In the spring of 2024, an image surfaced that purportedly showed a Greenland shark born before the Revolutionary War.
“This is a 393-year-old Greenland Shark found in the Arctic Ocean,” a Facebook post claimed on April 2, 2024. “It’s been swimming since 1627. It is the oldest known living vertebrate.”
Similar claims appeared on other social media platforms in March and April 2024, including X (formerly Twitter), Reddit, and TikTok, with most claims setting the shark’s age at 392 years. These posts also circulated in August 2020.
The image in question was identified as “mostly false” in December 2018. We now rate this newer version as “mixture” because while the 2020 image was of a Greenland shark, the exact age of the shark remains undetermined. The age of a Greenland shark can be estimated by its length, a topic explored further below.
Both viral memes originated from a study published in the journal Science in August 2016. Researcher Julius Nielsen, then a Ph.D. student at the University of Copenhagen, aimed to define the life history of the Greenland shark, scientifically known as Somniosus microcephalus. These deep ocean fish are described as an “iconic species of the Arctic seas” and remain one of the most mysterious creatures on Earth, mainly due to their ability to survive at depths of at least 7,200 feet.
When the research was first announced in 2016, many mainstream media outlets highlighted the study, declaring the Greenland shark as the longest-lived vertebrate known. Since then, various versions of the photograph and its claimed age have reappeared. A reverse-image search found 56 results dating back to 2018. Following another wave of social media interest, Nielsen addressed misleading claims on Instagram in December 2017:
“Social media are going wild over old Greenland sharks these days?? All of this is the same story from August 2016. Please note that we have not found any sharks to be 600 or 500 years old. We have ESTIMATED (meaning it has not been verified) that one shark was AT LEAST 272 years old or between 272-512 years old with 95.5% certainty (the latter also being an unverified estimate).”
Over a three-year project studying the Greenland shark, the team used radiocarbon dating to determine the ages of 28 specimens caught as by-catch over several years. The findings showed that this slow-growing species increases by about 0.4 inches each year and can reach lengths over 16 feet. The largest shark analyzed measured nearly 16.5 feet long and was estimated to be around 392 years old in 2016, making it about 396 in August 2020.
Radiocarbon dating studies typically determine age ranges rather than specific ages. Based on the analysis of 28 female Greenland sharks, which measured between 2.5 and 16.5 feet long, the study estimated an average species lifespan of at least 272 years. If the annual growth rate of 0.4 inches was strictly followed, the largest shark could be calculated to be 502 years old. However, range estimates suggested the largest shark was likely 392 years old, give or take 120 years.
A University of Copenhagen news release described Greenland sharks as “among the largest carnivorous sharks on the planet,” with an essential role as apex predators in the Arctic ecosystem, a role that is “completely overlooked.” Greenland sharks can reach up to 24 feet in length and weigh over 2,000 pounds.
It remains unclear whether the shark featured in the meme was the same large shark mentioned above or another one photographed during the research. While the photograph indeed depicts a long-lived Greenland shark, the exact age of the specimen is not clearly defined in the research.
Have you encountered other variations of this claim?
