In an exciting paper published today, palaeo-anthropologist Lee Berger and his team from the University of Witwatersrand in Johannesburg, South Africa, introduced us to a previously unknown species of hominin (our pre-human ancestors). The new species has been named after the Dinaledi cave system where it was discovered deep underground; meet Homo naledi. In the Sesotho language Dinaledi means Rising Star, so Homo naledi (pronounced na-LED-ee) means Star Man. And what a fascinating man he was!
The cave where Homo naledi was discovered lies 90 metres from the entrance and 30 mtres underground. The site is only 800 metres south-west of Swartkrans, one of Africa’s famous hominin discovery sites and where the earliest evidence for the use of fire was discovered. Parts of the cave system are just 20 centimetres wide, meaning that only the slenderest researchers could reach the remains; 6 women volunteered for the job.
At first Lee Berger and his team were unsure what they’d found. Many hominin fossils are just a fraction of the whole skeleton, so when the excavations revealed an almost complete skeleton celebrations were in order. But then more bones emerged, and still more. In the end about 1,550 bones were recovered, believed to be from an incredible 15 individuals. There were bones from adults, juveniles, the elderly and even infants. There were skulls, vertebrae, teeth, virtually intact hands, an almost complete foot. There were also tiny bones from the hominin’s inner ear, which may be the first time that such ancient examples of these bones have been found.
Homo naledi displays a fascinating mixture of traits from the Homo species and the Australopithecines, our even earlier ancestors. He would have stood roughly 1.5 metres tall, but had a brain only the size of a chimpanzee’s. He walked upright and had hands that closely resembled our own, only retaining a curved thumb to help with tree-climbing. Many of the teeth are similar to those found in Homo species, but the shoulders and hips are primitive.
Although some media outlets are already discussing where Homo naledi fits into our family tree, it’s worth remembering that many hominin species may have existed at the same time or overlapped with each other. There isn’t a direct line of descendants from the earliest hominins to later species and on to our own species of Homo sapiens. Any suggestion that a hominin is ‘the missing link’ between apes and humans is false; all hominins are links between us and our distant ancestors.
There has also been some suggestion that Homo naledi may have buried their dead, leading to the accumulation of many individuals in one place. As far as I can tell there’s little evidence for this beyond the presence of a large number of skeletons, but equally there isn’t much evidence to support alternate theories such as flooding or mass death. Perhaps we’ll know more when further excavations have taken place.
If you want to learn more about hominins, have a look at this article: who was the first person?