Article contributed by Dr.Pat Fazio from “UnBroken Spirits” via Buffalo Bill Historical Center, Cody Wyoming.
Between 13,000 and 11,000 years ago, during glacial retreat, mass extinction of mammals took place. Twenty-seven mammal species vanished worldwide. Eight species of large mammals, including the horse, became extinct only in North America. By this time, horses had migrated from North America, over the Bering Land Bridge or “Beringia” into northwestern Russia (Siberia) and Asia. From here, they radiated out onto all continents, except Australia and Antarctica. Why extinction took place in North America is still a mystery, although several hypotheses exist. One of these is called the “overkill” hypothesis. This belief holds that Clovis people (Paleoindians) hunted the horse, and other large mammals, to extinction, after humans migrated into North America, over the Bering Land Bridge, 15,000 to 12,000 years ago. A second popular hypothesis of extinction involves climate change. This idea has been around since extinct mammals were first recognized in 1800. It holds that at the end of the Ice Age (late Pleistocene Epoch), the climate changed so drastically that many mammals could not adapt to changes in temperature and/or vegetation, and either died off or migrated to other habitats. Climatic changes during this period were, by far, the most rapid in the history of the earth. Some anthropologists suggest that hunting pressure and changes in climate, combined, perhaps, with a virulent disease of epidemic proportions, wiped out the horse and other large North American mammals. Or could it have been due to extra radiation in this hemisphere from a super-nova or star explosion? All scenerios are possible, alone or in combination. We may never have a definitive answer.