Class Reptilia Linnaeus, 1758 - reptiles Subclass Archosauria Cope, 1869 see Division Archosauria Cope, 1869 Order †Ornithischia Seeley, 1887 Suborder †Ornithopoda Marsh, 1871 see Infraorder Ornithopoda Marsh, 1881 Family †Heterodontosauridae Romer, 1966