Analysis of prehistoric feces shows Stonehenge residents had parasites

Enlarge / The prehistoric monument of Stonehenge in Wiltshire, UK. A large Neolithic settlement known as Durrington Walls lies less than two miles away and is believed to be where the people who built the famous site camped during the main phase of construction.

Adam Stanford

About two kilometers from Stonehengethere is a large Neolithic settlement known as Durrington Walls, believed to be where the people who built the famous site camped during the main phase of construction. British archaeologists analyzed fossilized faeces collected from the site and found they contained parasitic worm eggs, according to a new paper published in the journal Parasitology. The preserved droppings belonged to both dogs and humans, indicating that people brought dogs to the site with them for winter feasting and likely shared the remains with the canids.

“This is the first time that intestinal parasites have been recovered from Neolithic Britain, and finding them in the Stonehenge environment is truly something,” said co-author Piers Mitchell, an archaeologist at the University of Cambridge. “The type of pests we find are consistent with previous evidence of winter feasting by animals during the construction of Stonehenge.”

For archaeologists eager to learn more about the health and diet of past populations — as well as how certain parasites evolved through the evolutionary history of the microbiome — preserved ancient poo samples can be a treasure trove. of information. For example, ancient Iron Age miners in what is now Austria were very fond of beer and blue cheese, according to an analysis 2021 of preserved paleo-poo extracted from the prehistoric underground salt mines of Hallstatt-Dachstein/Salzkammergut, a UNESCO World Heritage Site. Fecal samples are typically found in dry caves, desert areas, frozen areas, or waterlogged environments (such as bogs), where desiccation, freezing, and similar processes preserve the fecal matter for posterity.

As noted previously, it can be difficult to determine if fecal samples are human or were produced by other animals, especially dogs. Usually, only samples found with human skeletons or mummies could be designated as being of human origin with certainty. Scientists have recently developed a tool (called coproID) capable of determining whether paleofeces and coprolites recovered from archaeological sites are of human or animal origin. Among other findings, the researchers found that the archaeological record was surprisingly full of dog poo.

Human coprolite (preserved human excrement) from Durrington Walls, a Neolithic settlement near Stonehenge.
Enlarge / Human coprolite (preserved human excrement) from Durrington Walls, a Neolithic settlement near Stonehenge.

Lisa-Marie Shillito

Previous studies have compared faecal parasites found in hunter-gatherer and farming communities, revealing dramatic dietary shifts, as well as shifts in settlement patterns and social organization coinciding with the rise of the Agriculture. The wealthy and privileged elite of Jerusalem in the 7th century BCE were plagued by poor sanitary conditions and the resulting parasitic intestinal diseases, according to a document published earlier this year in the International Journal of Paleopathology. An analysis of soil samples taken from a stone toilet found in the ruins of a posh villa revealed the presence of parasitic eggs of four different species.

However, very little is known about the degree of parasite infection in Britain’s prehistoric population until the Neolithic period, Mitchell said. et al. The authors therefore decided to examine coprolites excavated from the Durrington Walls site (dated to around 2500 BCE) to determine if humans and animals living at the site were indeed infected with parasites and if it was possible to detect the eggs of non-infectious parasites some 4,500 years later.

Coprolites are not quite the same as paleofeces, which retain many organic components that can be reconstituted and analyzed for their chemical properties. Coproliths are fossils, so most of the organic components have been replaced by mineral deposits like silicate and calcium carbonates. It can be difficult to distinguish smaller coprolites from eggs, for example, or other types of inorganic granules. But coprolites usually show spiral or annular markings and may contain undigested food fragments.

(left) Microscopic Durrington Walls capillariid worm egg.  (right) Microscopic fish tapeworm egg found in dog coprolite.
Enlarge / (left) Microscopic Durrington Walls capillariid worm egg. (right) Microscopic fish tapeworm egg found in dog coprolite.

Evilena Anastasiou/University of Cambridge

Archaeologists excavated the site in 2004-2007 and found the floors of several houses, dumps (organic waste deposits) and more than 100 pits. They found a large collection of pottery, worked stone tools, and over 38,000 animal bones, mostly pigs, indicating this was a feasting site. And some of the pits contained coprolites. Mitchell et al. examined 19 samples taken from the site and subjected them to scientific analysis.

Five of these coprolites contained parasite eggs – four coprolites from dogs, one from human. A canine coprolite contained the fish tapeworm eggs, so the dog would have consumed raw freshwater fish at some point. Since there was no evidence of fish consumption at the site – which was probably mostly busy during the winter season – the authors believe the dog picked up the tapeworm eggs from one of the original settlements elsewhere.

The human coprolite and three of the canine coprolites contained lemon-shaped eggs of capillariid worms. It is unusual to find eggs in human stool because with human infections the eggs tend to end up in the liver and are never excreted. The authors interpret this to mean that the person in question had likely eaten raw or undercooked lungs or liver from an animal that already carried the parasite, so the eggs passed directly through the body. And that person probably shared the leftovers with the dogs.

“We know they had to eat internal organs like the liver, where this parasite would normally live, and they were feeding it to their dogs as well, because dogs had the same type of parasite,” Mitchell said. says New Scientist. “[The results] show in a very interesting way that humans lived with their pets thousands of years ago. They still treated their dogs like a member of the family even back then. It gave us this wonderful window of evidence that we didn’t have before.

DOI: Parasitology, 2022. 10.1017/S0031182022000476 (About DOIs).

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