Dimorphodon /daɪˈmɔrfədɒn/ was a genus of medium-sized pterosaur from the early Jurassic Period. It was named bypaleontologist Richard Owen in 1859. Dimorphodon means “two-form tooth”, derived from Greek δι/di meaning ‘two’,μορφη/morphe meaning ‘shape’ and οδων/odon meaning ‘tooth’, referring to the fact that it had two distinct types of teeth in its jaws – which is comparatively rare among reptiles.

The body structure of Dimorphodon displays many “primitive” characters, such as, according to Owen, a very small brain-pan^{[citation needed]} and proportionally short wings.^[1] The first phalanx in its flight finger is only slightly longer than its lower arm.^[1] The neck was short but strong and flexible and may have had a membraneous pouch on the underside. The vertebrae had pneumatic foramina, openings through which the air sacks could reach the hollow interior.Dimorphodon had an adult body length of 1 metre (3.3 ft) long, with a 1.45 metre (4.6 ft) wingspan.^[1][2] The tail of Dimorphodon was long and consisted of thirty vertebrae. The first five or six were short and flexible but the remainder gradually increased in length and were stiffened by elongated vertebral processes.^[1] The terminal end of the tail may have borne a Rhamphorhynchus-like tail vane, although no soft tissues have yet been found of Dimorphodon to confirm this speculation.^[1]

(From Wikipedia, February 2015)