A 400-year-old Greenland shark sets a new record for being the oldest living vertebrate animal on the planet.
The shark was born during the reign of King James I. It was a young shark when the era of colonialism peaked in intensity in the 1600s.
According to researchers, Greenland sharks grow at an incredibly slow growth rate of less than a centimeter per year.
This large yet slow-growing species don't reach sexual maturity until they're 150 years old. That is when they're about 13 feet long.

This oldest, largest female shark was born over 392 years ago. But some biologists suggest it could be between 272 and 512 years old.
This new discovery is published in the Journal Of Science.
Lead author of the study Julius Nielsen, a marine biologist from the University of Copenhagen, said:
"We had our expectations that we were dealing with an unusual animal. But I think everyone doing this research was very surprised to learn the sharks were as old as they were."

The former record-holder was a bowhead whale, which scientists estimated to be 211 years old.
If we bring invertebrates into longevity comparison, a 507-year-old clam, called Ming, holds the title of the oldest animal.

Greenland sharks are one of the world's largest and long-living creatures. But just how long they can live remains a mystery.
Steven Campana, a shark expert from the University of Iceland, said:
"Fish biologists have tried to determine the age and longevity of Greenland sharks for decades, but without success."
"Given that this shark is the apex predator (king of the food chain) in Arctic waters, it is almost unbelievable that we didn't know whether the shark lives for 20 years or 1000 years."
These sharks live in the icy, deep waters of the North Atlantic. According to the International Union for Conservation of Nature, these creatures are a near-threatened species.

Fishermen hunt Greenland sharks primarily for liver oil and food. Nielsen and his team have raised concerns about species conservation due to the commercial fishing industry.
On the study, they state:
"Our estimates strongly suggest a precautionary approach to the conservation of the Greenland shark...They are common bycatch in the arctic and subarctic groundfish fisheries...[and are subject] to several recent commercial exploitation initiatives."

The study also highlights the importance of conservation. Nielsen describes how it might be difficult for Greenland sharks' population to rebound:
"When you evaluate the size distribution all over the North Atlantic, it's quite rare that you see sexually mature females. And quite rare that you find newborn pups or juveniles."
"It seems most are sub-adults. That makes sense: if you have had this very high fishing pressure, all the old animals are no longer there. And there are not that many to give birth to new ones."
"There is still a very large amount of 'teenagers.' But it will take another 100 years for them to become sexually active."