Trithelodontids Fossil range: Late Triassic to Middle Jurassic PreЄ Є O S D C P T J K Pg N
restoration of Pachygenelus monus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Synapsida
Order:	Therapsida
Suborder:	Cynodontia
Infraorder:	Eucynodontia
Superfamily:	Probainognathia
(unranked)	Chiniquodontoidea
Family:	Trithelodontidae
Genera
See below

The Trithelodontids, also known as Ictidosaurs^[1], were small to medium-sized cynodonts. They were extremely mammal-like, highly specialized cynodonts, although they still retained a very few reptilian anatomical traits. Trithelodontids were mainly carnivorous or insectivorous, though some species may have developed omnivorous traits. Their skeletons show that they had a close relationship to mammals. Trithelodontids or its closest relatives may have given rise to primitive mammals. The trithelodontids were one of the longest lived non-mammalian therapsids, living from late Triassic to the Jurassic period. Trithelodontids became extinct in the Jurassic period possible due to competition with prehistoric mammals such as the triconodonts. They are known from finds in South America and South Africa, indicating that they may have only lived on the supercontinent of Gondwanaland.

[edit] Genera

• Riograndia (a primitive Trithelodontid)
• Subfamily Thrithelodontinae
  • Chalimia
  • Elliotherium
  • Diarthrognathus
  • Irajatherium
  • Trithelodon
  • Pachygenelus

[edit] See also

• Tritylodontidae
• Evolution of mammals

[edit] References