''Geochelone'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

tortoise Tortoises () are reptiles of the family Testudinidae of the order Testudines (Latin: ''tortoise''). Like other turtles, tortoises have a turtle shell, shell to protect from predation and other threats. The shell in tortoises is generally hard, ...

s. ''Geochelone'' tortoises, which are also known as typical tortoises or terrestrial turtles, can be found in southern

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

. They primarily eat

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

Species

The genus consists of two

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

species: A number of tortoise species have been recently removed from the genus. This taxon as formerly defined was "

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...

, representing at least five independent

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

s". Tortoises removed include members of ''

Aldabrachelys ''Aldabrachelys'' is the recognised genus for the Seychelles and Madagascan radiations of giant tortoises, including the Aldabra giant tortoise (''Aldabrachelys gigantea''). Naming This name is problematic in that the type specimen is actually r ...

'' (from the

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, V ...

and

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

), ''

Astrochelys ''Astrochelys'' is a genus of tortoises in the family Testudinidae. The two species are both found in Madagascar, and both classified as critically endangered on the IUCN Red List The International Union for Conservation of Nature (IUCN) R ...

'' (Madagascar), ''

Chelonoidis ''Chelonoidis'' is a genus of turtles in the tortoise family erected by Leopold Fitzinger in 1835. They are found in South America and the Galápagos Islands, and formerly had a wide distribution in the West Indies. The multiple subspecies of t ...

'' (

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

and the

Galápagos Islands The Galápagos Islands (Spanish: , , ) are an archipelago of volcanic islands. They are distributed on each side of the equator in the Pacific Ocean, surrounding the centre of the Western Hemisphere, and are part of the Republic of Ecuador ...

), '' Stigmochelys'' and ''

Centrochelys ''Centrochelys'' is a genus of tortoise. It contains one extant species and several extinct species: * ''Centrochelys atlantica'' * ''Centrochelys burchardi'' * ''Centrochelys marocana'' * ''Centrochelys robusta'' * ''Centrochelys vulcanica'' * ...

'' (Africa), and the

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

Megalochelys ''Megalochelys'' ("great turtle") is an extinct genus of cryptodiran tortoises that lived from the Miocene to Pleistocene. They are noted for their giant size, which is among the largest of any known testudine, with a maximum carapace length ove ...

'' (southern Asia). These species are also unique for their ability to remember patterns and spatial pathways. Similar to mammals, these tortoises can remember directions and pathways by remembering the correct pathways in their long-term memory.

Fossils

* ''

Geochelone burchardi The Tenerife giant tortoise (''Centrochelys burchardi'') is an extinct species of cryptodire turtle in the family Testudinidae endemic to the island of Tenerife, in the Canary Islands. Characteristics It was a large tortoise, similar to t ...

'' Tenerife giant tortoise * ''

Geochelone vulcanica The Gran Canaria giant tortoise (''Centrochelys vulcanica'') is an extinct species of cryptodire turtle in the family Testudinidae endemic to the island of Gran Canaria, in the Canary Islands. Characteristics This is one of the two describe ...

'' Gran Canaria giant tortoise * ''

Geochelone robusta ''Geochelone'' is a genus of tortoises. ''Geochelone'' tortoises, which are also known as typical tortoises or terrestrial turtles, can be found in southern Asia. They primarily eat plants. Species The genus consists of two extant species: A ...

'' Malta giant tortoise

"Self-righting" shell

The form of the shell of the Indian star tortoise resembles a ''

gömböc The Gömböc ( ) is the first known physical example of a class of convex three-dimensional homogeneous bodies, called mono-monostatic, which, when resting on a flat surface have just one stable and one unstable point of equilibrium. The ...

'', allowing it to turn over when lying upside down very easily.

References

*
Geochelone Report
' in

Integrated Taxonomic Information System The Integrated Taxonomic Information System (ITIS) is an American partnership of federal agencies designed to provide consistent and reliable information on the taxonomy of biological species. ITIS was originally formed in 1996 as an interagenc ...

. Retrieved January 12, 2008.

External links

*
Care tips
{{Taxonbar, from=Q132328 Turtle genera Taxa named by Leopold Fitzinger Extant Miocene first appearances