Ornithischia

Ornithischians Temporal range: Early Jurassic–Late Cretaceous, 200–66 Ma PreЄ Є O S D C P T J K Pg N (Possible Late Triassic record)
A collection o ornithischian fossil skelets. Clockwise frae upper left: Heterodontosaurus tucki (a heterodontosaurid), Stegosaurus stenops (a platit stegosaur), Scolosaurus thronus (an airmoured ankylosaur), Edmontosaurus annectens (a duck-billed hadrosaur), Stegoceras validum (a thick-heidit pachycephalosaur), an Triceratops horridus (a horned ceratopsian).
Scientific classification
Kinrick:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Order:	†Ornithischia Seeley, 1888
Subgroups
†Chilesaurus? †Eocursor †Laquintasaura †Lesothosaurus †Pisanosaurus? †Saphornithischia †Heterodontosauridae †Genasauria †Thyreophora †Neornithischia
Synonyms
Predentata[1] Marsh, 1894

Ornithischia (/ɔːrnᵻˈθɪskiə/ or-ni-THISS-kee-ə)^[2] or Predentata is an extinct order o beakit, yerbivorous dinosaurs. The name ornithischia is derived frae the Greek ornitheos (ορνιθειος) meanin 'o a bird' an ischion (ισχιον) meanin 'hip joint'. Thay are kent as the 'bird-hipped' dinosaurs acause o thair bird-lik hip structur, even though birds actually belang tae the 'lizard-hipped' dinosaurs (the saurischians).

Some commonly kent Ornithischians include the hornit dinosaurs (ceratopsians), armored dinosaurs (stegosaurs an ankylosaurs), Iguanodon, an the "deuck-billed" dinosaurs (hadrosaurids). Bein herbivores that bytimes lived in herds, thay wur mair numerous nor the saurischians. Mony were prey ainmals for the theropods an wur uisually smawer nor the sauropods.