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Museo Paleontologico Cittadino of Monfalcone, Via Valentinis 134, I-34074 Monfalcone (Gorizia), Italy fabdalla{at}tin.it
Since 1973, about 20 specimens of Triassic pterosaurs have been found in northern Italy, Austria and Greenland, belonging to Eudimorphodon, Peteinosaurus, Preondactylus and Austriadactylus. Their age is middle to late Norian and Eudimorphodon is the most common genus. The restudy of the specimens shows that Peteinosaurus presents trimorphodonty in the lower jaw and a fibula unreduced in length, distally expanded and fused to the tibiotarsus above the lateral condyle. Specimen MCSNB 3359 does not show diagnostic features of Peteinosaurus and is referred to it with doubt, whereas MCSNB 3496 is not Eudimorphodon but Peteinosaurus. Preondactylus, Peteinosaurus, ?Peteinosaurus and Dimorphodon could form a monophyletic group.
The tarsus of Triassic pterosaurs consists of two proximal tarsals, which fuse to the tibia during ontogeny, forming a tibiotarsus, and two distal tarsals. The larger of the two proximal tarsals was probably the calcaneum. The lateral condyle of the tibiotarsus is larger or more well formed than the medial one. The shape of the distal tarsals is similar to that of the distal tarsals in Dimorphodon. The metatarsals did not spread and the foot was ectaxonic; metacarpal length increases from metacarpal I to IV. This suggests that footprints of Triassic pterosaurs were different from Pteraichnus-like footprints.
Some features are unique to Triassic pterosaurs. and Austriadactylus have a multicuspid dentition, Peteinosaurus has cuspules in the distal teeth of the lower jaw and Preondactylus has serrated maxillary teeth. This could be a convergent feature or symplesiomorphic for their clade. and Austriadactylus have very large maxillary teeth below the ascending process of the maxilla. and possibly Preondactylus do not have the bundles of elongated caudal zygapophyseal and haemapophyseal processes which are present in Peteinosaurus and in the Jurassic long-tailed pterosaurs.
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  P. Wellnhofer A Late Triassic pterosaur from the Northern Calcareous Alps (Tyrol, Austria) Geological Society, London, Special Publications, 2003; 217: 5 - 22. [Abstract] [PDF]
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