Research suggests that Homo naledi intentionally buried their dead in two underground cave chambers 160,000 years ago. Homo naledi are extinct, small-brained hominids that lived in southern Africa between 335,000 and 236,000 years ago. However, this conclusion is subject to further investigation as the proposed discoveries have drawn skepticism from other scientists.

Searching for Clues About the Mysterious Human Species

An international team of researchers led by paleoanthropologist Lee Berger of Wits University in Johannesburg, South Africa, proposed that Homo naledi could have dug cave graves and carved marks into the cave walls, suggesting that they intentionally buried their dead. Berger refers to the 30 cave markings that they identified within the Dinaledi subsystem of the Rising Star Cave system. The abstract patterns and shapes include isolated lines that form squares, crosses, and triangles.

During their excavation in 2013, Berger's team also excavated skeletons of an adult Homo naledi whose body was placed in a shallow grave. The bones seem to come from corpses intentionally buried but have become detached due to decomposition or due to the digging of other burials in the chamber.

If this suggestion is correct, the discovery will indicate that an ancient Homo species with a tiny brain and humanlike features have already performed mortuary and symbolic rituals initially thought to have emerged in large-brained species such as Homo sapiens. It will have the potential to indicate that a significant level of cognitive abilities can also be found in species with smaller brain sizes before Homo sapiens or Neanderthals.

Berger's team returned to the excavation site to find a continuous layer of bones in Dinaledi. Their exploration revealed more fragments of bones, suggesting that Homo naledi used this area as a repository for the dead.

READ ALSO: Ancient Human Species Findings of Homo Naledi Bring More Questions of Human Evolution

Debate About the Proposed Discoveries

Some researchers are not convinced that the evidence is enough to confirm the burial activities of Homo naledi. Paleoanthropologist María Martinón-Torres from the Spanish National Research Center on Human Evolution suspects that the cave skeleton was accumulated after the bodies placed in cave shafts later fell through or had been left in the underground caves. She also claims that the sets of fossils discovered by Berger could have been produced by trampling or other activities of the Homo naledi in the caves.

Archeologist Paul Pettitt of Durham University supported Torres' argument, suggesting that the corpses of Homo naledi came to rest in a natural depression not because they were placed intentionally, as Berger claims, but because periodic water leakage into the underground caves moved them wholly or partially.

The engravings in the underground cave are still undated. According to Pettitt, it is still unsafe to assume that Homo naledi reached the chambers and carved those patterns in the cave wall. Although the reports do not establish the claim that Homo naledi dug cave graves, it is still evident that this early human did something different and unusual in the Rising Star Cave System, according to zooarchaeologist Aurore Val of Aix-Marseille University.

RELATED ARTICLE: New Human Species Called Homo Naledi Found In "Rising Star"

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