ScienceNOW for August 30, 2010 reported on a theory of an asteroid killing off mammoths.
Over the past 3 years, a loosely confederated group of researchers has argued that an asteroid or comet struck North America about 13,000 years ago, wiping out the woolly mammoth, the giant sloth, and other large animals. Experts say they have shot down most of the supposed evidence, but one finding remained: nano-scale diamond crystals that could have formed only under the extreme pressure of an impact. Now, a group of experts has dismissed this evidence as well, putting what many see as the final nail in the coffin of the mammoth-killer impact.
