Introduction:
Turtles are reptiles of the order Chelonii or Testudines characterised by a special bony orcartilaginous shell developed from their ribs and acting as a shield.Turtle may refer to the chelonian order as a whole (American English) or to fresh-water and sea-dwelling chelonians (British English).
The order Chelonii or Testudines includes both extant (living) and extinct species. The earliest known turtles date from 22 million years ago making turtles one of the oldest reptile groups and a more ancient group than lizards, snakes or crocodiles. Of the many speciesalive today, some are highly endangered.
Like all other extant reptiles, turtles are ectotherms—their internal temperature varies according to the ambient environment, commonly called cold-blooded. However, because of their high metabolic rate, leatherback sea turtles have a body temperature that is noticeably higher than that of the surrounding water.
Turtles are classified as amniotes, along with reptiles, dinosaurs (including birds), and mammals. Like other amniotes, turtles breathe air and do not lay eggs underwater, although many species live in or around water.
Intelligence:
One study found that wood turtles were better than white rats at learning to navigate mazes. They are considered to be social creatures and sometimes switch between monogamy and promiscuity in their sexual behavior. Case studies also exist of turtles that have enjoyed playing.
Diet:
A turtle's diet varies greatly depending on the environment in which it lives. Adult turtles typically eat aquatic plants;invertebrates such as insects, snails and worms; and have been reported to occasionally eat dead marine animals. Several small freshwater species are carnivorous, eating small fish and a wide range of aquatic life. However, protein is essential to turtle growth and juvenile turtles are purely carnivorous.
Sea turtles typically feed on jellyfish, sponge and other soft-bodied organisms. Some species of sea turtle with stronger jaws have been observed to eat shellfish while some species, such as the green sea turtle do not eat any meat at all and, instead, have a diet largely made up of algae.