Osteichthyes - Synapsida - Sphenacodontidae
Full reference: A. S. Romer. 1936. Studies on American Permo-Carboniferous reptiles. Problems of Paleontology 1:85-93
Parent taxon: Sphenacodontidae according to R. R. Reisz 1986
See also Berman 1977, Kuhn 1946, Kuhn 1966 and Romer 1936
Sister taxa: Cryptovenator, Ctenorhachis, Dimetrodon kempae, Eosyodon, Eosyodon hudsoni, Secodontosaurinae, Varanopsinae
Subtaxa: Bathygnathus Ctenospondylus Dimetrodon Macromerion Neosaurus Sphenacodon
Type: Sphenacodon
Ecology:
Distribution:
• Permian of Canada (1: Prince Edward Island collection), France (1), Germany (1), the United Kingdom (1), United States (95: New Mexico, Ohio, Oklahoma, Texas, Utah)
• Carboniferous to Permian of United States (3: New Mexico, Utah)
• Carboniferous of the Czech Republic (1), United States (1: New Mexico)
Total: 104 collections including 123 occurrences