The first of our kind: GARG discover the oldest Homo sapiens fossils at Jebel Irhoud, Morocco

New finds from the archaeological site of Jebel Irhoud in Morocco push back the origins of our species by 100,000 years and show that by about 300,000 years ago important changes in our biology and behaviour had taken place across most of Africa. Once again, state-of-the art techniques by Southern Cross University researchers has played a key role in direct dating the human remains.

An international research team led by Professor Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology (Leipzig, Germany) and Dr Abdelouahed Ben-Ncer of the National Institute for Archaeology and Heritage (INSAP, Rabat, Morocco) uncovered fossil bones of Homo sapiens along with stone tools and animal bones at Jebel Irhoud.

Southern Cross University geochronologist Dr Renaud Joannes-Boyau from Southern Cross GeoScience was part of the team.

The discoveries reported today in two papers in the journal Nature, reveal a complex evolutionary history of mankind that likely involved the entire African continent. DOI: 10.1038/nature22335

Dr Joannes-Boyau made a methodological breakthrough that allowed him to accurately date directly the fossil.

“I have dedicated a large part of my career in improving direct dating of fossils, and the new methodological breakthrough was extracted from my PhD research. The recalculated age of Irhoud 3 was the last chapter of my thesis, using all the new advanced we gathered in the previous years,” he said Dr Joannes-Boyau, now a Senior Research Fellow at the University.

Both genetic data of humans living today and fossil remains point to an African origin of our own species, Homo sapiens. Previously, the oldest securely dated Homo sapiens fossils were known from the site of Omo Kibish, in Ethiopia, dated to 195,000 years ago.

“The fact that we have already Homo Sapiens 100,000 years before and in Morocco changes our understanding and hypothesis of our species dispersal across Africa,” said Dr Joannes-Boyau.

The finds are dated to about 300,000 years ago and represent the oldest securely dated fossil evidence of our own species. This date is 100,000 years earlier than the previously oldest Homo sapiens fossils.

To provide a precise chronology for these finds, researchers used thermoluminescence dating method on heated flints and ESR dating on the fossil teeth directly, yielding an age of approximately 300 thousand years old, pushing back the origins of our species.

The team was able to recalculate a direct age of the Jebel Irhoud 3 mandible found in the 1960s. Using new dosimetric data from Jebel Irhoud sediments and methodological improvements in electron spin resonance dating method, this fossil’s newly calculated age is much older than previously realised.

“Irhoud 3 is the oldest Homo Sapiens accurately dated, it’s the first of our kind,” Dr Joannes-Boyau said.

The Jebel Irhoud fossils currently represent the most securely dated evidence of the early phase of Homo sapiens evolution in Africa.

“The new finds reshape our understanding of our species dispersal in Africa and potentially even our geographical origin,” Dr Joannes-Boyau said.


Renaud Joannes-Boyau