A partial fossil jaw (left side) of a small grison (Trigonictis cooki)

Hagerman Fossil Beds National Monument (~4.2-3.2 million years ago (mya)) is an extremely diverse site with over 150 animal species. Some of them, like the giant ground sloth, were vastly different from anything around today, but familiar animals like swans and otters also graced Hagerman during the Pliocene (5.33-2.58 mya). Trigonictis cooki is the smaller of two grisons found at Hagerman. Grisons are members of the family Mustelidae (which includes otters, badgers, and weasels) and are found today throughout South and Central America. Pliocene Hagerman was warmer and wetter than today but as the climate changed and the glaciers of the Pleistocene advanced animals had to adapt, migrate, or go extinct. The Hagerman grison is just one example of an animal that once lived in the higher latitudes of North America but whose ancestors today are restricted to the southern latitudes. The ancestors of the South American peccary, llama, and Giant Brazilian otter also once lived at Hagerman. Adapt, migrate, or go extinct: how will we respond to global climate change?