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 †Euornithopoda Sereno 1986 †Iguanodontia Dollo 1888 1 Genus †Tenontosaurus Ostrom, 1970 2.1 †Dryosauridae Milner & Norman 1984 see Family Dryosauridae Stefano, 1903 2.2 †Ankylopollexia Sereno 1986