Ornithischia is an order of beaked, herbivorous dinosaurs.
They are known as the 'bird-hipped' dinosaurs because of their hip structure. However, birds actually descended from the 'lizard-hipped' dinosaurs, the Saurischia. The name "Ornithischia" means "bird-hipped," and birds also have pelvises in which the pubis points backwards.
An alternative name for the order is the Predentata, because all of them are beaked herbivorous dinosaurs. The beak is in front of the jaw-bone, the dentary, so it is a 'predentary'. The upper half of the beak is the 'premaxilla' on the end of the upper jaw. The beak is a key adaptation for cropping plants for their food.
Their original (basal) form of locomotion was bipedal. However, from early in their evolutionary history, they were capable of both bipedal and quadrupedal locomotion. Several groups became entirely quadrupedal.
A new hypothesis of dinosaur relationships might upset this summary.
The ornithischia has two sub-orders:
Questions and Answers
Q: What does the name "Ornithischia" mean?
A: The name "Ornithischia" means "bird-hipped," referring to their hip structure.
Q: What is an alternative name for the order Ornithischia?
A: An alternative name for the order Ornithischia is the Predentata, because all of them are beaked herbivorous dinosaurs.
Q: What is a key adaptation of Ornithischian dinosaurs?
A: A key adaptation of Ornithischian dinosaurs is their beak, which is in front of the jaw-bone and used for cropping plants for their food.
Q: How did they originally move?
A: Their original (basal) form of locomotion was bipedal, but they were capable of both bipedal and quadrupedal locomotion. Several groups became entirely quadrupedal.
Q: How many suborders do ornithischians have?
A: Ornithischians have two suborders.
Q: Where does birds' pelvis point backwards compared to ornthishchians'?
A: Birds also have pelvises in which the pubis points backwards, similar to ornthishchians'.
