Homo naledi: New species of human relative discovered, contributed to by UJ researchers

Homo naledi: New species of human relative discovered, contributed to by UJ researchers

Publishing Date: 9/10/2015 12:00 AM

UJ Researchers from the Departments of Geology; and Human Anatomy and Physiology; contributed to the discovery of a new species of human relative.

Besides shedding light on the origins and diversity of our genus, the new species, Homo naledi, appears to have intentionally deposited bodies of its dead in a remote cave chamber, a behaviour previously thought limited to humans.

The discovery was announced on September 10, 2015 by the University of the Witwatersrand (Wits), the National Geographic Society, the Department of Science and Technology (DST) and the National Research Foundation (NRF) of South Africa, and published in the journal eLife.

An international team of scientists from 34 organisations took part in the research. The South African universities include Wits, the University of Johannesburg (UJ) and the University of Cape Town (UCT).

H. naledi was named after the Rising Star cave — “naledi” means “star” in Sesotho. “Overall, Homo naledi looks like one of the most primitive members of our genus, but it also has some surprisingly human-like features, enough to warrant placing it in the genus Homo,” said John Hawks of the University of Wisconsin-Madison, U.S., a senior author on the paper describing the new species. “H. naledi had a tiny brain, about the size of an average orange (about 500 cubic centimeters), perched atop a very slender body.” The research shows that on average H. naledi stood approximately 1.5 meters tall and weighed about 45 kilograms.

Prof Shahed Nalla from the UJ Department of Human Anatomy and Physiology contributed to the taxonomy of Homo Naledi as well as the analysis of the thoracic elements associated with the fossil find.

More about the discovery in the October issue of National Geographic Magazine: http://natgeo.org/naledi

H. naledi’s teeth are described as similar to those of the earliest-known members of our genus, such as Homo habilis, as are most features of the skull. The shoulders, however, are more similar to those of apes. “The hands suggest tool-using capabilities,” said Dr Tracy Kivell of the University of Kent, U.K., who was part of the team that studied this aspect of H. Naledi’s anatomy. “Surprisingly, H. Naledi has extremely curved fingers, more curved than almost any other species of early hominin, which clearly demonstrates climbing capabilities.”

This contrasts with the feet of H. naledi, which are “virtually indistinguishable from those of modern humans,” said Dr William Harcourt-Smith of Lehman College, City University of New York, and the American Museum of Natural History, who led the study of H. Naledi’s feet. Its feet, combined with its long legs, suggest that the species was well-suited for long-distance walking. “The combination of anatomical features in H. Naledi distinguishes it from any previously known species,” added Prof Lee Berger.

Berger is research professor in the Evolutionary Studies Institute at the University of the Witwatersrand and a National Geographic Explorer-in-Residence, who led the two expeditions that discovered and recovered the fossils.

Consisting of more than 1,550 numbered fossil elements, the discovery is the single largest fossil hominin find yet made on the continent of Africa. The initial discovery was made in 2013 in a cave known as Rising Star in the Cradle of Humankind World Heritage Site, some 50 kilometers northwest of Johannesburg, South Africa, by Wits University scientists and volunteer cavers.

The fossils, which have yet to be dated, lay in a chamber about 90 meters from the cave entrance, accessible only through a chute so narrow that a special team of very slender individuals was needed to retrieve them.

Prof Jan Kramers, Dr Georgy Belyanin and PhD student Mr Tebogo Vincent Makhubela, all from the UJ Department of Geology, performed mineral chemistry on sediment samples from Rising Star cave, to identify which minerals are present in the cave.

The papers “Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa” and “Geological and taphonomic context for the new hominin species Homo naledi from the Dinaledi Chamber, South Africa” can be freely accessed online at the ELife Journal at http://dx.doi.org/10.7554/eLife.09560 and http://dx.doi.org/10.7554/eLife.09561.

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More about the discovery in the October issue of National Geographic Magazine: http://natgeo.org/naledi and a NOVA/National Geographic Special (#NalediFossils).

Homo naledi, National Geographic
A reconstruction of Homo naledi’s head by paleoartist John Gurche, who spent some 700 hours recreating the head from bone scans. The find was announced by the University of the Witwatersrand, the National Geographic Society and the South African National Research Foundation and published in the journal eLife. Photo by Mark Thiessen/National Geographic.