article: Pelycosaur
links: Gorgonopsid Synapsid Permian Animal Europe Tetrapod Edaphosaurus South Africa Chordate Sphenacodon Dimetrodon Edward Drinker Cope P/Tr extinction event Genus Paraphyletic Order (biology) North America Dinosaur Cynodont Sphenacodontia Russia Scale (zoology) Pennsylvanian Sphenacodontoidea Triassic