Mesopithecus (Primates: Cercopithecoidea) from Villafranca d'Asti (Early Villafranchian; NW italy) and palaeoecological context of its extinction

Remains of the cercopithecid Mesopithecus monspessulanus are relatively rare. Two previously unpublished mandibles of M. monspessulanus (housed in the Basel Naturhistorisches Museum), from the Italian locality of Villafranca d'Asti are described. These remains belong to the assemblage of the Triversa Faunal Unit, dated to the Early Villafranchian, that is to the unit MN16a (Middle Pliocene) of the European mammal biochronology. According to this recently revised biochronological attribution, Villafranca d'Asti records the last Mesopithecus occurrence in Europe. The NOW (Neogene Old World) database has been used as a basis to evaluate both the mammalian faunal and the palaeoenvironmental context at the time surrounding this last occurrence of Mesopithecus. The comparison (taxonomical composition and ungulate hypsodonty), between the Villafranca d'Asti assemblage and other Plio-Pleistocene mammal communities of Europe, shows that the extinction of Mesopithecus is related to a faunal turnover and a change toward more open landscapes during the Early-Middle Villafranchian transition. This is consistent with the Elephant-Equus event, that occurred in Europe at 2.5 Ma. Furthermore, the co-occurring but more terrestrial cercopithecid Macaca crossed this faunal turnover. This strengthens the assumption that the latest Mesopithecus species, M. monspessulanus, had woodland-oriented adaptations.