Kinosternoidea is a

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

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 tu ...

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 numb ...

. 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 '' Acherontemy ...

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 nutri ...

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

, 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 ''Hoplochelys'' is an extinct genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy ...

'' :*Subfamily

Staurotypinae The Staurotypinae are a subfamily of the family Kinosternidae 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 ...

::*Genus ''

Claudius Tiberius Claudius Caesar Augustus Germanicus (; 1 August 10 BC – 13 October AD 54) was the fourth Roman emperor, ruling from AD 41 to 54. A member of the Julio-Claudian dynasty, Claudius was born to Nero Claudius Drusus, Drusu ...

'' ::*Genus ''

Staurotypus ''Staurotypus'' is a genus of aquatic turtles, commonly known as giant musk turtles, Mexican musk turtles, or three-keeled musk turtles, in the family Kinosternidae. The genus contains two recognized species, which are endemic to Mexico and Cent ...

'' :*Subfamily

Kinosterninae Kinosterninae is a subfamily of the family Kinosternidae, a family of aquatic turtles. Kinosterninae contains the genera ''Kinosternon'' and ''Sternotherus'', which are native to much of the United States and northern Mexico Mexico (Spanis ...

::*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 The big-headed turtle (''Platysternon megacephalum'') is a species of turtle in the family Platysternidae from Southeast Asia and southern China. Background Previously considered a distinct family placed on occasion in " Kinosternoidea", it w ...

(''Platysternon megacephalum'') was previously included in classification.

References

;Bibliography * {{Turtle-stub