Camptosaurus. Computer enhanced image of a fossilised Camptosaurus dinosaur skeleton. Campto- saurus (insflexible reptileins) was one of the earli- est members of the Iguanodontidae family of dino- saurs, living about 135-145 million years ago during the Jurassic period. Like other Iguanodont- ids, Camptosaurus was a herbivorous dinosaur which could walk on two legs or four. It is smaller than other Iguanodontids, being up to 7 metres in length. It is also more primitive, having four well-developed toes on its feet, having a narrower mouth, lacking fully-developed hooves on the second and third finger of its forelegs and lacking a large defensive spike on its thumbs.