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 †Hadrosauridae Cope, 1869 - hadrosaurs
Genus †Diclonius Cope, 1876, nom. dub.