The chronology of North American late pleistocene extinctions

For more than two decades, it has been assumed that all or virtually all North American terminal Pleistocene extinctions occurred between 12,000 and 10,000 years ago. However, analysis of the North American radiocarbon chronology shows that there are only 71 taxon dates pertaining to these genera that appear valid. These dates apply to nine genera, of which only seven have been dated to the terminal Wisconsin; 40 of these 71 taxon dates are for mammoth and Shasta ground sloth. The dates suggest that many of the extinctions may have occurred before 12,000 years ago, and show that most practitioners continue to extract dates of doubtful validity.