Hadrosaurs

Hadrosaurs were a large and common group of dinosaurs that are often referred to as duck-bills. They were herbivorous, herd-dwelling animals that reached 50 feet (15 m) in length. Named for Hadrosaurus, these dinosaurs had a peculiar beak on the end of their snouts that was somewhat wide and flat. Their mouths were filled with hundreds of teeth arranged in dental batteries that were used to grind up tough plant fibers.