Anomodontia

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Anomodontia
Venyukovia

Venyukovia

Temporal occurrence
Middle Perm to Lower Jurassic
268.0 to 189.6 million years
Locations
  • Worldwide
Systematics
Vertebrates (vertebrata)
Land vertebrates (Tetrapoda)
Amniotes (Amniota)
Synapsids (Synapsida)
Therapsids (Therapsida)
Anomodontia
Scientific name
Anomodontia
Owen , 1859

The anomodontia are the largest group of therapsids ("early mammalian relatives"). They were widespread worldwide from the Middle Permian ( Guadalupium ) to the Lower Jurassic . In 2003 a skull fragment from Australia was described, which comes from the Lower Cretaceous and is said to belong to an anomodont from the group of Dicynodontia . Anomodonts have also been found on the Antarctic continent. More than 40 genera have been described so far, but new discoveries, especially in Russia and China, mean that more new genera can be expected.

features

The Anomodontia were mostly large, herbivorous animals. The largest representatives reached the size of a hippopotamus . Its features include a shortening of the snout region of the skull, a large parietal bone , a reduced lateral wing of the wing bone , a deep-seated lower jaw joint, the reduction of the teeth of the upper jaw from front to back, and a mostly toothless lower jaw . In front of the sacrum they usually had 26 vertebrae , the sacrum itself consisted of four to six vertebrae.

With the exception of two large tusks in the upper jaw, the dicynodontia eventually lost most of the teeth, some shapes and all of the dentition, and instead developed a horned beak similar to that of the tortoise .

Systematics

Most anomodontia are the dicynodontia. They also include some more primitive taxa from Russia, as well as the Dromasauroidea from South Africa , which has only been proven by four fossil finds .

Ulemica
Australobarbarus

literature

  • Thomas S. Kemp: The Origin & Evolution of Mammals. Oxford University Press, Oxford 2005. ISBN 0-19-850761-5 .
  • Oskar Kuhn: The mammal-like reptiles . A. Ziemsen Verlag, 2003, ISBN 3-89432-797-9 .

Web links

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