Camptosaurus was a mid-sized dinosaur. These herbivores averaged about 16 feet long and just over 1,000 pounds. This member of the iguanodont family had few defenses against hungry predators like Ceratosaurus and Allosaurus. Their best chance would have been to run. They may have had a top speed of about 20 miles per hour. Camptosaurus lived in North America around 150 million years ago.