Callovosaurus (meaning "Callovian lizard") is a herbivorous genus of iguanodontian ornithopod dinosaur discovered in Middle Jurassic deposits of England. It was perhaps 9-13 feet long, stood 3 feet tall, and weighed 100-200 pounds. It is probably a dryosaurid. The type specimen consisted of a nearly complete thigh bone discovered in the Oxford Clay Formation and was designated to BMNH R1993. Callovosaurus leedsi is the type species. It was named by Peter Galton in 1980. Callovosaurus was originally called "Camptosaurus" leedsi in 1889. It shared its home with theropod dinosaurs, sauropods, ancient crocodiles, ichthyosaurs, plesiosaurs, pterosaurs, corals, fishes, sharks, mollusks, cephalopods, crustaceans, pliosaurs, the stegosaurs Loricatosaurus and Lexovisaurus, and the early ankylosaur Sarcolestes.