- a bipedal dinosaur of the genus Hadrosaurus, belonging to the ornithopod family Hadrosauridae of the late Cretaceous Period, having broad, flat jaws for scooping up water plants.
- any one of a large group of bipedal Upper Cretaceous dinosaurs of the genus Anatosaurus, Maiasaura, Edmontosaurus, and related genera: partly aquatic, with a duck-billed skull and webbed feet
