The Villafranchian equines from the Upper Valdarno ( Italy).

Abstract

From morphological analysis of old collections of fossil bones in the Florentine collections it seems that two different species lived in the Upper Valdarno between 1.7 and 1.5-1.4 Ma, viz: E. stenonis (large stature) and E. stehlini (small stature). The recent recovery of two stratigraphically located faunas, Matassino and Casa Frata, suggest that the two species did not live in association. Statistical analysis of the length of metatarsals and metacarpals of the old collections show that there were many samples of intermediate lengths, indicating a gradual transition between the species. The fossil documentation of the Valdarno basin suggests a possibility of co-existence of the two species in the same basin. An ecological separation and sympatric speciation could explain the origin of E. stehlini through E. stenonis.-after Author