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It has a very strong, black and yellow patterned carapace, used for defense against predators. The patterns are arranged in ray-like markings and help the tortoise blend in with its environment. This tortoise is very small, and a full grown tortoise can only reach about 5 to 6 inches in diameter.
While it shares much of its superficial outer appearance with its relatives in the genus Psammobates, it can be distinguished by the distinctively brightly coloured yellow stars of its shell scutes, the small nuchal and single axillary, the lack of buttock tubercles, and the only slightly upturned rear margins of the shell.
The geometric tortoise is naturally restricted to the far south-western corner of the Western Cape Province, South Africa. It used to also occur within what is now the city of Cape Town, but the last Cape Town population (at the tiny Harmony Flats Reserve) died out. It was believed to be extinct in the 1960s but a surviving population was discovered in 1972 and it now occurs in three isolated pockets where it is conserved. A population in the Ceres valley, one in the Tulbagh-Worcester valley, and a group surviving on the coastal lowlands to the southwest.
These colourful tortoises live only in lowland fynbos and renosterveld vegetation, meaning that their populations are easily isolated by mountains which they cannot cross.
It is one of the rarest tortoise species in the world
The geometric tortoise's diet consists mainly of the leaves, flowers, and shoots of a wide range of indigenous fynbos and renosterveld plants and grasses. In particular however, it is restricted by this diet to Alluvial Fynbos and Shale Renosterveld vegetation types. Its very specific diet of local plant species means that it soon dies when kept in captivity.
They are said to hibernate in the months of June through September, or when their natural environment is not normal, or when in captivity. Little is known about their reproductive behavior. When the female is ready to lay eggs, she digs a hole in the ground and covers it with grass or other vegetation.
Threats and conservation
The geometric tortoise has lost 97% of its habitat, and only 200 to 300 exist today.[when?] It is threatened for a number of reasons, but mainly due to loss of habitat. Restricted as it is to fertile lowlands and valleys, the vast majority of its tiny natural range has been covered with farms and housing. In addition, its eggs are a source of food for the African people and traders capture the adults for their shells which are used to make many different decorative items. This species is also preyed upon by other mammals, particularly introduced mammals such as pigs and dogs.
The South African government has set aside restricted park lands for this unique tortoise, and there are laws that prohibit the capture and the taking of its eggs.
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- Library.thinkquest.org entry
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