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