The Urar Brush-tailed Mouse, Calomyscus urartensis Vorontsov & Kartavseva, 1979, is distributed in the Lesser Caucasus and is reported only from the type locality in Nakhjivan, Azerbaijan, and two localities in Azerbaijan provinces, Iran. To evaluate genetic structure and karyologic variation a combination of molecular (cytochrome b and cytochrome oxidase subunit 1 genes sequences) and cytological approaches were used. Karyologic data highlighted the existence of a population from Khoy, north-western Iran, with differentiated chromosome components 2n=34 and FNa=42. This new population with a distinct Cytb haplotype showed a 2.2% genetic distance from the population from Kordasht, Iran, that located 150 kilometres away from Khoy. Considering time divergence estimation, we propose that vicariance might explain the divergences within C. urartensis that have accumulated by range restriction of populations as a result of Quaternary climate oscillations and glacial refugia.

Keywords