A large, multinational team of scientists has discovered a previously-unknown species of extinct hominin in the Rising Star cave, Cradle of Humankind, South Africa. Besides shedding light on the origins and diversity of the genus Homo, the new species — named Homo naledi — also appears to have intentionally deposited bodies of its dead in the cave chamber, a behavior previously thought limited to humans.
Homo naledi was discovered in 2013 in a remote cave chamber of the Rising Star cave system, located outside of Johannesburg, South Africa, in the Cradle of Humankind World Heritage Site.
This hominin species survived until 335,000-226,000 years ago, placing it in continental Africa at the same time as the early ancestors of anatomically modern Homo sapiens were arising.
Its fossilized remains have previously been reported from two localities in the Rising Star cave system: the Dinaledi Chamber (U.W. 101) and Lesedi Chamber (U.W. 102).
“Homo naledi remains one of the most enigmatic ancient human relatives ever discovered,” said Professor Lee Berger, director of the Centre for Exploration of the Deep Human Journey at the University of the Witwatersrand and an explorer at large for the National Geographic Society.
“It is clearly a primitive species, existing at a time when previously we thought only modern humans were in Africa.”
“Its very presence at that time and in this place complexifies our understanding of who did what first concerning the invention of complex stone tool cultures and even ritual practices.”
The new fossil assemblage — six Homo naledi teeth and 28 skull fragments, all consistent with a single immature individual — was recovered from a locality, designated U.W. 110, within a narrow fissure of the Dinaledi subsystem.
Named the ‘Leti’ after the Setswana word ‘letimela’ meaning the ‘lost one,’ this Homo naledi child lived approximately 250,000 years ago and was between 4 and 6 years old.
“This is the first partial skull of a child of Homo naledi yet recovered and this begins to give us insight into all stages of life of this remarkable species,” said Dr. Juliet Brophy, a researcher in the Department of Geography and Anthropology at Lousiana State University and the Centre for the Exploration of the Deep Human Journey at the University of the Witwatersrand.
“Having skull remains associated with teeth of the same individual is extremely important for understanding the growth and development of this species,” added Dr. Christopher Walker, a researcher in the Department of Molecular Biomedical Sciences at North Carolina State University, the Department of Evolutionary Anthropology at Duke University, and the Centre for the Exploration of the Deep Human Journey at the University of the Witwatersrand.
The size of Leti’s brain is estimated at around 480 to 610 cm3.
“This would have been around 90% to 95% of its adult brain capacity,” said Dr. Debra Bolter, a researcher in the Department of Anthropology at Modesto Junior College and the Centre for the Exploration of the Deep Human Journey at the University of the Witwatersrand.