Life image of Cotylorhynchus
- North America
The Caseasauria are known from the Permian taxon synapsids from the group of Pelycosaurier, so according to the classical view " reptiles ".
The common features of Caseasauria are the enlarged nostrils ( nares ) and a pointed snout, which is formed by the premaxillary bone. The skull is wide, the TMJ was sitting low on the head. The teeth of the Caseidae were uniform ( homodont ) and blunt, the Eothyrididae had two enlarged eckzahnähnliche teeth in the upper jaw.
The Caseasauria lived on the upper Carboniferous to Middle Permian. While the Eothyrididae are only known from the Upper Carboniferous / Lower Permian of North America, remnants of Caseidae were also found in Eurasia; this group is assigned to the Upper Permian and probably died in the mass extinction at the end of the period of.
Systematically form the Caseasauria the basal representatives of the synapsids and form the sister group of the Eupelycosauria of which have become the therapsids ( " mammal-like reptiles " ), and finally developed the mammals. The following cladogram illustrates this:
Therapsida (including mammals)