Parasaurolophus was a large 9.5-meter 2.5 tone large duck-billed dinosaur that had a big 6-foot long crest coming out of the back of its skull. It had a battery of teeth in its mouth. It lived 73 million years ago in the late cretaceous period in North America. Predators that hunted it include Gorgosaurus, Bistahieversor, Albertosaurus, Teratophoneus and Daspletosaurus. It was one of the strangest looking of all dinosaurs. It could run at speeds of 25m.