Mammoth skelton located in the Southeast Bavarian Natural History and Mammoth Museum. Image credit: Lou.gruber/Wikipedia

A new study by University of Wisconsin – Madison researchers sheds new light on why large North American mammals, like the Mammoth, became extinct.  Published in Science, this study focuses on fossil pollen, charcoal and fungus spores found in fossil dung.  The study illustrates that the decline of these large mammals started about 14,800 years ago.  This decline was essentially complete a thousand years later.  This study seems to rule out a mass extinction caused by a meteor strike about 12,900 years ago since the decline was well underway by then.  Other previously theories suggested that Clovis hunters created the extinction via over-hunting, but, again, the die off predates the arrival of Clovis hunters in North America.  Finally, this study contradicts the theory that significant changes in climate caused the extinction because it suggests that the extinction of these major species actually helped create the change in climate.  By losing these major plant-eaters, trees were able to become widespread.