The Greenland shark drifts through Arctic water at the pace of a slow walk and doesn't reach sexual maturity until roughly 150 years old, meaning individuals cruising the North Atlantic today were alr

Greenland sharks swim at a foot per second, grow a centimeter a year, and don't reach sexual maturity until roughly 150 years old — meaning adults reproducing today were born before the American Revolution. A Greenland shark moves through the black water off Baffin Island at roughly one foot per second — about the pace of a person strolling through a supermarket aisle. Its heart beats once every twelve seconds. It grows a single centimetre a year. And i... [8395 chars]