Turtles are reptiles of the order Testudinata, most of
whose body is shielded by a special bony shell developed
from their ribs. The term turtle is usually used for the
aquatic species, aquatic fresh-water turtles also being
referred to as terrapins. The term is also used (esp.
North America) to refer to all members of the order, including
tortoises, which are predominantly land based. The order
of Testudines includes both extant (living) and extinct
varieties. About 300 species are alive today. Sea turtles
grow to large sizes and live in the oceans in the temperate
and tropical regions of the earth. Pond turtles (or terrapins)
are generally of a much smaller size, while land based
terrapins (or tortoises) can be as big as the sea turtles.
|
