THE MICROSAURIAN FAMILY TUDITANIDÆ, FROM THE COAL MEASURES OF OHIO AND
PENNSYLVANIA.
=Family TUDITANIDÆ Cope, 1875.=
Cope, Geol. Surv. Ohio, II, pt. II, p. 357, 1875.
Lizard-like microsaurians; cranial elements strongly sculptured
with pits or grooves or almost smooth, with weak punctulations.
Orbits usually well forward; squamosal sometimes excluded from the
parietal; skull hornless; teeth pleurodont, conical and sharp,
smooth or slightly plicate; clavicle of a triangular shape, which
is characteristic of all the species; vertebræ well developed and
phyllospondylous, the osseous portion being merely a hollow cylinder,
hour-glass-shaped; ribs curved, long, attenuated and intercentral;
digits clawed; ventral armature absent in all but a single species and
the association of the species is doubtful; tail moderate in length.
Three genera with 13 species included in the family. These species are:
_Tuditanus punctulatus_ Cope, Linton, Ohio.
_brevirostris_ Cope, Linton, Ohio.
_longipes_ Cope, Linton, Ohio.
_minimus_ Moodie, Cannelton, Pennsylvania.
_walcotti_ Moodie, Linton, Ohio.
_Erpetosaurus radiatus_ Cope, Linton, Ohio.
_obtusus_ Cope, Linton, Ohio.
_tabulatus_ Cope, Linton, Ohio.
_minutus_ Moodie, Cannelton, Pennsylvania.
_sculptilis_ Moodie, Cannelton, Pennsylvania.
_acutirostris_ Moodie, Linton, Ohio.
_tuberculatus_ Moodie, Linton, Ohio.
_Odonterpeton triangularis_ Moodie, Linton, Ohio.
The association of these species in the one family is provisional and will
need revision on the acquisition of new and more complete material.
=Genus TUDITANUS Cope, 1874.=
Cope, Trans. Amer. Phil. Soc., XV, p. 271, 1874.
Cope, Geol. Surv. Ohio, II, pt. II, pp. 391, 1875.
Type: _Tuditanus punctulatus_ Cope.
The genus as here defined is a somewhat composite group and it is quite
probable that some of the species here included will have to be removed to
another genus when the anatomy of the forms is better known. The species
of the genus are all moderately small, the largest barely attaining a
length of 8 inches.
There are 5 species of Tuditanus thus far known. All of the species are
characterized by the possession of a peculiar triangular-shaped clavicle
with radiating grooves, and this has been taken as one of the distinctive
characters of the genus, as well as of the family. The structure of the
cranium where known is quite uniform among the different species. The
squamosal is quite large and the supratemporal is not always closely
joined to the parietal. The species are:
_Tuditanus punctulatus_ Cope, Linton, Ohio.
_brevirostris_ Cope, Linton, Ohio.
_longipes_ Cope, Linton, Ohio.
_minimus_ Moodie, Cannelton, Pennsylvania.
_walcotti_ Moodie, Linton, Ohio.
=Tuditanus punctulatus Cope.=
Cope, Trans. Amer. Phil. Soc., XV, p. 271, 1874.
Cope, Geol. Surv. Ohio, II, pt. II, p. 392, pl. xxxiv, fig. I, 1875.
Type: Specimen No. 110, American Museum of Natural History, where there is
also specimen No. 111.
Horizon and locality: Linton, Ohio, Coal Measures.
This species, together with the form, _T. brevirostris_, described on
p. 88, was used by Cope as the type of the genus _Tuditanus_. Cope
subsequently associated some reptilian remains from the Linton mines with
the type of _T. punctulatus_ and changed the generic term to _Isodectes_,
which was known by another species, _I. megalops_ Cope, from the Permian
of Texas. The remains associated by Cope with _I. megalops_ undoubtedly
represent a reptilian species and which has been described elsewhere
under the name _Eosauravus copei_ Williston. The species is of exceeding
interest because it is the _oldest known reptile_ and places the range of
the Reptilia down towards the base of the Pennsylvanian.
The species _Tuditanus punctulatus_ Cope was founded on well-preserved
remains of nearly the entire skeleton of a single individual. The bones
are represented by shining carbonaceous matter, and since both of the
slabs containing the impression were preserved, a great many characters
have been determined. The head, 1 fore-limb, and 23 consecutive vertebræ
with ribs are well defined, but of the pelvis and hind limbs nothing is
visible.
The cranium (fig. 19) is very similar to that of _T. minimus_, from
the Cannelton, Pennsylvania, slates. It is triangular in shape, with a
narrowed obtuse muzzle. The orbit of the left side is well defined and
lies well forward. It is oval in outline and its width is about two-thirds
of its length. The nostrils are small and are located well toward the tip
of the muzzle. The parietal foramen lies behind the median transverse line
which divides the skull equally.
The cranial elements are for the most part destroyed, but the outlines of
a few can be determined. Those elements which are preserved are ornamented
with a sculpturing of minute punctulations which, on the postfrontal,
assumes a radiating arrangement. The ornamentation of the other elements
consists of inosculating pits, but they seldom assume the form of ridges
or grooves. The bones of the premaxillary region of the cranium are
lacking. The first element which can be detected is the pref rental, which
occupies a position in front of the orbit. There seems to be space for
a lacrimal, but its outline is not distinct. The frontal can be readily
separated and is seen to be an elongate element occupying the median
region of the skull between the orbits. The parietal is apparently the
largest element of the cranial roof and the pineal foramen is located in
the anterior fourth of the median suture separating the parietal elements.
The form of the postparietal and the tabulare can not be determined, as
the greater part of this region is lacking. The squamosal seems to be
located well forward and is rather small, but has the usual relation of
this element. Only fragments of the other elements remain and nothing
can be said of their form. The mandibles of both sides are represented
by depressions, and they are ornamented with longitudinal grooves and
ridges. The teeth are not preserved, but there are evidences of the
maxillary teeth. These are minute and sharply conical. Just posterior to
the skull there is preserved the impression of a short, round rod which is
not definitely determined. It may be an element of the hyoid apparatus,
although it is rather stout for such. It does not have the relations
indicated by Cope in his figure (123, pl. XXXIV, fig. 1).
[Illustration: Fig. 19. Drawing of skull and skeletal elements of
_Tuditanus punctulatus_ Cope from the Coal Measures of Linton, Ohio. ×
1.5. _fr_, frontal; _ic_, interclavicle; _cl_, clavicle; _h_, humerus;
_ph_, phalanges; _par_, parietal; _pp_, postparietal; _tab_, tabulare,
supratemporal and squamosal; _u_, ulna; _r_, radius.]
There are three elements of the pectoral girdle preserved. These
undoubtedly represent the interclavicle and the clavicles. The
interclavicle is rhomboid in shape and is attenuated posteriorly. The
attenuation is abruptly truncate posteriorly and it is thus of quite
a different character from the acutely pointed interclavicle of _T.
minimus_. The clavicle has a somewhat semicircular form, but is not
attenuated at either end. It seems to be uniformly broad.
The forearm of the right side is preserved in part. The humerus is seen
to be a heavy, somewhat expanded element lying displaced with relation
to the pectoral girdle. It is greatly expanded at the ends. The ulna
presents characters similar to the humerus and only differs from it in
being shorter and less stout. The radius is not preserved. The carpus
is unossified and its position is occupied by a blank space. The digits
are represented by 4 metacarpals, and this may have constituted the
entire number of the fingers. The phalangeal bones preserved are a little
scattered. They are elongate with expanded ends.
Evidences of 23 consecutive osseous vertebræ are preserved. Their
character can not be determined, although Cope (123) describes them as
amphicœlous. This may be inferred to be the case, but I am unable to
verify his observation. In form the vertebra are subquadrate. The neural
spines are not evident. The osseous ribs articulate, apparently, between
the bodies of the vertebra. Cope figured them as intercentral. There are
22 or 23 pairs preserved. They are single-headed and the extremities are
attenuated. No traces of ventral scutellæ are present.
The entire length of the animal probably did not exceed 5 or 6 inches.
Its form was quite lizard-like and it was probably of an ambulatory type,
though it may have spent a part of its time in the old lagoon in which
its remains were finally buried. No traces of external gills have been
detected in this or any other Linton species.
Measurements of the Type of Tuditanus punctulatus Cope.
mm.
Length of entire specimen 94
Median length of skull 22
Width of skull at occiput 19
Depth of mandibular ramus 4
Length of the 23 vertebræ 61
Length of interclavicle 6.5
Width of interclavicle 4.5
Width of the three pectoral plates 10
Length of humerus 8
Width of humerus at proximal end 2.5
Length of ulna 6
Width of ulna at proximal end 2
Length of phalanx (metacarpal?) 2
Expanse of longest ribs 16
Length of rib 10.5
Width of rib .5
Length of a vertebra 2.5
=Tuditanus brevirostris Cope.=
Cope, Trans. Amer. Phil. Soc., XV, p. 272, 1874.
Cope, Geol. Surv. Ohio, II, pt. II, p. 393, pl. xxvi, figs. 3, 4, 1875.
Moodie, Bull. Amer. Museum Natl. Hist., XXVI, art. XXV, pl. lxiv, fig.
4, 1909.
Type: Specimen No. 8609 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures.
This species was associated by Cope with the type _T. punctulatus_ in the
description of the genus. Represented by a portion of the skeleton of one
individual, the skull is preserved on one block, with a considerable part
of the anterior ribs, pectoral girdle, and vertebral column, although this
last is not clearly represented, but as in so many of the coal specimens
the bones are covered with a thin layer of carbonaceous matter which makes
it impossible to definitely determine the form.
The cranium is large in proportion to the size of the body. The skull is
in the form of a wide oval and is wider than it is long. The elements of
the skull were ornamented with a coarse sculpturing which partakes of the
nature of incomplete radiations on the squamosal region. The different
elements of the cranium can not be distinguished, although I think the
outlines of the parietal are indicated. The position of the nostrils is
well forward and they are slightly elongate transversely. The pineal
foramen can not be determined. The orbits are oval in shape and their
width is about equal to two-thirds of their length. The interorbital space
is greater than the length of the orbit. Cope's figure of this specimen is
not accurate, since he has the orbits drawn too far to the side. They are
located near the central line of the skull and resemble in some respect
those of the preceding species. Cope has described teeth in the maxillary
region, but I am unable to detect them. There are portions of two pectoral
elements which may represent a clavicle and a portion of the interclavicle.
The clavicle has much the same shape and practically the same
ornamentations as has the clavicle in _Tuditanus minimus_. The clavicle
preserved shows a somewhat triangular shape and is slightly acuminate
at the anterior end, as preserved, and obtuse at the posterior end. The
nature of the interclavicle can not be determined.
The vertebral column is represented by a line which Cope suggests (123)
may be the chorda dorsalis (notochord). Osseous vertebræ were probably
present, but their nature is obscured by the carbonaceous matter covering
them.
The ribs as preserved are long and curved. They are slender and attenuated
at the distal ends. They were probably single-headed, but whether their
articulation was intercentral or not can not be determined.
The other specimens which are referred to this species show nothing of
importance in the way of structure. They consist for the most part of
fragments which may or may not represent the species.
The species differs from the type of the genus (_T. punctulatus_) in the
possession of a broadly rounded muzzle. This character will also separate
it from other species of the genus. The sculpturing of the bones of the
cranium is coarser in the present species than in the type. The form
of the clavicle is different in the two species. The above-described
species seems to be more closely allied to the form described as Tuditanus
walcotti than to other species of the genus. I have been unable to detect
the presence of limbs, although Cope says they are present.
Measurements of the Type of Tuditanus brevirostris Cope.
mm.
Median length of skull 15
Width of skull at posterior border 18
Width of skull across orbits 11.5
Length of orbit 3
Width of orbit 2
Interorbital space 4.5
Length of clavicle 7
Width of clavicle 3
Length of longest rib preserved 9
Length of entire specimen 54
The material consists of the type specimen with counterpart and two
fragments which probably are to be associated with this species. Collected
by Doctor J. S. Newberry.
=Tuditanus longipes Cope.=
Cope, Trans. Amer. Phil. Soc., XV, p. 210, 1874 (Sauropleura).
Cope, Geol. Surv. Ohio, II, pt. II, 398, pl. XXVI, fig. 2, 1875.
Type: Specimen No. 1099 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures.
The cranium of this species is quite unknown. The only genus with
which the specimen can be compared in the structure of the skeleton is
_Tuditanus_. From the other species of the genus the present form differs
in the presence of ventral chevron rods and the elongate character of the
limbs, as well as in the possession of large iliac bones, which, in the
only other species in which the ilia are known, are small and slender. It
seems best to locate the species in this genus for the present, although
it may eventually have to be removed to another group. Very little is
known of the main portion of the skeleton of the species of _Tuditanus_,
other than in _T. longipes_, so an exact comparison is impossible. From
all the species of Tuditanus thus far known the present species differs
in the elongate character of the limbs and in the presence of ventral
scutellation. There are three other species of Tuditanus in which the
limbs are known. These are: _T. walcotti_ Moodie, _T. minimus_ Moodie,
and _T. punctulatus_ Cope. In these three species the limbs are short
and weakly developed. From the other species of _Tuditanus_ the present
species maybe separated by its size principally, since nothing of the
bodies of the other species is known.
The body of the present species is elongate and slender, with a long neck
and probably a long tail. Ribs, as preserved, are 19 to 22, though there
may possibly have been more. They are moderately curved backwards, have
intercentral articulation, are attenuated at the distal extremity, and are
single-headed. The anterior ribs are stouter, with a widened upper portion
and attenuated distal part. The posterior ribs are more slender.
[Illustration: Fig. 20. Cope's drawing of Tuditanus longipes, from the
Linton, Ohio, Coal Measures. × 1.]
There are evidences of 28 vertebræ present. All regions of the vertebral
column are present and the dorsal region is preserved entire. The
cervical series is represented by the posterior vertebræ only. These are
very indistinctly preserved. The dorsal vertebræ are elongate and were
probably amphicœlous, although this has not been definitely determined.
They are expanded at each end, thus ending in a slightly raised rim. The
single-headed ribs articulate between the vertebræ. The exact number of
the dorsal series can not be ascertained, although this may have been
25. The spines of the vertebræ are not determinable, since the animal is
preserved on its back. The caudal vertebræ are represented by two patches
of the remains of what was once probably the entire series. Cope ascribes
70 mm. to the tail, but I do not find that much. The specimen may have
been mutilated since he studied it. The caudals are slender and, like the
dorsals, are expanded at the extremities.
The scapular arch is not preserved, but the pelvic arch is represented by
the two iliac bones in good state of preservation. These are short, flat
bones expanded at the anterior extremity, as preserved. They lie turned
a little to each side of the vertebral column and partially obscure the
femora. The iliac bones are quite characteristic of this form, since
similar-shaped elements have not been observed in any of the other
Carboniferous forms from the same deposit.
The greater part of the forelimb is preserved, although much of the hand
is missing. The humerus is an unusually elongate bone and lies somewhat
across the vertebral column. It is crushed flat and the ends are partly
destroyed. It shows evidences of expansion at the ends, although not a
great deal. It is much longer than the radius and ulna, which are of about
equal length. The ulna is larger than the radius and has expanded ends,
with the upper end more expanded than the lower and both ends slightly
truncate. The radius is a simple rod of bone and is but slightly expanded.
The carpus was evidently cartilaginous, since there is no evidence of
osseous material in its place. There is but one phalangeal bone preserved,
and, since this is displaced with reference to the ulna and radius, its
position can not be determined. It may have been a metacarpal. It is short
and expanded at the ends.
The hind limbs are represented by the two femora and the upper portion
of the tibia. The femur is almost as elongate as the humerus and is more
slender. It is not so much expanded as the humerus. Its ends appear to
have been cartilaginous and do not represent the well-formed articular
surfaces preserved in the _T. minimus_. The upper part of the tibia is
preserved, and appears to have been truncate.
If this species belongs with _Tuditanus_ it is of interest in that the
ventral chevrons are present. The species is particularly characterized by
the elongate limbs.
Measurements of the Type of Tuditanus longipes Cope.
mm.
Length of vertebral column between pelvis and
end of humerus 7
Length of vertebral column anterior to humerus 18
Length of caudals present 42
Length of humerus 19
Width of humerus 2
Length of radius and ulna 12
Length of a vertebra 3
Length of ilium 7
Length of femur, estimated 18
7 chevrons in 4 mm.
=Tuditanus minimus Moodie.=
Moodie, Jour. Geol., XVII, No. 1, p. 56, fig. 10, 1909.
Moodie, Proc. U. S. Nat. Mus., 37, p. 23, pl. 8, fig. 2, 1909.
Type: Specimen No. 4555, U. S. National Museum.
Horizon and locality: Cannelton slates of Pennsylvania (Upper Freeport).
The species is represented by a nearly complete skeleton preserved on a
slab of slate from the Cannelton shales of Pennsylvania. The obverse slab
has been lost, which is very unfortunate, since there is no doubt that
the entire skeleton was originally present. The species is placed in the
genus Tuditanus on account of the close resemblance to the type form _T.
punctulatus_ Cope, although it is much smaller than that species.
The type specimen of the species did not attain a length of more than
3.5 inches. Its form is very lizard-like, but its structure is typically
amphibian. The form of the skull is especially similar to that of the
type species _T. punctulatus_, which it resembles in the narrow posterior
truncation of the skull, as well as in the anterior position of the orbits.
The skull is in the form of a narrow oval, sharply narrowed posteriorly
and truncate. The orbits are located well forward and their posterior
border lies in front of the line dividing the skull transversely into
equal parts. The interorbital space is greater than the diameter of the
orbit. Impressions of teeth are preserved on the premaxillæ and maxillæ;
there are 8 of them in a distance of 3 mm. The teeth appear to be mere
blunt denticles and were possibly pleurodont.
The elements of the cranium are very poorly preserved. It has been
impossible to determine all of the sutures. The bones of the premaxillary
region have been destroyed, but the arrangement of them was probably not
far different from that which obtains in other members of the genus. The
posterior boundaries of the nasals are preserved and prove this element
to have had an obtuse posterior border. The sutures bounding the frontals
are clear and show that they were small and that they formed a part of
the inner boundary of the orbits. The parietal is recognized as a large
element, apparently the largest in the skull. Together the parietals form
a wide oval inclosing, on the median suture, the circular pineal foramen.
The parietals are sculptured with coarse radiating grooves and ridges,
much after the manner of _Erpetosaurus radiatus_ Cope. The pittings
present on that form are, however, absent in _T. minimus_. The sutures
bounding the postparietal are tolerably well defined and these show that
element to have been rather large and quadrate, with the usual relations.
The tabulare is distinct, triangular, and small. It is produced into an
angle on the posterior border strongly recalling a similar condition in
_T. punctulatus_. The boundaries of the prefrontals and the upper borders
of the maxillæ are not clearly ascertained. The lacrimal has not been
detected. The post-frontal and postorbital form the posterior boundary
of the orbit, although all of the limits of the latter element have not
been definitely determined. The position of the supratemporal is well
assured, although its entire boundaries are not determined. It has the
usual relations and joins the parietal broadly. The jugal is broad and
widens posteriorly to join the squamosal, which, as usual, forms the
quadrate angle of the skull. The sutures bounding the quadratojugal and
the posterior end of the maxilla are not determined.
There are but two fragmentary vertebræ preserved and an estimate based
on the length of these remains gives about 30 presacral vertebræ. The
structure of the vertebræ preserved can not be ascertained, but the neural
spines appear to have been low and stout.
There are six elements of the pectoral girdle preserved. These are: the
six clavicles, the interclavicle, the coracoid of one side, and the two
scapulæ. The interclavicle is rhomboid in form and acuminate posteriorly.
It is sculptured with radiating grooves and ridges. It is quite different
from the same element in _T. punctulatus_, in that the base is acuminate,
not truncate. The clavicle presents much the same shape as does that
element in _Erpetosaurus tabulatus_. It is ornamented by a sculpturing of
radiating lines which take their origin from the lower external angle as
the bone lies in the matrix. The clavicle is somewhat triangular in shape
and lies close to the skull, but this close approximation of the pectoral
elements to the cranium is due probably to post-mortem shifting, since the
scapulæ are shifted backward. There can be little doubt, however, that
the pectoral arch was close to the cranium. There is an oval fragment
preserved on the left of the specimen which I take to be a portion of
the coracoid. The scapula is preserved entire on the left side and is
represented by fragments on the right side. It is almost semicircular in
form and narrows externally until it is somewhat fan-shaped. There appears
to be an ornamentation of lines on the surface of the bone. These lines
follow the contour of the anterior border.
The arm is preserved nearly complete on the left side, and the right
side shows the humerus and the forearm. The humeri are unusual in having
well-developed articular ends as though the endochondral tissue was
well developed. The humerus is expanded at the ends and it is larger at
the upper than at the lower end. The ulna is expanded at the proximal
extremity, but is more attenuated at the distal portion. It is shorter
than the humerus by about one-third of its own length. The radius is a
mere slender rod of bone and presents well-developed articular ends. It is
slightly shorter than the ulna. The carpus is unossified and its position
is represented by a blank space. There are phalanges of 4 digits preserved
and they are 4 in number. The phalangeal elements, like the other bones of
the extremity, have the articular surfaces prominent, with the terminal
phalanx claw-like.
There are no ribs nor traces of them preserved, and a conjecture as to
their character can not be hazarded, since they are known in but two other
species, in which they are slender and curved. There is no evidence of a
ventral scutellation, and so far as is at present known this structure
is absent from all of the species of the genus, or at least it is weakly
developed.
The ilium is all that is preserved of the pelvis. The bone itself has
disappeared and has left a depression which shows this element to have
been an elongate rod very similar to that described for _Micrerpeton_. The
sacral vertebra seems to be indicated by a depression between the iliac
depressions.
One hind limb is preserved nearly entire and the greater part of the other
is also preserved, although some of the phalanges are disturbed. The
femur is slender and more elongate than the humerus. It has well-formed,
rounded, articular ends. The tibia presents unusual characters in that
its ends are truncate, as though the cartilage composing its articular
surfaces was not so highly calcified as in the other limb bones. It
is somewhat expanded at the ends and is throughout its length broader
than the femur. The fibula, like the tibia, is a slender rod of bone,
although it is somewhat shorter than the tibia. The tarsus is unossified
and its position is occupied by a blank space. Portions of both feet
are preserved, but only one digit in the right foot is complete. The
metatarsals are elongate and slightly expanded at the ends. There are
4 phalanges present in the complete digit, which possibly represents
the fourth. The first digit is wanting, with the only terminal phalanx
preserved claw-like.
Measurements of the Type of Tuditanus minimus Moodie.
mm.
Median length of skull 15
Width of skull at posterior border 16
Length of orbit 3.5
Width of orbit 2
Interorbital width 2.5
Length of clavicle 6
Width of clavicle, maximum 3.5
Length of interclavicle, estimated 5
Width of interclavicle 3.5
Length of scapula 3.5
Width of scapula, maximum 2.5
Length of coracoid (?) 2
Length of humerus 4
Length of radius and ulna 3
Length of metacarpal 1
Length of ilium 2.5
Length of femur 4.5
Length of tibia and fibula 3
Length of foot 3.5
Length of metatarsal .75
=Tuditanus walcotti Moodie.=
Moodie, Proc. U. S. Nat. Mus., XXXVII, p. 16, pl. 6, figs. 1, 2; pl.
7; 1909.
Type: Specimen No. 4474, U. S. National Museum.
Horizon and locality: Linton, Ohio, Coal Measures.
A small species of Microsauria is preserved as a smooth impression on a
block of soft coal from Linton, Ohio. Nearly the entire form of the body
is discernible. The specimen is especially interesting and valuable as
exhibiting for the first time among the Linton forms the shape of the
body of the small microsaurians of the Tuditanus type. It differs so
markedly in the form of the skull from other species of the genus that
it is regarded as a distinct form, and the name _Tuditanus walcotti_ was
proposed for it as an expression of the writer's indebtedness to the
Secretary of the Smithsonian Institution for the vise of the material
among which the present form was included.
[Illustration: Fig. 21. A. Outline drawing of type of _Tuditanus walcotti_
Moodie, from the Coal Measures of Linton, Ohio, showing impression of body
and muscle at _M_. × 25. _cl_, clavicle; _fr_, frontal; _f_, femur; _h_,
humerus; _nos_, nostril; _or_, orbit; _par_, parietal; _rb_, rib; _pp_,
postparietal; _v_, vertebra; _pfo_, pineal foramen.
B. Left leg of second specimen of Tuditanus walcotti. × 3.]
The specimen includes, besides the body impression, the complete skull, a
right clavicle, with portions of the left, a left humerus, 12 cervical and
dorsal vertebræ, 10 pairs of ribs somewhat disturbed as to position, and a
portion of the mandible. There are no traces of ventral scutellæ nor body
scales in the smooth impression of the carbonized skin. One would expect
to find impressions of the ventral scutæ in this specimen if they were
present. Cope remarked on the apparent absence of scutellæ from members of
the genus _Tuditanus_ as they were known to him, and no contrary evidence
has since been brought to light. Until such evidence is forthcoming the
absence of scutes will be taken as one of the generic characters of the
genus _Tuditanus_. Under a magnification of 50 diameters the carbonized
skin shows as folds and wrinkles, like muscle fibers, in some places; in
others no traces of the muscular structure can be detected. The wrinkles
may be impressions of the internal musculature of the body-wall of the
abdomen. It is especially well preserved in the pelvic and pygal regions.
Sections of the coal were made, but nothing definite could be determined
as to the character of the impressions, as they were too poorly preserved
and the coal was too soft to bear much handling.
The specimen is preserved on the belly, with the dorsum of the skull
uppermost. It has been practically impossible to determine the arrangement
of any of the cranial elements except the f rentals, parietals, and
postparietals, which have the relations indicated in figure 21, A. A
median suture is clearly evident, with the pineal foramen well back in
this suture. The bones of the skull are marked with faint radiating lines.
It is in the form of the skull and the position of the orbits that the
specific characters are found, as follows: the backward position of the
eyes and the oval, pointed shape of the skull. The species is closely
related to _Tuditanus minimus_ Moodie, from the Cannelton slates of
Pennsylvania, and serves further to connect the forms from the Ohio and
Pennsylvania localities. It differs from the last-named species in the
position and form of the orbits, these structures being more oval in the
present form and placed further back. The shape of the skull differs also
in the almost entire absence of the posterior table. The median points of
the orbits occupy the line which bisects the skull, and the interorbital
width is less than the width of the orbit. The mandible is heavy and
appears to have borne sharp, pleurodont teeth.
The vertebral column is represented by little more than a mold of the
form of the vertebræ, so that little can be said of its character. The
individual vertebræ are short and hour-glass-shaped. The ribs are borne
intercentrally, as in all the microsaurians which have been studied from
the Linton deposits. The ribs are rather long and somewhat heavy, slightly
curved and expanded at the proximal end, as though an incipient bicipital
condition were present.
The right clavicle, which is preserved as an impression, is entire. Its
impression shows this element to have been ornamented on its ventral
surface with radiating grooves and ridges which started at the lower angle
of the bone. The element is distinctly triangular, which is characteristic
of the genus _Tuditanus_, so far as known. The fragment of the left
clavicle adds nothing to our knowledge of the element.
The left humerus recalls in a striking way that of _Tuditanus longipes_
Cope, and it was once entertained as a possibility that the present
form might be a member of that species, since the skull is lacking in
_T. longipes_. Sufficient specific differences were found, however, in
the ribs, which, in _T. longipes_, are very long, slightly curved, and
delicate, but which, in the present form, are comparatively heavy. Other
characters sufficiently diagnostic are found in the form assumed by the
vertebræ in the two forms.
Measurements of the Type of Tuditanus walcotti Moodie.
mm.
Length of specimen 70
Length of skull 20
Posterior width of skull 14
Width of skull, anterior to orbits 10
Length of orbit 4
Width of orbit 2
Interorbital width 3
Length of clavicle 9
Greatest width of clavicle 4
Length of vertebral column, as preserved 50
Length of a vertebra 1.75
Width of a vertebra 50
Width of body impression 15
Length of humerus 6
Median width of humerus 50
Width at end of humerus 2
Length of rib 8
Width of rib 25
The above-described specimen was collected by Mr. R. D. Lacoe, of
Pittston, Pennsylvania, from Linton, Ohio.
A second individual (No. 4481, U. S. National Museum) of this species is
indicated by a rather poorly preserved specimen on a slab of soft coal
from the Linton mines. The following portions of the animal have been
detected and will be discussed: partial impression of the skull, with a
fragment of a minute jaw, in which are minute teeth; right clavicle; part
of the impression of the body; nearly entire left hind limb; impressions
of about a dozen vertebræ, very indistinct.
The impression of the skull is distinct only in a favorable light, and
even then the boundaries of the cranium are a little uncertain. For this
reason no representation of the form will be attempted. The sculpturing
on the parietals is, however, distinct enough to show relationship with
the previously described specimen, and the form of the body impression,
the absence of abdominal scutes, the shape of the clavicle and its
sculpture, and the proportions of the hind limbs all agree with the
characters which have been assigned to the genus _Tuditanus_. The fragment
of the jaw is interesting as giving the first information as to the
character of the mandible in the genus _Tuditanus_. It is very slender and
of uniform width as far as preserved. The teeth are short, blunt cones,
apparently pleurodont.
The clavicle is of the typical _Tuditanus_ form, with the sculpturing
lines radiating out from the angle. The impression of the body adds
nothing to that already described for the type specimen. The nearly entire
hind limb is of great interest as adding another example of the phalangeal
formula. The foot is almost perfectly preserved, and the formula was
probably 2-2-3-3-2. The endochondrium of the limb bones is not highly
developed. About a dozen vertebræ are represented by molds in the soft
coal, but nothing of their structure can be determined.
The sharp, reptile-like claws in which the toes end (fig. 21, B) recall
those of _Eosauravus_ and of _Tuditanus minimus_ Moodie. It is another
link in the chain of the suggested relationship between the microsaurians
and the early reptiles.
Measurements of the Second Specimen of Tuditanus walcotti Moodie.
mm.
Length of entire body impression 75
Width across belly, maximum 16
Length of skull ?17
Posterior width of skull ?14
Length of fragment of jaw 4
Width of fragment of jaw 1.5
Length of tooth in jaw .25
Length of clavicle 8
Width of clavicle, maximum 4
Length of hind limb 22
Length of femur 8
Length of tibia (?) 6
Length of metatarsal 2
Length of first digit 6
=Genus ERPETOSAURUS Moodie, 1909.=
Moodie, Bull. Amer. Mus. Nat. Hist., XXVI, p. 348, fig. 1, 1909.
Moodie, Proc. U. S. Nat. Mus., 37, p. 21, 1909.
Type: _Erpetosaurus radiatus_ Cope.
Skull stout, elements sculptured with radiating grooves, ridges, and
pits; orbits large and usually placed far forward; occiput sometimes
with posterior table; skull more or less rounded; lateral-line canals
consisting of supraorbital, suborbital, jugal, and temporal canals,
the last two uniting to form a circular canal in one species; clavicle
triangular, sculptured like the skull.
Our knowledge of the genus is confined to the skull. The genus was
established for certain members of the genus Tuditanus and other forms
which have been recently described. The species of the genus are: _E.
radiatus_ Cope type, _E. tabulatus_ Cope, _E. tuberculatus_ Moodie,
_E. obtusus_ Cope, _E. minutus_ Moodie, _E. acutirostris_ Moodie, _E.
sculptilis_ Moodie. All of the species are from the Linton, Ohio, Coal
Measures, with the exception of _E. sculptilis_ and _E. minutus_, which
are from the Cannelton, Pennsylvania, slates.
The position of the genus as to family is a little uncertain, since family
characters are not yet well understood among the Carboniferous forms on
account of the lack of information as to the structure of the animals. If
we take the absence of the ventral scutellæ as a family character, the
genus will be in the family Tuditanidæ, but the evidence on this point is
negative. For the present we may place the genus only provisionally in the
family Tuditanidæ. The arrangement will undoubtedly require revision later.
=Erpetosaurus radiatus Cope, 1874.=
Cope, Trans. Amer. Phil. Soc., XV, p. 273, 1874.
Cope, Geol. Surv. Ohio, II, pt. II, pp. 394-395, pl. xxvii, fig. 1;
pl. xxxiv, fig. 3; text-fig. 10, 1875.
Moodie, Bull. Amer. Mus. Nat. Hist., XXVI, p. 348, pl. lxii, fig. 1,
1909.
Type: Specimen No. 8600 G, American Museum of Natural History. Locality
and horizon: Linton, Ohio, Coal Measures. (Plate 25, fig. 1.) Cope
originally described this species from a portion of a skull. He (123)
characterized the form as follows:
"The marked character of this form is seen in the very anterior
position of the orbits and the contraction of the muzzle. The orbits
are large and are separated by a little more than their own diameter;
their posterior border is in front of a line measuring the anterior
third of the length to the supraoccipital crest, and nearly to the
line marking the fourth of the length to the quadrate region. The
posterior outline of the skull is deeply concave, the quadrate angle
projecting beyond the occipital condyles."
The base of the specimen is broken and there is no place for the occipital
condyles. Unless the specimen has been mutilated since Cope studied it,
the occipital condyles are not present.
The restoration of the skull given in figure 22, B varies but little from
that given by Cope in 1875. The elements are practically as he represented
them.
The premaxillæ are small and lie in the usual relations to the other
elements. Minute conical teeth are present as impressions. They are quite
similar to the teeth found in other Microsauria. The nasals are nearly
square and form the inner boundary of the somewhat oval nostril, which is
represented by a depression in the coal. The frontal is elongate. It is
about twice as long as wide. It forms a portion of the inner border of the
orbit, the remainder being made up by the prefrontals and the postfrontal.
The parietals are the largest elements of the skull, but they do not
greatly exceed the jugals. Together the parietals form a somewhat obtuse
oval in the median region of the skull and they contain between them, in
their posterior third, the small circular pineal foramen. The postparietal
forms the posterior boundary of the skull. The pref rental forms the
anterior border of the orbit and is triangular in shape. The lacrimal
is not identified. The maxilla is an elongate element the boundaries of
which are uncertain, though probably somewhat as given. The postfrontal
and the postorbital form the posterior boundary of the orbit, inclosing
between them the anterior projection of the squamosal. The squamosal is
an elongate element and is acuminate at each end. The tabulare is a large
element lying lateral to the postparietal. The jugal is a very elongate
element, apparently acuminate anteriorly. The quadratojugal is small and
elongate. The supratemporal is definitely bounded and its limits are as
indicated (fig. 22, B), being a large element which forms the quadrate angle.
There are two other specimens of this species in the collections and a
fragment of a fourth which it is difficult to make out. Cope identified
and figured one of these as _E. radiatus_ (Geol. Surv. Ohio, II, pt. II,
pl. 34, fig. 3), but the identification is doubtful and the figure shows
structures which I am unable to identify in the specimen. Nothing of
importance is to be learned from the other two specimens, except that they
show a diversity of size. They consist of incomplete skulls, concerning
which Cope (123) remarks:
"There are no mucous canals. The sculpture consists of strong ridges
radiating and inosculating. Radiation is more uninterrupted on both
jugal, supratemporal, and anterior part of the tabulare; on the first
they originate in front of the middle exteriorly; on the supratemporal
near the anterior part. The inosculation is honeycomb-like on the
parietal, postfrontal, and posterior parts of the tabulare."
Measurement of the Type Specimen.
mm.
Length of the skull along median line (estimated) 60
Length from muzzle to quadrate angle 71
Width at posterior border 69
Width at orbits 40
Length of orbit 9
Width of orbit 8
Interorbital width 8
Length of nostrils 2
Measurements of Another Specimen of the Species.
(No. 8598 G, American Museum of Natural History.)
mm.
Median length of skull 56
Length to quadrate angle 61
Width at posterior border 50
Length of orbit 7
Width of orbit 6
Interorbital width 4.5
The specimens of this species were collected by Dr. J. S. Newberry.
Erpetosaurus obtusus Cope, 1868.
Cope, Proc. Phil. Acad. Nat. Sci., 1868, p. 213.
Cope, Trans. Amer. Phil. Soc., XIV, p. 12, fig. 1, 1869.
Cope, Geol. Surv. Ohio, II, pt. II, p. 396, fig. 11, 1875.
Cope, Proc. Amer. Phil. Soc., 1885, XXII, p. 407 (Pal. Bull. 40).
Moodie, Bull. Amer. Mus. Nat. Hist., XXVI, p. 350, pl. lx, fig. 2.
Type: Specimen No. 8601 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures.
The species, _Tuditanus obtusus_, was first described by Professor Cope
as _Dendrerpeton obtusum_, but he subsequently referred the species
to the genus _Tuditanus_. It was removed by the writer to the genus
_Erpetosaurus_ in 1909. The species is known from two partially preserved
crania. The skull elements seem to have disappeared and left only the
impressions. The sutures are, for the most part, clearly represented, but
the skull shows no sculpturing. On the posterior third of one cranium
there is a small space which seems to be slightly sculptured, as Cope
indicated in his drawing. The general form of the skull is that of a
broad oval, truncate posteriorly. The orbits lie in the anterior third of
the skull, and the pineal foramen in the posterior third. Cope compared
the skull to that of Huxley's _Erpetocephalus_, to which it has some
resemblance. The nostrils are elongate and are situated at an obtuse angle
with relation to the main axis of the skull.
The premaxilla is small and forms the inner border of the nostril. There
seem to be impressions of small teeth, but no large ones are evident. The
nasals are separated by a zigzag suture, and are nearly square. They have
the usual relations. The frontals form a portion of the inner boundary of
the orbits and unite behind with the parietals, the anterior extensions
of which they inclose. The parietals are large elements and together
form a broad oval, truncate posteriorly. They inclose between them the
pineal foramen in the median suture. It lies in the posterior fourth of
the parietals. The postparietals are elongate transversely, and have the
usual relations. The pref rental is somewhat triangular and forms the
anterior boundary of the orbit. The lacrimal has not been detected. The
maxilla is elongate, and with the quadrate jugal forms the exterior border
of the cranium. No teeth are observed on the maxilla. The postfrontal and
the postorbital form the posterior border of the orbit, and between them
inclose the anterior extension of the squamosal. The supratemporal is
pointed anteriorly and has the usual relations of that element, joining
the postorbital, the postfrontal, the parietal, the tabulare, and the
squamosal. The tabulare is larger than the postparietal and is acuminate,
the point being inclosed by the squamosal and the supratemporal. The jugal
widens fan-shaped posteriorly. It forms a portion of the border of the
orbit. The supratemporal, as usual, forms the quadrate angle of the skull.
In front of it lies the elongate quadrate jugal.
[Illustration: Fig. 22.
A. Outline of skull and cranial elements of _Erpetosaurus minutus_
Moodie, from the Cannelton slates of Pennsylvania. Original
in U. S. National Museum. × 2. _fr_, frontal; _mx_, maxilla;
_par_, parietal; _po_, postorbital; _pp_, postparietal; =pr=,
postfrontal; _sq_, squamosal; _spt_, supratemporal; _tab_,
tabulare.
B. Outline of skull and cranial elements of _Erpetosaurus radiatus_
Cope, from the Coal Measures of Linton, Ohio; partially restored.
× 0.75. Original in American Museum of Natural History, _fr_,
frontal; _j_, jugal; _mx_, maxilla; _n_, nasal; _or_, orbit;
_par_, parietal; _pf_, postfrontal; _po_, postorbital; _pr_,
pref rental; _pp_, postparietal; _pmx_, premaxilla; _qj_,
quadratojugal; _sq_, squamosal; _spt_, supratemporal; _tab_,
tabulare.
C. Palate of _Erpetosaurus_ (_tabulatus?_), from the Coal Measures
of Linton, Ohio. × 1. American Museum of Natural History, _ex_,
exoccipital; _m_, mandible; _mx_, maxilla; _pal_, palatine; _pt_,
pterygoid; _prv_, prevomer; _pd_, parasphenoid; _x_, anterior and
posterior palatine vacuities.
D. Outline of skull and cranial elements of _Erpetosaurus
acutirostris_ Moodie, from the Coal Measures of Linton, Ohio.
Original in American Museum of Natural History. × 1. _ex_,
exoccipital; _fr_, frontal; _j_, jugal; _mx_, maxilla; _n_,
nasal; _or_, orbit; _po_, postorbital; _par_, parietal; _pp_,
postparietal; _pf_, postfrontal; _sq_, squamosal; _spt_,
supratemporal; _tab_, tabulare.
E. Outline of larger part of skeleton of _Odonterpeton triangularis_
Moodie, from the Coal Measures of Linton, Ohio. Original in U. S.
National Museum. × 4. _h_, humerus; _il_, ilium?; _v_, vertebræ,
all of which are not represented.
F. Right mandible of _Erpetosaurus tabulatus_ Cope, from the Linton,
Ohio, Coal Measures. Original in American Museum of Natural
History. × 2. _art_, articular; _cor_, coronoid; _d_, dentary;
_ang_, angular; _sa_, surangular.
G. Skull elements and lateral-line canals of _Erpetosaurus
tabulatus_ Cope, from the Coal Measures of Linton, Ohio. × 1.5.
_fr_, frontal; _j_, jugal; _jl_, jugal lateral-line canal;
_mx_, maxilla: _n_, nasal; _or_, orbit; _par_, parietal; _po_,
postorbital; _pf_, lacrimal or prefrontal; _so_, suborbital
lateral-line canal; _pp_, postparietal; _pmx_, premaxilla; _qj_,
quadratojugal; _spo_, supraorbital lateral-line canal; _sq_,
squamosal; _spt_, supratemporal; _tm_, temporal lateral-line
canal; _tab_, tabulare; _so_, supraoccipital cross-commissure of
lateral-line canal.
]
_Dendrerpeton_ is not well enough known for an exact comparison with
_Erpetosaurus obtusus_, but Cope separated the latter from _Dendrerpeton_
on the position of the orbits and the broadly rounded muzzle. This species
differs from the other species of the genus in the form of the cranium, as
well as in the characters which separate it from _Dendrerpeton_.
Measurements of the Type of Erpetosaurus obtusus Cope.
mm.
Median length of the skull 48
Width of skull at posterior border 56
Width across orbits 37
Length of orbit 12.5
Width of orbit 7
Interorbital space 15
Diameter of nostril 1.5
Diameter of pineal foramen 1.75
Two other specimens, Nos. 8602 G and 8608 G of the American Museum, are
associated in this species.
=Erpetosaurus tabulatus Cope.=
Cope, Proc. Amer. Phil. Soc., XVI, p. 577 (Tuditanus tabulatus).
Moodie, Jour. Geol., 17, p. 52, figs. 8, 9, 1909.
Moodie, Bull. Amer. Mus. Nat. Hist., XXVI, pp. 347, 351, pl. 59, fig.
2; pl. 62, fig. 2, 1909.
Type: Specimen in the Zoological Collection of Columbia University.
Horizon and locality: Linton, Ohio, Coal Measures. (Plate 25, fig. 2.)
The species is known from a single well-preserved skull and its obverse in
the collection of Columbia University in New York City. I am indebted to
Dr. Bashford Dean for the privilege of studying this interesting form. It
is from the Linton deposits of Ohio. The remains include a nearly complete
cranium and a complete clavicle of the right side. The species agrees in
all essential respects with the characters of the genus _Erpetosaurus_,
presenting a broad, flat head and a triangular clavicle.
[Illustration: MOODIE PLATE 13
_Dendrerpeton oweni_ Dawson. Above: Skull, mandible, and
bones of anterior limbs. Below: Posterior limb, pelvis, and bony scales.
Nearly natural size. Erect tree, South Joggins, Coal formation, Nova
Scotia. Photograph by Dawson, published through the courtesy of Dr.
Arthur Willey. Original specimen in the Peter Redpath Museum of McGill
University.]
The cranium is wider than long, the muzzle broadly rounded. The orbits are
wide ovals, and their posterior borders fall little behind the transverse
line dividing the skull equally. The interorbital width equals the long
diameter of the orbit. The posterior outline of the cranium is truncate
in a straight transverse line between the prominent tabulare angles. The
composition of the cranium is different from that of any other species
of _Erpetosaurus_ in the large size of the tabulare and the fact that
the supratemporal is excluded from the parietal by the extension of
the postorbitals and the tabulare. This may be a generic character and
entitles the species to be placed in a new genus, but it will be retained
here until more of the anatomy of the species is known. The elements of
the anterior part of the skull are not preserved, but they are indicated
by the broken lines in the drawing (fig. 22, G). The nostrils are,
however, clearly indicated as bosses of shale. There is a mere fragment
of the nasal preserved posterior to the crack indicated by the transverse
line in the drawing. The frontal is elongate as in other species of the
genus and forms the inner border of the orbit. The parietal, as usual,
is one of the larger bones of the skull roof and the pineal foramen is
inclosed in the median suture by the two parietal elements. The pineal
opening lies in the posterior half of the parietal. The postparietal is
almost square, being slightly elongate transversely, uniting laterally
with the tabulare, with which it forms the truncate table of the skull.
The suture separating the tabulare from the supratemporal is clearly
distinct. Although such a position for the supratemporal is unusual it is
not unique, since the same character has been observed in _Diceratosaurus
lævis_ Moodie, described elsewhere (p. 120) in this paper. The postfrontal
is rather small and it, together with the postorbital, forms the posterior
boundary of the orbit. The postorbital is truncate posteriorly and joins
the tabulare broadly. The supratemporal lies posterior to the postorbital
and jugal and borders the quadratojugal, which is an unusual condition,
but what significance the condition has remains to be determined.
Posterior to the supratemporal lies the squamosal, which forms the
quadrate angle of the skull. The quadratojugal is a small element and
forms part of the lateral boundary of the skull. The jugal is a large
element and forms the entire lateral border of the orbit. There are
no teeth preserved on the fragment of the maxilla, but there are some
impressions farther forward which resemble the pleurodont denticles of the
modern Amphibia.
The sculpture of the surface of the cranial bones consists of parallel
ridges which are separated by grooves equal to them in width. The ridges
radiate inward on the squamosals and f rentals and outward on the
supratemporals. They are somewhat interrupted on the other skull elements.
The right clavicle is ornamented with a sculpture of similar radiating
grooves and ridges.
Cope described an atlas in connection with this skull, but I do not find
it. The slender impressions to the right of the clavicle may possibly
represent ribs. They are gently curved and truncate at the inner end.
A nearly complete system of lateral-line canals has been detected on
this skull. The canals preserved are: the temporal, the jugal, the
infraorbital, the occipital cross-commissure, and the supraorbital. These
terms were used for the first time for the Amphibia by the writer (458)
in a discussion of the organs and their significance in the correlation
of the skull elements. The occipital cross-commissure in the present
skull is represented by a row of elongate pits, such as Andrews (8) has
described for _Ceraterpeton galvani_ Huxley from the Coal Measures of
England. The cross-commissure is contained within the tabulare. The jugal
and temporal canals form a complete ring, much as the same canals do
in _Trematosaurus_. The supratemporal in _Erpetosaurus tabulatus_ Cope
is excluded from the parietal by the extension of the tabulare and the
postorbital, and it is to be noticed that the temporal canal has a changed
position to correspond with the changed condition of the squamosal. This
is of considerable interest in connection with the correlation of the
supratemporal in fishes and amphibians. This subject has been fully
treated in another place (458) and it will only be necessary to state
here that on the basis of the lateral-line canals and their arrangement
in fishes and the Amphibia the true correlation of the supratemporal
elements in amphibians and fishes has been made. The temporal canal in the
present specimen has, apparently, an indication of a connection with the
supraorbital canal, but of this I am not sure. The jugal canal occurs on
the supratemporal and quadratojugal, and it joins the infraorbital on the
jugal. The infraorbital is indicated by a short portion a few millimeters
long under the orbit and the remainder, _i.e._, its connection with the
jugal canal, is restored (fig. 22, G). There is, nothing unusual to be
observed in that portion of the infraorbital canal which is preserved. The
supraorbital canal is indicated by a curved, broad, shallow groove on the
inner side of each orbit. As stated above, there seems to be a connection
between this canal and the temporal, but I am not sure. The primitive
conditions shown in the lateral-line canals in _Erpetosaurus tabulatus_
Cope are the presence of the occipital cross-commissure and the ring-like
formation of the temporal and jugal canals, which is too clearly indicated
to be overlooked.
Measurements of the Type of Erpetosaurus tabulatus Cope.
mm.
Median length of skull 29
Width of skull, posterior border, estimated 37
Width between tabulare angles 18
Length of orbit 8
Width of orbit 6.5
Diameter of nostril 1
Diameter of pineal foramen 1
Length of right clavicle 13
Width of right clavicle 5.5
Mandible Provisionally Associated With Erpetosaurus tabulatus Cope.
Moodie, Bull. Amer. Mus. Nat. Hist., XXVI, pp. 351-352, pl. lix, fig.
2; pl. lxiv, fig. 3, 1909.
This specimen is preserved almost completely on a slab of soft coal.
It is impossible to determine positively to what microsaurian species
the mandible belongs, but it may, for the present, be associated with
_Erpetosaurus tabulatus_ Cope on account of its size and the character
of its sculpture. This is the first and almost the only known example of
a mandible of an American microsaurian. The form of the jaw is perfectly
preserved, although the condition of the articular surface can not be
determined.
The proportions of the mandible, as maybe judged from the table of
measurements, are rather stout and the teeth are strong and numerous.
There are evidences of 19 teeth preserved. The sutures separating the
articular (_art_), angular (_ang_), surangular (_sa_), coronoid (_cor_),
and the dentary (_d_) (fig. 22, F) are clear for at least the greater
part of their length and they may be easily restored for the remainder of
their course. The surangular is thus seen to rival the dentary in size
and on it occurs the peculiar sculpturing which approximates so closely
that on the skull of _Erpetosaurus tabulatus_ Cope. The presence of the
long anterior tooth is strikingly characteristic of many Microsauria. It
is well developed in _Sauropleura longidentata_ Moodie and _Sauropleura
(Anisodexis) enchodus_ Cope. It is also present in well-developed form
in the later labyrinthodonts. The teeth are all, with the exception of
the fourth from the anterior end, rather short, curved, and sharply
pointed, with an indication of longitudinal fluting. The arrangement of
the mandibular elements recalls in a striking way the mandible of _Eryops
megacephalus_ Cope as figured by Branson (49).
Measurements of the Mandible Provisionally Associated With Erpetosaurus
tabulatus Cope.
(No. 8542 G, American Museum of Natural History.)
mm.
Length of mandible 32
Posterior width across surangular 6
Width of dentary 3
Width of jaw at tip 1.5
Length of one of the posterior teeth 1.25
Width across base of same tooth .50
Length of long anterior tooth 2
Width of same tooth at base .75
Another specimen of this same species is 8550 G, of the American Museum.
Linton, Ohio, Coal Measures.
PALATE OF ERPETOSAURUS TABULATUS COPE.
Moodie, Bull. Amer. Mus. Nat. Hist., XXVI, pp. 352-354, pl. lxi, fig.
2, 1909.
The specimen is half a cranium with its impression. It is referred to
_Erpetosaurus_ on the basis of the sculpturing of the mandible and the
posterior table of the skull. On the surangular there is seen the rugosity
which is common to other members of the genus. The characters presented
are those of _Erpetosaurus tabulatus_ Cope, but the reference is rather
uncertain.
The specimen is unique among the known American material in showing the
structure of the palate. Jaekel (347) has figured and described the palate
of _Diceratosaurus punctolineatus_ Cope from the Linton beds. The present
palate differs from that species only in the enlarged ectopterygoid and
the smaller palatine.
The parasphenoid, in the present form, does not differ from that element
in other Paleozoic Amphibia. Its form is slender, arising from an enlarged
base and separating the pterygoids by its own width. The exoccipitals
are probably represented in the specimen and they have been indicated in
the drawing (fig. 22 C). They are rather large and extend some distance
under the base of the skull to unite anteriorly with the pterygoids, a
very unusual arrangement. The pterygoids are elongate elements and are
bounded anteriorly by the vomer and laterally by the ectopterygoid. The
vomer shows no evidence of being toothed, although it may have been so
anteriorly. The same may also be said for the palatines. The relations of
the ectopterygoids are rather unusual for the Amphibia, especially in the
posterior extension of the element. The bone lies all along the side of
the pterygoid and anteriorly projects forward between the pterygoid and
the palatine. In this unusual posterior projection the ectopterygoid has
almost obliterated the infratemporal foramen, which possibly may be still
represented by the triangular space between the bases of the pterygoid
and the ectopterygoid. The anterior palatine foramen (internal nares)
lies between the anterior ends of the palatine and the vomer, its usual
relations in the labyrinthodonts. The foramen may be recognized as the
rounded depression slightly anterior to the palatine.
The mandible is rather heavy and is coarsely sculptured with radiating
grooves and ridges. The character of the teeth can not be determined, save
to say that they were present. The posterior end of the mandible projects
somewhat beyond the quadrate angle of the skull.
The interest in the present specimen is heightened by the light it throws
on the characters for the separation of the Amphibia and Reptilia. The
wide separation of the pterygoids by the parasphenoid is an amphibian
character of undoubted value. The reduction of the parasphenoid in this
specimen is noteworthy.
Measurements of the Skull of Erpetosaurus tabulatus Cope.
(No. 8607 G, American Museum of Natural History.)
mm.
Length of skull in median line 45
Estimated posterior width of skull 50
Estimated width of parasphenoid 6
Width of pterygoid 5
Length of ectopterygoid 17
Posterior width of mandible 12
=Erpetosaurus minutus Moodie.=
Moodie, Proc. U. S. Nat. Mus., 37, pp. 21-23, pl. 8, fig. 1, 1909.
Type: Specimen No. 4545, U. S. National Museum.
Horizon and locality: Cannelton slates, Pennsylvania (Upper Freeport).
(Plate 20 D.)
The specimen on which the species is based is composed of the greater
portion of a small skull preserved in the hard shale from Cannelton,
Pennsylvania, and was collected by Mr. R. D. Lacoe, of Pittston,
Pennsylvania. The characters of the specimen had not previously been
determined, since the museum label and number had partially obscured the
snout of the skull. The skull is very small, but has the form assumed by
other members of the genus. The specimen may belong to a young individual,
but even though it does, it is, nevertheless, quite distinct from the
other species of _Erpetosaurus_. At first sight the specimen looks like a
broken scute of some larger form. Close inspection, however, revealed the
two impressions representing the orbits, and a Zeiss binocular revealed
the characters. The large size and anterior position of the orbits,
the character of the sculpturing, the presence of the posterior table
of the skull, as in _Erpetosaurus_ (_Tuditanus_) _tabulatus_ Cope, are
the characters on which a specific diagnosis is possible. The specific
characters which distinguish this form from _E. tabulatus_ Cope, its
nearest ally, are the slight development of the posterior table, the more
delicate form of the sculpturing, the more posterior position of the
orbits, and the varying shape assumed by the parietals in the two species.
Any one of these characters would be valid as a specific character.
The pineal eye is indistinct, but is observed to lie in the broken tract
in the median line of the skull, in the middle of the portion posterior to
the orbits. The interorbital space is equal to the width of the orbit. The
orbits themselves are slightly oval and not round, as in the case of _E.
tabulatus_ Cope.
The skull elements are sculptured with radiating grooves and ridges, and
on the postparietals and tabulare the grooves take the form of pits in a
row, which undoubtedly represent the occipital cross-commissure of the
lateral-line system first observed in a microsaurian by Andrews (8) in
the skull of _Ceraterpeton galvani_ Huxley. The supraorbital canal is
represented by a slight elongate depression observable over each orbit
and extending, in one case, for about 5 mm. The presence of the circular
arrangement of the lateral-line canals in the jugal region is suggested by
a depression on the posterior edge of the squamosal.
The portion of the skull anterior to the orbits is wanting, curiously
enough, just as in _Erpetosaurus tabulatus_ Cope. In the remainder of the
skull, the post-parietals, the tabulare, the parietals, the supratemporal,
and a portion of the right frontal can be detected, although the
boundaries of but three can be accurately defined. The depression bounding
the anterior outline of the skull is taken to be the impress of the
mandible, in which case this structure would be of some depth, as in the
case of the mandible associated with _E. tabulatus_ Cope, described below.
This specimen is of interest in respect to the presence of the
lateral-line canals, its small size, and its generic identity with forms
from Ohio. There is still another form known from the Cannelton slates,
described below as _Erpetosaurus (Tuditanus) sculptilis_ Moodie.
Measurements of the Type of Erpetosaurus minutus Moodie.
mm.
Length of skull 18
Posterior width of skull 17
Width of skull across orbits 14
Length of orbit 4.5
Width of orbit 3.5
Interorbital width 3.5
=Erpetosaurus sculptilis Moodie.=
Moodie, Jour. Geol., 17, No. 1, p. 61, figs. 11, 12, 1909 (_Tuditanus
sculptilis_).
Moodie, Bull. Am. Mus. Nat. Hist., XXVI, p. 347, 1909 (_Erpetosaurus
sculptilis_).
Moodie, Proc. U. S. Nat. Mus., 37, p. 22, 1909 (describes pectoral
girdle).
Type: Specimen No. 12,315, University of Chicago, Walker Museum.
Horizon and locality: Cannelton slates, Pennsylvania (Upper Freeport).
(Plate 18.)
There is preserved in the collections of Walker Museum of the University
of Chicago a small amphibian skull pressed flat on a slab of slate from
Cannelton, Pennsylvania. It formed part of the Hall collection acquired by
the University of Chicago in 1908.
The specimen presents only a portion of the skull and fragmentary pectoral
plates. The skull is wider than long and the muzzle is broadly rounded.
The orbits are narrow ovals and their posterior border falls on the
transverse line dividing the skull equally. The interorbital width is
slightly greater than the width of the orbits and about equal to their
length. The posterior outline of the skull is somewhat truncate, as in _E.
tabulatus_ Cope and other species of the genus. The distal extremities of
the quadrates do not project as far backward as do the supraoccipitals.
The skull roof is formed of the regular elements, except that a quadrate
seems to be indicated by a scale of bone on the posterior angle. The
nostrils are oval and the pineal opening is small.
The premaxillæ are apparently relatively large elements, though their
boundaries are not definite. The nasal is of an oblong shape and borders
the frontal anteriorly. The frontal forms the whole of the interior border
of the orbit and borders the parietal broadly behind. The parietal is a
large element and the pineal foramen is inclosed in the median suture
about midway of the parietals. The postparietal is wider than long and
with the tabulare forms the greater part of the posterior border of the
skull. The prefrontal (plate 18, fig. 1) apparently forms the entire
anterior border of the orbit and sends an acuminate projection to the
side of it. The maxilla is excluded from the orbit and is an elongate
element with sharp conical teeth, of which there are 4 preserved. These
measure about 1 mm. in length. The jugal lies along the lateral border
of the orbit and it is acuminate both anteriorly and posteriorly. It
borders the supratemporal broadly. The postfrontal forms the greater part
of the posterior boundary of the orbit. It is triangular and acuminate
behind, and is bordered broadly by the parietal and supratemporal. The
supratemporal is also triangular and it borders the parietal broadly.
The squamosal is evidently the largest element in the skull and on
its posterior corner there is a flake of bone which may represent the
quadrate, though this is by no means certain. The quadrate has not been
detected in any of the Carboniferous Microsauria so far studied. The
tabulare is an elongate element in the transverse line of the skull. Its
entire boundary is uncertain, though part of the sutures are present. The
quadratojugal is elongate and lies posterior to the maxilla and with that
element forms the lateral boundary of the skull.
The canals of the lateral-line system have not been detected on the skull.
The sculpturing of the cranial elements consists of grooves and ridges
which radiate from a center. They are more prominent on the parietals than
elsewhere, although the other skull elements present a strong sculpturing.
There are also preserved on the slab of slate, about 10 mm. posterior to
the skull, fragments of the pectoral plates, probably representing the
clavicles and the interclavicle. They are so badly fractured that their
form can not be determined. No limbs or vertebræ have been observed.
Measurements of the Type of Erpetosaurus sculptilis Moodie.
mm.
Length of skull in median line 20
Width of skull at posterior
border (estimated) 24
Diameter of orbit 3
Length of orbit 4
Interorbital space 4
Diameter of nostril - 1
Pineal foramen, diameter .50
Pectoral Girdle Provisionally Associated With Erpetosaurus sculptilis
Moodie.
Moodie, Proc. U. S. Nat. Mus., 37, p. 22, 1909.
The present specimen is preserved on a block of slate from Cannelton,
Pennsylvania. It is associated with the previously described _Erpetosaurus
sculptilis_ Moodie on account of its size, the geological and geographical
distribution, and the character of the sculpture. It may pertain to an
unknown species. Other remains besides the 3 elements of the pectoral
girdle are preserved on the block of slate, but they are, for the most
part, too imperfectly preserved for recognition. Some of them are
phalanges, and I believe I detect a scapula in the rounded curved plate
lying near the right clavicle. The 3 pectoral elements, the interclavicle
and the 2 clavicles, are preserved intact, with the ventral surface
uppermost.
The specimen is particularly important in that it furnishes further
evidence of the simplicity of the microsaurian pectoral girdle, which
Jaekel regarded (347) as being extremely complex, in one species at
least, _Diceratosaurus punctolineatus_ Cope. The 3 elements are broken,
but either the elements or their impressions are present, so that
identification is possible. The elements are sculptured with radiating
grooves and ridges, as in so many of the Microsauria. The interclavicle
is spatulate and bears a general resemblance to the same element of
_Metoposaurus fraasi_ Lucas from the Triassic (383) of Arizona. The
clavicles are triangular, with rounded angles and the hypothenuse on the
interior border.
[Illustration: MOODIE PLATE 14
1 and 2. Photograph of the specimen of _Amphibamus grandiceps_
Cope, from the Mazon Creek shales. × 1.5. Original in possession
of Mr. L. E. Daniels, Rolling Prairie, Indiana.
3. Specimen of _Sauropleura (Colosteus) scutellata_ Newberry, from
the Linton Coal Measures. The species was the first known of the
Ohio Coal Measures Amphibia; at first ascribed by Newberry to the
fishes, but later correctly identified by Cope. × 1. Original in
American Museum of Natural History.
4. The type of _Diceratosaurus (Ceraterpeton) punctolineatus_ Cope,
from the Linton Coal Measures. × 1. Original in American Museum
of Natural History.
]
Measurements of Pectoral Girdle of Specimen No. 4539, U. S. National
Museum.
mm.
Width across the entire girdle 17
Length of interclavicle 15
Width of interclavicle 10
Length of clavicle 11
Width of clavicle, maximum 6
=Erpetosaurus acutirostris Moodie.=
Moodie, Bull. Amer. Mus. Nat. Hist., XXVI, pp. 349-351, pl. lxi, fig.
1, 1909.
Type: Specimen No. 8598 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures.
The present species adds another form to the diversity of structure
presented by the Carboniferous Microsauria. It is closely allied to
_Erpetosaurus_ (_Tuditanus_) _obtusus_ Cope, from the same beds (Linton,
Ohio), but differs from it especially in the position and shape of the
orbits and the acute form of the skull. Other characters which amount
almost to generic significance are found in the posterior prolongation of
the frontal and in the triangular form of the skull. Only the skull of the
animal is preserved. The character which is common to all members of the
genus _Erpetosaurus_, the cranial rugosity, is present in this species on
the squamosal and supratemporal. This character alone would not, however,
suffice to separate the form generically, but the general morphology and
arrangement of the cranial elements is such that reference to any other
genus save Erpetosaurus would not be possible.
The skull of _E. acutirostris_ takes the form of a rounded triangle. Its
base is some 50 mm. in extent, and this width gradually narrows to 31 mm.
across the orbits and still more towards the snout. The form of the skull
is not widely different from that of the type species, _E. radiatus_ Cope,
but the differences are sufficiently apparent.
Nearly all the elements of the cranium can be detected (fig. 22, D). The
bony portion of the cranium has nearly all been lost, leaving only the
impression; and the matrix in which the skull was embedded has been forced
up into the sutures between the cranial elements, thus forming ragged
ridges where the bones of the skull joined.
The position of the nostrils can not be determined accurately. The orbits
are placed well forward, a character common to several species of the
genus. The interorbital space is equal to the long diameter of the eye.
The orbits are separated by narrow prolongations of the postfrontals and
by the anterior portion of the frontals. The frontals are remarkable
in their great backward extension. In _E. obtusus_ the frontals are
nearly confined to the interorbital space. The parietals, which, on the
median suture, inclose the parietal foramen, lie well posterior, and the
parietals and the tabulare are small. A portion of the sculpturing of
these elements has been preserved and it is seen to be made up of pits
and elevations much as we find in the skull of _Saurerpeton latithorax_
Cope. The left squamosal also shows sculpturing, which here tends to
take the form of grooves and ridges, and also of pits and elevations. It
is quite probable that the anterior portion of the skull was ornamented
with grooves and ridges and undoubtedly the lateral-line canals were
well developed. The postfrontals and the postorbitals are both large
and elongated. The postorbital is especially large. The supratemporal
apparently separates the tabulare and the squamosal in their posterior
extremities. The squamosal projects posteriorly to the tabulare and
apparently even goes beyond the limits of the exoccipital. The outlines of
the jugal are fairly definite, as are also the limits of the maxilla.
Measurements of the Type of the Skull of Erpetosaurus acutirostris Moodie.
mm.
Length of skull 50
Interorbital space 9
Width of orbit 7
Length of orbit 10
Width across orbits 31
Posterior width of skull 50
Diameter of pineal foramen 1
Length from tip of snout to
posterior angle of skull 65
An additional specimen shows that the skull, of which the anterior half
is preserved, is practically of the same size as the type and shows
much the same characters, though more extensively. The sculpture of the
squamosal region is not confined to that portion of the skull, but extends
throughout the cranial elements, apparently including the premaxillæ.
The sutures, which are clearly distinct, are of the same type as has been
described for the type specimen. Perhaps one of the most interesting
characters discovered on the present specimen is that of the greater
part of the left supraorbital lateral-line canal, which is exhibited as
a rather deep and broad canal running in a slight curve across the lower
edges of the postorbital and the parietals and partly cutting the jugal.
On the left of the fossil, as it is preserved, there is an indistinct
impression of the clavicle, with the sculpture in radiating lines from
the apex as a center, such as have been found in other species of the
Tuditanidæ.
Measurements of Additional Specimen.
(No. 8607, American Museum of Natural History.)
mm.
Length of skull as preserved 40
Anterior width across orbital region 22
Greatest width of the skull 33
Length of clavicle 18
Greatest width of clavicle 9
Still a third specimen of this species is possibly represented by a nearly
complete skull of a small individual which exposes the mandible and the
ventral portion of the skull. The remains are crushed flat, though not at
all distorted. It is quite possible that the present specimen represents
a distinct species, but only a small portion of the dorsum is present and
the shape of the cranium is indistinct, so it is retained in this species.
The portion of the skull shows the sculpture to be quite similar to that
of _Erpetosaurus acutirostris_, so far as the species is known; and the
skull apparently tapers to a point anteriorly. It may be a dwarfed or
immature form. The sculpturing of the jaw is such as we would expect of
this species.
The specimen is about half the size of the type. The palate of the skull
is well preserved and is extremely interesting. The sutures separating
the various palatal elements are not distinct. The parasphenoid is
especially large and the exoccipitals are partly ossified, if we may judge
by the projecting condyles. Anteriorly the parasphenoid contracts and
then expands and on each side of the expanded part lie fragments of the
palatines. To the right of the posterior end of the parasphenoid lies a
portion of the dorsal element showing the cranial sculpture.
The left mandible is somewhat displaced to the right of the skull, and
crushed and weathered to such an extent that the sutures are entirely
obliterated. There are 3 teeth, with indications of others. They are
typically pleurodont and sharp and slender. The mandible tapers somewhat
anteriorly and at the tip bears an elongate enlarged tooth.
Measurements of the Third Specimen of Erpetosaurus acutirostris Moodie in
the American Museum of Natural History.
mm.
Length of skull, as preserved 25
Posterior width of skull 15
Anterior width of skull 10
Width across occipital condyles 4
Length of mandible 25
Anterior width of mandible 2
Length of large tooth 1
=Erpetosaurus tuberculatus Moodie.=
Moodie, Bull. Amer. Mus. Nat. Hist., XXVI, pp. 348-349, pl. lviii,
1909.
Type: Specimen Nos. 8693 G and 8610 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures.
This species is based on a fragmentary cranium (plate 26, fig. 1)
consisting of the posterior part of the right side of the skull. Its
association in the genus is solely on the character of the sculpturing
of the cranial elements. It is most closely related, in the characters
preserved, to the form described by Cope as _Tuditanus radiatus_, from
which it differs especially in the character of the sculpture and in
the position of the orbits, as well as the arrangement and size of the
various cranial elements, so far as these elements can be detected in the
present specimen. In _Erpetosaurus radiatus_ the skull is sculptured by
radiating grooves and ridges which did not arise from a definite center.
In _E. tuberculatus_ this center of radiation is marked by an elevation
or tubercle on each cranial element exposed, from which the grooves and
ridges radiate outward. These tubercles have an elevation of 4 mm. above
the cranial element proper. The orbit is located near the median line of
the skull, so far as can be determined. In _E. radiatus_ Cope the orbits
are located well forward. In that species also the postparietal is smaller
than in the present species and the squamosal is longer and more slender.
(Plate 25, fig. 1.)
The fragment of a skull on which the above comparison has been made
consists of the right postparietal, a portion of the tabulare, the
parietal, the frontal, and a portion of the squamosal. The other elements
are not clear. The elements in the median line are elongate, as in
_Erpetosaurus radiatus_. The pineal foramen is located well back on
the median line and lies posterior to two-thirds of the length of the
parietals. The sutures separating the frontal and parietal elements from
each other in the median line are of the zigzag form so characteristic of
the labyrinthodonts.
Measurements of the Type of Erpetosaurus tuberculatus Moodie.
mm.
Length of portion of skull preserved 52
Width across tabulare (estimated) 60
Length of parietal 15
Maximum width of parietal 11
Length of frontal 22
Width of frontal 12
=Genus ODONTERPETON Moodie.=
Moodie, Proc. U. S. Nat. Mus., 37, p. 19, 1909.
Type: _Odonterpeton triangularis_ Moodie.
The generic characters may be found in the triangular shape of the skull,
the large size of the teeth, the shape of the vertebræ, the small size
of the orbits, and their anterior position as shown in the type specimen
(fig. 22, E). The name of the genus is derived from the remarkable size of
the teeth as compared with the size of the skull.
=Odonterpeton triangularis Moodie.=
Moodie, Proc. U. S. Nat. Mus., 37, p. 19, pl. 6, fig. 3, 1909.
Type: Specimen No. 4465, U. S. National Museum.
Horizon and locality: Linton, Ohio, Coal Measures.
The specimen described under the above name is a representative of the
smallest species of the Microsauria so far described from North America.
_Orthocosta microscopica_ Fritsch, from the Carboniferous of Bohemia,
is a rival of the present form in size, but the form described by
Fritsch is an entirely different animal and was formerly included among
the so-called Aistopoda, which are regarded by the writer as merely
specialized microsaurians. The present form shows clear affinities with
the Microsauria.
As may be seen by referring to the list of measurements, the skull of this
form measures only 6.5 mm. in length. The form may possibly be larval,
though I do not think so, if I may judge from the well-developed condition
of the skull bones and the complete ossification of the vertebræ. The
sides of the skull are equal and the occiput is a straight table, so that
the skull forms almost an exact equilateral triangle. The orbits are very
small and are placed well forward. The interorbital space is four times
that of the diameter of the orbit, a very unusual character and in itself
worthy of ranking as a generic character. The median suture of the skull
is zigzag and incloses the minute parietal foramen near the posterior
end of the skull. The relations of the elements of the skull, with the
exceptions of those of the frontals and parietals, can not be determined
with accuracy, although there are here and there indications of sutures.
The characters of the cranial elements, so far as they can be determined,
are those of the family Tuditanidæ, and the form may, for the present, be
regarded as a member of that group. The teeth are very long, slender, and
sharp, and are placed close together. There is no indication of fluting on
the teeth. They are slightly curved inward.
There are 13 vertebræ present. The centra are hour-glass shaped, and are
apparently phyllospondylous, with the notochord largely persistent. The
vertebral centra are unusually long and slender, with the ends rounded.
The humerus of the right side is preserved. It is a long, slender bone
with expanded extremities. There is no evidence of abdominal armature nor
of ribs (fig. 22, E).
The discovery of this form in the Linton deposits is of considerable
interest in that it indicates a wide range in size and character of the
fauna of the time. The forms now known from the Linton beds range from
Odonterpeton, which possibly had a total length of 2 inches in life, to
the form designated _Macrerpeton huxleyi_ Cope, with a skull of at least 8
inches in length and whose body may have attained a length of some feet.
The large rib described below undoubtedly indicates a large form of the
ancient Amphibia from Linton, as do also the vertebræ described by Marsh
in 1863 from Nova Scotia.
Measurements of the Type.
mm.
Length of animal, as preserved 18
Length of skull 6.5
Posterior width of skull 5.5
Length of side of skull 6.5
Diameter of orbit 65
Interorbital width 2
Length of tooth 0.25
Length of vertebra 1.45
Width of vertebra 35
Length of humerus 2.25
Distal width of humerus 35