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Some hunter-gatherers probably kept sheep, or possibly gazelles, outside their huts before they even started farming crops, according to traces of ancient animal dung.

at the University of Connecticut and her colleagues have found spherulites – tiny spheres of calcium found primarily in the faeces of grass-eating ruminants like cattle, sheep and antelopes – outside groups of huts belonging to humans who lived in what is now Syria more than 12,000 years ago.

They also found charred spherulites in fireplaces. This suggests that humans lived with herbivores, like sheep, in this region approximately and were using their dung as a fuel source, says Smith.

“They’re still hunters and gatherers, and they’re still relying on hunted gazelle, but now they’re starting to bring live animals to the site and keep them for however long they need them,” says Smith. “And this result is a bit surprising, because it’s earlier than agriculture, and earlier than what we see in adjacent regions.”

Ruminants release significant quantities of spherulites in their faeces, whereas omnivores, including humans, release very small amounts, and carnivores and horses – which are herbivores but not ruminants – release even fewer, says Smith.

Smith was originally curious about when ancient populations first started burning animal dung as fuel, which is done because it can maintain a very high heat. So, she started looking for spherulites – which are about 5 to 20 micrometres across – in the dust at a human settlement at Abu Hureyra – in modern-day Syria near the Euphrates river – which was inhabited between about 13,300 and 7800 years ago.

In dust from as far back as 12,300 to 12,800 years ago, she found darkened spherulites suggesting that dung had been burned at high temperatures, probably as a heat source, she says. But to her surprise, she also found undarkened spherulites all around the outside of huts, suggesting these people were tending to sheep, goats, cows or gazelles just outside their front doors. The .

“Very quickly, I realised, ‘Oh, my goodness, we have an opportunity here to actually consider the antiquity of live animals on the site’,” she says.

By the late Neolithic period, about 8000 years ago, though, spherulites started to disappear from around the huts, says Smith. That may be because the herds had become so large that people were tending to them on pastures further away from the settlement. “It seems like kind of the opposite of what you’d expect,” she says. “But then, it makes sense, because if you have a huge number of animals, it’s not sustainable to keep them on site.”

This doesn’t mean the animals were domesticated, though, adds Smith. Nor does it indicate which ruminants were living outside the huts. What is more likely is that humans tethered wild animals and fed them to keep them alive as a later meat source. “At the end of the day, these animals were dinner,” she says.

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