Mammalian paleobiogeography and the distribution of Homo in early Pleistocene Europe

The first human settlement of Europe occurred around 1.6 Ma, although human populations were unable to cross parallel 45°N until 1.2 Ma We analyse the distribution of mammalian species during the early Pleistocene to evaluate the possible existence of a climatic or ecological barrier that prevented the northern expansion of those early colonisers. Differences in the composition of the Mediterranean and northern species pools existed during the early Pleistocene, but the differences attained were maximal during the 1.6-1.2 Ma time period. The two regional pools were more similar in species composition during the Galerian (1.2-0.8 Ma), coinciding with the expansion of early Homo northward. The two regional pools also differed in ecological structures during the early Pleistocene, although the northern pool became more similar to the southern pool during the Galerian.