Greenland shark
Somniosus microcephalus
at least 250 years
estimated lifespan of a Greenland shark
Greenland sharks live in water near freezing in the North Atlantic and Arctic, and swim at under 3 kilometers per hour. In that cold, everything about them runs slowly: they grow less than a centimeter a year and may not breed until they are about 150 years old.
Scientists dated the sharks using carbon in the proteins of their eye lenses, which form before birth and never change. The results put their lifespan at 250 years or more, and the largest shark in the study at roughly 400. That makes them the longest-lived animals with a backbone.
A Greenland shark swimming today may have been born before the United States existed.
