Chelonoidis is a genus of turtles in the tortoise family. They are found in South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 and the Galápagos Islands

Galápagos Islands

The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...

. They were formerly assigned to Geochelone

Geochelone

Geochelone is a genus of tortoises.Geochelone tortoises, which are also known as typical tortoises or terrestrial turtles, can be found in Africa and Asia. They primarily eat plants.The genus consists of three extant species:...

, but a recent comparative genetic analysis has indicated that they are actually most closely related to African hingeback tortoises

Kinixys

Kinixys is a genus of turtles in the family Testudinidae. They are native to Africa, and commonly known as hinged tortoises. Some of these species are herbivores , although some also feed on worms and insects.-Species:* Forest hinge-back tortoise * Home's hinge-back tortoise * Natal...

. Their ancestors apparently floated across the Atlantic

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

 in the Oligocene

Oligocene

The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...

. 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.

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

Pleistocene

The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

.

Species

• Red-footed tortoise
  Red-footed tortoise
  The red-footed tortoise is a tortoise native to South America. It has also been introduced to many islands in the Caribbean. It draws its name from the red or orange scales visible on its limbs, as well as its head and tail...
  
   (Chelonoidis carbonaria)
• Argentine tortoise
  Argentine Tortoise
  The Argentine tortoise is a species of turtle in the family Testudinidae. It is found in Argentina.- References :* Tortoise & Freshwater Turtle Specialist Group 1996. . Downloaded on 29 July 2007. Out of date.Bibliography...
  
   (Chelonoidis chilensis)
• Brazilian giant tortoise
  Brazilian Giant Tortoise
  The Brazilian giant tortoise, forest tortoise, South American tortoise, South American yellow-footed tortoise, or yellow-footed tortoise is a species of tortoise in the family Testudinidae...
  
   (Chelonoidis denticulata)
• Chaco tortoise
  Chaco tortoise
  The Chaco tortoise is a turtle from the family Testudinidae.- References :Bibliography...
  
   (Chelonoidis petersi)
• Galápagos tortoise
  Galápagos tortoise
  The Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
  
  (Chelonoidis nigra)