Multiproxy approach to reconstruct the climate and environment of a new late Middle Pleistocene vertebrate site in northwestern Italy

Abstract

The Moleto site (Ottiglio, AL, Piemonte, Italy) was discovered in the 1990s in an abandoned quarry carved into a Burdigalian–Langhian carbonate succession called Pietra da Cantoni. Sediment collection in three closely spaced fissures provided a rich vertebrate association whose age can be constrained to the late Middle Pleistocene on the basis of the presence of the extinct water vole Arvicola mosbachensis and its enamel characteristics (SDQ values ranging from 100 to 130). The very similar faunal content, evidenced by the common presence of Arvicola mosbachensis and its similar SDQ values, is indicative of a coeval deposition of the fillings of the three fissures. The vertebrate assemblage is represented by 30 taxa, including amphibians, squamate reptiles, birds, and mammals. Interestingly, a diverse fish assemblage from the embedded sediments of the Miocene Pietra da Cantoni has been found in the fissure fillings. We present here a multi-method approach using the small vertebrate assemblages (rodents, insectivores, amphibians, and squamate reptiles) from Moleto to characterize the environment and climate of the site. In order to reconstruct the palaeoenvironmental and palaeoclimatic conditions, we applied the Mutual Ecogeographic Range using UDA-ODA technique, the Bioclimatic Model, the Habitat Weightings, and the Quantified Ecology methods. The results revealed a landscape dominated by woodland habitats with presence of open humid meadows, under temperate and moist climatic conditions, although somewhat colder and drier than today. According to all evidence, the associations from Moleto would correspond to the interglacial MIS 7.