Diapsida Osborn 1903 [Laurin 1991] see Clade Diapsida Osborn 1903 [Gauthier & de Queiroz 2020]
   Archosauromorpha xxxHuene 1946 [Gauthier, Kluge & Rowe 1988] see Clade Archosauromorpha Huene 1946 [Benton 1985], nom. cl. inval.
     Archosauria Cope, 1869
       Ornithosuchia see [unranked] Avesuchia Benton, 1999
         Ornithodira Gauthier 1986 see Clade Ornithodira Gauthier 1986 [M. Ezcurra, S. Nesbitt, M. Bronzati, F. Dalla Vecchia, F. Agnolin, R. Benson, ..., M. Langer 2020]
           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
                 †Thyreophora Nopcsa 1915 see Suborder Thyreophora Nopcsa, 1915
                   Genus †Scelidosaurus Owen, 1859