Waxaa sidoo kale la soo jeediyay in Dinosauria lagu qeexo iyadoo la tixraacayo MRCA ee Megalosaurus iyo Iguanodon, maxaa yeelay kuwani waxay ahaayeen laba ka mid ah saddexda nooc ee uu soo xigtay Richard Owen markii uu aqoonsaday Dinosauria. Labada qeexitaanba waxay keeneen isla noocyada xayawaanka ee loo yaqaan dinosaurs: "Dinosauria = Ornithischia + Saurischia", oo ka kooban ankyloproposaurians (armored herbivorous quadrupod), stegoposaurians (plated herbivorous quadrupod), ceratopsians (herbivorous quadrupod with horns and horns), iyo frognithopeds (frognithopeds), ama frognithopeds (frognithop), kuwaas oo loo tixraacayo sida dinosaurs.
awoowayaashii ugu dambeeyay ee Triceratops iyo Neornithes (MRCA), iyo dhammaan faracooda