Order †Ornithischia Seeley, 1887
   Suborder †Ceratopia
     Family †Ceratopidae
       Genus †Anchiceratops Brown, 1914
       Genus †Arrhinoceratops Parks, 1925
       Genus †Centrosaurus Lambe, 1904, nom. illeg. see Genus Eucentrosaurus Chure & McIntosh, 1989
       Genus †Chasmosaurus Lambe, 1914
       Genus †Pachyrhinosaurus Sternberg, 1950
       Genus †Pentaceratops Osborn, 1923
       Genus †Styracosaurus Lambe, 1916
       Genus †Torosaurus Marsh, 1891
       Genus †Triceratops Marsh, 1889