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| The African Spurred Tortoise, Geochelone sulcata (Miller, 1779). Photograph of a zoo specimen. It inhabits arid grasslands and deserts from Ethiopia and the Sudan westward to Chad, Niger, Mali, and Senegal. The Spurred Tortoise is a vegetarian, using succulent plants and because water is scarce, it depends heavily on metabolic water. Adults can reach 760 mm and it is the largest species of tortoise not found on an island. |
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| The Desert Tortoise, Gopherus agassizii (Cooper, 1863). Photographed in Pima County, Arizona. This tortoise has also been placed in the genus Xerobates. Carapace length can reach 381 mm. This is a herbivorous tortoise that burrows in the soil and is often associated with moist areas in the desert where vegetation is available. Females lay 1-12 eggs in May or June, and the nests are often inside of the female's burrow. |
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| The Gopher Tortoise, Gopherus polyphemus (Daudin, 1802). Photographed in Alachua County, Florida in a slash pine forest. The Gopher Tortoise ranges from South Carolina to Florida and west to extreme southeastern Louisiana. Adults may reach 381 mm in carapace length. Burrows may be deep (10 m) and they may house a variety of other species of animals that use the as commensals. Females lay 1-9 eggs in a nest away from the burrow, and they need about four months to hatch. These tortoises are mostly herbivorous but they will eat insects and carrion. The eggs are frequently preyed upon by raccoons. |
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| The Red Footed Tortoise, Chelonoides (formerly Geochelone) carbonaria (Spix, 1824). The pair in copula were photographed in a zoo. The Red Footed Tortoise ranges from Panama southward into South America on both sides of the Andes and extends as far south as Bolivia, Paraguay, and Argentina. It inhabits moist savannas, and humid forests (when its relative G. denticulata is not present). Adults may reach 510 mm in carapace length. Clutches of 2-15 eggs and deposited in a shallow nest. It is primarily herbivorous but will feed on carrion. |
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| The Yellow Footed Tortoise, Chelonoides (formerly Geochelone) denticulata (Linnaeus, 1766). Photographed in Trinidad's Arima Valley. Yellow Footed Tortoises range from Venezuela to the Guyanas and Brazil and southward in the Amazon Basin. It also occurs naturally on Trinidad. This tortoise can reach a carapace length of 820 mm. Females lay 1-12 eggs that incubate for 4-5 months. Like most tortoises it is herbivorous and feeds on carrion when available. |
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| The Aladabra Tortoise, Dipsochelys elephantina Dumeril and Bibron, 1835) (formerly Geochelone gigantea). Photographs of a zoo animal. The record size for the species is 1050 mm, and a weight of 120 kg. Natural populations occur only on the Aladabra Atoll in the Indian Ocean, but a colony has been introduced into the Seychelles in the late 1970's. Its ancestry is nested within the Madagascar tortoise lineage. Tortoises are known to be able to survive long distance transport by ocean currents. Thus, the ancestor of Aladabra Tortoise floated to the remote islands from Madagascar. The habitats used by the Aladabra tortoise include grasslands and mangrove forest. It is herbivorous, but will feed on carrion. |
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| The Indian Star Tortoise, Geochelone elegans (Schoepff, 1795). Photographed in Sri Lanka. The upper photo shows a normal adult, the bottom photo is an adult that has survived a fire. The carapace length reaches at least 380 mm. It is endemic to peninsular India, Sri Lanka, and has populations on smaller islands in the area. It may be found in forests and grasslands, but in Sri Lanka we also observed this tortoise apparently free roaming in urban environments during the rainy season. It is herbivorous. |
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| The Elongated Tortoise, Indotestudo elongata (Blyth, 1853). Photographed in central Thailand in a dry tropical forest. Maximum size is about 275 mm in carapace length. It ranges from Nepal, Bangladesh, and northeast India eastward to Indochina and Malaya. This small tortoise is particularly active after rains. Females lay clutches of 2-4 eggs. Food includes fruits and flowers, as well as fungi and small invertebrates. It has also been placed in the genus Geochelone. |
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| The Serrated Hinge Back Tortoise, Kinixys erosa (Schweigger, 1812). Photograph of a captive from an unknown locality. Its distribution is West Africa, and includes Gambia, Gabon, the Congo, and Uganda. Maximum size is a carapace length of 323 mm. Habitats used include forests and wet lands such as marshes and the edges of streams. It is omnivorous. |
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| The African Pancake Tortoise, Malacochersus tornieri (Siebenrock, 1903). Photograph of a captive specimen from an unknown locality. This small (177 mm), flat tortoise inhabits arid scrub vegetation where boulders are abundant. It climbs well, and wedges its self into rock crevices to avoid predation. Food is mostly grasses, with some fruits. It is endemic to East Africa. |
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| Tortoises reach their greatest diversity in Africa and Asia, but some species occur in Europe and in the Western Hemisphere. About 13 genera and about 50 species of tortoises are currently recognized. Tortoises are primarily a terrestrial group that uses arid habitats but a few species inhabit rainforests and deciduous forests. They range in size from about 100 mm to about 1250 mm, with the largest being found on islands. Gigantism has evolved in several different lineages and today giant species are primarily island dwellers. Dwarf species also occur in this group and these tend to be species that live in dry, tropical or subtropical environments. Most species are herbivorous, some are omnivorous. Some tortoises as seed dispersal agents as they roam around their environment depositing undigested seeds in locations away from the parent plant. The earliest fossil tortoises come from the Eocene. During this time period (the Eocene) they are found on many continents and are clearly tortoises, thus the evidence suggests they appeared earlier than this. The fossil record also suggests that tortoises were more widespread in the past than they are today. |
