http://www.bbc.co.uk/news/world-18574279
Lonesome George was first seen by a Hungarian scientist on the Galapagos island of Pinta in 1972.
Environmentalists had believed his subspecies (Chelonoidis nigra abingdoni) had become extinct.
Lonesome George became part of the Galapagos National Park breeding programme.
After 15 years of living with a female tortoise from the nearby Wolf volcano, Lonesome George did mate, but the eggs were infertile.
He also shared his corral with female tortoises from Espanola island, which are genetically closer to him than those from Wolf volcano, but Lonesome George failed to mate with them.
He became a symbol of the Galapagos Islands, which attract some 180,000 visitors a year.