The Plio-Pleistocene Old World dirk toothed cat Megantereon ex gr. cultridens (Mammalia, Felidae, Machairodontinae), with comments on taxonomy, origin and evolution.

The taxonomical position of Old World smilodontine cats is discussed and new fossils from some late Villafranchian Italian localities are described. All the Plio- Pleistocene Old World forms are related to Megantereon ex gr. cultridens. The occurrence of a primitive form referable to Megantereon sp. from the latest Miocene of China (Pao Te Tsien loc. 44), if confirmed, could suggest an Asian origin. On the basis of the up-dated biochronological framework for the Italian mammal faunas an evolutionary trend for the Plio- Pleistocene European forms has been recognized with two alternative hypotheses: an European evolution of Megantereon, partially parallel to the American lineage Megantereon-Smilodon or a late Villafranchian dispersal of this genus from derived African forms.