Infraphylum Tetrapoda Goodrich, 1930 see Clade Tetrapoda Hatschek & Cori 1896 [Laurin 2020]
   Superclass Amniota Haeckel, 1866 see Clade Amniota Haeckel 1866 [Laurin & Reisz 2020]
     Paraclass Reptilia Linnaeus, 1758 [paraphyletic] - reptiles
       Parasubclass Diapsida Osborn, 1903 [paraphyletic] - diapsids see Clade Diapsida Osborn 1903 [Gauthier & de Queiroz 2020]
         Parainfraclass Archosauria Cope, 1869 [paraphyletic] see Clade Archosauria Cope 1869 [Gauthier & Padian 2020]
           Superorder †Ornithischia Seeley, 1887 see Order Ornithischia Seeley, 1887
             Paraorder †Pachycephalosauria Maryañska & Osmólska, 1974 [paraphyletic] 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 †Majungatholus Sues & Taquet, 1979
                 3 Genus †Ornatotholus Galton & Sues, 1983 see Genus Stegoceras Lambe, 1902
                 4 Genus †Pachycephalosaurus Brown & Schlaikjer, 1943, nom. cons.
                 5 Genus †Prenocephale Maryañska & Osmólska, 1974
                 6 Genus †Stegoceras Lambe, 1902
                 7 Genus †Stygimoloch Galton & Sues, 1983 see Genus Pachycephalosaurus Brown & Schlaikjer, 1943, nom. cons.
                 8 Genus †Tylocephale Maryañska & Osmólska, 1974
                 9 Genus †Yaverlandia Galton, 1971