| Therapsids | |
|---|---|
 | |
| From top to bottom and left to right, several examples of non-mammalian therapsids:Biarmosuchus (Biarmosuchia),Moschops (Dinocephalia),Lystrosaurus (Anomodontia),Inostrancevia (Gorgonopsia),Glanosuchus (Therocephalia) andChiniquodon (Cynodontia). | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Synapsida |
| Clade: | Sphenacodontia |
| Clade: | Pantherapsida |
| Clade: | Sphenacodontoidea |
| Clade: | Therapsida Broom, 1905[1] |
| Clades | |
| |
Therapsids, previously known as themammal-like reptiles,[2] are a group ofsynapsids.
Theclade includes themammals, which are descended from thecynodont therapsids.
The jaws of therapsids had frontalincisors for nipping, large lateral canines for puncturing and tearing, andmolars for shearing and tearing, and chopping food.
Therapsid legs were positioned more vertically beneath their bodies than were the sprawling legs ofSauropsids andPelycosaurs.
The therapsids were seriously affected by theP/Tr extinction event. The successfulgorgonopsians died out, and the remaining groups were much reduced.
Thedicynodonts were now a single family of large stocky herbivores, the Kannemeyeridae. The medium-sized cynodonts (including carnivorous and herbivorous forms), flourished worldwide in the early to middleTriassic. They died out across much ofPangea before the end of the Upper Triassic. Some survived for a while in the wet equatorial band and in the South.
At least three groups of eucynodonts survived. They appeared in theUpper Triassic. The extremely mammal-like family, theTritylodonts, survived into theLower Cretaceous. Another group,Morganucodon and its relatives, weremammaliaformes. That is, their descendants became the mammals.
