Kinosternoidea is a superfamily of aquatic

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...

s, which includes two families:

Dermatemydidae The Dermatemydidae are a family of turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side nec ...

, and

Kinosternidae The Kinosternidae are a family of mostly small turtles that includes the mud turtles and musk turtles. The family contains 25 species within four genera, but taxonomic reclassification is an ongoing process, so many sources vary on the exact num ...

. Kinosternoids are

cryptodires The Cryptodira ('' el, hidden neck'') are a suborder of Testudines that includes most living tortoises and turtles. Cryptodira differ from Pleurodira (side-necked turtles) in that they lower their necks and pull the heads straight back into the ...

, turtles whose necks are able to retract within their shell. Molecular studies suggest they are likely the sister group to the

snapping turtles The Chelydridae is a family of turtles that has seven extinct and two extant genera. The extant genera are the snapping turtles, ''Chelydra'' and ''Macrochelys''. Both are endemic to the Western Hemisphere. The extinct genera are ''Acherontemys' ...

of the family Chelydridae. They are also

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...

, oviparous, phosphatic, and actively mobile.

Classification

*Family

::*Genus ''

Dermatemys The hickatee (''Dermatemys mawii'') or in Spanish ''tortuga blanca'' ('white turtle'), also called the Central American river turtle, is the only living species in the family Dermatemydidae. The species is found in the Atlantic drainages of Cen ...

'' ::*Genus '' Baptemys''Walter G. Joyce (2007)
Phylogenetic Relationships of Mesozoic Turtles
" Bulletin of the Peabody Museum of Natural History *Family

:*Genus '' Hoplochelys'' :*Subfamily Staurotypinae ::*Genus '' Claudius'' ::*Genus '' Staurotypus'' :*Subfamily Kinosterninae ::*Genus ''

Kinosternon ''Kinosternon'' is a genus of small aquatic turtles from the Americas known commonly as mud turtles. Geographic range They are found in the United States, Mexico, Central America, and South America. The greatest species richness is in Mexico, a ...

'' ::*Genus ''

Sternotherus ''Sternotherus'' is a genus of turtles in the family Kinosternidae including six species commonly known as musk turtles. The genus is endemic to North America, occurring in the eastern third of the USA and southeast Ontario, Canada. Musk glands ...

Past classification

The entirely unrelated big-headed turtle (''Platysternon megacephalum'') was previously included in classification.

References

;Bibliography * {{Turtle-stub