Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Class Reptilia Linnaeus, 1758 - reptiles
       Subclass Diapsida Osborn, 1903 - diapsids see Clade Diapsida Osborn 1903 [Gauthier & de Queiroz 2020]
         Infraclass Archosauromorpha Huene, 1946 see Clade Archosauromorpha Huene 1946 [Benton 1985], nom. cl. inval.
           Superorder Archosauria Cope, 1869 - archosaurs see Clade Archosauria Cope 1869 [Gauthier & Padian 1985], nom. cl. inval.
             Order †Ornithischia Seeley, 1887
               Suborder †Ornithopoda Marsh, 1871 see Infraorder Ornithopoda Marsh, 1881
                 Family †Heterodontosauridae Romer, 1966
                   Genus †Abrictosaurus Hopson, 1975