Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Class Reptilia Linnaeus, 1758 - reptiles
       Subclass Archosauria Cope, 1869 see Division Archosauria Cope, 1869
         Order †Ornithischia Seeley, 1887
           1 Suborder †Ornithopoda Marsh, 1871 see Infraorder Ornithopoda Marsh, 1881
           2 Suborder †Stegosauria Marsh, 1877 see Infraorder Stegosauria Marsh, 1877
           3 Suborder †Ankylosauria Osborn, 1923 see Infraorder Ankylosauria Osborn, 1923
           4 Suborder †Ceratopsia Marsh, 1890 see Infraorder Ceratopsia Marsh, 1890