vertebrates Cuvier, 1812 - vertebrates
   Cohort Amniota Haeckel, 1866 see Clade Amniota Haeckel, 1866 [Gauthier, Kluge & Rowe 1988]
     Class "Reptilia" Linnaeus, 1758 - reptiles
       Subclass Sauropsida Huxley, 1864
         Superorder Archosauria Cope, 1869 - archosaurs see Clade Archosauria Cope 1869 [Gauthier & Padian 1985], nom. cl. inval.
           Order †Ornithischia Seeley, 1887
             1 Suborder †Ankylosauria Osborn, 1923 see Infraorder Ankylosauria Osborn, 1923
             2 Suborder †Ceratopsia Marsh, 1890 see Infraorder Ceratopsia Marsh, 1890