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 †Pachycephalosauria Maryañska & Osmólska, 1974 see Infraorder Pachycephalosauria Maryañska & Osmólska, 1974
                         Family †Pachycephalosauridae Sternberg, 1945
                           1 Genus †Gravitholus Wall & Galton, 1979, nom. dub. see Genus Stegoceras Lambe, 1902
                           2 Genus †Ornatotholus Galton & Sues, 1983 see Genus Stegoceras Lambe, 1902
                           3 Genus †Pachycephalosaurus Brown & Schlaikjer, 1943, nom. cons.
                           4 Genus †Stegoceras Lambe, 1902
                           5 Genus †Stygimoloch Galton & Sues, 1983 see Genus Pachycephalosaurus Brown & Schlaikjer, 1943, nom. cons.
                           6 Genus †Majungatholus Sues & Taquet, 1979
                           7 Genus †Prenocephale Maryañska & Osmólska, 1974
                           8 Genus †Tylocephale Maryañska & Osmólska, 1974
                           9 Genus †Yaverlandia Galton, 1971