Ornithischia includes a variety of species which were primarily herbivores . ( "'NB : "'the terms " lizard hip " and " bird hip " are misnomers birds evolved from dinosaurs with " lizard hips " .)
32.
Another difference is in the skull, the upper skull of the Ornithischia is more solid and the joint connecting the lower jaw is more flexible; both are adaptations to herbivory and both can already be seen in " Lesothosaurus ".
33.
Similar things happened between birds and ornithischia; the hip structure in birds evolved independently, but along similar patterns, as did that of the ornithischians .-- " 32 " 13 : 31, 12 January 2017 ( UTC)
34.
Godefroit " et al . " concluded that the filaments earlier reported in Ornithischia, with " Psittacosaurus " and " Tianyulong ", could be archosauromorphs, as some distinctive archosaurian integument features have appeared this far back.
35.
Various possible evolutionary trees place it as the sister taxon of Dinosauria, the most basal member of Ornithischia ( the group that includes most herbivorous Mesozoic dinosaurs ), or a member of Theropoda ( the group that includes most carnivorous dinosaurs as well as birds ).
36.
However, Harry Seeley disagreed with this interpretation, and split the Dinosauria into two orders, the Saurischia ( " lizard-hipped " ) and the Ornithischia ( " bird-hipped " ), which were seen as members of the Archosauria with no special relationship to each other.
37.
The term " dinosaur " is restricted to just those reptiles descended from the last common ancestor of the groups Saurischia and Ornithischia ( clade Dinosauria, which includes birds ), and current scientific consensus is that this group excludes the pterosaurs, as well as the various groups of extinct marine reptiles, such as ichthyosaurs, plesiosaurs, and mosasaurs.
38.
"' Dinosaur classification "'began in 1842 when Sir Richard Owen placed " Iguanodon ", " Megalosaurus ", and " Hylaeosaurus " in " a distinct tribe or suborder of Saurian Reptiles, for which I would propose the name of Dinosauria . " In 1887 and 1888 Harry Seeley divided dinosaurs into the two orders Saurischia and Ornithischia, based on their hip structure.
