Seychelles giant tortoise

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iSeychelles Giant Tortoise
Conservation status
Extinct in wild
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Order: Testudines
Suborder: Cryptodira
Family: Testudinidae
Genus: Dipsochelys
Species: Dipsochelys hololissa

Seychelles giant tortoise Dipsochelys hololissa has been thought to be extinct since the mid-19th century due to over-explotation on the granitic Seychelles islands. Similar giant tortoise species on other Indian Ocean islands such as Mauritius, Reunion and Rodrigues Island had also gone extinct. The only species of Indian Ocean giant tortoise that avoided this fate was the Aldabra Giant Tortoise due to its isolated location and 19th century conservation efforts.

This species inhabited islands of the Seychelles group where it thrived on vegetation on the edges of marshes and streams. By 1840 it had disappeared from the wild and was assumed to be extinct. As a grazing species it somewhat resembled the Aldabran tortoise with its domed shape.

Recently (1997) it has been suggested that some Seychelles island tortoises {12 known individuals} survive in captivity. The report of oddly-shaped captive tortoises prompted The Nature Protection Trust of Seychelles to examine the identity of the living tortoises. Examination of museum specimens of the 'extinct' Seychelles species by Dr. Justin Gerlach and Laura Canning seemed to show that some living tortoises possess characteristics of the extinct species.

However, recently published scientific papers on the genetics of the Seychelles and Indian Ocean tortoises provide conflicing results. Some studies suggest only one species was present historically but others support the presence of three, closely related species.


[edit] Source

[JEREMY J. AUSTIN, E. NICHOLAS ARNOLD and ROGER BOUR, 2003. Was there a second adaptive radiation of giant tortoises in the Indian Ocean? Using mitochondrial DNA to investigate speciation and biogeography of Aldabrachelys (Reptilia,Testudinidae). Molecular Ecology (2003) 12, 1415–1424. © 2003 Blackwell Publishing Ltd]

[ERIC P. PALKOVACS, MONIQUE MARSCHNER, CLAUDIO CIOFI, JUSTIN GERLACH and ADALGISA CACCONE. 2003. Are the native giant tortoises from the Seychelles really extinct? A genetic perspective based on mtDNA and microsatellite data. Molecular Ecology (2003)12, 1403–1413. © 2003 Blackwell Publishing Ltd]

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