There are 13 living species of Galápagos tortoises, which are also sometimes called giant tortoises. These reptiles are among the longest-lived of all land vertebrates, averaging more than a hundred years. The oldest on record lived to be 175. They are also the world's largest tortoises, with some specimens exceeding five feet in length and reaching more than 500 pounds.
Giant tortoises were once so abundant on the Galápagos archipelago off Ecuador that the Spanish sailors who explored the region in 1535 named the string of islands for them. (The Spanish word for tortoise is galápago.) Although the islands were once thought to be home to at least 250,000 tortoises, only about 15,000