  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. The association of these species in the one family is provisional and will need revision on the acquisition of new and more complete material. 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 Tuditanus punctulatus Cope, 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 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 amphicoelous. 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 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.
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.
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). 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. 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 amphicoelous, 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 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.
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 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 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.
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. 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 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.
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 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.
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 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 "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."
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 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.
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. MOODIE 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
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
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.
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.
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 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.
Pectoral Girdle Provisionally Associated 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. MOODIE 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.
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
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.
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.
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
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 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.
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