An additional specimen shows that the skull, of which the anterior half is preserved, is practically of the same size as the type and shows much the same characters, though more extensively. The sculpture of the squamosal region is not confined to that portion of the skull, but extends throughout the cranial elements, apparently including the premaxillæ.
The sutures, which are clearly distinct, are of the same type as has been described for the type specimen. Perhaps one of the most interesting characters discovered on the present specimen is that of the greater part of the left supraorbital lateral-line canal, which is exhibited as a rather deep and broad canal running in a slight curve across the lower edges of the postorbital and the parietals and partly cutting the jugal.
On the left of the fossil, as it is preserved, there is an indistinct impression of the clavicle, with the sculpture in radiating lines from the apex as a center, such as have been found in other species of the Tuditanidæ.
| Measurements of Additional Specimen. (No. 8607, American Museum of Natural History.) | |
| mm. | |
| Length of skull as preserved | 40 |
| Anterior width across orbital region | 22 |
| Greatest width of the skull | 33 |
| Length of clavicle | 18 |
| Greatest width of clavicle | 9 |
Still a third specimen of this species is possibly represented by a nearly complete skull of a small individual which exposes the mandible and the ventral portion of the skull. The remains are crushed flat, though not at all distorted. It is quite possible that the present specimen represents a distinct species, but only a small portion of the dorsum is present and the shape of the cranium is indistinct, so it is retained in this species. The portion of the skull shows the sculpture to be quite similar to that of Erpetosaurus acutirostris, so far as the species is known; and the skull apparently tapers to a point anteriorly. It may be a dwarfed or immature form. The sculpturing of the jaw is such as we would expect of this species.
The specimen is about half the size of the type. The palate of the skull is well preserved and is extremely interesting. The sutures separating the various palatal elements are not distinct. The parasphenoid is especially large and the exoccipitals are partly ossified, if we may judge by the projecting condyles. Anteriorly the parasphenoid contracts and then expands and on each side of the expanded part lie fragments of the palatines. To the right of the posterior end of the parasphenoid lies a portion of the dorsal element showing the cranial sculpture.
The left mandible is somewhat displaced to the right of the skull, and crushed and weathered to such an extent that the sutures are entirely obliterated. There are 3 teeth, with indications of others. They are typically pleurodont and sharp and slender. The mandible tapers somewhat anteriorly and at the tip bears an elongate enlarged tooth.
| Measurements of the Third Specimen of Erpetosaurus acutirostris Moodie in the American Museum of Natural History. | |
| mm. | |
| Length of skull, as preserved | 25 |
| Posterior width of skull | 15 |
| Anterior width of skull | 10 |
| Width across occipital condyles | 4 |
| Length of mandible | 25 |
| Anterior width of mandible | 2 |
| Length of large tooth | 1 |
Erpetosaurus tuberculatus Moodie.