Dipsochelys
Aldabra Giant Tortoise ( Aldabrachelys gigantea )
Seychelles giant tortoise ( Aldabrachelys, formerly Dispochelys ) are a genus of turtle in the family of tortoises ( Testudinidae ). Recent studies show the genus to only one extant species that is native to the Indian Ocean islands.
Dissemination
Giant tortoises inhabited many of the islands of the western Indian Ocean to the middle of the last century. In Madagascar they lived until about the year 1000. Populations in the Comoros and Glorieuse are known only from fragmentary remains, which are about 1100-125000 years old. On the Mascarene they were ( genus: Cylindraspis ) died from about 1795. In the Aldabra group of islands, Farquhar and the Seychelles, they survived until today. In the Seychelles, especially the less than 1 km ² island Moyenne, there is one of the largest contiguous populations. Demonstrably, there was until the 18th century on 20 islands off the East African coast large stocks of giant tortoises.
As to the question why there are giant turtles just on the remote and very remote from each other archipelagos ( Aldabra Atoll, Farquhar Atoll, Seychelles and Galapagos ), there are two theories. According to one, smaller, stranded with flotsam animals on the islands to giant forms developed (fruit 1985). The second is that these giant forms on the remote islands the last survivors, possibly even diminutives of their once most prevalent types are ( Pritchard 1996, Caccone 1999).
Indeed, genetic analysis revealed that the closest relatives of Aldabraschildkröte come from Madagascar and have probably colonized from there the Seychelles and the Mascarene Islands (Mauritius, Reunion, Rodrigues).
System
Extant species:
- Aldabra Giant Tortoise ( Aldabrachelys gigantea )
- Seychelles giant tortoise ( Dipsochelys hololissa )
- Arnold's Giant Tortoise ( Dipsochelys hololissa )
Extinct species:
- Aldabrachelys abrupta † ( extinct in the 10th century )
- Aldabrachelys grandidieri † ( extinct in the 10th century )