EXCEPTIONAL SOFT-TISSUE PRESERVATION IN A NEW MARINE PYTHONOMORPH FROM THE UPPER CRETACEOUS (CAMPANIAN) OF SOUTHERN ITALY

A new pythonomorph lizard gen. et sp. nov. with exceptional soft-tissues preservation was found in Upper Cretaceous marine sediments of the Apulia platform (Southern Italy). Phylogenetically related forms (‘dolichosaurs’, e. g. Pontosaurus and Adriosaurus) have been described from Upper Cretaceous deposits of the Middle East (Lebanon) and the Balkan Peninsula (Croatia, Slovenia). This is the first record of this group of marine lizards from southern Italy, and extends the known paleobiogeographic distribution of ‘dolichosaurs’ towards the center of the Tethys. This taxon also extends the known temporal range for these marine lizards both globally and from the Tethyan realm; the new taxon is Campanian in age, while related taxa are Cenomanian – Turonian. The new specimen consists of an almost complete, articulated skeleton, most of which is exposed in ventral view. Pachyostotic dorsal vertebrae and ribs suggest aquatic adaptations. The slender and elongated humerus and femur are indicative of a basal degree of aquatic adaptation. Presence of unfused epiphyses and unfused pelvic girdle elements may be indicative either of paedomorphosis in an adult form, or of a juvenile condition. The preservation of the bones is unusual, as the elements retain a ‘fresh brittle look’ despite being about 80 million years old. Spectroscopic analysis (EDX/SEM) of the specimen revealed that, the original composition of the bones is likely retained, and that there is very little calcification (high phosphorous content). Different types of squamation are also preserved: 1) deeply imbricated polygonal scales (close to the trunk and forelimbs); 2) large diamond-shaped scales (in the trunk and tail regions); and 3) broad ventral scales similar to those of Pontosaurus kornhuberi and some snakes (visible in lateral view along the ventral margin of the tail). This specimen also preserves portions of mineralized epaxial and hypaxial musculature along the trunk and tail. Due to its exceptional state of preservation this specimen provides new information about the anatomy of dolichosaurs.