By carbon dating Greenland sharks that had been killed in the commercial fish surveys between 2010 and 2013, Danish researchers proved that the species has a longer lifespan than any other species with a backbone (it’s pretty tough to beat the “immortal” Turritopsis dohrnii jellyfish). How does the shark manage to live so long? Well, the researchers say probably helps that they live in an incredibly cold environment, which should slow down their metabolisms. But it will take additional research to fully unlock the key to their longevity. Check out the video to find out exactly how many years Greenland sharks live in order to claim the title of world’s longest-living vertebrates.