The Neolithic people who built Stonehenge unknowingly created what would someday become one of the most iconic—and archaeologically intriguing—landmarks in the United Kingdom. In the process, they also left something else behind that would continue to fascinate scientists thousands of years later: their poop.
Now, new research published in the journal Parasitology takes a closer look at the excrement they left behind—and finds that not only did they eat undercooked organ meat, or offal, but they shared some of their dinner with their dogs.
Scientists reached these dietary conclusions after analyzing the preserved feces of humans and dogs found at Durrington Walls, a settlement roughly two miles from Stonehenge where builders likely lived while constructing the monument some 4,500 years ago. Excavations of the site’s trash heap between 2004 and 2007 unearthed partially mineralized ancient fecal material, which scientists call coprolites.
After analyzing 19 of these specimens, researchers determined that some came from humans and others came from dogs. Five of the samples contained parasite eggs, including capillariid eggs, suggesting that the builders feasted on the internal organs of animals they hadn’t cooked thoroughly.
"Pork and beef were spit-roasted or boiled in clay pots, but it looks as if the offal wasn’t always so well cooked,” Michael Parker Pearson, an archaeologist at University College London and one of the study’s authors, says in a statement.
Capillariid are a type of parasitic worm that typically infects rodents, followed by both wild and domestic carnivores, though human infection is relatively rare. The capillariid eggs in the Neolithic humans’ stools suggest that they ate the organs of an infected animal and likely did not suffer from an infection themselves. The eggs passed right through their digestive systems, the researchers write.
This finding supports earlier archaeologic work, which posits that Durrington Walls was the site of large seasonal gatherings and ceremonies related to Stonehenge and nearby monuments. People who gathered there ate pigs and cows, as well as milk and cheese, and though researchers had suspected that they ate every part of the animal, including the organs, this is the first find that backs up that theory.
Earlier research suggests that farmers herded cattle from as far as 60 miles away for feasts at the site. Once the cows arrived at Durrington Wall, cooks extracted bone marrow and chopped the beef meat into stews, per the researchers.
"This is a sort of meat fest extravaganza," Parker Pearson tells Insider’s Marianne Guenot. "It’s a sort of party-based consumer site, which is obviously a massive magnet for people to come from many, many miles away."
While chowing down on offal, Neolithic humans near Stonehenge also threw a few scraps to their dogs, researchers suspect, based on the presence of capillariid eggs in the canine coprolites, too. One of the dog coprolites also contained the eggs of fish tapeworm, which suggests that it had eaten raw or undercooked fish. Since there’s very little evidence that the people at Durrington Walls ate freshwater fish, researchers believe the dog was already infected when it arrived at the site.
The coprolites are noteworthy not just for what they reveal about Neolithic dining—they are the oldest of their kind ever found in Britain.
“It is the earliest where we know the origin of the person who went to the toilet,” Piers Mitchell, an archaeologist at the University of Cambridge and one of the study’s authors, tells the Guardian’s Nicola Davis.
The people feasting at Durrington Walls were likely responsible for the second phase of construction at Stonehenge, during which they erected the most iconic of the site’s stone arrangements: trilithons that consisted of two vertical stones holding up a third horizontal stone.
All told, it took around 400 years to complete Stonehenge, with builders starting around 3000 B.C.E., as Smithsonian’s Dan Jones reported in 2008.
Archaeologists remain split on the functions of the ancient megalith: Some suspect it was a burial site, while others believe it was an important religious or ceremonial destination believed to have had healing powers. Though the same can’t be said for the parasite-infested offal that the builders later defecated, Stonehenge’s construction seems to have been worth the many poop breaks it generated.