Scientists used genetic data to determine that a group of 250 of the slow-moving grazing reptiles was distinct from other tortoise species residing in the Pacific archipelago.
The newly identified species lives in a 40-square-kilometre area of Santa Cruz Island and is as different genetically from the other giant tortoise species on the island as species from other islands.
The research differentiated the new Eastern Santa Cruz tortoise, given the scientific name Chelonoidis donfaustoi, from a larger population of about 2,000 tortoises living about 6 miles away on the western part of the island that belong to the species Chelonoidis porteri.
In addition to genetic differences, the two Santa Cruz Island species also differ in the shape of their shell, with the Eastern Santa Cruz tortoise having one with a more compressed shape. The newly identified species lives in a drier part of the island.
Giant tortoises, which can reach some 225 kilograms are among the famous creatures of the Galapagos Islands closely studied by 19th century British naturalist Charles Darwin.