Infraphylum Tetrapoda Goodrich, 1930 see Clade Tetrapoda Hatschek & Cori 1896 [Laurin 2020]
   Superclass Amniota Haeckel, 1866 see Clade Amniota Haeckel 1866 [Laurin & Reisz 2020]
     Paraclass Reptilia Linnaeus, 1758 [paraphyletic] - reptiles
       Parasubclass Diapsida Osborn, 1903 [paraphyletic] - diapsids see Clade Diapsida Osborn 1903 [Gauthier & de Queiroz 2020]
         Parainfraclass Archosauria Cope, 1869 [paraphyletic] see Clade Archosauria Cope 1869 [Gauthier & Padian 2020]
           Superorder †Ornithischia Seeley, 1887 see Order Ornithischia Seeley, 1887
             Order †Ornithopoda Marsh, 1881 see Infraorder Ornithopoda Marsh, 1881
               1 Parafamily †Hypsilophodontidae Dollo, 1882 [paraphyletic]
               2 Family †Dryosauridae Milner & Norman, 1984
               3 Family †Camptosauridae Marsh, 1885
               4 Parafamily †Iguanodontidae Cope, 1869 [paraphyletic]
               5 Family †Hadrosauridae Cope, 1869 - hadrosaurs
               6 Family †Lambeosauridae Parks, 1923 see Subfamily Lambeosaurinae Parks, 1923