Class Reptilia Linnaeus, 1758 - reptiles Subclass †Synapsida Osborn, 1903 - synapsids see Class Synapsida Osborn, 1903 Order †Pelycosauria Cope, 1878 - pelycosaurs Suborder †Ophiacodontia (Romer & Price, 1940) see Order Pelycosauria Cope, 1878 Family †Eothyrididae Romer & Price, 1940