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 †Ornithopoda Marsh, 1871
see Infraorder Ornithopoda Marsh, 1881
Infraorder †Hypsilophodontia Cooper, 1985
see Family Hypsilophodontidae Dollo, 1882
1 Genus †Thescelosaurus Gilmore, 1913
2 Family †Hypsilophodontidae Dollo, 1882