Around 850 C.E., Vikings sailing on newly developed long-distance ships arrived on the remote Faroe Islands, located between Norway and Iceland in the North Atlantic. But a new study published in the journal Communications Earth & Environment suggests these Scandinavians weren’t the first people to get there. Instead, the team argues, ancient sheep feces found at the bottom of a lake indicates that the Celts set foot on the islands some 300 to 500 years before the Vikings.
“Lakes are amazing archives of environmental information, because they accumulate material from the surrounding landscape in sequential layers in their sediments,” lead author Lorelei Curtin, a geologist at the University of Wyoming, tells CNN’s Ashley Strickland.
Curtin and her colleagues used weighted tubes to collect nine-foot-long sediment cores representing 10,000 years of history from the bottom of a lake on the island of Eysturoy. Analysis of the material showed that large numbers of domesticated sheep appeared suddenly in the geological record, likely between 492 and 512 C.E. A layer of ash from a volcanic eruption known to have occurred in Iceland in 877 helped the researchers determine the historical timeline of the islands’ settlement.
No signs of mammal life on the islands predate the fifth century, meaning the sheep must have been brought over by settlers. In the fecal matter, the team found sheep DNA and distinctive biomarkers produced by the animals’ digestive systems.
“We knew that when people first showed up on the islands, because [they] had been uninhabited, we should be able to see the impacts of the changes they were making to their environment, specifically through the introduction of grazing animals,” says study co-author Nicholas Balascio, a geologist at the College of William and Mary, in a statement.
Per CNN, woody plants like willow, juniper and birch disappeared from the sediment record around the time of the sheep’s arrival. Grass-like, grazing-friendly vegetation soon replaced these plants.
The team’s findings corroborate a 2013 study of charred barley grains discovered beneath the floor of a Viking longhouse on Sandoy, another island in the archipelago, reports David Nield for Science Alert. These grains dated to between 300 and 500 years before Norse settlers’ arrival in the region.
“We see this as putting the nail in the coffin that people were there before the Vikings,” says Curtin in a separate statement.
This isn’t the first time scholars have suggested that people lived on the islands prior to the Vikings. In the 1980s, writes Kevin Krajick for the Columbia Climate School’s State of the Planet, researchers reported that Plantago lanceolata, a weed found in parts of Europe disturbed by pastures or other human activity, showed up on the islands in 2200 B.C.E. The plant can establish itself without humans’ presence, so it’s possible the seeds were blown onto the islands by the wind.
Other possible indications of early habitation of the islands are medieval texts suggesting that Irish monks reached far-off islands in the early sixth century, as well as undated Celtic grave markers and place names, reports Paul Rincon for BBC News. Early navigator Saint Brendan was said to have reached a site known as the Isle of the Blessed between 512 and 530 C.E. Some experts have speculated that the isle was part of the Faroes, but it could also have been in the Azores, the Canary Islands or North America.
DNA from modern Faroe Island residents shows that their paternal ancestry is mostly Scandinavian, while their maternal DNA is mainly British or Irish. This could be a sign of Vikings bringing non-Scandinavian women with them on their voyages or intermixing of the new arrivals with an existing Celtic-descended population. Despite their well-earned reputation for seafaring, Scandinavians only adopted long-distance sailing between 750 and 820 C.E., later than some other Europeans.
Kevin Edwards, an archaeologist at the University of Aberdeen in Scotland who coauthored the 2013 barley study, tells State of the Planet that the findings may point to other areas for future research.