Meet Homo naledi, a new species of human relative
- By Wits University
Our ancestor practiced a form of ritualised behaviour (or repeated behaviour) previously thought to be unique to humans.
The Homo naledi fossils were revealed for the first time during an international launch at the Maropeng Visitor’s Centre in the Cradle of Humankind World Heritage Site on 10 September 2015.
It has been much anticipated since Professor Lee Berger, research professor in the at Wits, and 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.
Biggest find in Africa
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,” Berger said.
Appearance of ritualised behaviour
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.
The team notes that the bones bear no marks of scavengers or carnivores or any other signs that non-hominin agents or natural processes, such as moving water, carried these individuals into the chamber.
“We explored every alternative scenario, including mass death, an unknown carnivore, water transport from another location, or accidental death in a death trap, among others,” said Berger.
“In examining every other option, we were left with intentional body disposal by H. naledi as the most plausible scenario.”
This suggests the possibility of a form of ritualised behaviour (or repeated behaviour) previously thought to be unique to humans. Read the full media release.