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."
The Josh Duggar Incident Reveals The Tactics And Hypocrisy of SJWs 2015-05-30 1:46
Last week, In Touch Weekly broke the news that Josh Duggar, eldest son of Jim Bob and Michelle Duggar from TLCâ€™s 19 Kids and Counting, had molested five under-aged girls in 2002 and 2003. Josh, who was 14 at the time, was accused of fondling his victims, touching their breasts and genitals while they slept.
A police report was released shortly ...
15 More Men of South Asian Descent Charged With Child Sex Offences 2015-05-30 0:42
Police in Keighley, West Yorkshire have charged 14 men and a 16-year-old boy with sex offences including the rape of a girl under the age of 16. The offences relate primarily to one female victim, with one allegation involving a second who was also under 16 at the time.
The offences are alleged to have occurred between 2011 and 2012. In ...
Anti-Semitic fliers left on Chevy Chase driveways 2015-05-29 22:45
Five streets in Chevy Chase, Md., were papered with anti-Semitic fliers on Wednesday morning.
Montgomery County police are looking for the person or people who left the hate-filled leaflets on almost every driveway on the streets.
â€śThis is very disturbing. My community is definitely disturbed,â€ť said Jean Sperling, the village manager of Martinâ€™s Additions, the community where the fliers were found. Sperling ...
German court says ex-SS officer unfit for trial 2015-05-29 22:32
Prosecutors in the northern German city of Hamburg have dropped their probe into a 93-year-old former Nazi SS officer. Gerhard Sommer, who suffers from dementia, allegedly took part in a World War II massacre in Italy.
Gerhard Sommer, a former company commander of a mechanized infantry division, had been accused of participating in the mass murder of 560 civilians by Nazi ...
The Age of Disinformation 2015-05-29 21:56 I have been a professional meteorologist for 36 years. Since my debut on television in 1979, I have been an eyewitness to the many changes in technology, society, and how we communicate. I am one who embraces change, and celebrates the higher quality of life we enjoy now thanks to this progress.
But, at the same time, I realize the instant ...