Ornithischia ( ) or
Predentata is an extinct
order of beaked,
herbivorous dinosaurs. The name
ornithischia is derived from the
Greek ornitheos (
ορνιθειος) meaning 'of a bird' and
ischion (
ισχιον) meaning 'hip joint'. They are known as the 'bird-hipped' dinosaurs because of their bird-like
hip structure, even though
birds actually belong to the 'lizard-hipped' dinosaurs (the
saurischians).