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 we’re 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 you’d 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."
Gunman Storms Dutch TV Station Demanding Airtime 2015-01-30 23:32
Dutch authorities have released few details about the bizarre case of 19-year-old Tarik Zahzah’s attack on the main news studio of television station NOS on Thursday. To get the obvious question out of the way first, the police say there is no evidence that Zahzah, who is half-Egyptian, acted on behalf of organized terrorism.
The authorities always say that on the ...
How Alan Dershowitz bullied rape victims to protect a serial child molester 2015-01-30 23:40 Harvard law professor Alan Dershowitz always felt children were fair game for Israeli missiles. Now the question is whether he thinks they are fair game for the sexual exploits of his powerful associates and himself.
Dershowitz and the UK’s Prince Andrew were accused in a recent court filing of raping a teenage girl who was forced into sexual slavery by ...
Alchemical Banksters 2015-01-30 22:39
This past week, the world's preeminent vultures, the economic power elite, met in Davos to discuss the maintenance of their global fiat hegemony. Highlights included furthering austerity, noting that the serf class can't have air conditioning and cars, as well as cheering on the death of privacy through the rise of technocracy. The degenerate elite, completely out of touch with ...
Men must prove a woman said ’Yes’ under tough new rape rules 2015-01-30 4:54
New guidance will be issued to all police forces and prosecutors as part of a ’toolkit’ to move rape investigations into the 21st century
Men accused of date rape will need to convince police that a woman consented to sex as part of a major change in the way sex offences are investigated.
The Director of Public Prosecutions said it was ...
4 beheaded in Saudi Arabia less than a week into King Salman's rule 2015-01-30 3:13 Comment: So when will the the "Human rights" promoting liberal west elite decide invade Saudi Arabia like they did Libya?
Members of Magic Movement stage a mock execution scene in protest of Saudi Arabia beheading of eight Bangladeshi workers in October 2011.
Four people have been executed in Saudi Arabia less than a week after 79-year-old King Salman assumed power following the ...