A South African cave yielded approximately 1,500 fossils of a previously identified hominid species in 2015.

Homo naledi was short, and possessed long arms, curved fingers, and a brain around one-third the size of contemporary humans. Early Africans lived them.

The same team of academics is making another huge announcement: Homo naledi buried their dead in graves despite their little brains. They carved graves on the cave walls and lit lamps to navigate.

The research leader, paleoanthropologist Lee Berger from the University of Witwatersrand in Johannesburg, said it was astonishing that a small-brained hominid performed such humanlike behaviors. It proves that large brains are not needed for complex thinking like symbol creation, risky missions, and death acceptance.

“Star Trek,” he said. “You meet a species that’s not human but equally complex to humans. Do what? Right now.”

Other engraving and burial experts disputed Homo naledi’s findings. They suggested numerous interpretations for the cave finds. The cave floor might hold skeletons. After Homo naledi died, modern humans may have left charcoal and engravings in the cave.

“The narrative seems more important than the facts,” Griffith University archaeologist Maxime Aubert said.

Monday’s scientific seminar included Berger’s results, which eLife will publish in three pieces. A journal representative said the findings will be peer-reviewed and published.

Two South African spelunkers uncovered Homo naledi fossils in Rising Star cave in 2013. Berger conducted an underground expedition.

Tebogo Makhubela joined in 2014.

The bones needed perilous caving. Some tunnels were too narrow for larger teammates.

27 skeletons were found. Berger and colleagues doubted they could have washed into the cave.

In 2015, Homo naledi “funerary cached” the deceased on the cave floor. It was contentious because Homo naledi appeared primitive. Berger and his colleagues felt the species belonged to a lineage that split from our ancestors 2 million years ago. Our ancestors were taller and wiser.

Scientists thought fossils were evenly scattered across chamber floors. Two entire skeletons were recovered in oval depressions in 2018.

The depressions didn’t look like bones had sunk into silt. Orange muck ringed the ovals. Lovely break.

This and other evidence convinced Makhubela and his colleagues that the bones were buried. “They paint the same picture,” he continued.

78,000-year-old human remains. Older Homo naledi. Makhubela estimated 240,000–500,000 years for these fossils.

Scientists found charcoal, charred turtle and rabbit bones, and soot on the cave walls near the fossils. They believed Homo naledi used burning coals and wood or other fuel to navigate tunnels. Animals were eaten or sacrificed.

After these discoveries, Berger visited Dinaledi, a possible burial chamber. He shed 55 pounds to fit through the tube. He departed July.

Berger studied fossils alone. He left past a pillar. The hard surface has hashtag-like markings.

Out was harder. Berger survived a torn rotator cuff. Princeton’s Agustín Fuentes and Wisconsin’s John Hawks welcomed him. Berger showed groove photos.

The two scientists instantly pulled up the same Gibraltar cave Neanderthal etching images on their phones. Like Berger’s.

Fuentes added Homo naledi may have buried their dead and left art at Rising Star for hundreds of years.

He thought culture needed language. “That requires complex communication,” he noted.

María Martinón-Torres, head of Spain’s National Research Center on Human Evolution, said such assertions were premature based on present facts. She said theories should be founded on evidence, not guesswork.

Since the bones were misaligned, Martinón-Torres thought the oval depressions were funerary stockpiles rather than tombs. Homo naledi’s bones may have separated. “Still, I think the possibility of funerary caching with this antiquity is stunning,” she said.

“I’m highly optimistic they have burials, but the jury is still out,” said Australian Research Center for Human Evolution director Michael Petraglia. Petraglia required more silt and documentation to confirm the ovals were burials. “They’re ahead of science,” he said.

Durham University archaeologist Paul Pettitt stated Homo naledi may not have cached or buried the bones. Bodies could’ve washed in. “I’m not convinced the team have demonstrated that this was deliberate burial,” he continued.

Experts debated whether Homo naledi generated the sculptures and fires. Modern visitors may have created them. João Zilhão, University of Barcelona archaeologist, called the whole affair implausible.

Sample engraving, charcoal, and soot to determine age.

These research were on Hawks’ team’s to-do list, but testing so many samples might take years. Hawks said the team immediately submitted their findings and began debating future actions with specialists.

“I value documenting and sharing over being right,” Hawks said.

If confirmed, the findings will disprove key human evolution hypotheses. Paleoanthropologists think huge brains helped humans and Neanderthals. Big brains have evolutionary disadvantages, therefore they must have benefits. Their large heads and high caloric demands make delivery dangerous for women.

Big brains can reason complexly. Neanderthals used tools, hunted together, and more. Modern individuals use symbols, language, and brainpower.

Emory University neurologist Dietrich Stout claimed that if Homo naledi could make engravings and construct tombs, advanced reasoning was not essential.

“The interesting question moving forward is what exactly big brains are needed for,” Stout said.