woolly mammoth

Woolly mammoths thrived during the last ice age until planetary warming--which the most recent evidence suggests came from a meteorite--killed them off thousands of years ago. (Image: Mauricio Anton, PLOS Biology)

Woolly mammoths thrived during the last ice age until planetary warming–which the most recent evidence suggests came from a meteorite–killed them off thousands of years ago. (Image: Mauricio Anton, PLOS Biology)

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