Class Reptilia Linnaeus, 1758 - reptiles
   Subclass †Synapsida Osborn, 1903 - synapsids see Class Synapsida Osborn, 1903
     Order †Pelycosauria Cope, 1878 - pelycosaurs
       Suborder †Edaphosauria Cope, 1882 see Order Pelycosauria Cope, 1878
         1 Family †Nitosauridae Romer & Price, 1940
         2 Family †Lupeosauridae Romer & Price, 1940
         3 Family †Edaphosauridae Cope, 1882
         4 Family †Caseidae Williston, 1912