At the end of the last Ice Age, most large animals in North America were wiped out, and others transformed themselves. Yet one has survived virtually unchanged to the present day. Where cars now drive along congested roads in the heart of modern Los Angeles, sabre-toothed cats once roamed. They stalked prey that ranged from hoofed mammals to creatures resembling elephants. The ferocious cats competed with dire wolves, American lions and short-faced bears.