A comet that hit Earth 12,900 years ago may have caused the extinction of woolly mammoths in North America, along with other animals such as saber-tooth tigers. The theory, originally proposed by Prof. James Kennett, was recently re-examined by a group of earth scientists at UC Santa Barbara, who found evidence for "nanodiamonds" in the sedimentary record, which would correlate with a cometary collision. More at Epoch Times.
Pictured: Specimen of a mammoth is displayed at an exhibition in Yokohama.