If you’ve ever snuck morsels of food to a dog under the table, you might have something in common with the people who built Stonehenge some 4,500 years ago in the Neolithic period, according to scientists who found parasites in ancient poops near this famous monument in England.
The discovery of these parasites in coprolites, the term for fossilized feces, suggests that humans and their dogs ate under-cooked cattle organs—like liver, lungs, or intestines—during feasts at Durrington Walls, a Neolithic village about two miles from Stonehenge.
Researchers led by Piers Mitchell, an archaeologist at the University of Cambridge, said the parasitic worm eggs found in the coprolites represent a “key discovery due to the important nature of the site” and also offer “the earliest evidence for parasite infection in Britain where we can be confident of the species of the hosts,” according to a study published on Thursday in the journal Parasitology.
“Until now, our evidence for how Neolithic people ate farm animals was from the cut marks on animal bone which showed they had sliced off the meat from the bones,” Mitchell said in an email. “This study shows for the first time that the people and their dogs must have also been eating the internal organs of these animals too.”
Human coprolite from Durrington Walls. Image: Lisa-Marie Shillito
Mitchell and his colleagues set out to examine these coprolites in part because there is “no data at all for parasites affecting people in Neolithic Britain,” according to the new study. This scarcity of evidence for parasitic infection in Britain during this period, which lasted from about 4,000 years to 6,300 years ago, stands in contrast to voluminous parasitic data in Neolithic coprolites found across Europe, at sites where human feces was more readily preserved.
“In the Neolithic period, the toilet had not yet been invented, so we have to look for other ways to find preserved human feces,” Mitchell explained. “Most of the research into parasites in Neolithic Europe comes from lakeside villages built on stilts, and the parasite eggs are preserved nicely in the mud around these houses. In Britain we don't have lots of Neolithic lakeside villages, and so the evidence for intestinal parasites is much harder to find.”
To fill this gap in the record, Mitchell and his colleagues turned to Durrington Walls, one of the largest and most important settlements in Neolithic England. Excavations at the site have unearthed pottery, tools, and a garbage heap containing an astonishing 38,000 animal bones—the remnants of vibrant winter feasts enjoyed by seasonal workers who built Stonehenge. This amazing trash-pile includes evidence that cows were herded across more than 60 miles to these village feasts, while pigs were sometimes brought from locations that were hundreds of miles away, demonstrating that Stonehenge attracted people from vast distances.
Now, Mitchell and his colleagues have added even more detail to the portrait of Neolithic life at Durrington Walls by liquifying small portions of 19 coprolites from the site, and hunting for parasites with a microsieve. The researchers thought they might find signs of direct parasitic infections in human and dog hosts, but were intrigued when instead, they discovered nematode eggs associated with farm animals in four human coprolites, and one dog coprolite, indicating that the people and their pets were consuming infected organs of livestock.
“We were surprised by the excellent quality of the eggs we did find, since they were 4,500 years old and we expected they might be damaged or partly decomposed,” Mitchell said. “We were also surprised that most of the eggs we found were not from worms that had infected the people living at Durrington Walls, but were eggs of parasites that infected the cattle that these people were eating.”
Moreover, the presence of the worm eggs in the dog coprolite “would suggest that Neolithic people treated their dogs as companion animals, unlike the herbivore animals they may have had on their farms to provide food,” Mitchell added.
In addition to the nematode eggs, the canine coprolite contained the eggs of a tapeworm associated with freshwater fish. Durrington Walls does not contain any other evidence of fish consumption at the site, so Mitchell’s team speculates that the dog may have eaten a fish elsewhere in England before traveling to the village.
The parasite eggs in these ancient poops may not be glamorous, but they are a powerful portal into the past lives of people who built one of the most famous monuments in the world, and the dogs who accompanied them. To that end, Mitchell and his colleagues plan to build on these novel findings, which they say “improve our understanding of both parasitic infection and dietary habits associated with this key Neolithic ceremonial site,” according to the study.
“It would be great to know what proportion of Neolithic people were infected by intestinal parasites, and how that compared with people living at other time periods, such as the Roman period or Medieval period,” Mitchell concluded.