In the cold waters of the Arctic, a denizen of the deep lurked for centuries. Now scientists calculate that this female Greenland shark was the Earth's oldest living animal with a backbone.

They estimated that the gray shark was born in the icy waters roughly 400 years ago and died only recently. That conclusion puts the entire species at the top of the longevity list for vertebrates.

Using a novel dating technique, an international team of biologists and physicists estimated the age of 28 dead female Greenland sharks based on tissue in their eyes. Eight of the sharks were probably 200 years or older, and two likely date back more than three centuries, according to a study published on Thursday in the journal Science.

Until now, the record holder was a bowhead whale that reached 211 years old, according to study lead author Julius Nielsen and AnAge, an animal longevity database.

The oldest of the Greenland sharks examined was nearly 5 meters long and estimated to be 392 years old when it was caught about four years ago.

But that calculation comes with a huge margin of error - plus or minus 120 years - due to the newness of the dating technique, said Nielsen, a marine biologist at the University of Copenhagen.

That means the shark was probably born sometime between 1500 and 1740, with the most likely birth year 1620.

"It's an estimate," Nielsen said. "It is the best we can do."

Even at the lowest end of the margin of error, the shark would have been 272 years old when it died, and still would be the longest-living animal with a backbone, Nielsen said.

Some animals without backbones live longer. An ocean quahog, a clam, lived for 507 years, while one type of sponge is said to survive for 15,000 years and another for 1,500 years.