The Pelsa/Vazzoler Fossil-Lagerstätte: a window into the Middle Triassic biodiversity of the paleotropics

The Dolomites (NE-Italy) are one of the most extensively studied mountains in the world, especially for their Triassic carbonate platforms and coeval basinal sequences. The newly discovered Pelsa/Vazzoler Fossil-Lagerstätte (Agordo Dolomites, Belluno) yielded a remarkably diversified fossil assemblage of late Ladinian age, deposited in a small intraplatform basin. It includes thousands of well-preserved silicified invertebrates belonging to more than 100 molluscs species and dozens of echinoderm, brachiopod, cnidarian, and porifera taxa. Studies on molluscs suggest that a significant radiation of modern benthic groups occurred as early as the late Ladinian. Furthermore, 250 fish specimens were found which belong to at least 10 species, including actinopterygians like Habroichthys and Marcopoloichthys, the flying fish Thoracopterus wushaensis, previously described from China, but also sarcopterygians and chondrichthyans. This makes the Pelsa/Vazzoler Fossil-Lagerstätte the most diverse vertebrate fossil deposit in the Dolomites. Abundant conifer, fern, and cycad remains, together with rare insects, help to reconstruct the surrounding terrestrial environment. Finally, ammonoids, conodonts, and radiolarians provide a biostratigraphic framework and insights into extraplatform basin faunas beyond the carbonate platform. Together, the Pelsa/Vazzoler Fossil-Lagerstätte is promising to provide further and new insights into the biodiversity of the western Tethys tropical ecosystem during the late Ladinian.