Intertaxon relationships
Alces americanus gigas Miller, 1899 - Alaska Moose 
Ovibos moschatus moschatus Zimmermann, 1780 - Barren Ground Muskox
Ovibos moschatus wardi Lydekker, 1900 - Greenland Muskox
Rangifer tarandus caribou (Gmelin, 1788) - Eastern Woodland Caribou
Rangifer tarandus granti J. A. Allen, 1902 - Grant's Reindeer
Rangifer tarandus groenlandicus Borowski, 1780 - Barren-ground Caribou
Deroceras laeve (O. F. Müller, 1774) - Meadow Slug