The middle triassic palaeoflora of monte Prà della Vacca / Kühwiesenkopf (NE Italy)-new investigations / Giuseppa Forte

The middle triassic palaeoflora of monte Prà della Vacca / Kühwiesenkopf (NE Italy)-new investigations / Giuseppa Forte, in colloque "1st Virtual Conference for Women Archaeologists and Paleontologists. Nouveaux apports à l’étude des populations et environnements passés" organisé par le laboratoire Travaux et Recherches Archéologiques sur les Cultures, les Espaces et les Sociétés (TRACES) de l’Université Toulouse Jean Jaurès et le laboratoire Paléontologie Évolution Paléoécosystèmes (PALEVOPRIM) de l'Université de Poitiers, sous la responsabilité scientifique de Julie Bachellerie, Ana Belén Galán López (Traces), Émilie Berlioz et Margot Louail (Palevoprim). Université Toulouse Jean Jaurès, 8-9 mars 2021. [Conférence enregistrée à distance].Session 4 : Paleoclimates andenvironmental changes.

The Triassic locality of Monte Prà della Vacca/Kühwiesenkopf (MPdV), in the Northern Dolomites (NE Italy), is considered a Fossillagerstätte for its richness and good preservation of its fossils, and represents one of the best witnesses of the biotic recovery after the end-Permian mass extinction. The paleontological assemblage includes marine and terrestrial fauna and flora, which permitted to reconstruct both marine and terrestrial middle-late Anisian (Middle Triassic) environments dating back to around 245 million years ago. Plant fossils occur in lens-shaped siltstone layers, which alternate with silty and marly limestone layers and represent rapid burial events caused by submarine flows within a marine basin, triggered by heavy storms. The terrestrial plant assemblage is very diverse and is well-documented by the rich macrofossil plant collection, stored at the Museum of Nature South Tyrol in Bozen/Bolzano: ca. 1200 specimens of leaves, branches, trunks, cones, and seeds of at least 36 different species and 29 genera, including lycopods, horsetails, ferns, seed ferns, cycads, and conifers. The MPdV flora corresponds with a local shift to more humid conditions during the otherwise arid Middle Triassic. This makes the flora of MPdV an ideal candidate for an integrated palaeobotanical, geochemical and palaeoclimatic study. We performed taxon-specific geochemical analyses on the organic carbon collected from plant fossils belonging from different taxa, providing insights on the isotopic composition of different groups of plants. A wide isotopic variability was observed in conifers, cycads and lycopods, while low variability was observed in ferns. The review of the palaeobotanical collection led to the discovery of one of the oldest records of amber worldwide. Moreover, the comparison between Triassic amber occurrences and humid episodes suggests some close causal-effect relationship between the two.