Archosaurs | |
---|---|
![]() | |
Crocodiles basking in the sun. Crocodiles can move quite fast on land by tucking their legs under their body: an archosaur feature. | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Eucrocopoda |
Clade: | Archosauria Cope, 1869 |
Subgroups | |
| |
Synonyms | |
Arctopoda Haeckel, 1895 |
Archosaurs are a large group of reptiles, including all crocodiles, birds, dinosaurs, and pterosaurs (flying reptiles). There are also a number of smaller extinct groups, mostly from the Triassic period.[1]
The Archosaurs are definitely a monophyletic clade, and do not include reptiles such as the Squamata (lizards and snakes) and the Sphenodontia (Sphenodon).[2]
They have these diagnostic features,[3] called synapomorphies in cladistics talk:
The archosaurs or their immediate ancestors survived the catastrophic Permian–Triassic extinction event. Benton comments: "The key tetrapods to benefit from the Permo-Triassic mass extinction was the Archosauromorpha".[4] Then, in the early and middle Triassic, there was rapid evolution into the types of aquatic and land tetrapods which dominated the rest of the Mesozoic era.