The original species of Camptosaurus is based on ten partial skeletons, ranging from juveniles to adults. The species is well-known from the mounted skeletons of a juvenile and an adult collected by Fred Brown and William H. Reed in the 1880s in Wyoming, USA, and put on display in the Smithsonian Institution in Washington DC. The English species is a nomen dubium and may not even be an ornithopod.
Name: Camptosaurus, meaning ‘flexible lizard’
Size: 7m long and up to 6m tall
Lived: 155-140 million years ago, in the Late Jurassic and Early Cretaceous Periods in western Europe and North America
Camptosaurus is very similar to its cousin Iguanodon, a genus which was a characteristic feature of the landscape of the later early Cretaceous period in Europe. However, its head is longer and lower, and it has four toes on the back foot rather than three. Its heavy body can be carried on four legs or on two, both its front five-fingered feet and its hind feet carrying weight-bearing hooves. Its long mouth contains hundreds of grinding teeth and it has a beak at the front. Its food would be kept in cheek pouches while chewed.
The curved thigh bone of this dinosaur enabled it to run quite fast on its powerful hind legs. As it ran, Camptosaurus balanced its bulky body with its heavy tail. This peaceful dinosaur had no weapons, such as horns or sharp claws, and the only way it could escape larger carnivorous dinosaurs was to run away. 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 how it got its name.
It is possible that the original species of Camptosaurus is the only true one. The others may be species of Iguanodon.