Callovosaurus leedsi

† Callovosaurus leedsi was a small iguanodontian ornithopod dinosaur from the Middle Jurassic (Callovian stage) of England, making it one of the oldest known iguanodontians. Known from a single femur collected by Alfred Leeds, it was a bipedal or facultatively bipedal herbivore browsing on low-growing vegetation. Its Callovian age places it near the origin of the ornithopod lineage that would eventually give rise to the larger hadrosaurs and iguanodontids of the Cretaceous.