Why did the Pleistocene end 10,900 years ago, with the extinction of mammoths, mastodons, horses and other megafauna across North America? [right: Rancho La Brea tarpits, copyright Bruce Molnia, Terra Photographics]
A new study by Vance Haynes Jr., a Regents’ Professor of anthropology and geosciences at The University of Arizona, ("Younger Dryas 'black mats' and the Rancholabrean termination in North America") is published in the April 21 issue of the Proceedings of the National Academy of Sciences’ Online Early Edition.
Haynes looks at the impact of the 1,100 year Younger Dryas cool period that began then and what role it played in the change in fauna. Others have proposed that humans hunted many species to extinction or that an asteroid impact wiped them out.