Order Rodentia - Family Muridae Author Guy G. Musser Author Michael D. Carleton text 1993 Smithsonian Institution Press Washington and London Editor Don E. Wilson Editor DeeAnn M. Reeder Mammal Species of the World (2 nd Edition) 501 755 book chapter http://doi.org/10.5281/zenodo.7353098 1-56098-217-9 7353098 Microtus hyperboreus Vinogradov, 1934 . Trav. L'Inst. Zool. Acad. Sci., 1933:1 . TYPE LOCALITY: Siberia, Verhoiansk Mtns . DISTRIBUTION: NE Siberia, basin of Yana River , Berhoiansk Range, and Taimyr Peninsula (see Ellerman and Morrison-Scott, 1951 ). SYNONYMS: swerevi. COMMENTS: Subgenus Alexandromys . Reviewed by Gromov and Polyakov (1977) . Corbet (1978c) included hyperboreus in M. middendorffi because Gileva (1972) had demonstrated their complete interfertility. Pavlinov and Rossolimo (1987) , however, recognized M. hyperboreus , noting that the two are clearly morphologically distinct and that material in published studies probably omitted true hyperboreus . Meier (1983) recognized the two species as closely related and noted that no study of variability within middendorffi had been made, and more importantly, that insufficient material from the type locality had been analyzed. Vorontsov and Lyapunova (1976) considered M. hyperboreus and M. middendorffi to be chromosomally closely related to North American M. miurus .