Ornithischia = "bird hipped." There's a whole lot of them for example triceratops and stegosaurs in the pictures below. Ornithischia dinosaurs are mainly hrebivores.
Stegasaurus is the largest plated dinosaur. It ate low laying plants. It lived in the late Jurassic.
This is a triceratops. It has a thick strong beak like a parrot. It had three horns, and two up above its eyes. The triceratops lived in the late cretaceous. It ate low laying plants. The triceratops looked like a three horned rhino.
This is a triceratops it is bird hippied.
These are 4 ornithischia dinosaurs.If a dinosaur has this bone it means it is an ornithischian dinosaur.