Dimorphodon

Dimorphodon was a genus of medium-sized pterosaur from the early JurassicPeriod. It was named by paleontologist Richard Owen in 1859. Dimorphodonmeans "two-form 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" characteristics, such as, according to Owen, a very small brain-pan and proportionally short wings. The first phalanx in its flight finger is only slightly longer than its lower arm.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 long, with a 1.45 metre wingspan. 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. The terminal end of the tail may have borne a Rhamphorhynchus-like tail vane, although no impressions have yet been found in Dimorphodon fossils to confirm this speculation.