Exostinus Cope, 1873

Conrad, J. L., 2008, Phylogeny And Systematics Of Squamata (Reptilia) Based On Morphology, Bulletin of the American Museum of Natural History 2008 (310), pp. 1-182 : 113-114

Exostinus Cope, 1873

(figs. 54D, 55D)

DEFINITION: Exostinus serratus , E. lancensis , and all descendants of their last common ancestor.

DIAGNOSIS: The two included species of Exostinus are united by 310(1) presence of thickened, irregularly shaped, osteoderms.

COMMENTS: Exostinus serratus and E. lancensis are nearly identical in the 42 characters for which they may both be scored. Exostinus lancensis possesses more well-developed subolfactory processes than E. serratus , but this is the only observed coding difference between the two for this analysis. Given the incomplete nature of the remains for both species, however, more difference might appear with the discovery of more complete remains for one or both species. Indeed, a preliminary review of available material suggests that Exostinus may be a paraphyletic assemblage of three or more taxa ( Bhullar, 2007).