Eudimorphodon was a pterosaur that was discovered in 1973 by Mario Pandolfi near Bergamo, Italy and described the same year by Rocco Zambelli. The nearly complete skeleton was retrieved from shale deposited during the Late Triassic (mid to late Norian stage),[1] making Eudimorphodon the oldest pterosaur then known.[2] It had a wingspan of about 100 centimetres (3.3 ft) and at the end of its long bony tail may have been a diamond-shaped flap like in the later Rhamphorhynchus. If so, the flap may have helped it steer while maneuvering in the air.[3] Eudimorphodon is known from several skeletons, including juvenile specimens.
Eudimorphodon was a small pterosaur, especially when compared to the later giant Quetzalcoatlus. Compared to it, Eudimorphodon was only 1 metre (3.3 ft) in length, and only weighed up to 10 kilograms (22 lb). Clearly a pterosaur, its fourth finger had a very large size, and attached to the membrane making up the wing.[4]
Dentition and diet
Eudimorphodon showed a strong differentiation of the teeth, hence its name, which is derived from ancient Greek for "true dimorphic tooth". It also possessed a large number of these teeth, a total of 110 of them densely packed into a jaw only six centimeters long. The front of the jaw was filled with fangs, per side four in the upper jaw, two in the lower jaw, that rather abruptly gave way to a line of smaller multipointed teeth, 25 in the upper jaw, 26 in the lower jaw, most of which had five cusps[2]
The morphology of the teeth are suggestive of a piscivorous diet, which has been confirmed by preserved stomach contents containing the remains of fish of the genus Parapholidophorus. Eudimorphodon had slightly differing dentition with fewer teeth and may have had a more insectivorous diet.[2] The top and bottom teeth of Eudimorphodon came into direct contact with each other when the jaws were closed, especially at the back of the jaw. This degree of dental occlusion is the strongest known among pterosaurs. The teeth were multi-cusped, and tooth wear shows that Eudimorphodon was able to crush or chew its food to some degree. Wear along the sides of these teeth suggests that Eudimorphodon also fed on hard-shelled invertebrates.[5] The teeth distinguish Eudimorphodon, because almost all other pterosaurs either had simple teeth, or lacked them altogether. Benson et al. (2012) noticed that the teeth would have been perfect for grabbing and crushing fish.[4]