(pronounced or-ni-THISS-key-an ) Ornithischian (bird-hipped) dinosaurs were herbivoroud dinoaurs that had hoof-like claws. Some ornithischians include the Ornithopods (Fabrosaurs, Hadrosaurs, Hypsilophodontids, Iguanodontids, Camptosaurids), Thyreophorans (Ankylosaurids, Stegosaurids), and Marginocephalians (Ceratopsians, Pachycephalosaurs).

Meaning bird-bird-hipped, is one of two main groups of Dinosauria and refers to the structure of pelvis or the hip-bone. The dinosaurios of Ornithischian had pelvis with the bone pubic that indicated the other way around and under socles of the hip. Also see Saurischian .