Order †Ornithischia Seeley, 1887
   Suborder †Ornithopoda Marsh, 1871 see Infraorder Ornithopoda Marsh, 1881
     Family †Hadrosauridae Cope, 1869 - hadrosaurs
       Genus †Anatosaurus Lull & Wright, 1942 see Genus Edmontosaurus Lambe, 1917
       Genus †Bactrosaurus Gilmore, 1933
       Genus †Corythosaurus Brown, 1914
       Genus †Edmontosaurus Lambe, 1917
       Genus †Hadrosaurus Leidy, 1858, nom. dub.
       Genus †Hypacrosaurus Brown, 1913
       Genus †Kritosaurus Brown, 1910, nom. dub.
       Genus †Lambeosaurus Parks, 1923
       Genus †Maiasaura Horner & Makela, 1979
       Genus †Parasaurolophus Parks, 1923
       Genus †Prosaurolophus Brown, 1916
       Genus †Saurolophus Brown, 1912
       Genus †Shantungosaurus Hu, 1973
       Genus †Tsintaosaurus Young, 1958