Homo naledi Mystery Grows: All Skeletons Found Were Female 2026

The Homo naledi mystery has taken a surprising turn: a new analysis of dental enamel from 23 teeth belonging to at least 20 individuals has revealed that all the specimens recovered from the Rising Star cave system in South Africa were biologically female. This finding, published a decade after the species was first announced, upends previous assumptions and deepens the enigma surrounding one of the most puzzling hominids in the human family tree.

When Homo naledi was discovered in 2013, paleoanthropologists were struck by its mosaic anatomy: a brain about one-third the size of ours, shoulders and head reminiscent of Australopithecus, but hands, feet, and face that looked strikingly like later Homo species. The uniformity of the skeletons also raised eyebrows—they seemed too similar to one another.

What the New Study Found

Researchers led by a team at the Rising Star cave site examined the enamel of 23 teeth from at least 20 individuals. They were specifically searching for amelogenin-Y, a protein encoded on the Y chromosome that is present only in males. The protein was absent in all samples.

That means every individual tested was biologically female. The study, the largest of its kind on an extinct hominid population, suggests that the Rising Star deposit may be the first known example of a female-only burial site for an ancient human relative.

Why the Earlier Assumption Was Wrong

Initially, scientists assumed the usual pattern: larger skeletons were male, smaller ones female. But that assumption had never been tested at the molecular level. The new protein analysis shows that size variation among these hominids did not correspond to sex as previously thought.

Why This Matters for Human Evolution

The discovery challenges conventional wisdom about Homo naledi social behavior and site formation. If all the individuals were female, what does that imply about how they ended up in the cave? Were they deliberately placed there as part of a burial ritual? Or did some other process selectively accumulate female remains?

Homo naledi already made headlines for its mix of primitive and modern traits, and for evidence suggesting it may have deliberately disposed of its dead in the cave—a behavior once thought unique to larger-brained hominins. Now, the female-only finding adds another layer to the puzzle.

• All 20+ individuals tested from Rising Star were biologically female, based on amelogenin-Y protein absence.
• The study is the largest molecular sex analysis ever conducted on an extinct hominid population.
• Previous sex assignments based on skeletal size were likely incorrect.
• The site may represent the first known female-only burial accumulation for a non-modern human species.
• Questions remain about whether the accumulation was intentional or accidental.

What the Skeletons Reveal

The Rising Star cave system has yielded an extraordinary number of Homo naledi remains—more than 1,500 fossils from at least 15 individuals in the Dinaledi Chamber alone. The new sex analysis focused on teeth because enamel preserves proteins exceptionally well over hundreds of thousands of years.

Amelogenin-Y is a reliable marker for biological sex in teeth, and its absence in all samples is a strong signal. The researchers note that the probability of randomly sampling only females from a mixed population is extremely low, reinforcing the conclusion that the deposit is female-dominated.

Who Was Homo naledi?

Homo naledi lived in southern Africa between 335,000 and 236,000 years ago, according to dating of the cave sediments. Its small brain—about 465 to 610 cubic centimeters—contrasts with its surprisingly human-like hands and feet, which suggest it was capable of tool use and bipedal walking.

The species was first described in 2015 by Lee Berger and colleagues, and its discovery sparked debate about the origins of complex behavior. If Homo naledi was deliberately caching its dead in a deep, dark cave, that would imply symbolic thought previously attributed only to Homo sapiens and Neanderthals.

The Burial Debate

Whether the Rising Star accumulations represent intentional burials or natural accumulations remains contested. Some researchers argue that the cave's geology and the lack of carnivore damage point to deliberate disposal. Others caution that the evidence is not yet conclusive.

The new female-only finding adds a twist: if the site was a burial ground, why only females? This could reflect a social structure where females were buried separately, or it could be a taphonomic bias—some process that preferentially preserved female remains. Context on how this played out before sits in Homo naledi Mystery Grows: All Skeletons Found Were Female. A companion piece, Ancient Humans Made Beds and Changed Them 200,000 Years Ago, approaches the same subject from another angle.

What to Watch Next

Future research will likely focus on expanding the molecular analysis to more individuals and other sites. If other Homo naledi localities show similar sex biases, it would strengthen the case for a unique social behavior. If not, Rising Star may be an anomaly. The background to this story is set out in Human Brain Evolution: Why Survival Beat Rational Thought. A related thread runs through Sugar, Not Meat, May Have Powered Human Brain Evolution.

Additionally, the study highlights the power of paleoproteomics—the analysis of ancient proteins—to answer questions that morphology alone cannot. As more ancient proteins are sequenced, we can expect similar surprises across the hominin family tree. Earlier coverage in Human Eye Evolution Tied to 600-Million-Year-Old Cyclops Worm shows how the argument developed. A closer look at the same subject appears in Trending: latest articles.

The Homo naledi saga is a reminder that human evolution is rarely straightforward. Each new technique reveals complexities that challenge our assumptions and force us to rethink what it means to be human. Anyone following the wider picture can start with Mummy Head Sales on Facebook Spark Biohazard Warning. The same theme surfaces in Humanity's 200,000-Year Journey: The Map That Tracks Our Route, which takes a different angle.