Odontochelys

= Odontochelys = Odontochelys semitestacea (meaning "toothed turtle with a half-shell") is a Late Triassic relative of turtles. On the other hand, a pathological study of Odontochelys performed by Rothschild & Naples (2015) discovered that both the left and right humeri (forearm bones) of the paratype specimen (IVPP 13240) of Odontochelys had been degraded near the shoulder sockets.

Odontochelys semitestacea was first described from three 220-million-year-old specimens excavated in Triassic deposits in Guizhou, China. The locale of its discovery at one time was the Nanpanjiang Trough basin, a shallow marine environment surrounded on three sides by land. These deposits preserve an ecosystem known as the Guanling biota, which was dominated by marine reptiles. Odontochelys differed grossly from modern turtles.

both modern and prehistoric alike, are their dorsal shells, forming an armored carapace over the body of the animal. Odontochelys only possessed the bottom portion of a turtle's armor, the plastron. It did not yet have a solid carapace as most other turtles do. Instead of a solid carapace, Odontochelys possessed broadened ribs like those of modern turtle embryos that still have not started developing the ossified plates of a carapace.

Odontochelys was considered the oldest undisputed member of Pantestudines (i.e. a stem-turtle). It is the only known species in the genus Odontochelys and the family Odontochelyidae.