What is "compsemys"

Compsemys is a genus of prehistoric turtles from the Late Cretaceous and Paleocene of North America. Although several species have been described, they are all considered synonyms of one species, C. victa, first described by Joseph Leidy in 1856. Its familial affinities are unclear, with recent authors favoring Dermatemydidae.

Compsemys was a moderately sized turtle, up to long, with a carapace covered with raised, flattened tubercles, which are not seen in any other turtle. This allows even small shell fragments to be identified as Compsemys. The skull resembles that of the alligator turtle, with a sharply hooked beak; Compsemys must have been an aquatic carnivore.