North America

Smilodon, last of the sabre-toothed cats. Artist: Caroll.L. Fenton. Source and copyright: Patricia Vickers-Rich.

In North America, a number of ice age mammals, including the mastodon, sloths, glyptodonts (an enormous armadillo-like animal), sabre-toothed cats and horses became extinct about 10,000 years ago, soon after the entry of humans across the Bering Land Bridge. Whether human hunting or climatic change was the main cause of the extinction of these animals in North America remains very controversial.

The remains of ice age mammals attracted the attention of the early European settlers, who began to systematically collect fossils in the early nineteenth century. Thomas Jefferson was an avid supporter of mastodon excavations, and at one stage, filled part of the White House with ground sloth remains. The amount of material recovered, however, was greatly expanded early in the twentieth century by excavations at the Rancho La Brea tar pits in Los Angeles. Forty mammal species and one hundred bird species have been retrieved from this site, including the mastodon, mammoth, ground sloths, western horse, tapir, giant vulture (with a four metre wing span), camels, antelope, American lion, dire wolf, Sabre-toothed cat, and giant bears-all now extinct-together with many species that still survive, like the puma and coyote.