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 †Ornithopoda Marsh 1881 see Infraorder Ornithopoda Marsh, 1881 †Heterodontosauridae Romer 1966 see Family Heterodontosauridae Romer, 1966