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
               †Dryosauridae Milner & Norman 1984 see Family Dryosauridae Stefano, 1903