Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates see Infraphylum Vertebrata Lamarck, 1801
     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 †Hypsilophodontidae Dollo, 1882
                   01 Genus †Atlascopcosaurus Rich & Rich, 1989
                   02 Genus †Fulgurotherium Huene, 1932, nom. dub.
                   03 Genus †Hypsilophodon Huxley, 1870
                   04 Genus †Laosaurus Marsh, 1878, nom. dub.
                   05 Genus †Leaellynosaura Lambert, 1991, orth. inval. see Genus Leaellynasaura Rich & Rich, 1989
                   06 Genus †Orodromeus Horner & Weishampel, 1988
                   07 Genus †Othnielia Galton, 1977, nom. dub.
                   08 Genus †Parksosaurus Sternberg, 1937
                   09 Genus †Phyllodon Thulborn, 1973, nom. dub.
                   10 Genus †Rhabdodon Matheron, 1869, nom. cons.
                   11 Genus †Tenontosaurus Ostrom, 1970
                   12 Genus †Yandusaurus He, 1979
                   13 Genus †Zephyrosaurus Sues, 1980