Chelydra is one of the two extant genera of the snapping turtle family, Chelydridae, the other being Macrochelys, the much larger alligator snapping turtle. The snapping turtles are native to the Americas, with Chelydra having three species, one in North America and two in Central America, one of which is also found in northwestern South America.
The genus Chelydra has the following species:
The three extant Chelydra species were once all considered to be several subspecies of Chelydra serpentina, along with a fourth subspecies in Florida, Chelydra serpentina osceola. C. s. osceola is now considered to be synonymous with C. serpentina.