Llamas, guanacos, alpacas, and vicunas are the remaining American camelids. True camelids began to develop in North America, then migrated south to South America and north across the Bering Strait, into Asia and Africa. As the populations moved apart, they began evolving to adapt to their habitats and became distinct species. Still, until the last ice age, the different camelids existed throughout the Americas. According to Donald Prothero (no relation to Ernest) in his 2002 book Horns, tusks, and flippers: the evolution of hoofed mammals, the North American camelids survived until nearly the end of the last ice age, and there is evidence that they were hunted by the early North American natives.
The Handy Natural History. Ernest Protheroe, 1910.