Order †Ornithischia Seeley, 1887
   Parvorder †Genasauria Sereno, 1986 see Clade Genasauria Sereno 1986
     Nanorder †Cerapoda Sereno, 1986 see Suborder Cerapoda Sereno, 1986
       Hypoorder †Euornithopoda Sereno, 1986 see Clade Euornithopoda Sereno 1986
         Suborder †Heterodontosauria Cooper, 1985 see Family Heterodontosauridae Romer, 1966
           Family †Xiphosauridae Sereno, 1986, nom. inval. see Family Heterodontosauridae Romer, 1966
             Genus †Heterodontosaurus Crompton & Charig, 1962