Archaeologists in western Norway have recovered a grooved, 66-pound stone from the seabed beneath a Stone Age quarry. They believe it may be a stone anchor, potentially the oldest discovered.The stone was found on a pile of quarry waste below Hespriholmen, a rocky islet off Bomlo. People quarried greenstone there to make axes between 5,000 and 9,000 years ago.Researchers identified the stone in 2025 at a depth of about 65 feet and retrieved it this year. The groove encircles the entire stone.Archaeologist Leif Inge Astveit of the University Museum of Bergen co-leads the project with archaeologist Arild Skjæveland Vivas of Stavanger Maritime Museum.Why a Stone Age boat would need a stone anchorStone Age boats typically did not have anchors, according to Hein Bjerck, professor emeritus at the NTNU University Museum and not involved in the project. Settlements were located on beaches where crews could pull boats ashore, according to Forskning.no.Vivas noted that the waters around the islet are hazardous, allowing visits only in calm conditions. Bjerck suggested an anchor likely helped crews keep boats near the rocks while loading heavy greenstone blocks. Archaeologists believe greenstone axes may have served as gifts or status symbols.Astveit said he is “absolutely convinced” it was an anchor, citing its location in waste from an older Stone Age quarry. The report notes the waste came from the largest quarry on the islet, and the stone is too large to have served as a fishing net weight.According to the report, the oldest securely dated stone anchors are from the Bronze Age Mediterranean. If confirmed, this would be the oldest known stone anchor in Norway, and possibly in the world.What is still unprovenVivas stated that the findings must undergo peer review before confirmation. The report notes there is no direct dating of the stone, so its age is based on its position in quarry waste. The quarry was active for approximately 4,000 years.Bjerck, who has reviewed photos of the stone, said he has never seen anything similar. He favors identifying it as an anchor, mainly because of where it was found.Norway has no known Stone Age boat remains, the report said, so for now it is unknown what carried the stone anchor. Astveit believes skin boats, which are covered in animal hide, were primarily used along the coasts. The report said a raft is also possible.What comes nextThe team’s main goal is to estimate the amount of greenstone removed from the islet using 3-D models from the underwater archaeology survey. According to the report, a 1987 estimate was about 430 cubic meters (15,000 cubic feet), or roughly 30 to 40 large truckloads. Astveit stated the updated figure is not yet available but expects it to be significantly higher.