10 Animals With Lifespans That Surprise Most People

2. The Ancient Giants - Greenland Sharks and Their Centuries-Long Lives

Lurking in the frigid waters of the Arctic and North Atlantic, Greenland sharks (Somniosus microcephalus) are living relics that can survive for over 400 years, making them among the longest-lived vertebrates on Earth. These massive predators, which can grow up to 24 feet in length, achieve their remarkable longevity through an incredibly slow metabolism and growth rate, adding only about one centimeter to their length each year. Recent scientific studies using radiocarbon dating of proteins in their eye lenses have revealed that some specimens alive today were born before the American Revolution, swimming through centuries of human history while remaining virtually unchanged. Their extreme longevity is attributed to the cold Arctic waters they inhabit, which dramatically slow their metabolic processes, and their unique physiological adaptations that allow them to thrive in near-freezing temperatures. These ancient sharks possess high concentrations of trimethylamine oxide (TMAO) in their tissues, which acts as a natural antifreeze and may contribute to their cellular preservation over centuries. The discovery of their extraordinary lifespan has revolutionized our understanding of vertebrate aging and has made Greenland sharks valuable subjects for longevity research, as scientists seek to understand how these creatures maintain cellular integrity across multiple human generations.