Ancient humans were regularly making tools out of animal bones 1.5 million years ago – more than a million years earlier than previously thought. This indicates that they could adapt the techniques they used to make stone tools to repurpose bone, a very different material.
It also raises the question of why there is no record of people consistently making bone tools for another million years. Have examples in that gap not been preserved or discovered, or did people abandon them in favour of something better?
While hominins have been making stone tools for at least 2.6 million years, the archaeological record suggests they only came up with more recently. These from about years ago, especially in . There are , but they are isolated, so it isn’t clear that people were consistently making them.
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“There was one bone tool here, one bone tool there,” says at the University of Bordeaux in France.
Between 2015 and 2020, d’Errico and his colleagues excavated a site called T69 in the Frida Leakey Korongo west gully in Olduvai gorge, Tanzania. In seven trenches, they found more than 10,900 stone tools and over 22,000 bones. Of the latter, 9419 could be identified: they included many from fish, crocodiles, bovids, such as antelopes, and hippopotamuses, as well as some from elephants.
The team also identified 27 bone tools, which had been carefully shaped into cutting implements with two faces and sharp edges. Eight of these came from elephants, six from hippos and two from bovids.
Sometimes such objects can be formed accidentally, for instance by carnivores biting the bones. But apart from two possible toothmarks, there was no evidence of this, which suggests hominins were responsible, and given that there weren’t many other elephant bones at the site, “probably these people came to the site with the elephant bones”, says d’Errico.
The team also uncovered evidence that ancient humans were repeatedly making the same kind of tools in the same place. “All the bones that we interpret as bone tools come from a single layer,” says d’Errico. The layer had previously been dated to 1.5 million years ago.
Many of the tools had notches in the middle, suggesting that is where people held them. “It’s probable that this was used as a heavy-duty tool for breaking something,” says d’Errico.
No hominin bones have been identified at the site, so we can’t be confident who made the tools. “It could be Homo erectus, but it could even be Homo habilis”, which was an earlier species, says d’Errico. Both are thought to be our ancestors or at least close relatives.
It is also conceivable that the tools were made by Paranthropus: hominins with smaller brains and larger teeth than Homo, who ate a lot of tough plants, like grasses. It was long assumed that Paranthropus weren’t smart enough to make tools, but in 2023, stone tools from Kenya were tentatively attributed to them.
The biggest mystery is “this incredible gap” between the T69 bone tools and the next reliably-identified sets more than a million years later, says at the Natural History Museum in London.
D’Errico’s team suggests that at around the same time, hominins were starting to make new types of stone tools called Acheulean. Heavy-duty bone tools like those at T69 may not have been as good at cutting as the Acheulean stone tools, prompting people to stop making them. “If something works better, you go with the thing that works better,” says Bello. When people reinvented bone tools a million years later, they may have used them for different purposes.
However, Bello says there is another possibility: maybe ancient humans were using bone tools the whole time, but most of them have been lost because bone doesn’t preserve as easily as stone. It has been assumed that bone tools are harder to make than stone ones, and were therefore invented later, but she says that isn’t necessarily true. “Bone is something easily available, particularly if you butcher an animal.” If it is available, curious hominins are probably going to start experimenting with it, she says.
Bello wants archaeologists to re-examine their finds in search of bone tools. “No one was looking for these bone tools,” she says. “Now that you know that they could be there, let’s see.”
Nature
Neanderthals, ancient humans and cave art: France
Embark on a captivating journey through time as you explore key Neanderthal and Upper Palaeolithic sites of southern France, from Bordeaux to Montpellier, with Â鶹´«Ă˝â€™s Kate Douglas. Visit iconic archaeological sites and deepen your knowledge of Neanderthals and early human ancestors, all while journeying from Bordeaux across the picturesque south of France. Traverse through charming medieval towns and breathtaking countryside, culminating in the vibrant city of Montpellier.
