The oldest recorded “turtle” typically refers to the order Testudines, which includes sea turtles and land tortoises. While many sea turtle species live for decades, giant tortoises hold the records for extreme longevity among terrestrial animals. Accurate age verification for these creatures is often difficult, relying on historical records, photographs, and scientific estimation.
The Current Record Holder: Jonathan the Tortoise
The current verified record holder for the world’s oldest living land animal is Jonathan, a Seychelles giant tortoise. Born around 1832, he is currently over 190 years old and resides on the island of St. Helena, grazing on the grounds of Plantation House.
The evidence for his age relies on a historical record from 1882, when he was brought to St. Helena. A letter noted he was “fully mature” upon arrival. Since this species reaches maturity around 50 years of age, his hatching year was estimated to be no later than 1832. This estimate was supported by an 1886 photograph showing Jonathan as a fully grown tortoise.
In 2022, the governor of St. Helena officially declared December 4, 1832, as Jonathan’s official birthday, solidifying his record claim. His species, Aldabrachelys gigantea hololissa, is a subspecies of the Aldabra giant tortoise known for its long lifespan.
Other Documented Long-Lived Individuals
While Jonathan holds the current title, other giant tortoises have claimed greater, though less verified, ages. The highest-reported age belongs to Adwaita, an Aldabra giant tortoise who died in 2006 at the Alipore Zoological Gardens in India. Adwaita was estimated to be 255 years old, reportedly born around 1750.
This age estimate is based on historical records linking him to Robert Clive of the British East India Company in the 18th century, but definitive proof is elusive. Verifying such ancient ages is challenging due to the lack of formal documentation from their early lives.
Another notable long-lived individual was Harriet, a Galápagos tortoise (Chelonoidis niger porteri), who lived to an estimated 175 years old before her death in 2006. Harriet was believed to have been collected by Charles Darwin in 1835. Her age was later corroborated through DNA analysis.
The radiated tortoise, Tu’i Malila, died in Tonga in 1965 at an estimated age of 188 or 189. These examples demonstrate that extreme longevity is a recurring pattern across multiple species within the tortoise family.
The Biology of Extreme Longevity in Chelonians
The remarkable lifespans of giant tortoises are linked to their unique biology and physiology. Many tortoise species exhibit negligible senescence, meaning their mortality rate does not increase after reaching maturity. This contrasts sharply with most mammals, where the risk of death rises exponentially with age.
One primary factor contributing to longevity is the protective shell, which significantly reduces extrinsic mortality risks like predation and injury. By shielding them from external threats, the shell allows tortoises to reach their maximum biological lifespan potential.
At a cellular level, research suggests adaptations that enhance maintenance and repair. Studies have identified gene variants associated with efficient DNA repair and the regulation of telomeres, the protective caps on chromosomes that shorten with age. This molecular robustness contributes to their resistance to age-related diseases, including cancer.
Furthermore, the ectothermic (cold-blooded) nature of reptiles results in a slower metabolism compared to endothermic (warm-blooded) mammals. A slower metabolic rate is hypothesized to reduce the accumulation of oxidative stress and cellular damage over time. This combination of genetic, structural, and metabolic traits allows giant tortoises to survive for centuries.