Preliminary Analysis of European Small Mammal Faunas of the Eemian Interglacial: Species Composition and Species Diversity at a Regional Scale

Small mammal remains obtained from the European localities dated to the Eemian (Mikulino) age have been analyzed for the first time at a regional scale based on the present biogeographical regionalization of Europe. The regional faunas dated to the warm interval in the first part of the Late Pleistocene display notable differences in fauna composition, species richness, and diversity indices. The classification of regional faunal assemblages revealed distinctive features of small mammal faunas in Eastern and Western Europe during the Eemian (=Mikulino, =Ipswichian) Interglacial. Faunas of the Iberian Peninsula, Apennine Peninsula, and Sardinia Island appear to deviate from the other regions. In the Eemian Interglacial, the maximum species richness of small mammals (≥40 species) with a relatively high proportion of typical forest species was recorded in Western and Central Europe and in the western part of Eastern Europe. The lowest species richness (5–14 species) was typical of island faunas and of those in the north of Eastern Europe. The data obtained make it possible to reconstruct the distribution of forest biotopes and open habitats (forest-steppe and steppe) in various regions of Europe. Noteworthy is a limited area of forests in the south and in the northeastern part of Europe. In these regions, it seems likely that under conditions of relatively high temperatures characteristic of the Last Interglacial and an insufficient moisture supply there could exist open forest stands or forest-steppe landscapes, as suggested by the presence of species indicative of forest-steppe and steppe north of the forest zone. The results obtained are useful in modeling changes in the mammal faunas as well as environmental changes in entire Europe due to global climatic changes (including the global warming recorded at present)