Order †Ornithischia Seeley, 1887
   Suborder †Ankylosauria Osborn, 1923 see Infraorder Ankylosauria Osborn, 1923
     1 Family †Scelidosauridae Huxley, 1869
     2 Family †Nodosauridae Marsh, 1890
     3 Family †Ankylosauridae Brown, 1908