Before the earliest signs of burial by modern humans, researchers have found evidence that members of a mysterious ancient human species buried their dead and engraved symbols on cave walls, The New York Times reported.

The findings highlighted that Homo naledi, an ancient species, had brains that were around one-third the size of a contemporary human brain.

The discoveries may alter how people think about human evolution, since then up until now, these behaviors were only thought to be exhibited by more intelligent Homo sapiens and Neanderthals.

The team of experts --headed by Lee Berger, a paleoanthropologist at the University of Witwatersrand in Johannesburg and the leader of the project-- announced another big discovery after years of studying the surfaces and sediments of the intricate underground cave: Despite having little brains, Homo naledi buried their dead in graves. The burials were marked with inscriptions on the cave walls, and they lit torches to light their way down.

It is worth noting that two South African cavers excavating the Rising Star cave came up with the Homo naledi fossils in 2013. The cave system is a component of South Africa's Cradle of Humankind, a UNESCO World Heritage Site that includes a region where researchers have discovered fossils of several early human progenitor species, remains that are assisting in unraveling the history of human evolution.

The markings uncovered on the cave walls --during the process of identifying the cave tombs-- are thought to be between 241,000 and 335,000 years old, but further testing is needed to determine their exact age.

The study team is continuing their efforts to learn more about Homo naledi, including its age, to know more about how close it is to humans, and whether any DNA has been retained in the bones discovered in the cave system.

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