Greenland sharks are among the largest creatures on Earth, growing to a length of 20 feet (6.1 m) in the cold, deep water around the Arctic Circle. But they don’t get to be that size overnight. Scientists say that these lethargic giants grow very slowly -- possibly as little as a centimeter each year. It’s not surprising, then, to learn that according to a University of Copenhagen study published in Science magazine in 2016, the Greenland shark can live more than 250 years, making it the longest-lived vertebrate on Earth. The researchers used a technique called eye lens radiocarbon dating to estimate the age of 28 females caught off the coast of Greenland between 2010 and 2013. “I am 95 percent certain that the oldest of these sharks is between 272 and 512 years old,” said marine biologist Julius Nielsen, the study’s lead author.
A 16th-century clam, and other ancient mariners: