Data from: Forest snail faunas from Crimea (Ukraine), an isolated and incomplete Pleistocene refugium

The land snail faunas of 26 forest sites and two open rocky sites in the Crimean Mountains were sampled in 2011. Of the 40 species found within the forests (about half the known fauna of Crimea as a whole), 28 were species with wide western Palaearctic distributions, and only eight were endemic to Crimea. While there were significant differences in the faunas of different sampling areas, these seemed to be a consequence of ecological differences among them rather than a product of geographical isolation and differentiation. Endemic species were large, and not entirely restricted to forest; known endemics not found in these forests are mainly typical of more open habitats. There is no local radiation of small species living in damp forest litter, as with Leiostyla species in the Transcaucasian forest refugium, and families such as the Clausiliidae with many endemic forest species in both Transcaucasia and the Carpathians are sparsely represented. The one endemic clausiliid genus, Mentissa, occurs in open as well as in wooded habitats. The present faunas are rather poor considering the soil conditions and climate, and the forests hold widespread species often associated with open habitats elsewhere. While there is evidence that these mountains provided a refuge for many animals and plants during glacial episodes further north, the forest snail fauna suggests that full forest cover did not survive throughout the Pleistocene. Rather, the present fauna contains endemics that survived in other habitats and widespread species with good powers of passive dispersal.