Order †Pachycephalosauria Maryañska & Osmólska, 1974 see Infraorder Pachycephalosauria Maryañska & Osmólska, 1974 Family †Pachycephalosauridae Sternberg, 1945 Genus †[Homalocephale] Maryañska & Osmólska, 1974 1 †Homalocephale calathocercos T. Maryañska & H. Osmólska, 1974