Dinosauria Owen 1841 [Padian & May 1993], nom. cl. inval. see Clade Dinosauria Owen 1842 [Langer, Novas, Bittencourt, Ezcurra & Gauthier 2020]
   †Ornithischia Seeley 1887 [Padian & May 1993] see Order Ornithischia Seeley, 1887
     †Genasauria Sereno 1986
       †Neornithischia Cooper 1985
         †Marginocephalia Sereno 1986
           †Pachycephalosauria Maryañska & Osmólska 1974 see Infraorder Pachycephalosauria Maryañska & Osmólska, 1974
             1 Genus †Stenopelix Meyer, 1857
             2.1 Genus †Goyocephale Perle, Maryanska & Osmólska, 1982
             2.2.1 Genus †Homalocephale Maryañska & Osmólska, 1974
             2.2.2 †Pachycephalosauridae Sternberg 1945 see Family Pachycephalosauridae Sternberg, 1945