Testudinidae – Tortoises (terrestrial)

Renowned for its longevity and the remarkable size of some of its members, notably the Galápagos tortoise, the largest living species of land turtle. These gentle giants have become symbolic of the Galápagos Islands, an archipelago that has played a pivotal role in our understanding of evolution and natural history.

Tortoises are land-dwelling creatures found on every continent except Antarctica and Australia, exhibiting a wide range of sizes and adaptations to various habitats, from deserts to tropical rainforests. The adaptability of these animals is further demonstrated by their ability to survive for long periods without water or food. This attribute historically made them valuable to sailors on long voyages. In the age of sail, tortoises were often kept aboard ships as a source of fresh meat, as they could be stored in the hold for months without sustenance.

The longevity of tortoises is one of their most extraordinary features, with some individuals living up to 150 years or more. This impressive lifespan is due to their slow metabolism and robust physiological adaptations that protect against the wear and tear of aging.

The shell of a tortoise is an iconic adaptation, protecting it from predators and the environment. The shell is an integral part of their skeleton, with the ribs fused to the carapace, creating a solid protective barrier. The shell’s shape and size can vary significantly among species, reflecting their diverse ecological roles and evolutionary histories.

The popularity of tortoises as pets has had unintended consequences for wild populations. Over-collection for the pet trade, habitat destruction, and climate change pose significant threats to many tortoise species. This has led to a decrease in their numbers in natural habitats and has placed some species on the endangered list.