Allosaurus and Camptosaurus

An Allosaurus (back) and Camptosaurus (front) are poised in combat at the Natural History Museum of Los Angeles Country.

Natural History Museum of Los Angeles County


Period: Late Jurassic

Order, Suborder, Family: Ornithischia, Ornithopoda, Camptosauridae

Location: North America, Europe

Length: 17 feet (5 meters)

Few plant-eating dinosaurs of the Late Jurassic were small. Camptosaurus was an exception; it reached an adult weight of no more than 1,000 pounds. This slender, graceful ornithischian stood around five feet tall at the hips. Some paleontologists compare Camptosaurus with a deer in today's forests. Camptosaurus browsed on low vegetation. The chisellike teeth on the sides of its jaws were strong and well suited for crushing tough plants. Instead of front teeth for nipping, the fronts of both jaws were covered with a beak.

The strong, agile rear legs were made for running. It needed to be able to escape from an Allosaurus that could easily overpower even the largest Camptosaurus. Its front legs were small but strong and were used for slow movement during feeding and grubbing around in the brush. It fed with its short front legs on the ground, and the tall hips and rounded curve of the tail gave Camptosaurus a curved or bent profile. This is why it got its name, which means "bent reptile."

This early herbivore is probably close to the ancestry of the family Iguanodontidae of the Cretaceous, which included the enormous Iguanodon and giant hadrosaurs such as Parasaurolophus and Maiasaura. Like its descendants, Camptosaurus lived in herds, which gave it protection from predators.