The reptile class, encompassing turtles, crocodiles, snakes, and lizards, includes some of the most long-lived animals in the world, frequently surpassing the maximum ages achieved by similar-sized mammals. This longevity is often attributed to their cold-blooded nature, associated with slower metabolic rates.
The Record Holder for Extreme Longevity
The undisputed champions of reptile longevity belong to the order Testudines, specifically the giant tortoises. The longest documented lifespan for any land animal is currently held by Jonathan, a Seychelles giant tortoise (Aldabrachelys gigantea hololissa) residing on the island of Saint Helena. Jonathan’s age is conservatively estimated to be around 191 years old; he was documented as fully mature when he arrived on the island in 1882, suggesting a birth year of approximately 1832.
While Jonathan is the oldest living individual with a highly verified record, the longest estimated reptile lifespan belongs to Adwaita, an Aldabra giant tortoise (Aldabrachelys gigantea). Adwaita lived at the Alipore Zoological Gardens in India and was believed to have been born around 1750, reaching an estimated age of 255 years at his death in 2006. Although Adwaita’s age is not conclusively proven, it highlights the immense lifespan potential of these chelonians. Giant tortoises, including Galápagos and Aldabra species, regularly exceed 150 years in both captive and wild settings.
Biological Mechanisms Driving Reptile Age
The remarkable age reached by these reptiles is connected to negligible senescence. After reaching sexual maturity, the risk of mortality and the decline in reproductive fitness do not measurably increase with age. This contrasts sharply with mammals, where the probability of death generally increases exponentially as an individual gets older.
A key factor supporting this resilience is a “protective phenotype,” such as the hard shell of a tortoise, which significantly lowers the risk of death from external causes like predation. Reducing the external mortality rate lessens the evolutionary pressure for the animal to reproduce quickly and age rapidly.
Long-lived reptiles, particularly turtles, also possess superior mechanisms for maintaining DNA integrity. Studies on leatherback sea turtles, for instance, indicate an absence of telomere shortening with age, suggesting high activity of the telomere-restoring enzyme telomerase.
Furthermore, many long-lived reptiles, including tortoises and crocodilians, exhibit indeterminate growth, meaning they continue to grow in size throughout their lives. This growth is linked to their ability to exhibit negligible senescence. While ectothermy (being cold-blooded) has been hypothesized to cause slower aging due to lower metabolism, recent studies suggest that specific protective traits and negligible senescence are more influential than metabolism alone.
Other Notable Long-Lived Species
While giant tortoises claim the extreme age records, longevity is observed across other reptilian orders. Crocodilians, such as saltwater and Nile crocodiles, are known for impressive lifespans, with many individuals estimated to live over 70 years in the wild. Some captive crocodilians have exceeded a century, with one Nile crocodile named Henry reaching 121 years.
The tuatara (Sphenodon punctatus), a unique reptile endemic to New Zealand, is another example of reptilian endurance. Often called a “living fossil,” the tuatara possesses an extremely slow growth rate, reaching sexual maturity only after 10 to 20 years. This slow life allows them to commonly reach ages exceeding 60 years, with many estimated to live over 100 years.
Even among snakes, which generally have shorter lifespans, larger constrictors demonstrate considerable longevity. Large species like the boa constrictor and various pythons (including reticulated and Burmese pythons) typically live between 20 and 30 years. In captivity, some individuals have surpassed this, with one ball python documented to have lived for 47 years.