Meet Homo naledi (Image: Wits University)

It’s not every day that the discovery of a new extinct species of human is announced. What’s more, the discovery of Homo naledi resulted from a cache of bones of 15 ancient people, found in one of the recesses of a cave system in South Africa.

Alia Gurtov, one of the “underground astronauts” who helped excavate the bones, compares the discovery to the sequencing of the Neanderthal genome. “It’s got that same wow factor,” she says.


The find raises a host of questions, some of which cannot be answered definitively – although we can make informed guesses.

Whose bones are these?

A primitive species of human. The adult male stood 1.5 metres tall, and the structure of the feet suggest it was bipedal for much of the time. The curvature of the fingers, however, similar to that seen in ape ancestors, and the shape of the shoulders, show that Homo naledi was also at home in the trees.

There is a remarkable lack of diversity in the remains, which suggests that the bones were all from a single species, or even from a group of closely related individuals within a single species – perhaps a tribe or family. There is a range of ages, from infant to adult, and both males and females are probably present.

Where exactly were the bones found and how did they get there?

The bones, over 1500 of them, come from the Dinaledi chamber, part of the Rising Star cave system north-west of Johannesburg, in a region nicknamed the Cradle of Humankind for the trove of human fossils found there. To reach the chamber, you have to descend through a narrow, 12-metre vertical shaft. The cave layout seems not to have changed in thousands of years, so either bodies were dragged into the caves and “posted” down the shaft, or else people crawled down there alive and subsequently died.

Could Dinaledi be a burial site?

Perhaps it would be better to call it a tomb, but whatever term you use, it is very rare to find so many early human bones in one place. The researchers suspect the bodies were indeed deposited down there deliberately.

How else might the bones have got into the chamber?

It might be that the people entered as a group, perhaps to escape a battle or natural disaster, and then became trapped and died. But since the cave is so hard to access, it seems more likely that the bodies were added one by one.

If it is a tomb, what does this say about how the dead were disposed of?

It is unprecedented. The most similar example comes from a cave in the Atapuerca mountains in Spain called the Sima de los Huesos (“the pit of bones”). It contains thousands of bones from 28 early humans, possibly Homo heidelbergensis, dated to around 350,000 years ago. The bodies at Sima de los Huesos seem to have been thrown down into the pit in a deliberate act of disposal – and they belonged to a relatively advanced species that had a brain almost as big as ours.

H. naledi‘s brain is much smaller, only about the size of a gorilla’s and a third the size of ours. If such primitive people were disposing of their dead, we will have to completely rethink the evolution of cognition and the appreciation of death.

It’s pitch black inside the cave. When the ancient people went in, how were they able to see what they were doing?

The team suggest that Homo naledi used torches. Good evidence for the control of fire among our ancient ancestors is rare and is, ahem, hotly contested.

Recreating the skull with a 3D printer (Image: Greatstock/Barcroft Media)

Could H. naledi speak?

There’s a suggestion that a cranial cast of the one of the specimens shows similarities to our brain in regions associated with speech. However, although it may be possible to get impressions of grooves and ridges of the brain from fossil skulls, there is no consensus on how that corresponds to our own larger brain, nor what it means for cognitive ability. We have no idea if they could speak, although the bones could give us clues.

Our ancient ancestors – the australopithecines that were around before Homo evolved – had a hyoid bone in their neck that is vestigial in us. If this structure is present in H. naledi, it will give us clues as to how the species vocalised.

The middle and inner ear bones should be examined – they are different in humans and other apes so the structure will give an idea of how H. naledi processed sound.

How is H. naledi related to us?

The bones have such a strange mixture of primitive and modern features that we don’t yet know how H. naledi fits into the burgeoning human family tree.

We don’t even know how old H. naledi was. It could be millions of years old, making it one of the very earliest species of Homo, or only tens or hundreds of thousands of years old, making it a relict species of human that survived into modern times, like H. floresiensis – the “hobbit” found in Indonesia.

The team say it may be possible to use isotope testing to age the remains, and that no attempt has yet been made to extract DNA.

Click here to read more about the discovery of Homo naledi and explore amazing pictures

And read all about the initial find in the feature “Bone bonanza: Chamber of secrets yields human remains”