On the Italian Journal of Paleontology and Stratigraphy the discovery of new fossil remains on the Bergamo Alpsbelonging to Macroplacus raeticusa marine reptile lived approx 200 million years ago. This species, until now, was known only through fossils found in the Bavarian Alps.
The fossil was found by Pio Carlo Brizzi in 2010 in the locality of Oschioloin the municipality of Gazzaniga in the province of Bergamo, but has only recently been studied by Stefania Nosotti And Simone Maganuco (Natural History Museum of Milan) e Federico Confortini (Civic Museum of Natural Sciences “Enrico Caffi” of Bergamo). This is a skull of approx 6.3cm in length and 6.1cm wide, found in a geological formation of the chronostratigraphic plane Rhaetianthe last one into which the Upper Triassicwhich is placed between 206 and 199 million years ago. It owes its name to the Rhaetian Alps, between Switzerland, Austria and Italy.
The fossil skull has been attributed to Macroplacus raeticusa turtle-like marine reptile. The attribution was made on the basis of a comparison with theholotype (the model of a biological description) of this species, found in Germany. Macroplacus raeticus belonged to the order of Placodontsa subdivision of the superorder dei Sauropterygii. The most famous exponent of this superorder is certainly the Plesiosaurquite well known in popular culture. Unlike the Plesiosaur however, the Placodonts they did not have a long neckbut were more morphologically similar to turtles: stocky and with strong flattened teeth to split the molluscs they fed on.
The skull of Macroplacus raeticus found in the province of Bergamo was subjected to a computed tomographywhich allowed compare their traits with those of the German holotype. In this way it was possible to establish that it was the same speciesalthough in different moments of growth: the holotype is twice as large as the Bergamo fossil. Morphologically it is therefore the same species, but the specimen found in Gazzaniga was smaller.
This discovery allows improve our knowledge about Triassic marine wrecks and the internal evolution of the Placodonts, as well as increasing the number of prehistoric fossils present in Italy.
