http://www.bbc.co.uk/news/science-environment-26359012 (http://www.bbc.co.uk/news/science-environment-26359012)
http://antiquity.ac.uk/ant/088/ant0880173.htm (http://antiquity.ac.uk/ant/088/ant0880173.htm) - subscription required for the main article but there's a link to other material on free access.