Camptosaurus is a middle weight herbivore that lived in North America during the Jurassic. It lived in large herds with the large herbivore Stegosaurus. The Camptosaurus has no real defense except there speed. They can out run large predators like Allosaurus. To be able to out run a Allosaurus it uses a strategy of having a sentry looking for predators, and when a predator is spotted a single is called out and the herd runs away leaving the stegosaurus to stop the large predator.