Turtles

Turtles are reptiles of the order Testudines (the crown group of the super order Chelonia), characterised by a special bony or cartilaginous shell developed from their ribs that acts as protection Kingdom:Animalia Phylum:Chordata Class:Reptilia Superorder: Chelonia Macartney, 1802 Order:Testudines Classification Like other reptiles, turtles are ectotherms, cold blooded animals. Their internal temperature varies according to the ambient environment. However, leatherback sea turtles have noticeably higher body temperature than surrounding water because of their high metabolic rate. Like other amniotes (reptiles, dinosaurs, birds, and mammals), they breathe air and do not lay eggs underwater, although many species live in or around water. The largest turtles are aquatic. The largest living turtle is the leatherback sea turtle (Dermochelys coriacea), which reaches a shell length of 200 centimetres (6.6 ft) and can reach a weight of over 900 kilograms (2,000 lb). Freshwater turtles are generally smaller, but with the largest species, the Asian softshell turtle Pelochelys cantorii, a few individuals have been reported up to 200 cm (6.6 ft). This dwarfs even the better-known alligator snapping turtle, the largest chelonian in North America, which attains a shell length of up to 80 cm (2.6 ft) and a weight of about 60 kilograms (130 lb). Turtles lay eggs, deposited in holes dug into mud or sand which are then covered and left to incubate by themselves. When the turtles hatch, they squirm their way to the surface and head toward the water. The eggs of the largest species are spherical, while the eggs of the rest are elongated. In some species, temperature will determine whether an egg develops into a male or a female: a higher temperature causes a female, a lower temperature causes a male.

Skeleton of a Turtle 1.Mandible 2.Skull 3.Vertebra 4.Ulna 5.Radius 6.Scapula 7.Proscapular process 8.Coracoid 9. Back bone 10. Pelvic girdle 11. Fibula 12. Femur 13. Tibia 14. Phalanges 15. Humerus Carapace 16. Gular scutes 17. Humeral scutes 18. Pectoral scutes 19.Abdominal scutes 20. Femoral scutes 21.Anal scutes 22. Bridge