Tortoise 20cm

Physical Characteristics
The tortoise has both an endoskeleton and an exoskeleton. Tortoises can vary in size from a few centimeters to two meters. Tortoises are reptiles, meaning they are cold-blooded, have scales but not hair or feathers, have skeletons inside their bodies, have hearts with three chambers, and lay eggs. The tortoise carapace, or top part of its shell, is dome shaped and higher than a turtle, allowing them to roll back onto their feet if tipped onto their backs. The largest tortoises are the giant Galapagos, which lives in the Galapagos Islands in the Pacific Ocean off the coast of South America, and the Aldabran, which lives in the Aldabra Islands off the coast of east Africa. The Galapagos Tortoise can grow to about 1.5 metres (4.9 feet). The Aldabran can weigh up to 300 kgs (660 lbs).

Habitat
Tortoises live in many different types of environments from deserts and semi-arid areas to lakes, lagoons and swamps and tropical forests.

Behaviour
Tortoises live in burrow anywhere from 5 to 50 feet deep. Each tortoise usually has more than one burrow. The number of burrows the tortoise uses may depend on age and sex, as well as on the season. The burrow is usually the size and shape of the tortoise--half moon in shape and flat on the bottom. The tortoise burrow provides protection from the extremes of heat, cold, lack of moisture, and too much moisture. The burrow is especially important because it provides (a) a cool place for the tortoise during the dry hot days in late spring and summer when water and food are unavailable and (b) a relatively "warm" site for winter hibernation. The tortoise spends most of its life in the burrow.

Breeding
Female tortoises dig burrows to lay their eggs in. After 3-4 months, the hatchlings break the eggshells open with their beaks and dig their way up to the surface. Once on the ground they move into their mother's burrow and she protects them for another two months or so.

Diet
Some tortoises are herbivores, and eat only plants. Others are omnivores, meaning they will eat anything available including plants, fruit, live prey and carrion. Tortoises need calcium to build their bones in the same way that humans do. Those that live in warmer climates bask in the sun. The rays produce vitamins in the tortoise's body, which work with the plants they eat to produce calcium. Colder climate tortoises get less sunshine, so they eat more protein and foods that contain calcium.

Strange and Interesting Facts
Tortoises evolved over 200 million years ago and are relatively unchanged over time. Their success in adapting to the environment is probably due to the protective ability of their shell or carapace. This shell is made up of 60 bone-like plates.