A team of researchers, cavers and explorers announced in November 2013 that they had discovered a significant fossil find in a cave known as Rising Star in the Cradle of Humankind, some 50 kilometers northwest of Johannesburg.
They launched the Rising Star Expedition and have since then discovered more than 1 550 numbered fossil elements, the discovery is the single largest fossil hominin find yet made on the continent of Africa.
The fossils, which have yet to be dated, lay in a chamber about 90 meters (some 100 yards) from the cave entrance, accessible only through a chute so narrow that a special team of very slender individuals was needed to retrieve them.
So far, the team has recovered parts of at least 15 individuals of the same species, a small fraction of the fossils believed to remain in the chamber. “With almost every bone in the body represented multiple times, H. naledi is already practically the best-known fossil member of our lineage,” Professor Lee Berger said.
Perhaps most remarkably, the context of the find has led the researchers to conclude that this primitive-looking hominin may have practiced a form of behaviour previously thought to be unique to humans. The fossils — which consist of infants, children, adults and elderly individuals — were found in a room deep underground that the team named the Dinaledi Chamber, or “Chamber of Stars”.
That room has “always been isolated from other chambers and never been open directly to the surface,” said Dr Paul Dirks of James Cook University in Queensland, Australia, lead author of the eLife paper on the context of the find. “What’s important for people to understand is that the remains were found practically alone in this remote chamber in the absence of any other major fossil animals.”
So remote was the space that out of more than 1,550 fossil elements recovered only about a dozen are not hominin, and these few pieces are isolated mouse and bird remains, meaning that the chamber attracted few accidental visitors. “Such a situation is unprecedented in the fossil hominin record,” Hawks said. This suggests the possibility of a form of ritualised behaviour (or repeated behaviour) previously thought to be unique to humans.