Giant tortoises are characteristic of certain reptilian tropical island wildlife. They occur (some species are now extinct) in such places as Madagascar, the Seychelles, Mauritius, Réunion, the Galápagos Islands, Sulawesi, Timor, Flores and Java, often reaching enormous size. However, giant tortoises also once lived on the mainland of Asia, as follows from fossil finds in the Siwalik Hills in India.

These animals belong to the most ancient group of reptiles, appearing about 250 million years ago. In the Upper Cretaceous, 70 or 80 million years ago some already became gigantic and about 1 million years ago these reptiles reached the Galápagos Islands. Until 100,000 years ago most of the gigantic species began to disappear for unknown causes and only 250 years ago there were at least 20 species and subspecies in islands of the Indian Ocean and 14 or 15 species in the Galapagos Islands. From those, only one of the species of the Indian Ocean survives and 11 in Galápagos.

They are commonly known as the world's longest living animals, with an average lifespan of 177 years.

Species and subspecies

• Cylindraspis indica - Réunion Giant Tortoise (Extinct)
• Cylindraspis inepta - Saddle-backed Mauritius Giant Tortoise (Extinct)
• Cylindraspis peltastes - Domed Rodrigues Giant Tortoise (Extinct)
• Cylindraspis triserrata - Domed Mauritius Giant Tortoise (Extinct)
• Cylindraspis vosmaeri - Saddle-backed Rodrigues Giant Tortoise (Extinct)
• Geochelone nigra - Galapagos Giant Tortoise
  • Geochelone nigra abingdoni - Abingdon Island Tortoise (Extinct in the wild)
  • Geochelone nigra becki - Volcan Wolf Tortoise
  • Geochelone nigra chathamensis - Chatham Island Tortoise
  • Geochelone nigra darwini - James Island Tortoise
  • Geochelone nigra ephippium - Duncan Island Tortoise (Extinct in the wild)
  • Geochelone nigra galapagoensis - Charles Island Tortoise (Extinct)
  • Geochelone nigra guntheri - Sierra Negra Tortoise
  • Geochelone nigra hoodensis - Hood Island Tortoise
  • Geochelone nigra microphyes - Volcan Darwin Tortoise
  • Geochelone nigra porteri - Indefatigable Island Tortoise
  • Geochelone nigra vandenburghi - Volcan Alcedo Tortoise
  • Geochelone nigra vicina - Iguana Cove Tortoise
• Geochelone denticulata - Brazilian Giant Tortoise
• Geochelone gigantea - Aldabra Giant Tortoise
• Gopherus flavomarginatus - Mexican Giant Tortoise
• Manouria emys - Asian Giant Tortoise

External links

• A giant Aldabra tortoise

References

• IUCN 2006. 2006 IUCN Red List of Threatened Species. . Downloaded on 20 May 2006.

Tortoises