Anthropologists have discovered three human fossils that are between 1.78 and 1.95 million years old. The specimens are of a face and two jawbones with teeth.
The finds back the view that a skull found in 1972 is of a separate species of human, known as Homo rudolfensis. The skull was markedly different to any others from that time. It had a relatively large brain and long flat face.
But for 40 years the skull was the only example of the creature and so it was impossible to say for sure whether the individual was an unusual specimen or a member of a new species.
With the discovery of the three new fossils researchers can say with more certainty that H.rudolfensis really was a separate type of human that existed around two million years ago alongside other species of humans.
For a long time the oldest known human ancestor was thought to be a primitive species, dating back 1.8 million years ago called Homo erectus. They had small heads, prominent brows and stood upright.
A new species of human: One of several co-existing in Africa two million years ago
But 50 years ago, researchers discovered an even older and more primitive species of human called Homo habilis that may have coexisted with H. erectus. Now it seems H. rudolfensis was around too and raises the distinct possibility that many other species of human also existed at the time.
This find is the latest in a growing body of evidence that challenges the view that our species evolved in a smooth linear progression from our primate ancestors.
Instead, according to Dr Meave Leakey of the Turkana Basin Institute in Nairobi, who led the research the find shows that there was a diversity early on in the evolution of our species.
"Our past was a diverse past," she told BBC News, "our species was evolving in the same way that other species of animals evolved. There was nothing unique about us until we began to make sophisticated stone tools."
In other groups of animals many different species evolve, each with new traits, such as plumage, or webbed feet. If the new trait is better suited to the environment then the new species thrives, if not it becomes extinct.
According to Professor Chris Stringer of the Natural History Museum in London, fossil evidence is increasingly suggesting that human evolution followed the same pattern.
"Humans seem to have been evolving in different ways in different regions. It was almost as if nature was developing different human prototypes with different attributes, only one of which, an ancestor of our species, was ultimately successful in evolutionary terms," he said.
According to Dr Leakey, the growing body of evidence to suggest that humans evolved in the same way as other animals shows that "evolution really does work".
"It leads to amazing adaptions and amazing species and we are one of them," she said.
The newly discovered face and lower-jaw fossils, uncovered within a radius of just more than 6 miles (10 kilometers) from where KNM-ER 1470 was unearthed, now suggest that KNM-ER 1470 and the novel finds are indeed members of a distinct species of early Homo that stands out from others with its uniquely built face.
"It had very flat facial features you could draw a straight line from its eye socket to where its incisor teeth would be," researcher Fred Spoor at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, told LiveScience. "This shows east Africa about 2 million years ago was quite a crowded place with many diverse species of early Homo," Spoor said.
The environment was more verdant back then than it is today, with a larger lake. "There was plenty of opportunities ecologically to accommodate more than one hominid species," Spoor said.
Other researchers suggest these new fossils are not enough evidence of a new human species. However, "these are really distinctive shape profiles it really shows something completely different," Leakey said. "I feel pretty confident that were not just dealing with variation in one species."
In principle, researchers might be able to reconstruct what this new species might have eaten by looking at its teeth and jaws. "The incisors are really rather small compared to what youd find in other early Homo," Spoor said. "In the back of the mouth, the teeth are large, telling us a lot of food processing was going on there ... it may be possible it ate more tough, plantlike foods than meat."
Where the Islamic State Gets Its Weapons 2015-05-04 21:26
Early one morning in late February, a European investigator working in Kobani, the northern Syrian city that for months had been a battleground between Kurdish fighters and militants from the Islamic State, stepped outside the building where he was staying and saw something unusual. A Kurd on the street was carrying a long black assault rifle that the investigator thought ...
Garland Shooter Elton Simpson âHandledâ By Paid FBI Informant 2015-05-05 4:49 In our story released late last night, we posed this question to our readers:
âWere these supposed âdead gunmenâ part of the drill, or were they patsies handled by a counter-terrorism federal âinformantâ?â
We didnât know it at the time, but it turns out that we were right.
Image: âGarland Gunmanâ Elton Simpson, adjusting his CCTV camera at his apartment in Phoenix, AZ.
What is Sacred to Americans? 2015-05-05 4:32 The free speech fest in Texas that resulted in the police shooting of two apparent terrorists at the Curtis Culwell Center in Garland marks growing prominence and qualified support for the movement for free speech for anti-Muslim satire, led by the American Freedom Defense Initiative, a well-financed New York group.
No similar type of organization in America dares to test ...
A Lesson for New York Cops: How to Subdue Brawlers Without Hurting Them 2015-05-04 23:07
Every day in America police assault, injury and kill people who do not pose a threat to them.
âThe increase in police brutality in the U.S. is a frightening reality. In the last decade alone the number of people murdered by police has reached 5,000. While the number of soldiers killed since the inception of the Iraq war is 4,489,â The ...
Israel Is Preparing For Alien Invasion - Are The 'Tall White' Aliens Coming? 2015-05-04 21:00
Earlier in the week, the Israel Defense Forces (IDF) conducted a training exercise for its Air Force cyber unit, the âOfekâ (Horizon). The training exercise was based on a scenario in which the world is under attack by alien invaders, and IDF tech forces are faced with the challenge of sabotaging the advanced technological systems of attacking alien spacecraft.
Although Lt. ...