New York - A group of scientists say they have conclusive evidence that fossils they discovered in Kenya in 1995 are from the earliest known ancestor of man to walk erect, more than four million years ago.
In today's issue of the British journal, Nature, the scientists said tests on volcanic material from the area of the find confirm the fossils' age at between 4.07 million years to 4.12 million years, pushing the emergence of walking on two legs back more than 500,000 years.