Human

Kenyan Fossils Shed Light on New Human Species

Brooke Miller
First Posted: Aug 09, 2012 06:42 AM EDT

The discovery of skull fossils in Kenya, east of Lake Turkana support the existence of a human ancestor first suggested in the 1970s, shedding light on the origins of modern people. The discovery confirms that there were two additional species of our genus 'Homo' living alongside our direct human ancestral species, Homo erectus, almost two million years ago.

The findings that were announced in the scientific journal Nature on August 9 were uncovered between 2007 and 2009 which included a remarkably complete lower jaw and a part of a second lower jaw.

They were uncovered by the koobi Fora Research Project ( KFRP) led by Meave and Louise Leakey. They had earlier discovered a fossil known as KNM-ER 1470. It was distinguished by its large brain size and long flat face, ignited a longstanding debate about just how many different species of early Homolived alongside Homo erectus during the Pleistocene epoch.

"The variation between the new fossils and existing Homo remains means scientists now have a good idea of what the second ancestral human species looked like," said Fred Spoor, study author and professor of evolutionary anatomy at University College London, on a conference call with journalists.

"The face is very different, reflecting a different mechanical function," said Meave Leakey, one of the paper's authors and a paleontologist at the Turkana Basin Institute in Nairobi, Kenya. "We now have two specimens with very distinctive profiles, which are not down to regular variation."

Found within a radius of just over 10 km from 1470's location, the three new fossils are dated between 1.78 million and 1.95 million years old.

Even after the new findings, the relationship between the 1972 fossil and human origins remains unclear, said Chris Stringer, researcher at the Natural History Museum in London.

Whether we descended from the species of these ancient creatures is unknown. There could be some other, yet undiscovered species from around this time that is a more probable ancestor.

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