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 †Ceratopsia Marsh 1890 see Infraorder Ceratopsia Marsh, 1890 †Neoceratopsia Sereno 1986 †Coronosauria Sereno 1986 1 †Protoceratopsidae Granger & Gregory 1923 see Family Protoceratopsidae Granger & Gregory, 1923 2 †Ceratopsoidea Hay 1902 see Superfamily Ceratopsoidea Marsh, 1888