Vertebrata Cuvier, 1812 - vertebrates see Infraphylum Vertebrata Lamarck, 1801
   Gnathostomata
     Teleostomi Bonaparte, 1836
       Tetrapoda Hatschek & Cori 1896 [Gauthier, Kluge & Rowe 1988], nom. cl. inval. see Clade Tetrapoda Hatschek & Cori 1896 [Laurin 2020]
         Amniota Haeckel, 1866 [Gauthier, Kluge & Rowe 1988], nom. cl. inval. - amniotes see Clade Amniota Haeckel 1866 [Laurin & Reisz 2020]
           Class Reptilia Linnaeus, 1758 [paraphyletic] - 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.
                   †Dinosauria Owen 1841 [Padian & May 1993], nom. cl. inval. see Clade Dinosauria Owen 1842 [Langer, Novas, Bittencourt, Ezcurra & Gauthier 2020]
                     Order †Ornithischia Seeley, 1887
                       Suborder †Ceratopsia Marsh, 1890 see Infraorder Ceratopsia Marsh, 1890
                         Family †Ceratopsidae Marsh, 1888
                           01 Genus †Anchiceratops Brown, 1914
                           02 Genus †Arrhinoceratops Parks, 1925
                           03 Genus †Centrosaurus Lambe, 1904 see Genus Eucentrosaurus Chure & McIntosh, 1989, nom. illeg.
                           04 Genus †Chasmosaurus Lambe, 1914
                           05 Genus †Eoceratops Lambe, 1915
                           06 Genus †Monoclonius Cope, 1877, nom. dub.
                           07 Genus †Pachyrhinosaurus Sternberg, 1950
                           08 Genus †Pentaceratops Osborn, 1923
                           09 Genus †Styracosaurus Lambe, 1913
                           10 Genus †Torosaurus Marsh, 1891
                           11 Genus †Triceratops Marsh, 1889