Villafranchian: The long story of a Plio-Pleistocene European large mammal biochronologic unit

European continental mammal biochronology has been developed in Italy since the pioneering work of Augusto Azzaroli. The Villafranchian is a Mammal Age, a biochronological unit. Biochronology is a sub-division of geological time on the basis of the succession of evolutionary stage of faunal assemblages and dispersal events. The Villafranchian Mammal Age is based on European large mammals and corresponds, in the International Stratigraphic Scale, to a time span from Late Pliocene to most of the Early Pleistocene. Within these limits the Villafranchian spans from around 3.5 Ma to about 1.0–1.1 Ma. “Villafranchian” is a concept relatively common within the scientific literature of continental stratigraphers in Europe. Unfortunately, it is sometimes used in the wrong way or in wrong contexts, especially because the term Villafranchian has been used with the meaning of a continental stage, totally misunderstanding its significance as a biochronologic unit. The authors provide an update of the Villaranchian Mammal Age and its present significance.