Roy Lee Moodie

THE MICROSAURIAN FAMILY UROCORDYLIDÆ, FROM THE COAL MEASURES OF OHIO.

Family UROCORDYLIDÆ Lydekker, 1890.

Lydekker, Cat. Fossil Reptilia and Amphibia, pt. IV, p. 196, 1890.

Moodie, Bull. Am. Mus. Nat. Hist., XXVI, art. XXV, p. 357, 1909.

Type of the family: Urocordylus wandesfordii Huxley.

Locality and horizon: Coal Measures of Kilkenny, Ireland.

Stout and long-tailed forms, with the tabulare cornua frequently much produced and pitted cranial bones; lateral lines well-developed; palate with teeth on palatines, vomers, premaxillÆ, and maxillÆ, the two latter elements bearing conical teeth and the others bearing short, stumpy cones, at least in one species; pineal foramen well forward; nostrils and orbits in the anterior part of skull; scapula peculiarly curved and pointed; other pectoral elements sculptured; neural spines and chevrons of caudal vertebrÆ much dilated at their extremities, and pectinated; no caudal ribs; vertebrÆ in one genus apparently capped with a sculptured plate as in Zatrachys; tail very long and tapering to a point, 50 to So caudal vertebrÆ; dorsal region short; limbs well developed, with clawed digits; carpus and tarsus cartilaginous; endochondrium well formed.

There are 4 genera which constitute this family: Urocordylus, from the Coal Measures of Ireland; Ceraterpeton, from the Coal Measures of Ireland and England; Diceratosaurus, from the Coal Measures of Linton, Ohio; Eoserpeton, from the Coal Measures of Linton, Ohio.

These may be distinguished by the following characters:

I.	Skull triangular, truncated behind, with rounded muzzle and aborted tabulare cornua, neural spines of caudal vertebrÆ long, slender, and expanded in a fan-like manner; tail with about 80 vertebrÆ; ventral scutes oat-like	Urocordylus.
II.	Skull parabolic and of great width, with short cornua projecting from the supratemporal; tabulare cornua nearly twice as long; neural spines of caudal vertebrÆ low and wide; ventral scutes oblong; caudal vertebrÆ about 50	Ceraterpeton.
III.	Skull broad with obtuse snout, tabulare cornua absent, large, pointed posterior expansions from supratemporal, posterior table within the cornua truncate; vertebrÆ with an apical sculptured plate; caudal vertebrÆ numerous, over 75; ventral scutellÆ bristle-like, arranged en chevron	Diceratosaurus.
IV.	Skull a broad oval, with large posterior projecting supratemporal horns, posterior table of skull between cornua truncate without the small lateral projection from the supratemporal, orbits a long oval, ribs long, curved and slender, tail unknown, possibly shorter than in other members of the family; it is restored as short in Journal of Geology, XVII, p. 77, fig. 20, 1909, but this is uncertain; the skull has all the characters of the family	Eoserpeton.

The relationships of the family are not far to seek. They fall in immediately with the AmphibamidÆ and HylonomidÆ in being among the most reptile-like of the Paleozoic Amphibia. The group is, however, distinctly amphibian in the possession of 4 fingers, with the usual microsaurian phalangeal formula.

Genus DICERATOSAURUS Jaekel, 1903.

Jaekel, Neues Jahrbuch f. Mineral., Geol. u. Paleon., Bd. 1, p. 112, 1903.

Moodie, Jour. Geol., XVII, pp. 63-69, figs. 13-15, 1909.

Type: Diceratosaurus punctolineatus Jaekel.

Orbits in the anterior two-thirds of the axial skull length, nostrils near to the anterior end of the skull; pineal foramen in the center of the skull roof; skull provided with tabulate cornua and a broad backwardly directed process; quadrate angle does not project on the border of the skull; sculpture of the cranial elements impressed as radial grooves; 12 presacral vertebrÆ, 1 sacral with expanded neural spine which is sculptured at the top, with simple long, apparently separately ossified transverse processes; extremities small; foot with 5 digits; phalangeal formula 2-3-3-4-3.

The most important differences between Diceratosaurus and Ceraterpeton, the most nearly allied genus, is (in Diceratosaurus) in the more anterior position and small size of the orbits, the backward extension of the quadrate region, and the dorsal expansion of the vertebral spines. A further, and more important, difference between the genera is in the location of the backwardly directed processes from the skull. In Ceraterpeton they project backward from and are a portion of the tabulare element, while in Diceratosaurus the projection consists almost entirely of squamosal and supratemporal.

Diceratosaurus punctolineatus Cope.

Cope, Proc. Phila. Acad. Nat. Sci., 1875, p. 16.

Cope, Geol. Surv. Ohio, II, pt. II, p. 372, pl. xli, fig. 4, 1875.

Moodie, Bull. Am. Mus. Nat. Hist., XXVI, art. XXV, p. 356, pl. lxv, 1909.

Type: Specimen No. 8606, American Museum of Natural History.

Horizon and locality: Linton, Ohio, Coal Measures.

The species was first described by Cope as Ceraterpeton punctolineatum (122). It was redescribed on more abundant material (plate 19) by Jaekel (347), and the following is taken from the discussions of these two authors, checked by my own observations on the type specimen. This shows a portion of the skull, consisting of the squamosal and supratemporal with a projecting, convergent horn. The sculpturing on the skull is similar to that on the pectoral plates, of which there are three preserved (plate 14, fig. 4). The bones of the fore limbs are stout and short. The ribs are only slightly curved. The character of the vertebrÆ can not be ascertained. The sculpturing of the bones consists of radiating ridges, grooves, and pittings.

Jaekel (347) described from the museum collection at Berlin 3 specimens of this species, among which were 2 skulls. There were associated with these remains some pectoral plates and limb bones with a nearly complete series of vertebrÆ. A modified translation of Jaekel's description follows:

The skull of the largest specimen has, including the horns, a length of 35 mm. and a width of 30 mm. on the occipital border. From the anterior end to the posterior border of the skull (exclusive of the horns) there is a length of 25 mm. The pineal foramen lies about midway of this length. The orbits are rather large, almost circular, and lie about midway between the pineal foramen and the anterior border of the skull. The nostrils, which lie anterior to the orbits, are a rather oblique oval and narrowed on the lateral ends. The distance between them is about the same as that between the orbits, which measures 7 mm.

1. Type specimen of Diceratosaurus punctolineatus Cope, from Linton, Ohio, beds. × 1. Drawn from photograph. cl=clavicle; h=humerus; ic=interclavicle; mc=metacarpals; r-u=radius-ulna; rb=rib; sc=scapula; sq=squamosal; vs=ventral scutellÆ.

2. Skull of Sauropleura longidentata, Moodie, from the Coal Measures of Linton, Ohio. × 1. Drawn from photograph. fr=frontal; m=maxilla; n=nasal; or=orbit; par=parietal; pp=postparietal; tab=tabulare.

3. Mandible of Sauropleura longidentata, Moodie, from Coal Measures of Linton, Ohio. × 1.5. Drawn from photograph.

4. Type specimen of Sauropleura enchodus Cope, from the Coal Measures of Linton, Ohio. × 1.

5. Additional specimen of Diceratosaurus punctolineatus Cope, from the Coal Measures of Linton Ohio. × 1. f=femur; il=ilium; mc=metacarpal; mt=metatarsal; ph=phalanx; r=radius; t=tibia.

The skull roof is sculptured with pits much like those of Archegosaurus. The larger the bones, the rougher the sculpture. The bones of the middle of the skull (that is, the parietals, frontals, premaxillÆ, nasals, and postparietals) are of the normal form and only show an unusual difference in that they are large in the inverse order. The pineal foramen lies in the anterior third of the parietals; that is the primitive condition which occurs in the young forms of the BranchiosauridÆ. The nostrils are inclosed by the premaxillÆ in front, in the median line by the nasals and laterally by the maxillÆ. The jugals, by their backward prolongation, form, behind the maxillÆ, the border of the skull, and only attain to some size on the upper side of the cranium.

Jaekel's "perisquamosal" (see plate 15), which is of a doubtful nature, is not indicated in the type specimen nor in the specimens of the other two species (462) assigned to this genus. In D. robustus and D. lÆvis the "perisquamosal" region is easily separable into its component elements. The sutures between the elements may have been indistinct in his specimen, but it is hardly conceivable that a union of the skull bones would occur in one species and not in another of the same genus. Jaekel's suggestion (347) that "Etwas mehr Wahrscheinlichkeit mÖchte ich der Vorstellung beimessen, dass diese Ausbreitungen zum Schutz freier Kiemen dienten, wie sie z. B. bei den Perennibranchiaten als baumfÖrmige Organe weit am Halse herausragen" can hardly find acceptance with students of the Paleozoic Amphibia, since there is not the slightest evidence that the Microsauria ever possessed external gills and considerable presumptive evidence that they did not. His comparison of the "perisquamosal" to the "Kiemendeckel" of the fishes is also very unhappy on morphological grounds, since the elements of his "perisquamosal" form constituent parts of the skull roof, which the operculum never does.

The palate of the skull (plate 15, fig. 2) has been determined by removing the skull bones of one specimen. Anteriorly the premaxillÆ and maxillÆ are clearly recognizable as large dentiferous elements. The premaxillÆ have 4 to 7 teeth, the short maxilla has 3 to 4. All the teeth are of nearly equal size. Smaller teeth seem to be indicated by impressions found between the larger ones. The vomers, which are tolerably large, unite with the premaxillÆ behind and inclose at least half of the palatine foramen on the inner side. They are furnished with small teeth, which in the anterior part are very irregularly placed, but they are more regular posteriorly.

The palatines and transverse bones are questionably identified. They seem to lie posterior and lateral to the vomers, but the sutures are indistinct. The large parasphenoid seems well displayed and is more or less heart-shaped. There would seem to be a slight indication of double occipital condyles. The pterygoids are broad plates which inclose the parasphenoid and form the lateral boundary of the palate. The cotyli are very indistinct, but appear as elongate grooves.

The pectoral girdle (plate 15, fig. 3) consists, apparently, of seven elements, three paired and one unpaired. The unpaired element (the interclavicle) is truncate posteriorly and acuminate in front, with its surface radially grooved and the anterior borders beveled for articulation with the clavicles. The clavicles are triangular, as is usual with the Microsauria. They are sculptured with radiate grooves and ridges, with decided inosculations at the ossific center. The coracoids have only part of their surface ornamented; most of their surface is smooth for articulation with the interclavicle and scapula. A long spine projects from the inner surface of the coracoid. A pair of small elements lie one on either side of the clavicles and Jaekel (347) interprets them as the cleithra. If they are cleithra they are unique among the Microsauria. The pectoral girdle does not, however, indicate that Diceratosaurus is "unique among all known quadrupeds."

Jaekel regards the limb which is preserved with the material as an arm (plate 15, fig. 4), but there is no reason stated for his conclusion. It has all of the characters of the leg and may be regarded as such. Only a part of the lower end of the femur is preserved. The tibia and fibula are preserved as separate rod-like elements with one of the bones longer and larger, probably the tibia. There are 5 toes which have the customary phalangeal formula for a microsaurian foot of 2-3-3-4(?)-3. The tarsals are unossified.

The vertebrÆ (plate 15) were perforated for the notochord, and are hour-glass-shaped, with the neural arch thickened to support a heavy spine which bore a sculptured plate. These apical plates occur in the dorsal region, but diminish toward the caudal vertebrÆ. The number of the vertebrÆ in the dorsal region is very small and in the tail very large. There are possibly 2 vertebrÆ in the cervical, 11 in the dorsal series; the thirteenth carries the pelvis. There are over 100 vertebrÆ in the tail.

The ribs have an expanded head and the transverse processes of the vertebrÆ are long.

The following account is based on the writer's study of the type specimen and he is able to add several points of interest to a knowledge of the anatomy of the type of this interesting microsaurian.

The type specimen consists of 11 consecutive vertebrÆ with a portion of the skull, the greater portion of the pectoral girdle, parts of both fore limbs, ribs, and ventral scutellÆ (plate 14, fig. 4). The species is represented in the collection by yet another specimen, on which Cope based his Tuditanus mordax (plate 22, fig. 5), of which he himself says: "Further examination of the specimen on which the latter (T. mordax) was founded leads to the belief that it is an imperfect cranium of Ceraterpeton (Diceratosaurus) punctolineatum Cope." The plates referred to are rather to be regarded as elements of the pectoral girdle and I believe they represent the clavicle and a portion of the interclavicle.

The skull of the present species is fully described by Jaekel. The type specimen does not offer any evidence in support of Jaekel's "perisquamosal," but rather tends to the idea that he is incorrect in his assumption of the fusion of these elements of the skull. The direction taken by the ridges and grooves on the elements preserved indicate a separation between the supratemporal and the squamosal. I do not find that the grooves have the tendency to arise from a common center of ossification in the squamosal, as suggested in the figures of Jaekel. The horn which projects backward from the squamosal is rather large and heavy for the size of the skull, and after curving slightly inward ends in a blunt point and not sharply, as Jaekel figures in his specimens. The vertebral column is indistinctly preserved and I have nothing to add to Jaekel's account given above.

In the structure of the pectoral girdle my results are greatly at variance with those of Jaekel. I do not find the remarkable elements which Jaekel has figured (347) in his specimens. On the other hand, I find a normal microsaurian pectoral arch (464), such as has been described for numerous other forms. There are present, distinctly preserved in the type specimen, the scapulÆ, the clavicles, and the interclavicle, with the possibility of the coracoid. The peculiar element referred to by Cope as resembling a "lacertilian pubis" is without doubt the left scapula of the animal (plate 16, fig. 1). Its form compares very favorably with that of Ceraterpeton as figured by Woodward (630). The coracoid may be represented by the fragment which lies close to the scapula. The sculptured element lying next to the supratemporal horn of the skull is the right clavicle preserved bottom side up. Of the other two sculptured elements, one is the interclavicle, only a portion of which is preserved. The left clavicle lies beside it. The clavicles in this species have a tendency to assume the triangular shape so common in other species of Microsauria, and the interclavicle, so far as can be determined, was shield-shaped. The upper surfaces of the pectoral elements are marked by grooves for the attachment of the pectoral muscles.

The ventral scutellation is present in a small patch (plate 16, fig. 1) near the horn of the skull. The scutÆ are oat-shaped and take the usual form. The ribs are not long, are rather stout, and beyond the proximal curve are nearly straight to the obtuse tips. The heads of the ribs are so obscure that it is impossible to determine whether they were two-headed or not. They are expanded proximally and there is a slight tendency to a division of the head.

Portions of both fore limbs are preserved. The right limb possesses the humerus, separate radius and ulna, and 2 metacarpals. The other possesses only the radius, 3 metacarpals, and a portion of a phalanx. The humerus is a very stout bone and at once recalls that of Amblyrhynchus. The ends are expanded and there are roughnesses on the bone for the attachment of muscles. The radius and ulna are subequal in size. They are both expanded more proximally than distally. The carpus was cartilaginous. An additional specimen of this species is figured on plate 16, fig. 5. This adds to our knowledge of the pelvis especially.

The specimen (No. 2566, Am. Mus. Nat. Hist.) on which Cope based his Tuditanus mordax is composed of two plates of the above-described species.

Diceratosaurus lÆvis Moodie.

Type: Specimen No. 102 (8680 G), American Museum of Natural History, where it forms part of the Newberry collection.

Horizon and locality: Linton, Ohio, Coal Measures.

The species is represented by an almost complete skull, which had been identified previously by Cope as Tuditanus radiatus. The specimen consists of the impressions of the bones of the cranial roof, the bones themselves having disappeared. It is not probable that the dorsum of the skull was smooth. The details in the structure of the skull have been ascertained quite definitely. There can be no doubt that the arrangement of the elements is accurate, as shown in figure 24 A. The supratemporal, as in Erpetosaurus tabulatus Cope, is excluded from the parietal.

The form of the skull at once recalls that of the species D. punctolineatus, as figured by Jaekel (see plate 15). The orbits are located in nearly the same region of the skull and the sutures separating the cranial elements are quite similar in the anterior portions. The species D. lÆvis is based on the divergent character of the horn-like protuberances which project from the squamosals. The horns of D. punctolineatus are convergent. The present skull is also smaller and the parietals in D. lÆvis are much larger than in the type species. In the type species, also, the pineal foramen is located well forward in the parietal, while in the present form the foramen is located well posterior.

The skull is almost rectangular. The nostrils are elongate ovals. The orbits are circular and the distance between them is equal to two-thirds of the dimensions of the orbit. They are located well forward in the skull and are bounded laterally by the maxillaries. The nostrils have much the same character as in the type form, being broadly oval.

The premaxillÆ are elongate transversely, being about twice as long as wide. They are identical in shape and relations with the same elements in D. punctolineatus Cope. The nasal is nearly square and forms the interior boundary of the nostril. The frontal is elongate in the median length of the skull and it is acuminate posteriorly, where the acumination is inclosed by the parietal and postfrontal. The parietals are by far the largest elements in the cranium. They form together an oval which is elongate in the longitudinal diameter of the skull. They inclose between them, in the median suture, the small pineal foramen. They are acuminate in front, with a broad truncate posterior base, where they are bounded by the postparietals. The postparietal is nearly square, being somewhat wider than long. It joins the tabulare and the parietal. The tabulare is elongate in the long diameter of the skull. It ends anteriorly in a point which is inserted between the postorbital and the parietal, and bears a short protuberance posteriorly, much as does the same element in the type species.

There are four elements which take part in the formation of the posterior border of the skull. These are the postparietal, the tabulare, the squamosal, and the supratemporal. It is very unusual for the supratemporal to reach the posterior edge of the cranium. The pref rental lies anterior to the orbit, of which it forms the anterior border. The lacrimal has not been detected, although Jaekel (347) has indicated it in his drawings of the skull of the type species. The maxilla is elongate and forms the lateral border of the skull. No teeth have been detected, although they were doubtless the same as Jaekel has figured in D. punctolineatus. The jugal is an elongate element joining the maxilla posteriorly. Jaekel included this element in his "perisquamosal," but the sutures are clearly evident in the present specimen and there is no evidence of a structure at all similar to a "perisquamosal." The postorbital is fully as large as the jugal which it joins, forming a part of the posterior border of the orbit and ending posteriorly in a point which is inclosed by the tabulare and the squamosal. The postfrontal with the foregoing element forms the entire posterior border of the orbit and it likewise ends in a point inclosed by the parietal and the postorbital. The quadratojugal has much the same shape and relations as in D. punctolineatus, although it is located further back. The squamosal is also elongate, as are most of the posterior cranial elements, and it also has an acumination which is directed forward and is inclosed by the postorbital and jugal. The anterior suture of this element is rather indistinct, but it is, I believe, as represented (fig. 24). The element is elongate and is prolonged posteriorly to form the horn, which ends in a blunt point and is not sharp, as in the type species.

Jaekel (347) regards the species Diceratosaurus punctolineatus Cope as being unparalleled among known vertebrates in the possession of a "perisquamosal" element. In closely allied species the "perisquamosal" is easily separated into its component elements, and the morphology of the present skull would throw considerable doubt on Jaekel's interpretation of the skull of the type species. Another specimen, described below as another species of this genus, shows no evidence of this fusion. So far as I can learn, there have been no cases of true fusion of cranial elements correctly reported, unless it be that which possibly exists between the two frontals in the skull of Diplocaulus. It was on the basis of such fusions that Maggi (397) proposed to derive the interparietals of the primates from the tabulare of the stegocephalians.

The posterior outline of the skull in the present specimen is not well preserved and the outline as given may be slightly inaccurate. The indentation figured by Jaekel in the posterior border of the skull of the type form is not present in the species under discussion.

Diceratosaurus robustus Moodie.

Type: Specimen No. 8611 G, American Museum of Natural History.

Horizon and locality: Linton, Ohio, Coal Measures.

The present species is indicated by the left portion of a cranium representing a large individual. The characters of the skull are so clearly marked that it seems worthy of description. The presence of horns as given in the restoration of the skull (fig. 24, B) is based on the analogy with the other two species of this genus, in both of which horns are present. The generic determination of the species is based on the large size of the postorbital, which is essentially characteristic of the other species of Diceratosaurus.

The characters which distinguish the species from others of the genus are the large postorbitals and the small parietals, which are excluded from union with the postfrontals on account of the large size of the frontal. In the other two known species the frontal is small and the parietal comes forward to join the postfrontal. The present species exhibits a skull which is nearly twice as large as that of D. lÆvis and nearly three times the size of the skull of D. punctolineatus.

The portion of the skull preserved shows the cranium to have had a rather acuminate snout, not blunt as in the type species. The orbit is an elongate oval, although it has the same relative position in the skull as in the other species. The nostril is indicated by an oval depression near the anterior edge of the skull. The frontals, as indicated by the sutures present on the portion of the skull which is preserved, are fully as long as the parietals. Whether they were as wide as is represented is uncertain. The postfrontals are very small bones, the sutures of which are somewhat uncertain, although they can not be far from what is represented (fig. 24, B). The postorbital is large and elongate, and is distinctive of this species on account of its unusual size, although it does not attain the same proportions as in other members of the genus. The parietals are elongate and narrow. The pineal foramen is represented by its lateral edge and its position is about midway of the longitudinal diameter of the parietals. The narrow postparietal is represented by its anterior border; as restored (fig. 24, B) it may be too long. The tabulare, also, is represented by an anterior portion and it shows this element to have the position and form which is typical of the form Diceratosaurus lÆvis. Such other of the cranial elements as are indicated are based on the relations discovered in D. lÆvis.

The heavy line on the left of the drawing (fig. 24, B) represents the outline of the preserved portion. The skull, as restored, may be a little too long, and the shape of the horns is conjectural. In the orbit there are preserved 2 misplaced teeth showing longitudinal fluting. The longest tooth is about 3 mm.

Genus EOSERPETON Moodie, 1909.

Type: Eoserpeton tenuicorne Cope.

The genus was proposed for the reception of a single species originally referred by Cope to Ceraterpeton (C. tenuicorne). The species can not be placed in the genus Ceraterpeton on account of the form and structure of the skull, which varies widely from that of the type species, Ceraterpeton galvani Huxley, from the Kilkenny Coal Measures of Ireland. The most important character in which the present species differs from C. galvani is the peculiar form taken by the squamosal and by the position of the "horn." These characters will be evident on referring to figure 25. No undoubted remains of Ceraterpeton have been found outside the British Isles. Fritsch referred (251) a species, previously described as Scincosaurus crassus, to this genus, but Andrews (8), Jaekel (347) and Woodward (630) all unite in placing the species in the genus where it was formerly described. Jaekel even says that the Scincosaurus has no horns, so far as he can determine. Cope referred 3 species (123) from the Linton Coal Measures of Ohio to the genus Ceraterpeton, but it has been shown elsewhere (347) that no one of them belongs in the genus, nor in fact do they all belong in one genus.

Eoserpeton tenuicorne Cope.

Type: Specimen in the American Museum of Natural History. There are also specimens Nos. 4472 and 4473 in the U. S. National Museum.

Locality and horizon: Linton, Ohio, Coal Measures.

The species was founded on a complete skull preserved on obverse sides of a block of coal. Cope (123, pl. XLII, fig. 2) figured this skull. The figure is poorly executed and does not do justice to the specimen, which is really well preserved. In general the skull is oval, with the orbits located well towards the acuminate snout. The interorbital space is equal to twice the width of the orbit. The pineal foramen lies near the center of the skull. The quadrate angles are drawn out into slender acuminate, longitudinally striate horns, processes from the squamosal. The "horn" arises from an expanded base, which is a portion of the cranial element at the postero-lateral angle of the skull. This character is taken as the distinctive one of the genus. It is possessed by no other form of Carboniferous air-breathing vertebrate, in association with the other characters of the form.

The boundaries of the premaxillÆ are indefinite, but what remains of the sutures indicates that the elements were small. No teeth have been detected. The nasal is likewise not clearly defined, but the frontal is an elongate element which occupies the space between the orbits and joins the parietal posteriorly. The parietals form a large oval space, so characteristic of many of the Carboniferous Microsauria, in the anterior third of which occurs the median parietal foramen. The postparietal is almost square, and forms part of the posterior boundary of the skull. The tabulare has the usual position and relations. The prefrontal is ill defined. The postfrontal is small and forms a slender rod on the postero-inner boundary of the orbit. The postorbital is small and its bounding suture with the postfrontal is indefinite. The jugal is only partially represented in the specimen, and that part forms the outer boundary of the orbit. The maxillary sutures are not defined. There are no evidences of teeth, since the skull is compressed dorso-ventrally. The quadratojugal is, apparently, a larger element than usual, with the visual relations. The supratemporal lies in great part in front of the squamosal, but still has the normal relations of that element. The squamosal is the characteristic feature of the skull. It is very tumid at its base and projects into a long, slender, acuminate horn, the tumid portion being ornamented by radiating striÆ.

Another specimen of this species presents the greater part of the skeleton. However, very little can be added to our knowledge of the skull structure. It is barely possible that the second specimen may be distinct from the type. The horns are curved inward, but otherwise there is little or no difference. One of the most interesting and important features of the complete specimen is the unusual preservation of a leg, with impressions of 15 or more vertebra;, and traces of curved ribs which are intercentral in position.

The femur is slender and expanded at the ends, with the articular surfaces well formed. The tibia and fibula are mere rods of bone, although the tibia has slightly expanded extremities. There is no osseous tarsus. There are 5 digits in the foot; the second one is entire and contains 4 phalanges; the other digits are incomplete. The foot is remarkably long and slender, and is fully as long as the tarsal space plus the tibia, with the terminal phalanx clawed.

There are impressions of 2 oval and elongate clavicles in the pectoral region. The outer end is not expanded as is usual, and the surface is ornamented with grooves and ridges which radiate from a common center.

The entire remains measure scarcely 3 inches in length and it is to be doubted if the creature attained a length of more than 4 inches. It is probably a young form, but there are no evidences of external gills. The chevron armature is but poorly preserved, but so far as can be determined it is not different from that of other Microsauria, such as Amphibamus.