Abstract
The northern region of Beringia is ecologically and biogeographically significant as a corridor for biotic dispersals between the Old and New Worlds. Large mammalian predators from Beringia are exceedingly rare in the fossil record, even though carnivore diversity in the past was much higher than it is in this region at present. Here we report the first fossils of cursorial hyenas, Chasmaporthetes, in Beringia and north of the Arctic Circle. Two isolated teeth recovered in the Old Crow Basin, Yukon Territory, Canada, were identified amongst over 50,000 known fossil mammal specimens recovered from over a century of collecting in the Old Crow Basin. These rare records fill an important intermediary locale in the more than 10,000 km geographic distance between previously known New and Old World records of this lineage. The Pleistocene age of these fossils, together with its Arctic Circle occurrence, necessitate a rethinking of the role of large-bodied hunter-scavengers in Ice Age megafaunas in North America, and the implications of lacking an important energy flow modifier in present day North American food webs.