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.

1. ↑ Ferigolo, J.; Langer, M. C. (2007). "A Late Triassic dinosauriform from south Brazil and the origin of the ornithischian predentary bone". Historical Biology. 19: 23–33. doi:10.1080/08912960600845767.
2. ↑ OED