LATE PLEISTOCENE MAMMALIAN EXTINCTIONS IN NORTH-AMERICA - TAXONOMY, CHRONOLOGY, AND EXPLANATIONS

Toward the end of the Pleistocene, North America lost some 35 genera of mammals. It has long been assumed that all or virtually all of the extinctions occurred between 12,000 and 10,000 years ago, but detailed analyses of the radiocarbon chronology provide little support for this assumption, which seems to have been widely accepted because of the kinds of explanations felt most likely to account for the extinctions in the first place. Approaches that attribute the losses to human predation depend almost entirely on the assumed synchroneity between the extinctions and the onset of large mammal hunting by North American peoples. The fact that only two of the extinct genera have been found in a convincing kill context presents an overwhelming problem for this approach. Climatic models, on the other hand, are becoming increasingly precise and account for a wide variety of apparently synchronous biogeographic events. While a role for human activities in the extinction of some taxa is fully possible, there can be little doubt that the underlying cause of the extinctions lies in massive climatic change. © 1991 Plenum Publishing Corporation.