Eothyrididae
| Eothyrididae | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Eothyris |
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| Temporal occurrence | ||||||||||||
| Upper carbon to lower perm | ||||||||||||
| 305 to 279.5 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Eothyrididae | ||||||||||||
| Romer & Price , 1940 |
The Eothyrididae are a family of synapsids from the group of pelycosaurs . According to the classical view, they are "reptiles", but related to the animals from which the " mammal-like reptiles " and finally the mammals developed.
So far, only the skulls of two genera are known, Eothyris and Oedaleops , which were each around 6 centimeters long, from which it can be concluded that the total length of the animals was less than 1 meter. The skulls are characterized by a strikingly broad, flat shape and a large skull window . In the upper jaw of Eothyris there were two enlarged, canine-like teeth per half of the jaw , which have no counterpart in the lower jaw - in Oedaleops these teeth were much weaker. The other teeth are uniform, small and pointed, which suggests meat or insects as food for the Eothyrididae. No fossils of the rest of the body have yet been found.
Both genera are known from the Upper Carboniferous and the Middle Permian from North America . The Eothyrididae and the Caseidae systematically form the group of the Caseasauria which is at the base of the synapsids and which forms the sister group of the Eupelycosauria , from which the therapsids (the "mammal-like reptiles") have developed.
literature
- Thomas S. Kemp: The Origin & Evolution of Mammals . Oxford University Press, Oxford 2005, ISBN 0-19-850761-5 .
