Class Reptilia Linnaeus, 1758 - reptiles Subclass †Synapsida Osborn, 1903 - synapsids see Class Synapsida Osborn, 1903 Order †Therapsida Broom, 1905 see [unranked] Therapsida Broom, 1905 Suborder †Dinocephalia Seeley, 1894 see [unranked] Dinocephalia Seeley, 1894 Family †Estemmenosuchidae Tchudinov, 1960