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.