Earliest known Homo sapiens fossils discovered

June 7, 2017 | Updated: 8:22 p.m., June 7, 2017

(CNN) – The oldest fossil remains of Homo sapiens, dating back to 300,000 years, have been found at a site in Jebel Irhoud, Morocco. This is 100,000 years older than previously discovered fossils of Homo sapiens that have been securely dated. The discovery was presented in a study in the journal Nature on Wednesday.

This marks the first discovery of such fossils in north Africa, and widens the “cradle of mankind” to encompass all of Africa, the researchers said. Previous finds were in south or east Africa. The fossils, including a partial skull and a lower jaw, belong to five different individuals including three young adults, an adolescent and a child estimated to be 8 years old. Stone tools, animal bones and evidence of fire were also found within the same layer at the site.

But what the researchers found to be most remarkable about these fossils is that they capture a moment in time of evolution. The facial features of the skull look like a modern human, but the brain case is very elongated and archaically characteristic of early humans.

There has been increasing evidence that the modern human lineage diverged from Neanderthals and Denisovans 500,000 years ago, making us close relatives rather than direct descendants. Before this discovery, it was believed that the early modern humans we evolved from were in Africa 200,000 years ago and looked very similar to modern humans. But what happened in between that time?

This is still unknown, although the researchers suggest the possibility that there were multiple groups of hominins, or human ancestors, overlapping and having complex relationships.

Because they didn’t previously have fossil evidence of Homo sapiens from 300,000 years ago, this helps to fill a small part of that gap in the fossil record. The fossils provide insight about this evolutionary time for Homo sapiens before the early modern stage 200,000 years ago.

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“Our analysis convinced us that this material represents the very root of our species, the oldest Homo sapiens ever found in Africa or elsewhere,” said Jean-Jacques Hublin, lead study author, paleoanthropologist and professor at Max Planck Institute for Evolutionary Anthropology.

“We confirmed that they display this surprising combination of very advanced features and more archaic conditions. It allowed us to envision a more complex picture for the emergence of our species with different parts of the anatomy evolving at different rates, some features being fixed very early in a modern way and others taking a longer time to reach the modern condition.”

If we could see these Homo sapiens from 300,000 years ago walking around today, they would look very similar to us — if they were wearing a hat, Hublin said. Their faces would be short, flat and retracted compared to Neanderthals, and even some of the dental aspects are similar to ours.

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But that elongated skull would give them away as being not quite like us. Their brains, and specifically the cerebellum, wasn’t shaped like ours. But based on the brain case they discovered, these Homo sapiens did have a larger cerebellum than Neanderthals.

“The story of our species in the last 300,000 years is mostly the evolution of our brain and in this time period, a number of mutations occurred affecting brain connectivity,” Hublin said.