Equus stenonis (Equidae, mammalia) from the early pleistocene of pantalla (italy) and the dispersion of stenonine horses in europe

Stenonine horses roamed across Eurasia for a long-time interval between the Early Pleistocene and the early Middle Pleistocene. These forms probably derived from North American Equus simplicidens and recent research suggests that they can be at the basis of the radiation of the extant African zebras. Equus stenonis is the most widespread stenonine horse in the Early Pleistocene of Europe. Here we describe the Equus record from Pantalla (Italy) and we refer it to E. stenonis based on a combination of morphometric analyses of metapodials and tibia. In particular, our comparisons show remarkable similarities between the Pantalla horse and E. stenonis from Saint Vallier (France). The studied sample allows suggesting an age close to the beginning of the late Villafranchian (~2 Ma) for the Pantalla assemblage, thus representing one of the earliest records of E. stenonis in Italy. Furthermore, our analyses highlight a substantial morphometric homogeneity in European E. stenonis samples, supporting that they may represent intraspecific variation of a single long-lasting widespread species.