Microtus irani Thomas, 1921, is known with certainty from two localities which are separated by a gap of almost 2000 km. In this paper we describe a population from Balkusan in Turkey as a new subspecies Micron's irani karamani.
In a complete sequence for cytochrome b gene (1140 bp), the new subspecies has unique mutations when compared with a sequence of M. i. irani from the type locality (Shiraz, Iran) at 32 positions, and differs in 35 mutations and a mean nucleotide divergence of 3.19% +/- 0.50. It has 60 acrocentric chromosomes in the diploid complement.
Morphologically. M. i. karamani ssp. n. is smaller than M. i. irani, with a shallower braincase, shallower rostrum, and shorter bullae.
The new subspecies can be reliably separated from social voles occupying Turkey, Iran and adjacent regions of the Near East, by a combination of morphological, chromosomal and molecular data.