Oldest known human fossils discovered

Scientists have unearthed the world's oldest known human fossils in Morocco dating back to about 300 thousand years, a finding which shows that our species evolved much earlier than previously thought.

Researchers, including those from National Institute for Archaeology and Heritage (INSAP)in Morocco uncovered fossil bones of Homo sapiens along with stone tools and animal bones at Jebel Irhoud, in Morocco which represent the oldest securely dated fossil evidence of human species.

"We used to think that there was a cradle of mankind 200 thousand years ago in east Africa, but our new data reveal that Homo sapiens spread across the entire African continent around 300 thousand years ago," said Jean-Jacques Hublin, palaeoanthropologist at Max Planck Institute for Evolutionary Anthropology in Germany.

"Long before the out-of-Africa dispersal of Homo sapiens, there was dispersal within Africa," he said.

The fossil remains from Jebel Irhoud comprise skulls, teeth, and long bones of at least five individuals, researchers said.

They were found in deposits containing animal bones showing evidence of having been hunted, with the most frequent species being gazelle. The stone tools associated with these fossils belong to the Middle Stone Age, they said.

Researchers used the thermoluminescence dating method on heated flints found in the same deposits.

These flints yielded an age of approximately 300 thousand years ago and, therefore, push back the origins of our species by one hundred thousand years, researchers said.

"Well dated sites of this age are exceptionally rare in Africa, but we were fortunate that so many of the Jebel Irhoud flint artifacts had been heated in the past," said Daniel Richter, geochronology expert Max Planck Institute in Leipzig.

The team was able to recalculate a direct age of the Jebel Irhoud 3 mandible found in the 1960s. This mandible had been previously dated to 160 thousand years ago by a special electron spin resonance dating method.

Using new measures of the radioactivity of the Jebel Irhoud sediments and as a result of methodological improvements in the method, the fossil's newly calculated age is in agreement with the thermoluminescence ages and much older than previously realised, researchers said.

The crania of modern humans living today are characterised by a combination of features that distinguish us from our fossil relatives and ancestors, a small and gracile face, and globular braincase, researchers said.

The fossils from Jebel Irhoud display a modern-looking face and teeth, and a large but more archaic-looking braincase, they said.

"Our findings suggest that modern human facial morphology was established early on in the history of our species, and that brain shape, and possibly brain function, evolved within the Homo sapiens lineage," said Philipp Gunz Max Planck Institute for Evolutionary Anthropology in Leipzig.

"North Africa has long been neglected in the debates surrounding the origin of our species. The spectacular discoveries from Jebel Irhoud demonstrate the tight connections of the Maghreb with the rest of the African continent at the time of Homo sapiens' emergence," said Abdelouahed Ben-Ncer from INSAP.

The new findings from Jebel Irhoud elucidate the evolution of Homo sapiens, and show that our species evolved much earlier than previously thought, researchers said.

The study was published in the journal Nature