Highly divergent lineage of narrow-headed vole from the Late Pleistocene Europe

During the Late Pleistocene, narrow-headed voles (Lasiopodomys gregalis) inhabited Eurasia's vast territories, frequently becoming the dominant small mammal species among steppe-tundra communities. We investigated the relationship between this species' European and Asiatic populations by sequencing the mtDNA genomes of two extant specimens from Russia and 10 individuals from five Central European sites, dated to the post-LGM period. Phylogenetic analyses based on a large portion of mtDNA genomes highly supported the positioning of L. gregalis within Arvicolinae. The phylogeny based on mtDNA cytochrome b sequences revealed a deep divergence of European narrow-headed voles from Asiatic ones and their sister position against the extant L. gregalis and L. raddei. The divergence of the European lineage was estimated to a minimum 230 thousand years ago. This suggest, contrary to the current biogeographic hypotheses, that during the interglacial periods narrow-headed vole did not retreat from Europe but survived the unfavourable conditions within the refugial areas. Based on this result, we propose to establish a cryptic species status for the Late Pleistocene European narrow-headed vole and to name this taxon Lasiopodomys anglicus.