Galapagos Giant Tortoise

The Galápagos giant tortoises (the Chelonoidis niger complex) are the largest living tortoises, weighing up to about 400 kilograms. Different islands have different forms, and they helped inspire Darwin's ideas about evolution.

🧬 Field Guide Specimen: Open Galapagos Giant Tortoise in the CRV Science Field Guide to log the specimen, see its place among the Reptilia lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.

Tortoises on wetter islands with lush ground vegetation tend to have domed shells, while those on arid islands, where they must reach up for cactus pads, have saddle-shaped shells with raised fronts and longer necks. Darwin was told that officials could tell the island of origin of a tortoise by its shell.

Sailors took thousands of tortoises as live food in the 1700s and 1800s, and introduced goats, rats and pigs ate vegetation and eggs. Several island forms are extinct, including the Pinta Island tortoise after the death of Lonesome George in 2012.

Captive breeding and removal of invasive animals have helped populations to rebound. A tortoise named Harriet was said to have lived about 175 years. In 2019, a tortoise of the Fernandina species, thought extinct for a century, was rediscovered. See Marine Iguana.