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Giant Tortoise

 
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Giant tortoises are characteristic reptiles of certain tropical islands. They occur (some species
Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring....
 are now extinct
Extinction

In biology and ecology, extinction is the death of every member of a species or group of taxon. The moment of extinction is generally considered to be the death of the last individual of that species ....
) in such places as Madagascar
Madagascar

Madagascar, or Republic of Madagascar , is an island nation in the Indian Ocean off the southeastern coast of Africa. The main island, also called Madagascar, is the List of islands by area, and is home to 5% of the world's plant and animal species, of which more than 80% are Endemism to Madagascar....
, the Seychelles
Seychelles

Seychelles , officially the Republic of Seychelles , is an archipelago Country of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
, Mauritius
Mauritius

Mauritius , officially the Republic of Mauritius, , is an island nation off the coast of the African continent in the southwest Indian Ocean, about 900 kilometres east of Madagascar....
, Réunion
Reunion

Reunion may refer to:...
, the Galápagos Islands
Galápagos Islands

Gal?pagos Islands are an archipelago of Island#Volcanic islands distributed around the equator in the Pacific Ocean, 972 km west of continental Ecuador....
, Sulawesi
Sulawesi

Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands....
, Timor
Timor

Timor is an island at the south end of the Malay Archipelago, north of the Timor Sea. It is divided between the independent state of East Timor, , and West Timor, belonging to the Indonesian province of East Nusa Tenggara....
, Flores
Flores

Flores is one of the Lesser Sunda Islands, an island arc with an estimated area of 14,300 km? extending east from the Java island of Indonesia....
 and Java, often reaching enormous size — they can weigh as much as 300 kg (660 lbs) and can grow to be 1.3 m (4 ft) long. However, giant tortoises also once lived on the mainland of Asia and Australia, as follows from fossil finds in the Shivalik Hills in India
India

India, officially the Republic of India , is a country in South Asia. It is the List of countries and outlying territories by total area country by geographical area, the List of countries by population country, and the most populous liberal democracy in the world....
.






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Giant tortoises are characteristic reptiles of certain tropical islands. They occur (some species
Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring....
 are now extinct
Extinction

In biology and ecology, extinction is the death of every member of a species or group of taxon. The moment of extinction is generally considered to be the death of the last individual of that species ....
) in such places as Madagascar
Madagascar

Madagascar, or Republic of Madagascar , is an island nation in the Indian Ocean off the southeastern coast of Africa. The main island, also called Madagascar, is the List of islands by area, and is home to 5% of the world's plant and animal species, of which more than 80% are Endemism to Madagascar....
, the Seychelles
Seychelles

Seychelles , officially the Republic of Seychelles , is an archipelago Country of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
, Mauritius
Mauritius

Mauritius , officially the Republic of Mauritius, , is an island nation off the coast of the African continent in the southwest Indian Ocean, about 900 kilometres east of Madagascar....
, Réunion
Reunion

Reunion may refer to:...
, the Galápagos Islands
Galápagos Islands

Gal?pagos Islands are an archipelago of Island#Volcanic islands distributed around the equator in the Pacific Ocean, 972 km west of continental Ecuador....
, Sulawesi
Sulawesi

Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands....
, Timor
Timor

Timor is an island at the south end of the Malay Archipelago, north of the Timor Sea. It is divided between the independent state of East Timor, , and West Timor, belonging to the Indonesian province of East Nusa Tenggara....
, Flores
Flores

Flores is one of the Lesser Sunda Islands, an island arc with an estimated area of 14,300 km? extending east from the Java island of Indonesia....
 and Java, often reaching enormous size — they can weigh as much as 300 kg (660 lbs) and can grow to be 1.3 m (4 ft) long. However, giant tortoises also once lived on the mainland of Asia and Australia, as follows from fossil finds in the Shivalik Hills in India
India

India, officially the Republic of India , is a country in South Asia. It is the List of countries and outlying territories by total area country by geographical area, the List of countries by population country, and the most populous liberal democracy in the world....
. Today, the world's largest population inhabits Aldabra Atoll
Aldabra

Aldabra is a raised coral atoll in the Aldabra Group of islands in the Indian Ocean that form part of the Seychelles. The island is more than 700 miles from Mah? and is closer to the coast of Africa and Madagascar....
 in Seychelles, where there are approximately 100,000 individuals.

These animal
Animal

Animals are a major group of multicellular, eukaryotic organisms of the Kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life....
s belong to the most ancient group of reptile
Reptile

Reptiles, or members of the class Reptilia, are air-breathing, cold-blooded vertebrates that have skin covered in scale as opposed to hair or feathers....
s, 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
Indian Ocean

The Indian Ocean is the third largest of the world's oceanic divisions, covering about 20% of the water on the Earth's surface. It is bounded on the north by Asia ; on the west by Africa; on the east by Indochina, the Sunda Islands, and Australia; and on the south by the Southern Ocean ....
 and 14 or 15 species in the Galapagos Islands. From those, only one of the species of the Indian Ocean survives in the wild, the Aldabra Giant Tortoise (two more are claimed to exist in captive or re-released populations, but some genetic studies have cast doubt on the validity of these as separate species) and 11 in Galápagos.

They are one of the world's longest-living animals, with an average lifespan of 100 years or more. Harriet the Turtle, (Charles Darwin
Charles Darwin

Charles Robert Darwin Royal Society was an English people natural history who realised and presented compelling evidence that all species of life have evolution over time from common descent, through the process he called natural selection....
's turtle) as reported by the Australia Zoo
Australia Zoo

Australia Zoo is located in the Australian state of Queensland on the Sunshine Coast, Queensland near Beerwah, Queensland/Glass House Mountains National Park....
 was 175 years old.

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)
  • Dipsochelys hololissa - Seychelles giant tortoise
    Seychelles giant tortoise

    The Seychelles giant tortoise has been thought to be extinction since the mid-19th century due to over-exploitation on the granitic Seychelles islands....
     (extinct in the wild)
  • Dipsochelys arnoldi - Arnold's Giant Tortoise
    Arnold's Giant Tortoise

    Arnold's Giant Tortoise also known as the Seychelles saddle-backed tortoise inhabited the granitic Seychelles islands until around 1840. At that time it was presumed to be extinct along with the Seychelles giant tortoise; a species which shared the same islands....
     (extinct in the wild)
  • Geochelone gigantea/Dipspchelys dussumieri - Aldabra Giant Tortoise
    Aldabra Giant Tortoise

    The Aldabra Giant Tortoise , from the islands of the Aldabra Atoll in the Seychelles, is one of the largest tortoises in the world.This species is widely referred to as Geochelone gigantea but is now placed in the genus Dipsochelys as Dipsochelys dussumieri....
  • Geochelone nigra - Galapagos Giant Tortoise
    • Geochelone nigra abingdoni - Abingdon Island Tortoise
      Lonesome George

      Lonesome George is the last known individual of the Pinta Island Tortoise, subspecies Geochelone nigra abingdoni, one of eleven subspecies of Gal?pagos tortoise native to the Gal?pagos Islands....
       (Extinct in the wild
      Extinction

      In biology and ecology, extinction is the death of every member of a species or group of taxon. The moment of extinction is generally considered to be the death of the last individual of that species ....
      )
    • 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 vaicina - Iguana Cove Tortoise
  • Meiolania platyceps
    Meiolania

    Meiolania is an extinct genus of Cryptodira turtle from the Oligocene to Holocene, with the last relic populations at New Caledonia which survived until 2000 years ago....
     (extinct)


See also

  • Island gigantism
    Island gigantism

    Island gigantism is a biological phenomenon where the size of animals isolated on an island increases dramatically over generations. It is a form of natural selection in which bigger size provides a survival advantage ....


External links