Trionychia

Trionychia
Spiny softshell turtle (Apalone spinifera)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Superclass:	Tetrapoda
Class:	Sauropsida
Subclass:	Anapsida
Order:	Testudines
Suborder:	Cryptodira
Superfamily:	Trionychia Hummel, 1929
Families
Carettochelyidae Trionychidae and see text
Synonyms
Kinosternoidea Trionychoidea

Trionychia is a superfamily of turtles which encompasses the species that are commonly referred to as softshelled turtles as well as some others. They are found throughout the temperate regions of the world.

It traditionally consisted of a single family, two subfamilies, and 14 genera. However, more recently it was realized that the supposed "Kinosternoidea" are actually early offshoots of the Trionychoidea and not as closely related among each other as it was believed. These two families lack the characteristic trionychoid apomorphies, but possess some highly derived characters of their own, which they moreover evolved independently from each other.

Systematics

Except for those not assigned to a family, only living genera are listed here.

Basal and incertae sedis

• Genus †Hoplochelys (fossil)
• Genus †Emarginachelys (fossil)

Family †Adocidae (fossil)

• Subfamily Shachemydinae
  • Genus Shachemys

Family Carettochelyidae

• Subfamily Carettochelyinae
  • Genus Carettochelys

Family Trionychidae

• Subfamily Plastomeninae (fossil)
• Subfamily Cyclanorbinae
  • Genus Cyclanorbis
  • Genus Cycloderma
  • Genus Lissemys
• Subfamily Trionychinae
  • Genus Amyda
  • Genus Apalone
  • Genus Chitra
  • Genus Dogania
  • Genus Nilssonia
  • Genus Palea (genus)
  • Genus Pelochelys
  • Genus Pelodiscus
  • Genus Rafetus
  • Genus Trionyx

The eastern mud turtle (Kinosternon subrubrum) is a primitive relative of the true softshells which still has a typical hard turtle shell

External links

• Haaramo, Mikko (2008): Mikko's Phylogeny Archive - Trionychoidea. Version of 2008-MAR-11. Retrieved 2008-MAY-06.