The Galapagos tortoise is the largest tortoise in the world. They are native to 7 of the Galapagos Islands. Spanish explorers discovered the islands in 1543 and named them after the Spanish word galapago, which means tortoise.
According to National Geographic, there may only be 10 species left of the 15 species that existed when Darwin arrived to the Galapagos islands in 1835. You can see a list of species on Wikipedia: List of species of Galapagos tortoise
They were hunted for food during the 17th through 19th centuries. Invasive species (pigs, rats, dogs, cats, goats, cattle) that were brought to the islands are still a threat by eating their eggs, killing young tortoises, and destroying their food supply. Adult tortoises have no natural predators.
The Charles Darwin Research Station and some zoos have ongoing breeding programs to help save the remaining species.
There are 2 types of Galapagos tortoises, ones that have a round shell and ones that have a saddleback shell that curls up in the front. The saddleback tortoises have longer necks and are able to reach higher.
Giant tortoises such as the Galapagos tortoise are the longest-lived vertebrates. Their lifespans average over 100 years. There are reports of captive tortoises living over 170 years.
The largest recorded Galapagos tortoises were over 880 pounds and 6.1 feet long, but the average male is about 500 pounds and females 250 pounds. Males are larger than females.
Since they are cold-blooded animals, they like to start their day by basking in the sun to warm up. Then, they spend their day mostly eating and sleeping. They are herbivores and eat prickly pear cactus, grass, leaves, flowers, and fruit.