Scientists find impact-related microspherules in the skulls of animal bones dug up from Alaska dated to the Late Pleistocene, suggesting they may have died from comet impacts 11,000-46,000 years ago.

See the source article by following the link below:
Scientists find impact-related microspherules in the skulls of animal bones dug up from Alaska dated to the Late Pleistocene, suggesting they may have died from comet impacts 11,000-46,000 years ago.