The Coal Measures Amphibia of North America

by Roy Lee Moodie

The species Tuditanus punctulatus Cope was founded on well-preserved remains of nearly the entire skeleton of a single individual. The bones are represented by shining carbonaceous matter, and since both of the slabs containing the impression were preserved, a great many characters have been determined. The head, 1 fore-limb, and 23 consecutive vertebræ with ribs are well defined, but of the pelvis and hind limbs nothing is visible.

The cranium ([fig. 19]) is very similar to that of T. minimus, from the Cannelton, Pennsylvania, slates. It is triangular in shape, with a narrowed obtuse muzzle. The orbit of the left side is well defined and lies well forward. It is oval in outline and its width is about two-thirds of its length. The nostrils are small and are located well toward the tip of the muzzle. The parietal foramen lies behind the median transverse line which divides the skull equally.

The cranial elements are for the most part destroyed, but the outlines of a few can be determined. Those elements which are preserved are ornamented with a sculpturing of minute punctulations which, on the postfrontal, assumes a radiating arrangement. The ornamentation of the other elements consists of inosculating pits, but they seldom assume the form of ridges or grooves. The bones of the premaxillary region of the cranium are lacking. The first element which can be detected is the pref rental, which occupies a position in front of the orbit. There seems to be space for a lacrimal, but its outline is not distinct. The frontal can be readily separated and is seen to be an elongate element occupying the median region of the skull between the orbits. The parietal is apparently the largest element of the cranial roof and the pineal foramen is located in the anterior fourth of the median suture separating the parietal elements. The form of the postparietal and the tabulare can not be determined, as the greater part of this region is lacking. The squamosal seems to be located well forward and is rather small, but has the usual relation of this element. Only fragments of the other elements remain and nothing can be said of their form. The mandibles of both sides are represented by depressions, and they are ornamented with longitudinal grooves and ridges. The teeth are not preserved, but there are evidences of the maxillary teeth. These are minute and sharply conical. Just posterior to the skull there is preserved the impression of a short, round rod which is not definitely determined. It may be an element of the hyoid apparatus, although it is rather stout for such. It does not have the relations indicated by Cope in his figure ([123, pl. XXXIV, fig. 1]).

Fig. 19. Drawing of skull and skeletal elements of Tuditanus punctulatus Cope from the Coal Measures of Linton, Ohio. × 1.5. fr, frontal; ic, interclavicle; cl, clavicle; h, humerus; ph, phalanges; par, parietal; pp, postparietal; tab, tabulare, supratemporal and squamosal; u, ulna; r, radius.

There are three elements of the pectoral girdle preserved. These undoubtedly represent the interclavicle and the clavicles. The interclavicle is rhomboid in shape and is attenuated posteriorly. The attenuation is abruptly truncate posteriorly and it is thus of quite a different character from the acutely pointed interclavicle of T. minimus. The clavicle has a somewhat semicircular form, but is not attenuated at either end. It seems to be uniformly broad.

The forearm of the right side is preserved in part. The humerus is seen to be a heavy, somewhat expanded element lying displaced with relation to the pectoral girdle. It is greatly expanded at the ends. The ulna presents characters similar to the humerus and only differs from it in being shorter and less stout. The radius is not preserved. The carpus is unossified and its position is occupied by a blank space. The digits are represented by 4 metacarpals, and this may have constituted the entire number of the fingers. The phalangeal bones preserved are a little scattered. They are elongate with expanded ends.

Evidences of 23 consecutive osseous vertebræ are preserved. Their character can not be determined, although Cope ([123]) describes them as amphicœlous. This may be inferred to be the case, but I am unable to verify his observation. In form the vertebra are subquadrate. The neural spines are not evident. The osseous ribs articulate, apparently, between the bodies of the vertebra. Cope figured them as intercentral. There are 22 or 23 pairs preserved. They are single-headed and the extremities are attenuated. No traces of ventral scutellæ are present.

The entire length of the animal probably did not exceed 5 or 6 inches. Its form was quite lizard-like and it was probably of an ambulatory type, though it may have spent a part of its time in the old lagoon in which its remains were finally buried. No traces of external gills have been detected in this or any other Linton species.