Scientists say they’ve discovered a new member of the human family tree, revealed by a huge trove of bones in a barely accessible, pitch-dark chamber of a cave in South Africa.
The creature shows a surprising mix of human-like and more primitive characteristics — some experts called it “bizarre” and “weird.”
And the discovery presents some key mysteries:
How old are the bones? And how did they get into that chamber, reachable only by a complicated
pathway that includes squeezing through passages as narrow as about 7½ inches (17.8 centimeters)?
The site, about 30 miles northwest of Johannesburg, has yielded some 1,550 specimens since its discovery in 2013. The fossils represent at least 15 individuals.
Researchers named the creature Homo naledi (nah- LEH-dee). That reflects the “Homo” evolutionary
group, which includes modern people and our closest extinct relatives, and the word for “star” in
a local language. The find was made in the Rising Star cave system.
The creature, which evidently walked upright, represents a mix of traits. For example, the hands
and feet look like Homo, but the shoulders and the small brain recall Homo’s more ape-like ancestors, the researchers said.
Lee Berger, a professor at the University of the Witwatersrand in Johannesburg who led the work,
said naledi’s anatomy suggest that it arose at or near the root of the Homo group, which would make
the species some 2.5 million to 2.8 million years old.
The discovered bones themselves may be younger, he said.
The researchers announced the discovery on Thursday in the journal eLife and at a news
conference in the Cradle of Humankind, a site near
the village of Magaliesburg. They said they were unable to determine an age for the fossils because
of unusual characteristics of the site, but that they are still trying.
Berger said researchers are not claiming that neledi was a direct ancestor of modern-day people, and experts unconnected to the project said they believed it was not.
According to the scientists, Homo naledi is a strange mosaic of the ancient and the thoroughly modern.
Naledi’s brain was no bigger than an orange, scientists say. Its hands are superficially human-
like, but the finger bones are locked into a curve — a trait that suggests climbing and tool-using
Homo naledi was relatively big: it stood about 5 feet tall, had long legs, and its feet are almost
identical to ours, suggesting it had the ability to walk long distances.
“Overall, Homo naledi looks like one of the most primitive members of our genus, but it also has
some surprisingly human-like features, enough to warrant placing it in the genus Homo,” says John
Hawks of the University of Wisconsin-Madison, a senior author on the papers describing the new species that were published on Thursday.
The scientists made these claims, in part, because of the sheer scale of the find.
In the vault at the University of Witwatersrand, hundreds of priceless specimens lie in padded
cases across the room.
In totally they’ve unearthed more than 1,500 fossil remains — the largest single hominin find yet
revealed on the continent of Africa, the cradle of human evolution.