Chelonoidis

Chelonoidis
Brazilian giant tortoise
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Subclass:	Anapsida
Order:	Testudines
Suborder:	Cryptodira
Superfamily:	Testudinoidea
Family:	Testudinidae
Genus:	Chelonoidis Fitzgerald, 1835[1]

Chelonoidis is a genus of turtles in the tortoise family.^[1] They are found in South America and the Galápagos Islands. They were formerly assigned to Geochelone, but a recent comparative genetic analysis has indicated that they are actually most closely related to African hingeback tortoises.^[2] Their ancestors apparently floated across the Atlantic in the Oligocene.^[2] This crossing was made possible by the their ability to float with their heads up and to survive up to six months without food or water.^[2]

The members of this genus on the Galápagos Islands are among the largest extant terrestrial chelonians. Giant members of the genus were also present in mainland South America during the Pleistocene.^[3]

Species

• Red-footed tortoise (Chelonoidis carbonaria)^[1]
• Argentine tortoise (Chelonoidis chilensis)^[1]
• Brazilian giant tortoise (Chelonoidis denticulata)^[1]
• Chaco tortoise (Chelonoidis petersi)^[1]
• Galápagos tortoise (Chelonoidis nigra)^[1]

References

1. ^ ^{a b c d e f g} Rhodin, Anders G.J.; Paul van Dijk, Peter; Inverson, John B.; Shaffer, H. Bradley (2010-12-14). "Turtles of the World 2010 Update: Annotated Checklist of Taxonomy, Synonymy, Distribution and Conservation Status" (pdf). Archived from the original on 2010-12-15. http://www.webcitation.org/5uzfktoIh. Retrieved 2010-12-15. 
2. ^ ^{a b c} Le, M.; Raxworthy, C. J.; McCord, W. P.; Mertz, L. (2006-05-05). "A molecular phylogeny of tortoises (Testudines: Testudinidae) based on mitochondrial and nuclear genes". Molecular Phylogenetics and Evolution 40 (2): 517–531. doi:10.1016/j.ympev.2006.03.003. PMID 16678445. http://www.iucn-tftsg.org/wp-content/uploads/file/Articles/Le_etal_2006.pdf. 
3. ^ Cione, A. L.; Tonni, E. P.; Soibelzon, L. (2003). "The Broken Zig-Zag: Late Cenozoic large mammal and tortoise extinction in South America". Rev. Mus. Argentino Cienc. Nat., n.s. 5 (1): 1–19. ISSN 1514-5158. http://www.ege.fcen.uba.ar/materias/general/Broken_ZigZagMACN_5_1_19_.pdf. Retrieved 2011-02-06.