After probing deeper into the South African cave system known as Rising Star, researchers discovered new fossils representing the remains of at least three adult and juvenile specimens – including a “wonderfully complete skull.”
The remains help complete the picture of a species that scientists now believe lived in the same period as modern humans – as well as other hominid species – 335,000 to 226,000 years ago.
“When we first identified the fossils, most of the paleoanthropologists on site were convinced that they would be a million or two million years old, but we have now shown they are much more recent,” said Paul Dirks of James Cook University in Australia.
Dirks, who has spent the past few years analyzing the fossils, said the structure of H. naledi’s hands suggests it could have been a toolmaker, which changes the working theory of tool creation in Africa.
“The new dating puts it on the landscape at a time from which we find lots of tools in Africa in the Middle Stone Age,” he said. “One of the implications of the new dates is that it’s no longer automatically possible for us to assume that early Homo sapiens were making these tools.”
John Hawks, who led research efforts at the Rising Star system, also pointed to the apparent H. naledi practice of storing its dead, which seems to be confirmed by the similar collection of fossils at the new site.
“This likely adds weight to the hypothesis that H. naledi was using dark, remote places to cache its dead,” he said. “What are the odds of a second, almost identical occurrence happening by chance?”
So far, the team has discovered more than 130 new H. naledi fossils from the Lesedi Chamber, which means “light” in the Setswana language. The Lesedi Chamber is about 300 feet away from the Dinaledi Chamber where the first H. naledi fossils of at least 15 individuals of different ages were found.
The newly reported remains, discovered in 2013, come from at least three individuals – a child and two adults. The team believes that more fossils will be recovered as excavations continue.
“The skeleton of ‘Neo’ is one of the most complete ever discovered, technically more complete than the famous Lucy fossil given the preservation of the skull and mandible,” said Lee Burger, a paleoanthropologist from the University of Witwatersrand in South Africa, and a co-leader of the research team.
The fossils provide the most complete record of a hominid species other than Neanderthals and modern humans, according to the team.
“With the new fossils from the Lesedi Chamber, we now have approximately 2,000 specimens of H. naledi representing the skeletons of at least 18 individuals,” Hawks said. “There are more H. naledi specimens than any other extinct species or population of hominins except for Neanderthals.”
The discovery was announced Tuesday with the publication of several papers in the journal eLife.