Trionychia
Trionychia is a superfamily of turtles which encompasses the species that are commonly referred to as softshelled turtles as well as some others. The group contains two families, Carettochelyidae, which has only one living species, the pig-nosed turtle ("Carettochelys insculpta") native to New Guinea and Northern Australia, and Trionychidae, the softshelled turtles, containing numerous species native to Asia, North America and Africa. The oldest known stem-tryonychian is "Sinaspideretes" from the Late Jurassic of China. Systematics. Except for those not assigned to a family, only living genera are listed here.