Scientists have identified a new species of giant tortoise on the Galapagos Islands, using 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 15-square-mile 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 scientists said on Wednesday (21 October). Galapagos National Park released video of the tortoise on Wednesday, but the images were filmed in August of this year. Scientists long had thought all the giant tortoises on the island were from the same species.
The researchers used two types of genetic data to determine that it merited being recognized as a separate species, bringing to 15 the number of Galapagos giant tortoise species. 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, researchers said.
"In front, they are a very steep front. And the tortoise from West Santa Cruz have a more flat front. The same thing occurs in the back. In this tortoise, are very steep. The tortoise from West Santa Cruz are flat like Santiago or Alcedo or other don species," explained local researcher Washington Tapia.
Giant tortoises, which can reach 225 kg are among the famous creatures of the Galapagos Islands closely studied by 19th century British naturalist Charles Darwin. The Galapagos Islands are one of only two locales inhabited by giant tortoises, along with the Indian Ocean's Aldabra Atoll. Galapagos tortoises graze on grasses, leaves, cactus and fruit but can survive up to a year without food or water.