Podocnemididae

Podocnemididae
Yellow-spotted River Turtle (Podocnemis unifilis)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Superclass:	Tetrapoda
Class:	Reptilia
Subclass:	Anapsida
Order:	Testudines
Suborder:	Pleurodira
Superfamily:	Pelomedusoidea
Family:	Podocnemididae
Genera
Erymnochelys Peltocephalus Podocnemis and see text
Synonyms
Podocnemidinae

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, 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 prehistoric genus Stupendemys also belongs to this family. Living around 5.5 million years ago in northern South America, these were the largest freshwater turtles and the largest pleurodires known to date.

References

• Obst, Fritz Jürgen (1998): [Pelomedusinae]. In: Cogger, H.G. & Zweifel, R.G. (eds.): Encyclopedia of Reptiles and Amphibians: 112-113. Academic Press, San Diego. ISBN 0-12-178560-2

External links

"Podocnemididae". http://www.jcvi.org/reptiles/families/podocnemididae.php. Retrieved 2008-01-22.