Geopalaeontological setting, chronology and palaeoenvironmental evolution of the Baccinello-Cinigiano Basin continental successions (Late Miocene, Italy)

The Latest Miocene succession of the Baccinello-Cinigiano Basin in southern Tuscany (Italy)recorded a faunal turnover documenting the extinction of an older, insular, endemic fau-nal complex characterised by the extinct ape Oreopithecus bambolii and the setting of anew, continental, European faunal complex including the colobine monkey Mesopithe-cus. A similar turnover pattern (Late Miocene ape/Latest Miocene Cercopithecidae) isgenerally observed in Late Miocene continental successions of Eurasia, from Spain to cen-tral Europe, Southwest Europe, the near East, and Southwest Asia. Abundant literaturereports that the Late Miocene Eurasian hominoid primate distribution closely tracks theclimatic/environmental changes occurring during the 12–9 Ma interval, until their extinc-tion in western Europe. In the primate record, the dispersion of Cercopithecidae and thecontraction of hominids is interpreted as an event depicting a pattern of “continentalisa-tion” in the Old World. The sedimentary succession of the Baccinello-Cinigiano basin, oneof the longest continuous vertebrate-bearing continental successions in the Neogene Ital-ian record, contributes to the debate on this hypothesis. This paper provides an overviewof the main characteristics of the sedimentary succession, the chronological constraints(biochronology, radiometric datings, magnetostratigraphy), and the palaeoenvironmentalevolution as derived from palaeobiological approaches and from the study of stable carbonand oxygen isotope contents along the entire sedimentary succession. The 2 myr geolog-ical history of the Baccinello Cinigiano Basin, which documents the evolutionary historyof Oreopithecus and associated faunas, does not have a direct relation with the event ofthe Messinian Salinity Crisis. The evolutionary history of Baccinello-Cinigiano Basin andits palaeontological record have been mainly driven by the regional tectonism and palaeo-geographic changes that affected the northern Tyrrhenian regions in Late Miocene (LatestTortonian–Messinian) times.