Thrinaxodon
Thrinaxodon | ||||||||||||
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![]() Live reconstruction of Thrinaxodon liorhinus . |
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Temporal occurrence | ||||||||||||
Middle Triassic | ||||||||||||
245 to 230 million years | ||||||||||||
Locations | ||||||||||||
Systematics | ||||||||||||
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Scientific name | ||||||||||||
Thrinaxodon | ||||||||||||
Seeley , 1894 |
Thrinaxodon is a genus of extinct therapsids that lived 245 to 230 million years ago during the Middle Triassic . Fossil remains of the only known species Thrinaxodon liorhinus have been found in South Africa in the same formation in which Lystrosaurus was found and in Antarctica .
Thrinaxodon was a carnivore and grew to be about half a meter long, the legs were under the body, and the tail was quite short. It is one of the original Cynodontians (Cynodontia), a group of mammal-like reptiles, and was therefore very close to the mammals . The animals were small carnivores with sharp teeth. They had strong hind legs, which indicates that they were quick runners. Small depressions were found on the skulls that indicate whiskers . This needs to be but not necessarily seen as evidence that thrinaxodon a fur had. The whiskers were probably used for orientation in the dark.
The chest region was clearly separated from the lumbar region. The animal thus presumably had a diaphragm that enabled rapid exhalation and inhalation. This allows the body temperature to be regulated by panting . It also had a secondary roof of its mouth , which enabled it to breathe and chew at the same time. Compared to its ancestors, the dental one , in reptiles one of several bones of the lower jaw ( mandible ), was enlarged and bore all the teeth.
literature
- Thomas S. Kemp: The Origin & Evolution of Mammals. Oxford University Press, Oxford 2005. ISBN 0-19-850761-5 .
- Barry Cox: Dinosaurs and Other Animals of Ancient Times. Mosaik Verlag, Stuttgart, 1989, ISBN 3-8112-1138-2