1.relating or belonging to an order of dinosaurs that had a backward-rotating pelvis similar to that of birds. The order includes the triceratops and stegosaur.
1.an ornithischian dinosaur, e.g. an ankylosaur
1.any of numerous large bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet;
众多的大型两足鸟臀目恐龙,长有鸭嘴状的角形嘴和蹼足;