Podocnemididae is a family of turtles native to Madagascar and northern South America. They are side-necked turtles (Pleurodira), which means they do not retract their heads backwards, but hide it sideways. These turtles are all aquatic, inhabiting streams, and other flowing water. Their shells are streamlined to aid in swimming.

Taxonomy and systematics

The Podocnemididae have been united with their closest living relatives, the Pelomedusidae, under the latter name, with both groups being treated as subfamilies. Under that scheme, the present group is named Podocnemidinae. Some authors still maintain this classification,^[1] but here it is preferred to keep them distinct families in the superfamily Pelomedusoidea instead.

The family Podocnemididae contains only three living genera, two of them monotypic:

• Erymnochelys – Madagascar big-headed turtle
• Peltocephalus – big-headed Amazon River turtle
• Podocnemis – South American side-necked river turtles

The family also contains a number of prehistoric genera, including Albertwoodemys, Bairdemys, Bauruemys, Brontochelys, Caninemys, Cordichelys, Dacquemys, Lapparentemys, Latentemys, Lemurchelys, Mogharemys, Neochelys, Papoulemys, Peiropemys, Pricemys, Shweboemys, Stereogenys, Turkanemys, Cambaremys, Cerrejonemys, Kenyemys, Roxochelys and Stupendemys.^[2] Stupendemys lived around 5.5 million years ago in northern South America, and was the largest freshwater turtles and the largest pleurodire known to date.

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