Dicrostonyx richardsoni Merriam 1900

Dicrostonyx richardsoni Merriam 1900, Proc. Wash. Acad. Sci., 2: 26.

Type Locality: Canada, Manitoba, Fort Churchill.

Vernacular Names: Richardson's Collared Lemming.

Distribution: W coast of Hudson Bay west to vicinity of Great Slave Lake, District of MacKenzie, Canada; extent of westward distribution unknown.

Conservation: IUCN – Lower Risk (lc).

Discussion: Autosomal polymorphisms and distinctive sex chromosomes based on standard karyotypes reported by Van Wynsberghe and Engstrom (1992), who retained richardsoni as distinct from D. groenlandicus and postulated its differentiation in a SC periglacial refugium. Strong divergence of mitochrondrial DNA genotypes, based on restriction fragment analysis, indicates that the origination of D. richardsoni predated the Wisconsin glaciation (Engstrom et al., 1993).