Alongside the wild horse, camels evolved in the drier regions of North America. Although camelids are extinct in North America, they have survived in South America until today: the guanaco and vicuña, and the domesticated llama and alpaca. North America links the South American camelids with those of the Old World (the dromedary, Bactrian camel and wild Bactrian camel). Pleistocene rewilding suggests that the closest relatives of the North American species of camelid be reintroduced. The best candidates would be the wild Bactrian as a proxy for "Camelops", the guanaco as a proxy for "Hemiauchenia", and possibly the Vicuña as a proxy for "Palaeolama". These species would live in the arid regions and grasslands of North America. Free-ranging camels face predators typical of their regional distribution, which include wolves and lions. The main predator of guanacos and vicuñas is the cougar.