Wooly mammoths, sabre-toothed tigers, and giant cave bears lived alongside man during the Ice Age. But while humans persisted, these big beasts–along with other “megafauna”–became extinct. Scientists had suggested that their demise was caused by a comet or asteroid impact that left tiny traces in upper-level rock layers around the world, but new research gives this Ice Age-ending scenario a cold shoulder.
In a study published in the Proceedings of the National Academy of Sciences, a team of British and American scientists refuted the last remaining piece of evidence supporting this particular impact theory–nanodiamonds. If impacts led to the extinction of the Ice Age megafauna, the resulting heat would have turned some organic carbon into tiny diamonds.