Subfamilia Staurotypinae

Gray, 1869a
Tropical musk turtles

The two genera, Claudius (one species) and Staurotypus (two species), range from central Mexico into northern Central America. These are rather large musk turtles with reduced, cross-shaped plastra, having only seven or eight scutes. An entoplastron is present. The carapace is three-keeled and contains six to eight neural bones. On the pelvic girdle, the pubic and ischiadic symphyses are widely separated. Bickham and Carr (1983) would elevate this subfamily to family status, Staurotypidae, on the basis of chromosomal differences from the Kinosterninae. Claudius and Staurotypus have genetic sex determination.