Dinosauria Owen 1841 [Padian & May 1993], nom. cl. inval. see Clade Dinosauria Owen 1842 [Langer, Novas, Bittencourt, Ezcurra & Gauthier 2020]
Count: -
   †Ornithischia Seeley 1887 [Padian & May 1993] see Order Ornithischia Seeley, 1887
  Count: -
     †Genasauria Sereno 1986
    Count: -
       †Neornithischia Cooper 1985
      Count: -
         †Marginocephalia Sereno 1986
        Count: -
           †Ceratopsia Marsh 1890 see Infraorder Ceratopsia Marsh, 1890
          Count: -
             †Neoceratopsia Sereno 1986
            Count: -
               †Coronosauria Sereno 1986
              Count: -
                 1 †Protoceratopsidae Granger & Gregory 1923 see Family Protoceratopsidae Granger & Gregory, 1923
                Count: -
                 2 †Ceratopsoidea Hay 1902 see Superfamily Ceratopsoidea Marsh, 1888
                Count: -