South Africa – An international team of scientist led by Professor Lee R. Berger, announced on Thursday the discovery of a new hominin species named Homo naledi from the fossils found in the Rising Star cave in South Africa. This adds a new branch to the human species family tree.

Modern humans, who belong to a species named Homo sapiens, continue to be until today the only living species in our genus. But 20,000 years ago there were other species of the genus Homo that are now referred as “hominins”.

The discovering of Lee R. Berger, an American paleoanthropologist who is a professor of human evolution studies at the University of the Witwatersrand in Johannesburg, describes an unusual collection of hominins fossils found in Africa belonging to a species called Homo naledi that could be an antecessor of the human species.

Homo Naledi, New Species in Human Lineage, Is Found in South African Cave. Credit: National Geographic

There were approximately 1550 specimens of hominin remains of most of the bones in the skeleton from at least 15 individuals, representing a small portion of the total fossil content according to eLife magazine.  It constitutes one of the greatest and most complete discoveries of hominins rests found until this date.

The remains have similarities between both humans and apes. The creature, which evidently walked upright, represents a mix of traits. The hands and feet look like Homo, but the shoulders and the small brain recall Homo’s more ape-like ancestors, the researchers said.

Pieces of a skeleton of Homo naledi, a newly discovered human species. Credit John Hawks/University of Wisconsin-Madison, via European Pressphoto Agency

“It’s brain was no larger than a baseball, its shoulders and torso primitive, its fingers long and curved, allowing H. naledi to climb and swing from the trees. […] Its long legs and feet, nearly indistinguishable from those of modern man, allowed it not only to walk upright but also to travel for many miles at a time” reported from The Washington Post Amy Ellis Nutt.

Scientists also believe that Homo naledi buried their dead. The number of bodies, their location, and the hard access characteristic of the cave makes scientists believe that Naledi species left deliberately bodies in caves as a way of burying them. This has been considered as a behavior limited to modern humans and never seen before in such a primitive human, reported The New York Times. This could have big implications for understanding the origins of modern human behavior.

Lee R. Berger, leader of a research team, in the Rising Star Cave near Johannesburg, where over 1,550 fossil elements were found. Credit Naashon Zalk for The New York Times

They may have used tools. The hands suggest tool-using capabilities as they had extremely curved fingers. More curved that almost any other species at such early state of hominin, suggesting they had climbing capabilities.

The species may have 2.5 million to 2.8 million years old. Lee Berger, who led the work, said naledi’s anatomy suggest 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, however, discovered bones themselves may be younger.

But until the fossils age is certain, there is no way of making an appropriate judgement of the evolutionary significance of the discovery. If the bones are about as old as the Homo, it would make the Naledi prove of the evolution going on at that time. If the fossils were to be significantly younger it would mean the species managed to retain the primitive body characteristics much longer that any known creature, experts say.

The 1400 bones, 140 teeth, belonging to at least 15 individual skeletons found, may not be that closely related with the human species, but the evidence suggest that even so, they might have presented cognitive abilities equally essential to our species and can have the possibility to rewrite Homo sapiens history.

Source: eLife