Champsosaurus vaccinsulensis (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 : 353

Champsosaurus vaccinsulensis , sp. nov.

This reptile is indicated by a posterior dorsal vertebra in which the common base of the neural arch and diapophysis is decurved to below the middle of the side of the centrum. This surface has somewhat the outline of the section of a T-rail, the inner portion being on the superior face of the centrum. The centrum is shorter than the corresponding ones of the C. annectens and C. profundas , so that the basis of the neural arch approaches near the borders of the articular faces above. The centrum is perforated by two vertical foramina as in most Sauropleryyía . The osseous tissue of the bone is quite dense, and the surface is smooth.

Measurements.	n.
antero-posterior Diameter of ceutrnm {vertical transverse	. 026.029. 045

Besides the much larger size, this species differs from those previously referred to this genus in almost all details of proportion, etc.