''Geochelone'', from

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

γῆ (''gê''), meaning "earth", and χελώνη (''khelṓnē''), meaning "turtle", is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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

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

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

. They primarily eat

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

Species

The genus consists of two

extant Extant or Least-concern species, least concern 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 * Exta ...

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 that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

, representing at least five independent

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

s". Tortoises removed include members of ''

Aldabrachelys ''Aldabrachelys'' is genus of giant tortoises, including the Aldabra giant tortoise (''Aldabrachelys gigantea'') native to the Seychelles, as well as two extinct species, '' Aldabrachelys abrupta'' and '' Aldabrachelys grandidieri'' known from M ...

'' (from the

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (; Seychellois Creole: ), is an island country and archipelagic state consisting of 155 islands (as per the Constitution) in the Indian Ocean. Its capital and largest city, Victoria, ...

and

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

), ''

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. Species A single extinct Extinction is the termination ...

'' (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 ...

'' (

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

and the

Galápagos Islands The Galápagos Islands () are an archipelago of volcanic islands in the Eastern Pacific, located around the equator, west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of sli ...

), ''

Stigmochelys ''Stigmochelys'', from Ancient Greek στίγμα (''stígma''), meaning "spot", and χέλυς (''khélus''), meaning "turtle", is a genus of tortoise endemic to Africa. ''Stigmochelys pardalis'', the leopard tortoise, is the only extant species. ...

'' and ''

Centrochelys ''Centrochelys'' is a genus of tortoise. It contains one living species, the African spurred tortoise (''Centrochelys sulcata''), native to the Sahel and adjacent areas. A number of fossil species have been attributed to this genus, but their p ...

'' (Africa), and the

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

Megalochelys ''Megalochelys'' ("great turtle") is an extinct genus of tortoises that lived from the Miocene to Pleistocene. They are noted for their giant size, the largest known for any tortoise, with a maximum carapace length of over 2 m (6.5 ft) ...

'' (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.Wilkinson, A., Chan, H. M., & Hall, G. (2007). Spatial learning and memory in the tortoise (Geochelone carbonaria). Journal of Comparative Psychology, 121(4), 412.

"Self-righting" shell

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

gömböc A gömböc () is any member of a class of convex set, convex, three-dimensional and homogeneous bodies that are ''mono-monostatic'', meaning that they have just one stable and one unstable Mechanical equilibrium, point of equilibrium when r ...

'', 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
{{Authority control Turtle genera Taxa named by Leopold Fitzinger Extant Miocene first appearances