Microtus guentheri’nin topotipleri Bat› Anadolu’da yay›l›fl gösteren Microtus cinsinin 2n 54 kromozomlu örnekleri ile karfl›laflt›r›ld›. Morfolojik ve biyometrik karfl›laflt›rmalar sonucu M. guentheri’nin M. lydius’tan ayr› bir takson oldu¤u belirlendi. Dorsal renk ve bakulum flekli M. guentheri’yi M. lydius’tan ay›rmaktad›r. Bunlara ilaveten, M. guentheri’nin kulak uzunlu¤u, interorbital geniflli¤i, mastoid geniflli¤i, timpanik bulla yüksekli¤i ve a¤›rl›¤› M. lydius’un nominatif alttüründen istatistiki olarak farkl› bulundu (p<0.05). Bu bulgular dikkate al›narak ‹ç Anadolu’dan Microtus lydius ankaraensis ssp. n. tan›mland›. Ayr›ca bulgular›m›z Avrupa’da M. guentheri olarak bilinen populasyonun tekrar taksonomik bir de¤erlendirmeye al›nmas› gerekti¤ini ortaya koymufltur.

Topotypes of Microtus guentheri were compared with specimens of the genus Microtus with 2n=54 chromosomes from western Anatolia. According to morphological and biometrical comparisons, it was determined that M. guentheri is a different species from Microtus lydius. The dorsal colour and the shape of the baculum distinguish M. guentheri from M. lydius morphologically. In addition, ear length, interorbital constriction, mastoid breadth, height of tympanic bulla and weight of M. guentheri were found to be statistically different from those of the nominate subspecies of M. lydius (p