British scientists made an incredible discovery about the Greenland shark, specifically that it is the longest living vertebrate with an incredibly long lifespan. The oldest living shark is 272 years old, but a process called eye lens radiocarbon revealed that the species had centuries of longevity, up to 400 years.
We tend to think of vertebrates as living about as long as we do, give or take 50 to 100 years. Marine species are likely to be very long-lived, but determining their age is particularly difficult. Nielsen et al. used the pulse of carbon-14 produced by nuclear tests in the 1950s—specifically, its incorporation into the eye during development—to determine the age of Greenland sharks. This species is large yet slow-growing. The oldest of the animals that they sampled had lived for nearly 400 years, and they conclude that the species reaches maturity at about 150 years of age.