Phylum [Vertebrata] Lamarck, 1801 see Infraphylum Vertebrata Lamarck, 1801
   Class Reptilia Linnaeus, 1758 - reptiles
     Subclass Diapsida Osborn, 1903 - diapsids see Clade Diapsida Osborn 1903 [Gauthier & de Queiroz 2020]
       Infraclass Archosauromorpha Huene, 1946 see Clade Archosauromorpha Huene 1946 [Benton 1985], nom. cl. inval.
         Superorder Archosauria Cope, 1869 - archosaurs see Clade Archosauria Cope 1869 [Gauthier & Padian 1985], nom. cl. inval.
           Order †Ornithischia Seeley, 1887
             Suborder †Ceratopia see Suborder Ceratopsia Marsh, 1890
               Family †Ceratopidae see Family Ceratopsidae Marsh, 1888
                 1 Genus †Anchiceratops Brown, 1914
                 2 Genus †Arrhinoceratops Parks, 1925
                 3 Genus †Centrosaurus Lambe, 1904 see Genus Eucentrosaurus Chure & McIntosh, 1989, nom. illeg.
                 4 Genus †Chasmosaurus Lambe, 1914
                 5 Genus †Pachyrhinosaurus Sternberg, 1950
                 6 Genus †Pentaceratops Osborn, 1923
                 7 Genus †Styracosaurus Lambe, 1913
                 8 Genus †Torosaurus Marsh, 1891
                 9 Genus †Triceratops Marsh, 1889