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.