Champsosaurus profundus (Cope) Cope ED, 1876

Cope, E. D., 1876, On some extinct reptiles and batrachia from the Judith River and Fox Hills beds of Montana, Proceedings of the Academy of Natural Sciences of Philadelphia 28, pp. 340-359 : 350

Champsosaurus profundus , sp. nov.

This species is chiefly known from a series of vertebrae found together, and having every appearance of pertaining to the same animal. It consists of a cervical, three dorsal, and a sacral vertebrae. Other isolated vertebrae of several individuals present similar characters.

The primary feature is the great vertical diameter of the dorsal vertebrae as compared with the transverse measurement. This is occasioned by the great development of the inferior keel, to which the sides of the centrum converge, without concavity. In corresponding centra of the C. annectens the inferior face is merely angulate. Another character is the obliquity of the articular faces to a vertical plane drawn at right angles to the long axis of the Centrum. This is most strongly marked on posterior dorsals, where the inferior keel is less prominent. The sacral vertebra has a depressed form.

An anterior caudal vertebra may belong to this or an undescribed species. It has rudiments only of the chevron-facets, and having a large neural arch, is doubtless from the anterior part of the series. It is more compressed than the corresponding one in C. annectens , and has an acute inferior angle, which is wanting in the latter.