli

His examination of a

made

his distinctions

possible.

FMNH UC

2000 have a

is

Y-

The

straight

medial border with no sign of a posteromedial

YPM 794, however,

process on either side. this character

on both

sides.

shows The posteromedial

process in A. grandiceps covers part of the posterior side of the dorsal process of the quadrate, rather than

embracing

it

as in Eoscopus.

The quadratojugal

does not contribute to the condylar surface, contra

Watson (1940), but

as observed

by Bolt (1979).

A ventral prefrontal process is visible in the right orbit of

AMNH 6841.

area are not certain.

Other features of the

A

laterally

orbital

exposed palatine

may be present in the ventral rim. Another character diagnostic of the Dissorophoidea. the supratym-

Because Amphibamus was previously described,

panic flange, has never been observed on Amphiba-

my original intent was to only point out characters of

mus. The preservation of available specimens does

UNIV.

26

KANSAS MUS. NAT.

HIST. MISC. PUB. No. 85

Amphibamus grandiceps Cope. The neotype,

Fig. 18.

YPM 794, x 4. A cast of the dorsal impression.

YPM 794 the dorsal process was leaf-shaped; on

not permit inspection of the dorsal side of the otic

of

notch.

the right

it

had a medial point and a lateral lobe

(Fig.

FMNH UC

20).

The

depicted for the American species of Amphibamus

2000 bears an impression similar to the left nasal of YPM 794 (the

(Milner, 1982:fig. 3). Examination of the cast of

right

is

AMNH 6841

the dorsal processes

Dorsal processes of the premaxillae have been

revealed narrow, sharp processes on

either side of the muzzle. skulls

On the two A.

grandiceps

examined, the dorsal parts of the premaxillae

are not preserved, but the slots they

are observable

on the nasal bones.

once lapped into

On

the left nasal

left

nasal of

damaged). In

FMNH UC 2000, the points of were joined across the midline

by thinner extensions of the premaxillae; possibly a The form of the right premaxilla of YPM 794 has been described for Platyhystrix (Berman et al., 1981) and is depicted on

juvenile characteristic.

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI) the right side of the

muzzle of Micropholis

(Broili

and Schroder, 1937).

A nearly complete palate is visible on YPM 794 FMNH UC 2000. All of the dermal bones are

covered with denticles except the anteriormost part of the vomers. Denticulated skin

is

absent, unlike

it was unossified except bony cover. On the left, the internal process of

pression, indicating that for a

and

27

the pterygoid

is

a narrow hollow cylinder laterally.

The cylinder enlarges to match the wide oval of the opposite side of the joint. The concave internal surface of the internal process of the. pterygoid

The epipterygoids of A.

the palate of A. lye Hi (Carroll, 1964). Tubercle-

faces posteriorly.

bearing platelets described by Steen (1931, as

grandiceps are ossified with large ventral ends. As

Platyrhinops) were also absent. This does not

mean

that such a covering was not originally present, or

that

might not appear

it

The parasphenoidal teriorly

later in

ontogeny.

denticle field continues an-

on the rostrum, borne on a raised

strip that

conforms to the width of the bone. The denticle field terminates in a point. A. grandiceps specimens have a groove for the internal carotid that crosses the base

of each basipterygoid process, resulting in sharp borders on the denticle

field.

Each groove becomes

a canal into the braincase, just posterior to the basal articulation.

An

denticle field

indentation in each side of the

marks the position of these canals.

YPM 794 bears a vomerine fang on the anterior end of one internal naris, but not on the other. A fang is

present on each palatine and ectopterygoid. In

contrast,

FMNH UC 2000 has three small fangs or

large denticles

on

the anteromedial rim of each

There are no palatine or ectopterygoid The row of palatine teeth described by Watson (1940) is present, as confirmed by Bolt (1979). There are additionally three more palatine teeth on internal naris.

fangs.

the opposite side of the palate, close to the maxillary series.

when

The

palatine

intact, set

row included

eight to ten teeth

along the contact with the maxilla.

Change with age

most plausible explanation for the difference between YPM 794 and FMNH UC 2000 (Bolt, 1979). Similar ontological change apis

the

parently occurs in A.

lyelli as

well (Milner, 1982).

Details of the basal articulation are well pre-

served on the two nodule skulls (Fig. 21). The internal process of the pterygoid

and the basiptery-

goid region of the parasphenoid are seen in near-life

in

Eoscopus, they could not have participated

di-

rectly in the basal articulation.

A reconstruction of the basal shown

lyelli,

in Carroll's

articulation of A.

Figure 22 (1964), re-

sembles the morphology in A. grandiceps. The accompanying text stated that the relevant areas of the best available specimen were damaged and that the reconstruction was made using Tersomius from Archer City. Tersomius is depicted in Carroll's Figure

4.

Milner (1982) presented the palate of

juvenile A. lyelli with a conventional reconstruction

of the articulation;

i.e.,

a right-angle rather than

oblique contact. Thus the configuration of the basal articulation of A. lyelli

is

undescribed and

still

unknown. Vertebrae.— Carroll (1964) stated that AMNH 6841 has 25 presacral vertebrae and this has been verified.

YPM 794, the neotype of A. grandiceps, FMNH UC 2000 seems to have

has 20 presacrals.

20 presacrals, as Watson (1940) thought For

my

count of

sacral as the last vertebra with a

did Watson), because

my

it

might.

FMNH UC 2000, 1 identified the I

wide pedicel

(as

cannot discern sacral ribs on

cast.

In general, the neural arches of Amphibamus are as described

of A.

lyelli

by previous authors. The

atlantal arch

resembles that of Eoscopus, except that

A. lye Hi's neural spine does not slant posteriorly as

much and the arch is fused to a central element. The atlantal arch of A.

grandiceps

view on the ventral fused to

its

cast of

is

visible in lateral

YPM

794, and

large parachordal processes of

is

not

youth.

The

Amphibamus

are

centrum, possibly due to

its

2000. The

Eoscopus. The transverse processes parallel the posterior edges, which are longer

processes appear to be transverse cylinders with an

than the anterior edges. Only the dorsal portions of

positions on the left side of

FMNH UC

oblique contact. The palate of

YPM

794 affords

separated views of the pterygoid and basipterygoid processes.

On the right, the free end of the basiptery-

goid process faces anteriorly and slightly

laterally. It

consists of a projecting rim enclosing an oval de-

much

like those of

the transverse processes are preserved on

UC

FMNH

2000 and they are as Watson (1940) described

them.

The impressions of the nodule halves of YPM 794 were completely cleaned for this study. The

28

UNIV.

KANSAS MUS. NAT.

HIST. MISC. PUB. No. 85

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI)

Fig. 2 1

x

Amphibamus grandiceps Cope. The posterior palate, from casts. Left: FMNH UC 2000,

.

10. Right:

YPM 794, x 7.5. column shows

dorsal view of the vertebral

the

chain of neural arches lying in order. The neural spines, if present,

cannot be seen.

29

would extend

into the

nodule and

Many of the anterior zygapophyses

of

YPM 795. This is clearest in the posterior dorsal

and anterior caudal portions 1979:fig. 9).

graph (Fig. 23)

can be inspected and their articular surfaces are

neural arch.

unossified, as in Eoscopus.

(Fig. 23; also Bolt,

The element in the center of the photo-

may be

the inside of the opposite

view of the ventral sides of the neural arches. Im-

The pleurocentra of A. lyelli are well preserved in the posterior column of USNM 4461 (Fig. 24). This specimen was laterally compressed, causing the

pressions of the lower parts of the prezygapophyses

long pleurocentra to be flattened out onto a plane.

identified this previously mysterious vertebral se-

Their bluntly-pointed ventral extensions project

The

ries.

ventral nodule half of

The portion of

YPM 794 presents a

the arch that rests

on the noto-

chord possesses an anterior and posterior widening, delimited by a slight annular constriction. eighth and ninth arches the neural canal

On

the

is visible.

The neural canal has anterior and posterior chambers, separated by a definite ridge. These chambers are not opposite their counterparts

on the para-

chordal portion. If these are traces of resegmentation (sensu Williams, in separate

of

1

959), the arches must have formed

parachordal and neural parts. The ridges

YPM 794 may be homologous

with the vertical

ridges described within the neural canals of

Doleserpeton (Bolt, 1968).

ventral to the column, and their shape

observed. These

easily

is

pleurocentra are clearly cornered

anteriorly, as in Eoscopus.

An unflattened, disarticu-

lated pleurocentrum lies ventral to the vertebral

column on AMNH 2002. The dorsal intercentra are like those of Eoscopus. The well-preserved intercentra of USNM 446 1 show a low projecting angle on either side of their posterior edges,

where the intercentra change

their con-

tacts with the neural arches and the pleurocentra.

Articular facets for the capitula of the ribs are lacking.

The pleurocentra

in the tail of

YPM

795 are

The

The pleurocentra of A. grandiceps are clearly visible on YPM 795 (Fig. 22). In lateral view, the

dorsal portion of the caudal intercentra are broken

pleurocentra are the largest central elements and the

off on the nodule-half bearing the dorsal side of the

similar to those illustrated in Gregory (1950).

The

intercentra are reduced in comparison to

pleurocentral pairs must have a long contact ventral

skull.

to the notochord. Ventrally, the pleurocentra are

the trunk vertebrae, and

nearly as large anteroposteriorly as the intercentra.

partly cartilaginous (Fig. 23).

it is

possible that they were

The preserved

tails

of

AMNH 2002 and FMNH UC 2000 bear large, well-

Watson (1940) based his description on the nearventral view available on FMNH UC 2000, where the central elements have been rotated around the notochord. In its original condition, the column of

those of Eoscopus.

FMNH UC 2000 must have closely resembled that

are anteroposteriorly

ossified intercentra, in contrast to

YPM

795.

The haemal arches of Amphibamus resemble

On

FMNH UC

2000,their legs

expanded as they approach

the

30

UNIV.

KANSAS MUS.

NAT. HIST. MISC. PUB. No. 85 intercentra to

which they are attached. The caudal

intercentra of

AMNH 2002 appear to be fused in the On YPM

ventral midline. is

795, the

first

haemal arch

probably borne on the fourth postsacral. This also

appears to be the case

Watson (1940)

in

FMNH UC 2000.

identified the very large,

nant central elements of the anterior

domi-

FMNH

of

tail

UC 2000 as pleurocentra, because of their rhombic shape.

tempting to identify them as intercentra,

It is

because of the prominence of the the intercentra

immediately posterior to them. Examination of the region of

tail

YPM

795 revealed large cylindrical

elements. In this specimen, these elements are best identified as pleurocentra, because they are

domi-

nant posteriorly; furthermore, only pleurocentra

extend the

height of the notochord. Restudy of

full

FMNH UC

2000 shows

that the large central ele-

ments are incomplete cylinders sally

and have a

open dor-

that are

slight angulation to their anterior

edges. Therefore, the large central elements in the anterior

of

tail

pleurocentra, as

Ribs.

—A.

FMNH UC

2000 probably

are

Watson thought.

lyelli

has short ribs throughout the

ribs begin on the Absence of axial ribs is related to the position of the occiput, which is considerably ante-

column. Three pairs of shoulder third vertebra.

jaw

rior to the

articulation.

The shoulder

ribs are

thicker than those posterior to them, with double

joined heads and expanded ends. Unlike the shoulder ribs of Eo scopus, they are not noticeably longer

than the other

ribs.

Two

pairs of transitional ribs

follow (see Fig. 23 in Carroll, 1964). rib

and one

transitional rib can be seen

so A. grandiceps probably

der ribs are preserved on

was

One shoulder on YPM 794,

similar.

Two

shoul-

YPM 795.

Typical mid-dorsal ribs are slender, slightly curved, and square-ended.

heads joined by a

The

web

They have two

of bone

distinct

(FMNH UC

2000).

flanges described by Carroll are visible only on

the large specimen,

USNM

4461

(Fig. 24).

The

square ends of the dorsal ribs indicate cartilaginous continuations in the living animal.

nodule from

Mazon Creek

had preserved ule

is lost

(1916).

An Amp hibamus

(the Daniels

The nodMoodie

(Gregory, 1950), but figured in

The apparently long

ribs of the Daniels

specimen previously caused confusion

onomy

specimen)

rib extensions (Hay, 1900).

in the tax-

of Amphibamus.

The tapering, pointed lumbar ribs are

best

shown

1

.

A NEW AMPHIBAMID GENUS (AMPHIBIA: TEMNOSPONDYLI)

31

head and has a prominent knob or excrescence on the dorsum of the angle (Fig. 24).

The unfused knob

rough or incomplete

is

on the side toward the specimen shows flattened.

2002

is

The

USNM 4461

visible sacral rib of

and

AMNH

also angled distal to

is

A poorly

can be seen on

A

The other

shorter and thicker than those of

the head. rib

ilium.

that the ribs are slightly

preserved right sacral

AMNH 6841

well-preserved sacral rib of A.

grandiceps

is

visible

on

YPM 794 on the

dorsal half-nodule. This rib

is

flattened in

and uniformly

the plane of the rib heads

curved from end to end. Another example Fig. 23.

Amphibamus grandiceps Cope. The

vertebrae in an

anterior caudal

is

SEM photomicrograph of a cast, lateral view, YPM

795, x 30.

halves.

on the cast of USNM 446 1

(Fig. 24), as described

by

YPM

preserved on

795, divided

longitudinally between the It

is

more strongly curved than

that of

YPM 794. have FMNH UC 1

Carroll (1964). Their elongated, joined heads ex-

not been able to identify sacral ribs on

ceed the length of the transverse processes, and the

2000.

heads must have articulated with the intercentra, although there are no visible facets for them.

Both

sacral ribs of A. lyelli are visible

on

USNM

two nodule

deeper dorsoventrally and

Carroll (1964) found five postsacral ribs side of

Two

AMNH 6841,

caudal ribs

lie

with the

along the

last

tail

on

These

edgewise one shows a definite angle just distal to the

length and are straight-shafted distally.

curved

in the

short.

AMNH 2002.

4461, one edgewise and the other broadside. The

ribs are

on one

one very

proximal third of their

*±FK** ~W>

i

\ \ \ 1

Fig. 24.

4461, x

3.

Amphibamus lyelli (

Wyman). A cast of the lumbar vertebrae and ribs, sacral rib. and half pelvis of USNM

UNIV.

32

KANSAS MUS. NAT.

A few caudal ribs are present on YPM 794. Those that seem to be in place are angled posteriorly and stand away from the tail at a 45° angle. Distal to the

head, the caudal ribs are straight-shafted. last pair

on

visible

is

FMNH UC

short and smoothly curved. visible as well,

A

is

third-to-last rib is

as long,

and

—The

pectoral girdle has been so well

described by others that there

is

very

added. The well-preserved clavicle of

2000 resembles

that of Dendrerpeton

figured in Carroll is

more

(

1967a:fig. 12C).

Eoscopus

like that of

mentation, although

in

little

to

is

shape and orna-

is

narrow and it.

YPM 795, lying near the

preserved on

950) believed

it

to

be part of the ventral plate, but

Moodie (1916) an ilium. The dorsal

further preparation revealed that

was correct

in identifying

part of this ilium

is

FMNH UC 2000.

it

as

twice as long as that preserved on

It is

a flattened rod with a posterior

edge or crest. At midlength the ilium curves dorsally

and

The

blade in A.

iliac

lyelli

is

straight, tall,

uninfected, and widens dorsally. Each of the three ilia in

the collection

is

individually recognizable.

Those of AMNH 6841 and 2002 are inclined a

little

posteriorly relative to the ventral edge of the pelvis.

AMNH near

its

2002

is

narrow, even diminishing slightly

dorsum, whereas

idly dorsally.

On

AMNH 6841

widens rap-

USNM 4461, the iliac blade rises

posterior to the acetabulum and has a distinct £/7^

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CO

CO

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