Macrochelys temminckii (Gray 1856, originally Macroclemys temminckii, Troost in Harlan, 1835; extant) the alligator snapping turtle has powerful jaws, a long extensible neck and sharp ridges on the shell. This cryptodire turtle nests in the large reptile tree with Terrapene.
Terrapene carolina (Linneaus 1758) is the common box turtle, with the distinctive hinged plastron that permits it to completely enclose itself. Derived from a sister to Kayentachelys, in the small sampling of turtles in the large reptile tree Terrapene is a sister to the green sea turtle, Chelonia.
Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.