MAROPENG (South Africa) • The fossilised bones of 15 bodies from a previously unknown human species have been discovered in a cave in South Africa, it was announced yesterday, in what scientists hailed as a breakthrough in evolution research.
About 1,500 fossils were found in a cave system outside Johannesburg, hidden in an underground chamber only accessible via steep climbs and rock crevasses.
The new species has been named "Homo naledi", after the Rising Star cave where the bones were found. Naledi means "star" in Sesotho, a local language.
Experts are uncertain how old the bones are, but say they were probably placed there after death - a discovery that shines fresh light on the origin of the mankind.
"We have just met a new species of human relative that deliberately disposed of its dead," said Dr Lee Berger, research professor at the University of the Witwatersrand in Johannesburg.
"Until (now), we thought the idea of ritualised behaviour directed towards the dead... was actually unique to Homo sapiens.
"We saw ourselves as different. We have now seen... a species that had that same capability - and it is an extraordinary thing."
The bones were first found in 2013 by Witwatersrand University scientists and volunteer cavers in the Cradle of Humankind, a Unesco World Heritage Site, 50km north-west of Johannesburg. Ancient human remains have been found in the area since excavations started in the 1920s.
"The discovery of so many fossils belonging to at least 15 individuals is remarkable," said Professor Chris Stringer from the Natural History Museum in London, a lead analyst on the discovery. He said the find highlighted "the complexity of the human family tree and the need for further research to understand the history and ultimate origins of our species".
Scientists say the hands, wrists and feet of the bodies were similar to modern humans, but the brain size and upper body were much more like the earliest humans.
"Homo naledi had a tiny brain, about the size of an average orange, perched atop a very slender body," said Dr John Hawks of the University of Wisconsin-Madison, a senior author on the academic paper detailing the new species.
Homo naledi stood about 1.5m tall and weighed about 45kg. "The hands suggest tool-using capabilities," said Dr Tracy Kivell, of the University of Kent.
"This chamber has not given up all of its secrets," Dr Berger said. "There are potentially hundreds, if not thousands, of remains of Homo naledi still down there."