In the Ice Age (which included warm spells), mammals such as the woolly mammoth, muskox, wild horse, giant deer, brown bear, spotted hyena, cave lion, Arctic lemming, Norway lemming, Arctic fox, European beaver, wolf, Eurasian lynx, and reindeer flourished or migrated depending on the degree of coldness. The Irish brown bear was a genetically distinct (clade 2) brown bear from a lineage that had significant polar bear mtDNA. The closest surviving brown bear is Ursus arctos middendorffi in Alaska. Excavations of Barbary macaque remains indicate the species was artificially brought to Ireland at some point in the past.