Analisi tassonomica e climatica della paleoflora oligocenica di Bagnasco (NW-Italy) in un contesto europeo.

The aim of this work is to classify and analyse some fossil leaves gathered in the site of Bagnasco (NW-Italy), and to define the temperatures occurring locally through the leaf margin analysis, in order to create a model of the palaeoclimate, expand the knowledge of the floristic successions through time and evaluate a possible dating of the Bagnasco basin. The single opportunity to provide an up-to-date review of the palaeoflora has been represented by a comparison with the best-preserved Eocene to Miocene leaf floras described in Europe, through collaboration with experts (Z. Kvaček and V. Teodoridis). Thanks to a broad integration of data on various fossilized parts (pollen, wood, fruits and seeds), carried out by several authors, the early Cenozoic palaeoflora of Europe has been delimited as to comprise only a definite list of taxa, which greatly helps the assignment of leaf morphologies to a restricted range of taxa. Consequently, several taxa cited only in the older literature (e.g., Artocartpus, Banksia, Eucalyptus) have been excluded not being supported by well-grounded evidence. The results obtained for the palaeotemperatures of Bagnasco (Leaf-estimated Mean Annual Temperature: 14,8°C±3,5°C), even if not-so-precise due to the small dimensions of the sampling, reflect a general trend of temperatures occurring in the South-Europe bio-province. In conformity with the floristic evidences (the abundance of Eotrigonobalanus furcinervis and the occurrence of Acer tricuspidatum, Alnus gaudinii and Alnus julianiformis), the Bagnasco basin can be dated to the early Chattian.