Lemmus trimucronatus (Richardson, 1825)

Wilson and Reeder (1993) submerge the American brown lemming in Lemmus sibiricus (Kerr, 1792). Chernyavsky et al. (1993) and earlier breeding experiments cited therein suggest that all brown lemmings east of the Kolyma River, including American brown lemmings, are separate from L. sibiricus.

Species diagnosis

General Characteristics

Cheek teeth longitudinally simplified (few loops)
inner salient angles of upper molars and outer angles of lower molars smaller than those of the opposite sides
m1 with 3 closed triangles between termination loops (or with traverse loops if close triangles absent)
supraorbital ridges fusing in adults, forming median orbital crest

Alaska subspecies

Subspecies	Type Locality
Lemmus trimucronatus alascensis Merriam	Point Barrow
Lemmus trimucronatus harroldi Swarth	Nunivak Island
Lemmus trimucronatus minusculus Osgood	Kakhtul River, near its junction with Malchatna River
Lemmus trimucronatus nigripes (True)	St. George Island, Pribilof Islands
Lemmus trimucronatus subarcticus Bee and Hall	Lake Schrader, 145 09' 50" W, 69 24' 28" N, 2900 ft. Brooks Range
Lemmus trimucronatus yukonensis Merriam	Charlie Creek, Yukon River

Literature Cited

Chernyavsky, F. B., Abramson, N. I., Tsvetkova, A. A., Anbinder, E. M. & Kurysheva, L. P., 1993, Zoologicheskii Zhurnal 72:111-121.