Order †Ornithischia Seeley, 1887 Parvorder †Genasauria Sereno, 1986 see Clade Genasauria Sereno 1986 1 Nanorder †Thyreophora Nopcsa, 1915 see Suborder Thyreophora Nopcsa, 1915 2 Nanorder †Cerapoda Sereno, 1986 see Suborder Cerapoda Sereno, 1986