The Greenland shark (Somniosus microcephalus), also known as the gurry shark, grey shark, or by the Kalaallisut name eqalussuaq, is a large shark of the family Somniosidae ("sleeper sharks"), closely related to the Pacific and southern sleeper sharks. The distribution of this species is mostly restricted to the waters of the North Atlantic Ocean and Arctic Ocean. Greenland sharks have the longest known lifespan of all vertebrate species (estimated to be between 300–500 years), and the species is among the largest extant species of shark. As an adaptation to living at depth, it has a high co...