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Pelycosaur
Informal grouping composed of basal or primitive Late Paleozoic synapsids / From Wikipedia, the free encyclopedia
Pelycosaur (/ˈpɛlɪkəˌsɔːr/ PEL-ih-kə-sor)[1] is an older term for basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants. Previously, the term mammal-like reptile had been used,[2] and pelycosaur was considered an order, but this is now thought to be incorrect, and seen as outdated.
Pelycosaurs | |
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Mounted skeleton of Dimetrodon mileri, Harvard Museum of Natural History | |
Scientific classification![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Superclass: | Tetrapoda |
Clade: | Reptiliomorpha |
Clade: | Amniota |
Clade: | Synapsida |
Informal group: | †Pelycosauria Cope, 1878 |
Groups included | |
Cladistically included but traditionally excluded taxa | |
Because it excludes the advanced synapsid group Therapsida, the term is paraphyletic and contrary to modern formal naming practice.[3][4] Thus the name pelycosaurs, similar to the term mammal-like reptiles, had fallen out of favor among scientists by the 21st century, and is only used informally, if at all, in the modern scientific literature.[5][6] The terms stem mammals, protomammals, and basal or primitive synapsids are instead used where needed.