THE MICROSAURIAN FAMILY SAUROPLEURIDÆ, FROM THE COAL MEASURES OF OHIO.
=Family SAUROPLEURIDÆ Hay, 1902.=
Hay, Bull. U. S. Geol. Surv., No. 179, p. 419, 1902.
The present family is an association of related forms due to similar
structure of vertebræ, ribs, ventral scutellation, and limbs. There is no
character in the skull which would indicate a separation of the genera
here included, at least in the light of present knowledge.
The family may be characterized as: Subaquatic or terrestrial vertebrates
with a typically amphibian development of the ventral armature; ribs
intercentral, as in all members of the order; skull elongate and slender
or broad and obtuse; cranial and dermal elements of the pectoral girdle
sculptured; lateral-line canals indicated in one genus, Saurerpeton; limbs
well developed, with well-developed digits and ungual phalanges claw-like;
body usually slender, broad in Saurerpeton; the ribs broad and heavy; the
vertebræ relatively stout; ventral armature highly developed, reaching
the height of specialization among the Microsauria; scutellæ consisting
of rods, plates, or stout bristles. The family is represented by 5
genera: _Sauropleura_, _Saurerpeton_, _Ctenerpeton_, _Leptophractus_, and
_Eurythorax_, the association of the last two genera being provisional.
The genera may be distinguished as follows:
I. Pectoral elements sculptured, clavicles triangular, interclavicle
diamond-shaped, ventral scutellæ rods, arranged _en chevron_
with anterior angle _Sauropleura_
II. Pectoral elements slightly sculptured, cranium broad, obtuse and
sculptured, ventral armature broad imbricated plates extending
on to the throat _Saurerpeton_
III. Limbs, skull, arches and dorsal vertebræ unknown, caudal
vertebræ with fan-shaped neural and hæmal spines which may
indicate relationship with _Ptyonius_ and _Œstocephalus_,
but in those genera the ventral armature is weakly
developed; ventral scutellæ curved rod-like plates arranged
_en chevron_ with anterior angle, marked in abdominal
region by distinct rounded pits _Ctenerpeton_
IV. Known only from fragments of the skull, teeth large and fluted;
association in family provisional _Leptophractus_
V. Known only from a single interclavicle of peculiar form which
resembles that of _Saurerpeton_; association in the
family provisional _Eurythorax_
The members of this family are confined to the deposits of the Coal
Measures at Linton, Ohio. _Ctenerpeton_, and possibly _Sauropleura_, were
highly developed swimmers, but the strength of the limbs as exhibited,
especially by Sauropleura and Saurerpeton, indicates that they had not
entirely forsaken the land.
=Genus SAUROPLEURA Cope, 1868.=
Newberry, Proc. Phila. Acad. Nat. Sci., VIII, p. 98, 1856 (Pygopterus
scutellatus).
Cope, Trans. Am. Phil. Soc., p. 22, 1869.
Cope, Geol. Surv. Ohio, II, pt. II, p. 402, 1875.
Hay, Bull. U. S. Geol. Surv., No. 179, p. 419, 1902.
Type: _Sauropleura scutellata_ Newberry.
Vertebra and ribs well developed; limbs 4, rather large; 5 digits in the
forefoot; carpus cartilaginous. Ventral armature of closely arranged
rhomboidal scuta, arranged in lines, which are closely placed in chevrons,
with the angle anterior.
In none of the species of this genus have the usual 3 thoracic shields
(clavicles and interclavicles) been observed. The abdominal scutæ, on the
other hand, are much like those of _Saurerpeton_, being, however, smaller.
The species formerly described by Cope in the genus _Colosteus_ are
included in _Sauropleura_, where they find their closest allies.
There are 7 species belonging in this genus: _Sauropleura digitata_
Cope, _S. newberryi_ Cope, _S. foveata_ Cope (_Colosteus_), _S.
scutellata_ Newberry (_Colosteus_) (type of genus), _S. pauciradiata_
Cope (_Colosteus_), _S. longidentata_ Moodie, _S. enchodus_ Cope
(_Anisodexis_). The species described by Cope as _Sauropleura latithorax_
is regarded as belonging to a distinct genus, _Saurerpeton_.
=Sauropleura scutellata Newberry.=
Newberry, Proc. Phila. Acad. Nat. Sci., p. 98, 1856 (_Pygopterus
scutellatus_).
Cope, Proc. Phila. Acad. Nat. Sci., p. 215, 1868.
Cope, Trans. Am. Phil. Soc., p. 22, 1869.
Cope, Geol. Surv. Ohio, II, pt. II, p. 402, 1875.
Type: Specimen No. 8669 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures. (Plate 14, fig. 3.)
This species was first described by Newberry as a fish belonging to the
genus _Pygopterus_. Cope later placed it under the genus _Colosteus_
and clearly showed its amphibian characters. The genus _Colosteus_ was,
however, based on a misconception. Cope in 1897 and Hay (317) referred
the species to _Sauropleura_, where it is retained. The species is
represented by a single individual preserved on a block of coal from
Linton, and is also indicated by an interclavicle and its obverse; this
element is of larger size than that of the type and was referred by Cope
to _Colosteus pauciradiatus_. The characters of the plate are, however, so
identical with those of the interclavicle in the type specimen that it is
unhesitatingly referred to the present form.
The type specimen consists of the supero-lateral view of a crushed cranium
with the anterior part of the body, exhibiting the interclavicle and the
ventral scutellation. No limbs have been observed in this species. The
mandibles are crushed across the cranium in such a way as to obscure its
structure. The boundary of the left orbit is doubtfully determined as
being a little back of the median line of the skull. There are small teeth
present on the mandibles, but their number can not be determined. The
cranial elements are sculptured with radiating grooves and ridges, but
these are weakly developed. The snout is broad and but little narrower
than the base of the skull. (Plate 21, fig. 5.)
The interclavicle, somewhat displaced, is the only element of the
pectoral girdle preserved. It is peculiar in the possession of a backward
extension which shows a beveled edge. The plate is ornamented by radiating
grooves and ridges which are strongly developed. The larger specimen of
an interclavicle shows the same characters as the one described, and it
differs only in being about twice as large. There are no traces of limbs.
The ventral armature of the body is rather weak as compared to that of
_Sauropleura pauciradiatus_, but it is still composed of closely packed
scutes arranged _en chevron_. The character of the ventral armature and
the sculpturing of the interclavicle are taken as the principal specific
characters. From the other species of the genus the present form differs
in its more slender elements of the ventral armor and in the form of the
skull. The ribs are not clearly defined.
Measurements.
mm.
Median length of skull 70
Posterior width of skull 40
Anterior width of skull 20
Length of jaw 50
Anterior width of jaw 7
Posterior width of jaw 12
Length of mandibular tooth 1.5
Length of entire specimen 150
Width across belly, maximum 47
Length of interclavicle 27
Width of interclavicle 13
Width across posterior extension 4
=Sauropleura digitata Cope.=
Cope, Proc. Phila. Acad. Nat. Sci., p. 216, 1868.
Cope, Trans. Am. Phil. Soc., XIV, p. 15, 1869.
Cope, Geol. Surv. Ohio, II, pt. II, p. 403, pl. xxxvii, fig. 1, 1875.
Type: Specimen No. 8004 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures. (Plate 20, fig. 4.)
This species is represented by a single individual which is quite distinct
from other members of the genus. The specimen has been spread over a
surface of the coal, and exhibits ventral armature, dorsal region with
ribs, and anterior and posterior limbs. Skull and caudal region not
present.
The ventral armature is arranged in parallel lines directed obliquely
forwards and continuous on the median line, forming there a chevron. The
individual elements are oat-shaped, and acuminate at both ends. They are
moderately imbricate in an antero-posterior section. On the pectoral
region between the fore limbs the series of scutellæ assume different
directions, forming chevrons directed backwards, and forming with those of
the belly a complete =X=.
The humerus, ulna, and radius are rather stout, and of a size relative
to the body, as in common types of existing lizards; the ulna and radius
separate. The carpus is cartilaginous; the digits are 5 well-developed
fingers having phalanges in the following numbers, commencing on the
inside: 3, 4, 5, 6, 5. The last phalanx of the second is obscured, and it
is not positive that the number is as given; it is more probable that it
was 4 than 3. The outer toe was more slender than the others; the distal
phalanges of all the toes are stout, as in modern Caudata.
The ribs are long and curved as in reptiles, and judging by their
distances the vertebræ are short; the latter are not well-defined, but
there is no indication of prominent spines of any kind. The pelvic bones
and portions of the hind limbs are present, but so obscured and confused
as not to be easily made out. Enough remains to show that the hind limbs
were longer than the fore. Thirteen ribs on one side and twelve on the
other are preserved, with short ribs in the sacral region. The specimen
is very indistinct and it is difficult for one to be sure of all the
characters described by Cope.
Measurements of the Type of Sauropleura digitata Cope.
mm.
Length of specimen 115
Greatest width 80
Diameter of ventral scute .75
Length of rib 15
Width of rib 1
Length of humerus 20
Length of radius 10
Length of ulna 9
Length of metacarpal 4
Length of fourth digit of hand 22
Length of interclavicle 20
Width of interclavicle 11
The interclavicle is diamond-Shaped, with surface punctate and edges
radiately grooved at a distance of 1.5 mm. from the edge. The hand on the
right side of the specimen contains 3, 3, 3, 6, 3 phalanges. The vertebræ
are all imperfectly preserved.
Other specimens of this species are 2567 (48), 8376 G, 8704 G, American
Museum of Natural History. Coal Measures of Linton, Ohio. Collected by Dr.
J. S. Newberry.
=Sauropleura newberryi Cope.=
Cope, Geol. Surv. Ohio, II, pt. II, p. 404, pl. xxxvii, figs. 2 and 3;
pl. xli, fig. 5, 1875.
Type: Specimen No. 8612 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures.
The type specimen of the species exhibits a portion of the posterior
part of the skull, a considerable part of the body, with the fore limbs
and abdominal scutellæ. No vertebræ can be definitely discovered and
the ribs are not distinctly visible. The cranial fragment is the upper
surface of the tabulare and adjacent elements, and a broad band of the
posterior parts of these is seen to be smooth, and is preceded by a
slightly roughened surface. The abdominal scutæ are diamond-shaped, and
are thin and light, not massive, as in _S. scutellata_, and are sometimes
marked with a median longitudinal keel. The fore limb is large, especially
the humerus, which is much dilated distally, and has a strong crest
on the outer side from near the proximal end. The ulna and radius are
much shorter, and more dilated proximally than distally; they are well
separated. No phalanges are preserved.
The species is represented by other specimens, all of which are
unsatisfactory in determining the structure of the form. A skull,
apparently complete, is crushed out flat, so that little can be said of
structure. The teeth are rather long, straight, acute, and striate at the
base. The orbits are long and narrowed in front.
Measurements of Sauropleura newberryi Cope.
(No. 8612 G, and two unnumbered specimens, American Museum of Natural
History.)
mm.
Length of humerus 35
Proximal width of humerus 8
Distal width of humerus 14
Length of ulna 19
Proximal width of ulna 8
Posterior width of skull 67
Width at anterior angle of orbits 40
Interorbital space 13
Width of orbit 13
Length of orbit 27
Length of a maxillary tooth 4
Diameter of same at base 2
=Sauropleura pauciradiata Cope.=
Cope, Trans. Am. Phil. Soc., XV, p. 275, 1874.
Cope, Geol. Surv. Ohio, II, pt. II, p. 408, pl. xl, figs. 1-2, 1875.
Type: Specimen No. 8671 G, and obverse, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures.
The species was founded on a median and a lateral plate of 2 individuals.
The clavicle is here associated with _S. scutellata_ and the interclavicle
thus remains as the type specimen. There are other remains associated by
Cope with _S. scutellata_ which are here shown to have closer affinities
with the _S. pauciradiata_.
The clavicle is a right-angled triangle, the inner and thin edge concave
posteriorly, the posterior convex. The ridges and grooves are well
developed on the specimen. The visceral side of the element is smooth.
Cope referred to _S. scutellata_ the larger part of an individual with
strongly developed ventral scutellation. This he figured on plate XXXVI,
fig. 2 (123). Even a cursory glance will, however, suffice to show that
the sculpturing of the clavicle just described and that exhibited by the
specimen there figured are identical. Closer examination shows important
differences between the species, the principal distinctions being the
strongly developed ventral scutellæ in _Sauropleura scutellata_, the
difference in form and sculpture of the interclavicles, and the posterior
extension of the interclavicle in _S. scutellata_ which is wanting in _S.
pauciradiata_. The sculpturing of the interclavicle in the form figured
by Cope as _S. scutellata_, just referred to, is identical with the
sculpture of the clavicles, as would be expected. The ridges on all of the
pectoral elements of _S. pauciradiata_ are strong and are rather few in
number, while in _S. scutellata_ the sculpturing is more in the form of
interrupted grooves.
The specimen (plate 14, fig. 3) exhibits the great part of the body with
one fore limb. The skull is wanting. The belly was very broad and strongly
protected by broad, long scutes arranged _en chevron_. The scutes are
close together and form a compact ventral armor for the animal. The fore
limb is very weak. The humerus is represented by its distal end only. The
radius and ulna are very short and weakly developed in comparison to the
size of the animal. The limbs could not have supported the animal on land
and served, probably, merely as organs of equilibration, for the animal
was undoubtedly aquatic. The fingers are not all preserved and there is no
carpus.
Numerous other remains formerly associated with _S. scutellata_ are here
referred to _S. pauciradiata_, on account of the strongly developed
ventral armor, which is different from that of the type of _S.
scutellata_. The remains do not, however, add to our knowledge of the
anatomy of the forms, as they are very fragmentary.
Two skulls are provisionally associated with this species. One of these
skulls is figured by Cope (123) on plate XXXIII, fig. 1. It is there
referred to _S. scutellata_. That it can not, however, be referred to
that species is manifest when the teeth are observed. In the type of
_S. scutellata_ the teeth are very small, sharp denticles, while in the
skull under discussion the teeth are well developed and their bases are
longitudinally grooved. The teeth are elongate in the anterior part of
the skull and are shorter posteriorly. They are, however, all strong. The
skull is acuminate and the orbit is located about midway of its length.
The jaw is slightly longer than the cranium. The structure of the cranium
can not be determined in either skull, and in one only the position of the
orbits and the teeth.
[Illustration: Fig. 34.
A. Interclavicle of Sauropleura pauciradiata Cope. × 1. (After Cope.)
B. Left clavicle of Sauropleura pauciradiata Cope. × 1. (After Cope.)
]
Measurements of the Specimens of Sauropleura pauciradiata Cope.
mm.
Length of clavicle, left 43
Width of clavicle 25
Space between ridges 2
_Large specimen No. 8657 G and obverse (13) described us Colosteus
scutellatus Newb._
mm.
Length of specimen, as preserved 117
Width of specimen, maximum 61
Length of forearm 9
Length of hand 10
Length of metacarpus 5
Length of clavicle 4
Width of clavicle 18
Length of interclavicle 40
Width of interclavicle 23
Width of a ventral scute 1.5
Length of scute from angle to end 35
_Skull No. 8666 C, plate xxiii, fig. 1 (Cope, 123), Colosteus scutellatus._
mm.
Length of skull, as preserved 65
Width of skull 40
Diameter of orbit 6
Length of mandible 7
Width of mandible, maximum 10
Length of longest tooth 5
Width of tooth at base 1.5
_Skull Nos. 8602 G and 8608 G._
mm.
Length of skull, as preserved 50
Width of skull 60
Diameter of orbit 15
Length of mandibular tooth 4.5
Other specimens associated with this species: Nos. 8668 G, 86746, 85540,
8661 G. All specimens in the American Museum and all from Linton, Ohio.
Scutes of Sauropleura.
There are found associated with the remains of the genus _Sauropleura_
a number of heavy scutes or scales. There are three of them on the same
block as the specimen of _S. longidentata_ and are provisionally referred
to the genus. There are a number of scutes preserved separately, but they
agree in their characters with those discovered on the specimens. The
scutes are elongate and usually acuminate at one end and having a broad
base at the other. The acuminate end is slightly bent to one side so as
to present the appearance of a hook. Others are shield-shaped and are
quite large, while the majority of the hook-shaped ones are small. The
shield-shaped elements have a rounded boss near the center of the plate
and the edges are imbricated. Their nature and their proper location on
the animal are a puzzle. They may not belong to the genus, but have been
noticed with the remains of at least 3 species.
Measurements (in Millimeters) of Scutes Associated with the Specimens of
Sauropleura.
No. 4513 U. S. National Museum:
Length 27
Width, maximum 14
Width, minimum 3
Scutes associated with the specimen of _Sauropleura longidentata_:
Width across base 3
Width across tip 1
Additional specimens are: Nos. 3, 8673 G and 8470 G, American Museum of
Natural History.
=Sauropleura longidentata Moodie.=
Moodie, Jour. Geol., 17, No. I, pp. 74-76, figs. 18, 19, 1909.
Type: Specimen No. 8619 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures.
[Illustration: MOODIE PLATE 22
1. Type of _Leptophractus lineolatus_ Cope, from the Coal Measures
of Linton, Ohio. Portions of maxilla and mandible of left side
with teeth. × 1. Original in American Museum of Natural History.
2. Type of _Proterpeton gurleyi_ Moodie, from the Coal Measures
of Illinois, near Danville. Cervical of an otherwise unknown
vertebrate. Neural spine to the right. Original in Walker Museum,
University of Chicago × 2.
3. Amphibian phalanx from the Coal Measures near Breeze, Illinois,
of an unknown species. The probable form of the element is
represented. × 3.
4. Large rib of a stereospondylous stegocephalan otherwise unknown.
The rib may represent a species of _Macrerpeton_ or may even
belong with _Macrerpeton deani_ Moodie, but exact identification
will have to wait for future discoveries. From the Coal Measures
of Linton, Ohio. Original in U. S. National Museum. × 1.
5. Type of Cope's species _Tuditanus mordax_ referred by him to the
cranium, on account of the sculpturing of the elements. We
now know the specimen to be portions of the interclavicle and
clavicles of _Diceratosaurus punctolineatus_, as Cope suggested
they might be. Original in American Museum of Natural History. ×
1.
6. Skull of _Baphetes planiceps_ Owen from the Coal Measures of Nova
Scotia. × 0.45. Original in the British Museum. South Kensington.
After Owen.
]
This species may be distinguished from other members of the genus by the
large size and shape of the cranium (462) and the broad mandible (plate
16, figs. 2, 3) with its very long teeth. The skull of _Sauropleura
digitata_ Cope is not known, but the body of that animal as preserved
represents far too small a form for the skull to be referred to that
species. The skull is fully half as long as the dorsal region of
_S. digitata_ Cope, so that an association of the remains would be
incongruous. It differs from the skull of _S. scutellata_ Newberry in
size and proportions. The skull of _S. scutellata_ is narrow, while in
_S. longidentata_ it is quite broad. The teeth of the latter are also
characteristic of the species, since in all other known species of this
genus in which the skull is preserved the large anterior tooth is wanting.
The bones of the skull show the coarse sculpturing of the larger species
of Microsauria. It consists more of radiating grooves than of pits. The
skull, as restored (462), is broadly ovate, with the posterior border
truncate. The muzzle is broad and the nostrils are, apparently, located
near the anterior margin.
The posterior border of the orbits lies near the median transverse line of
the skull. They are circular and are removed some distance from the margin
of the cranium. Only the frontal and parietal can be determined with
certainty.
The mandible is heavy and is provided with pleurodont, heterodont teeth.
Near the anterior end of the mandible there is a very long fang-like
tooth, longitudinally striated and slightly recurved, which arises from
a broad base and attains to considerable prominence. The other teeth are
smaller, though the next succeeding one is still of considerable size.
All of the teeth preserved are longitudinally striated, but only the two
anterior ones are recurved to any extent.
Measurements of the Type.
mm.
Length of the skull in median line 75
Width of skull at posterior border, estimated 80
Width of skull across orbits 60
Width of orbit 10.6
Length of orbit 12
Interorbital space 16
Length of jaw, as preserved 48
Width of jaw, maximum 16
Width of jaw, minimum 5
Length of largest tooth 11
Width of longest tooth at base 4.5
Length of shortest tooth 3
Width of shortest tooth at base 1
=Sauropleura foveata Cope.=
Cope, Trans. Am. Phil. Soc., XIV, p. 24, 1869.
Cope, Geol. Surv. Ohio, II, pt. II, p. 406, pl. xxxvi, fig. I, 1875.
Type: Specimen No. 8676 G and obverse No. 8675 G, American Museum of
Natural History.
Horizon and locality: Linton, Ohio, Coal Measures.
This species is represented by an interclavicle and its impression, which
show a beautiful sculpturing entirely distinct from that of the other
species of this genus. In size it is intermediate between the largest of
the interclavicles of _S. scutellata_ and _S. pauciradiata_. The pattern
of the sculpturing is, however, its main distinction. The plate is finely
pitted and there are few evidences of grooves. Near the posterior border
of the plate the pits become somewhat defined by ridges which take on a
radiating pattern with the center of the plate as the center. The beveled
margins are rugose, except at the edges.
Measurements of the Type Specimen of Sauropleura foveata Cope.
mm.
Median length of interclavicle 43
Width of interclavicle, maximum 23
=Sauropleura enchodus Cope.=
Cope, Proc. Am. Phil. Soc., p. 406, 1885 (_Anisodexis_).
Type: Specimen No. (51) 2558, American Museum of Natural History, Newberry
Collection.
Horizon and locality: Discovered by Sam Huston at the Linton, Ohio, Coal
Measures.
An examination of the type specimen (plate 16, fig. 4) of this form
resulted in no new facts. The reference of the species to the Permian
genus _Anisodexis_ by Cope is probably incorrect. Our knowledge of the
two known species of this genus is not sufficient to separate them, but
for the sake of convenience the Linton species is placed in the genus
_Sauropleura_. It is located here principally on account of the form and
structure of the teeth. Cope's original description is given below:
"The generic characters are apparent in the very unequally sized
teeth with round section. The portion upon which the species is
based is a part of the right ramus of the mandible, which is in the
specimen viewed from the inner side. The jaw is obliquely and smoothly
truncated from below, for the symphysis and surface of the bone is
smooth. There is a very large tooth near the extremity of the dentary
bone. Behind it is an interval equal to three times the diameter of
its base, which is followed by a tooth of about one-third the length
of the first tooth. Posterior to this one are two teeth of the same
size as the second, all being separated from each other by about a
tooth's diameter. These are followed by three subequal teeth of about
two-thirds the length of the first tooth, and separated by about their
own diameter from each other. They are all perfectly straight, very
acute, and without the trace of a cutting-edge. The inflection-grooves
extend to or a little beyond the middle of the length."
The present species is smaller than the type of _Anisodexis imbrecarius_
from the Texas Permian, to which genus Cope originally referred the
present species, and the apices of the teeth do not display the opposite
cutting-edges seen in the Texas form.
Measurements of the Type Specimen.
mm.
Length of jaw, including 7 teeth 31
Depth of ramus at second tooth 10
Length of first tooth 10.5
Length of third tooth 3.5
Length of sixth tooth 7.5
Skin of Sauropleura Sp.
Moodie, Bull. Am. Mus. Nat. Hist., XXVI, p. 355, pl. lx, fig. 1, 1909.
The present specimen is interesting on account of the presence of what I
take to be a portion of the skin, which is preserved as a smooth mold over
the ribs and ventral scutellæ. The skin was undoubtedly that of the back,
since the creature is preserved on its belly, and is interesting in not
showing the slightest trace of scales or other hard plates. The ventral
scutellæ are characteristic of the species of the genus _Sauropleura_.
With one species of this genus, _Sauropleura scutellata_ Newberry, the
writer has found associated scutes of some size, and the same fact has
been noted by Cope.
=Genus SAURERPETON Moodie, 1909.=
Moodie, Jour. Geol., XVII, No. 1, p. 80, fig. 23, 1909.
Type: _Saurerpeton latithorax_ Cope.
This generic name is erected for the reception of a single species
described by Cope in 1897. The name is made necessary by the wide
divergence of the characters exhibited by the present species from those
of the species of the genus (_Sauropleura_) to which Cope (176) referred
this species. The form is not a member of the genus _Sauropleura_, for
reasons given below.
The species of the genus _Sauropleura_ have a lanceolate head with
homodont dentition or nearly so. The orbits are located well back in the
skull. The form of the body is elongate and slender and the limbs where
known are long and attenuated. The ventral scutellation consists of
oat-shaped scutes arranged in a chevron series. The form here described
as _Saurerpeton latithorax_ Cope has nearly the opposite of all of these
characters, and it is incongruous to locate the form under the former
genus. The skull of _Saurerpeton latithorax_ Cope is broad and heavy.
The teeth are heterodont. The body is broad and stout and the limbs are
of unusually strong proportions. The character of the ventral armature
is also of a very different type. In _Saurerpeton_ it consists of very
broad imbricating scutes which form a single piece across the abdomen and
are angulated to form the chevron pattern which is so common among the
Stegocephalia.
=Saurerpeton latithorax Cope.=
Cope, Proc. Am. Phil. Soc., XXXVI, p. 86, pl. iii, fig. 4, 1897.
Moodie, Jour. Geol., XVII, No. 1, p. 80, fig. 23, 1909.
Type: Specimen No. 4471, U. S. National Museum.
Horizon and locality: Linton, Ohio, Coal Measures. Collected by R. D.
Lacoe.
This species is indicated by remains of the anterior half of a large
amphibian (plate 17) preserved on a block of bituminous coal from the
Linton mine. The form is unusual in the proportions of the head and the
width of the thoracic region. In these characters it stands alone among
the Amphibia from this locality, where the forms are for the most part of
rather slender build and tapering, pointed head.
The skull is represented in a fairly complete condition and shows the
usual stegocephalian arrangement of the skull elements, as well as the
sculpturing of the bones, which is similar to that found in other members
of the Microsauria. The skull is broadly rounded, with the posterior
border incised, the broad tympanic notches thus rendering the shape of the
skull somewhat like that of the branchiosaurs. The orbits are broad ovals
and lie well forward in the skull. They are separated by a space which is
greater than the greatest diameter of the orbit. The pineal foramen lies
well back and is clearly indicated as a circular opening which lies in the
median suture in the posterior half of the parietals. The nostrils seem to
be elongate and have an oblique position, as is represented in the diagram
(fig. 35), but this character is not ascertained definitely.
The borders of the premaxillæ and the anterior suture of the nasal can
not be determined, though they may have had some such arrangement as
suggested. The nasal is represented, so far as is determinable, by an
oblong element lying between the frontal and the anterior border of the
skull. The f rentals are very large and form a portion of the inner border
of the orbit. The parietal is probably the largest bone in the cranium
and together the two elements form a large quadrangular space in the
posterior half of the skull. They inclose the circular pineal foramen.
The postparietal is a small element lying on the posterior border of the
skull and with the tabulare and a part of the supratemporal forms the
projection. The prefrontal is probably a small element, especially if
the lacrimal is present. There seems to be an indication of a suture
separating the lacrimal from the prefrontal, but this character is not
assured. The boundaries of the maxillæ are clear anteriorly. They indicate
that this element was elongate, as is usual, and impressions of teeth
borne on the mandible would indicate the probability that the teeth were
heterodont. In the premaxillary region there is a long, strong tooth
preserved, and on the maxillary near the posterior extremity of this bone
there are impressions of teeth which are no more than one-fourth as large
as the premaxillary one. The borders of the jugal can not be ascertained,
since the skull is injured on both sides in this region. Likewise the
quadratojugal is conjectural. The boundaries of the postfrontal and
the postorbital are clearly ascertained. They together form the entire
posterior border of the orbit and send prolongations along the lateral
borders of these openings. They are both acuminate posteriorly and these
points are inclosed by the tabulare and supratemporal for the postfrontal
and by the squamosal and prosquamosal space for the postorbital. The
boundaries of the tabulare show this element to be quite large and
extending forward into an acumination which is inclosed by the parietal
and the postfrontal. The sutures bounding the squamosal have been obscured
by injury in removing the specimen and are indeterminable.
[Illustration: Fig. 35.--Outline drawing of the skull and skeleton, as
preserved, of _Saurerpeton latithorax_ (Cope), from the Linton, Ohio, Coal
Measures. Original in U. S. National Museum. × 0.75.
Skull: _fr_, frontal; _j_, jugal; _mx_, maxilla; _n_, nasal; _no_,
nostril; _or_, orbit; _par_, parietal; _pof_, postfrontal;
_po_, postorbital; _pp_, postparietal; _pf_, prefrontal;
_pmx_, premaxilla; _qj_, quadratojugal; _m_, mandible; _spa_,
supraorbital lateral-line canal; _spt_, supratemporal; _sq_,
squamosal; _tab_, tabulare; _y_, pineal foramen.
Skeleton: _cl_, clavicle: _c_, carpus; _rb_, ribs; _h_, humerus; _ic_,
interclavicle; _met_, metacarpals; _psc_, pectoral scutellæ; _r_,
radius; _vs_, ventral scutellæ; _u_, ulna.
]
The vertebral column is represented by a ridge showing along the median
plane of the specimen. Its characters can not be ascertained. There are a
few evidences of ribs. They represent long, slender, non-alate elements,
their mode of articulation with the vertebræ being obscured by the
plate-like ventral armature which covered the abdomen of the animal.
The pectoral girdle is represented by the remains of three elements which
are interpreted as being the interclavicle and the two clavicles. The
interclavicle is broad and is rounded posteriorly. There is no evidence
of the usual acumination posteriorly. The element is nearly as wide as
long. There is a prominent longitudinal keel on the ventral surface of
the interclavicle and radiating lines which may indicate the courses of
blood-vessels or nerves or may be the ornamentations of the element,
probably the latter. The clavicle has the usual microsaurian form. It has
three points and is truncate exteriorly. It is ornamented with radiating
grooves of a shallow and not strongly pronounced character. There is no
evidence of the coarse sculpture of the later forms. If the scapula is
represented it is merely by an indeterminate fragment insufficient for
description.
The pectoral limbs are preserved nearly entire. The left fore limb lacks
only a few phalangeal bones, and these were preserved with the remainder
of the skeleton but were lost in the mining process. The humerus is an
extraordinary element on account of its robust dimensions. It is very
stoutly built and represents a powerful limb. It is expanded at each
extremity and the width of its shaft is about equal to one-fourth of its
length. The ulna and radius present the same characters as the humerus,
_i.e._, in being robust, with stout shaft and expanded ends. The ulna
is slightly longer than the radius and has an expanded upper end. The
radius is short and does not have the proximal expansion. The carpus was
cartilaginous. Its position is represented by a blank space on the coal.
There are 4 digits preserved and in all probability this was the entire
number. The metacarpals are elongate and expanded at the extremities. The
first and second digits are represented nearly complete. The first digit
is extremely interesting in the possession of a claw-like terminal phalanx
which much resembles that of some lizards. There are 3 phalanges in the
first digit and 4 in the second. The phalangeal formula may have been
3-4-4?.
The ventral scutellation of this species is of an unusual character. It
consists of broad, imbricated scutes which are in a single piece and which
are arranged in the usual chevron pattern. The scutes were, apparently,
broadest in the middle and tapered somewhat at the extremities. This
character alone is sufficient for separating the genus from that of any
other known form.
The genus finds its nearest allies in the forms of the species of the
genus _Sauropleura_, in which Cope formerly located the present species.
The skull of the form described as _Tuditanus radiatus_ Cope is quite
similar to the present form, both in the sculpturing and arrangement
of the elements. The characters wherein the present form resembles the
species of _Sauropleura_ are the possession of broad pectoral plates
and strong, digitate limbs. The general form of the body and skull is
different in the two groups. It is slender in _Sauropleura_ and decidedly
stout, short, and heavy in Saurerpeton.
Measurements of the Type.
mm.
Length of specimen 130
Median length of skull 51
Width of skull at posterior border 62
Width of skull across orbits 48
Length of orbit 14
Width of orbit 10
Interorbital space 16
Length of longest tooth preserve 14
Length of shortest tooth preserved 1
Length of the interclavicle 26
Width of interclavicle, maximum 23
Length of clavicle 22
Width of clavicle 18
Length of abdominal scutes 28
Length of humerus 19
Width of humerus at upper end 6.5
Length of ulna 11
Length of radius 9
Length of metacarpal 3
Length of first digit 12
Length of terminal phalanx 3.5
Length of lower jaw on the curve 70
Width of lower jaw, maximum 8
Length of rib 30
=Genus CTENERPETON Cope, 1897.=
Cope, Proc. Am. Phil. Soc., XXXVI, p. 83, pl. iii, fig. 1, 1897.
Type: _Ctenerpeton alveolatum_ Cope.
The genus _Ctenerpeton_ was founded by Cope for the reception of a single
species which presents some very unusual characters. The form shows close
relationships to the genera _Urocordylus_ (334), _Œstocephalus_, and
_Ptyonius_. These genera agree with the present one in the possession
of very characteristic vertebræ which are signalized by the elongate
and ornamented characters of the neural and hæmal spines. These project
prominently from the body of the vertebra and have the ends of the
projections truncate and divided into fine points, thus causing the spine
to have much the appearance of a comb. The surface of the neural spine is
sometimes marked with a shallow groove. The spines are longer and more
slender in the genera _Œstocephalus_, _Urocordylus_, and _Ctenerpeton_
than they are in the species of the genus _Ptyonius_, where they are
short, although the usual pectinations are present.
The character on which this genus rests is the shelf-like extension (plate
23, fig. 2) of the abdominal plates. This is of a very unusual character
and entirely unknown in any other species of Carboniferous Amphibia.
The term Ctenerpeton has reference to the fact that the ends of these
shelf-like plates project in a pectination along the side of the abdomen.
=Ctenerpeton alveolatum Cope.=
Cope, Proc. Am. Phil. Soc., XXXVI, p. 83, pl. iii, fig. 1, 1897.
Moodie, Proc. U. S. Nat. Mus., 37, p. 24, pl. 10, 1909.
Type: Specimen No. 4475, U. S. National Museum, Lacoe Collection.
Horizon and locality: Linton, Ohio, Coal Measures.
The species rests on a single specimen (plate 19) from Linton, Ohio, and
is preserved on a block of bituminous coal. It is in a very good state
of preservation. There are present on the block of coal a part of the
right fore limb, the greater part of the dorsal portion of the animal,
and the anterior part of the tail. There are no evidences of hind limbs,
although this may not be taken as evidence that they were not present on
the animal. No thoracic plates have been observed. The chevron armature
is present beyond the cloacal region, but there are no evidences of the
specialized clasping organs which are apparently developed from the
abdominal armature in some forms (251).
Each dermosseous rod of the abdominal scutellation consists of three
pieces a median angulated portion and the two lateral parts which form
the shelf-like projection along the side of the abdomen (plate 23, fig.
2). The marginal chevron differs in form from the other plate, aside
from the fact that it is not angulated. The lateral shelf is composed of
flattened plates which articulate with the median piece, and at the place
of articulation there is a ridge present in the specimen. The exterior
plates are curved backwards and are somewhat attenuated distally. They
are broader than the median piece and differ also in the absence of the
characteristic alveoli. The median plate is angulated and is of more
slender proportions than the lateral pieces. Its ventral surface is
ornamented with a single row of closely placed alveoli which resemble in
a great degree the alveoli of the jaw of some small animal. The ventral
scutellation is broad anteriorly, but becomes more slender posteriorly and
shortly posterior to the cloacal region disappears.
[Illustration: MOODIE PLATE 23
1. Left leg and pelvis of _Ichthycanthus platypus_ Cope, from the
Coal Measures of Ohio. × 1.7. Original the property of the
Department of Geology of Columbia University. _c_=centrale;
_F_=fibula; _fi_=fibulare; _Fe_=femur; _i_=intermedium;
_Il_=ilium; _T_=tibia; _t, 1-5_=distal tarsalia; _ti_=tibiale;
_V_=caudal vertebræ; _I-V_=digits.
2. Ventral scutellæ of _Ctenerpeton alveolatum_ Cope, from the Coal
Measures of Ohio. × 3.5. Original in U. S. National Museum.
]
The fore limb is represented by the upper portions of the ulna and radius
and 2 digits of the right hand. The digits are long and slender and
seem to represent digits I and II, since they show evidences of 3 and 4
phalanges respectively. The portions of the forearm preserved are too
meager for description.
The vertebræ have already been characterized as of the type first
described in Urocordylus. The neural fans are not much, if any, wider than
the hæmal fans. They are both situated on an elongate spine with a slender
base. The edges of the two fans are pectinated and the dorsal spine is
distinguished by the presence of a longitudinal groove in the center of
the spine. The length of the tail may have been considerable, judging from
the character of the vertebræ preserved
Measurements.
mm.
Length of specimen 150
Width of belly, maximum 28
Length of lateral chevron plate 7
Width of lateral chevron plate 1.75
Length from tip of lateral chevron to median angle 10
Length of a caudal vertebra 10
Width of the same vertebra with spines 20
Height of neural spine 8
Height of hæmal spine 8
Width at distal end of hæmal spine 3
Width at distal end of neural spine 3.5
Length of foot, as preserved 12
=Genus LEPTOPHRACTUS Cope, 1873.=
Cope, Proc. Phila. Acad. Nat. Sci., p. 340, 1873.
Cope, Geol. Surv. Ohio, II, pt. II, p. 399, 1875.
Cope, Proc. Am. Phil. Soc., XX, p. 461, 1882.
Type: _Leptophractus obsoletus_ Cope.
The genus was established on various parts of the cranium of a large
amphibian. The only parts which can with certainty be referred to the
genus are the upper and lower jaws of 3 specimens. These bear large teeth,
round in section at the base, but with acute compressed apex, with a
cutting-edge on the anterior face; the enamel is delicately grooved, as an
external indication of the labyrinthic structure. A characteristic feature
is seen in the presence of a large elongate tooth in the upper jaw, in the
position of a canine which much exceeds in length any of the others. The
sculpture of the cranium is but little marked in the known specimens. In
the type the lower jaw is marked with inosculating grooves. Three species
are known, which are among the largest of the Linton Amphibia.
=Leptophractus obsoletus Cope.=
Cope, Proc. Phila. Acad. Nat. Sci., p. 340, 1873.
Cope, Geol. Surv. Ohio, II, pt. II, p. 399, 1875.
Cope, Proc. Am. Phil. Soc., XX, p. 461, 1882.
Type: Specimen Nos. 55 G and 57 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures.
The species was about as large as an adult Florida alligator, and probably
exceeded or at least equaled in size any of the Carboniferous Amphibia.
The following account is taken directly from Professor Cope's "Batrachia
of the Ohio Coal Measures" (123). The description has been verified from
an examination of the type material.
"The teeth are rather distantly grooved for some distance above the base.
They are of different sizes; the smaller are compressed, and with fore and
aft cutting edges. The external surface of the dentary bone is marked with
short oblique grooves along its middle region; above these are grooves
which inosculate, forming a figure like an open net dragged in the long
direction.
"Excepting the grooves the teeth are smooth. The smaller ones are close
together and their crowns are curved backwards; the larger ones are at
more remote intervals; both have enlarged bases. Whether both forms are in
the same series I can not determine. There are from four to five of the
smaller to an inch.
Measurements of Type of Leptophractus obsoletus Cope.
mm.
Depth of fragment of jaw 75
Length of smaller teeth 19
Length of longer tooth 23
Width of vertex at middle scuta 176
Width of paired median scuta 56
Width of single scute 36
Length of single scute 48
"Some vertebræ were found at the same locality, but there is no evidence
as to the species to which they may have pertained. They are short,
concave on one end, and probably so on the other. The centrum of one is 12
mm. in diameter; neural spines injured." (Geol. Surv. Ohio, II, pt. II,
pl. 39, fig. 3.)
"A third and larger specimen was found by Professor Newberry during the
field season of 1874. It includes an oblique view of one side, and the
top of the cranium from the posterior part of the orbits to the end of
the muzzle, with the corresponding part of the alveolar region of the
dentary bone, with teeth. The bones of the skull appear to have been
rather light, and though the surface is irregular, the sculpture consists
only of shallow impressions of varying size and intervals. The orbits are
also badly defined, but appear to have been large, and separated by a
narrow frontal bone. The premaxillary bone is preserved, and shows clearly
the sutures that separate it from its fellow and from the maxillary. A
large foramen--perhaps the nostril--separates it from the maxillary, so
that it forms an irregular crescent. It supports two teeth, of which the
anterior is the larger, but there were perhaps others in advance, as the
alveolar border is imperfect towards the end of the muzzle. The anterior
two teeth of the maxillary bone are followed by a strong groove which
rises towards the sides of the muzzle. At first sight this gives the
impression of the maxillo-premaxillary suture, and makes it appear that
both the premaxillary bones are preserved, and that the foramen above
described separates the premaxillary spines, instead of representing the
nostril. The cutting edges of the teeth of these bones have, however, one
direction, whence they represent one side of the cranium only; were both
sides represented, the directions of the tooth axes would be reversed.
"The premaxillary and maxillary teeth exhibit a cutting edge on the outer
posterior margin of the distal half; the base of the crown is subround
in section. The line-like grooves are distinct but not numerous, their
intervals measuring 75 mm. Beyond them the enamel is smooth. The second
maxillary tooth is larger than the first, which is equal to the last
premaxillary. The third and fourth maxillaries are equal to the second,
but the fifth is larger and longer, exceeding all the others. The teeth of
the dentary bone differ from those of the upper jaw in having the cutting
edge of the crown on the anterior aspect, while the posterior border is
obtuse. There is an obtuse cutting edge on the posterior margin of the
anterior mandibular teeth.
"This description is derived from an adult animal, as the maxillary teeth
in some instances are partially worn away by friction on their anterior
and outer faces."
Measurements.
mm.
Length of maxillary bone preserved 146
Length of same supporting five teeth 73
Length of first maxillary tooth 15
Diameter of same at base 6
Diameter of second at base 8
Length of basis of fifteen teeth of the dentary 145
=Leptophractus dentatus new species.=
Type: Specimen No. 10850, American Museum of Natural History. Collected by
Dr. J. S. Newberry.
Horizon and locality: Linton, Ohio, Coal Measures.
[Illustration: Fig. 36. Mandible of _Leptophractus dentatus_ new species,
from the Linton, Ohio, Coal Measures. × 1. Original in American Museum of
Natural History.]
The type is a single right mandible, nearly entire, of a rather large
animal. The specific characters for the separation of the new form from
the previously described _L. obsoletus_ and _L. lineolatus_ are the
smaller size and slenderness of the mandible, associated with uniform
teeth, which are slender and delicately fluted.
There are 17 teeth preserved, the largest of which is 8 mm. in length.
From the posterior tooth the series gradually descends to half this length
0.5 inch from the anterior end of the mandible.
The exact form of the mandible can not be determined, but so far as can
be seen it is very slender, coming almost to a point at the anterior end.
The posterior portion is wide, but apparently not very heavy. There is a
fragment associated with the specimen which discloses a few teeth, but its
position in the cranium can not be determined.
Measurements of the Type of Leptophractus dentatus Moodie.
mm.
Length of mandible, as preserved 80
Anterior width of mandible 3
Posterior width 28
Length of most anterior tooth 4
Length of tenth posterior tooth 7
Width of this tooth at base 3
=Leptophractus lineolatus Cope.=
Cope, Proc. Am. Phil. Soc., XVI, p. 576, 1877.
Type: Specimen No. 1088 G, American Museum of Natural History.
Horizon and locality: Linton, Ohio, Coal Measures. (Plate 22, fig. 1.)
Cope's description of this species, to which I have nothing to add, is as
follows:
"This species is based on portions of the skull of two individuals of
large size. Both upper and lower jaw with teeth are represented and
the teeth are of very large size. The deepest element preserved has
been provisionally referred to the mandible and will be so described.
This element bears two types of teeth in very heterodont fashion. The
teeth in the back portion of the jaw are rather short and slender.
The teeth more anteriorly are, some of them, very long, rather stout,
with their bases longitudinally fluted, as are they all v The longest
tooth in the jaw measures slightly less than an inch. The bone is not
well preserved, but seems to have been ornamented with grooves of no
great depth. The most anterior teeth of the jaw are smaller than the
posterior ones.
"The upper jaw is set with teeth which are more uniform in size and
there is but little tendency to heterodonty. These teeth are also
striated at their base and all end in a sharp point. They are all,
apparently, straight. There is no tendency to curve as there is in the
genus _Macrerpeton_. The upper teeth are more closely set than are
those of the lower jaw, which are rather distantly placed.
"Another specimen of a smaller individual presents the same portions
of the skeleton and the same characters. It is possible that this
skull will be found to belong to _Ichthycanthus ohiensis_ Cope, which
is based on very large vertebræ and limb bones. The remains described
as _Leptophractus lineolatus_ are, however, unlike any other skull
remains which are thus far known.
"This species represents one of the largest types of the Carboniferous
Amphibia of Ohio. It probably attained a length of several feet. It
was also the most carnivorous of any of the forms."
Measurements of the Type Specimen of Leptophractus lineolatus Cope.
mm.
Length of specimen, as preserved 98
Depth of dentary bone at the middle 30
Anteroposterior diameter of mandibular tooth at base 3.5
Length of a posterior mandibular tooth 9
Length of longest tooth in jaw 22
Anteroposterior diameter of the same at base 6
Length of small maxillary tooth 7
Anteroposterior diameter of same at base 2
Collected by Dr. J. S. Newberry. Other specimens of the species are Nos.
1086 G and 1087 G, American Museum.
=Eurythorax sublævis Cope.=[C]
[Footnote C: Dr. Hussakof now regards (Bull. Amer. Mus. Nat. Hist., vol.
35, p. 128, 1916) the type specimen of this species as an opercular
element of one of the dipnoan fishes [_Sagenodus sublævis_ (Cope)]. The
discussion is left here, however, as a matter of historical interest.]
Cope, Proc. Am. Phil. Soc., p. 177, 1871.
Cope, Geol. Surv. Ohio, II, pt. II, p. 401, pl. xl, fig. 4, 1875.
Type: Specimen No. 8605 G, American Museum of Natural History, Collection
of Dr. J. S. Newberry.
Horizon and locality: Linton, Ohio, Coal Measures.
The genus and species were established on a single, large, almost perfect
interclavicle of peculiar form. It may or may not be distinct, but it
can not be associated definitely with any known genus, so that it will
be designated as Cope described it. It exhibits on its outer or lateral
borders broad, smooth surfaces for the contact of the overlapping margins
of the lateral plates. The form is subround, with a large excavation from
the posterior margin on each side. The narrowed portion left in the middle
behind has a convex outline. Some delicate radiating grooves occur on the
exposed surface, but they are very shallow.
Measurements of Type.
mm.
Length of interclavicle 71.5
Greatest width 78
Width of lateral concavity 39
[Illustration: Fig. 37.--So-called interclavicle of _Eurythorax sublævis_
Cope. (_Sagenodus._) No. 75. (After Cope.)]