Turtle Wikipedia. Turtles are reptiles of the order. Testudines or Chelonii3 characterised by a special bony or cartilaginousshell developed from their ribs and acting as a shield. Turtle may refer to the order as a whole American English or to fresh water and sea dwelling testudines British English. The order Testudines includes both extant living and extinct species. The earliest known members of this group date from 1. Of the 3. 27 known species alive today, some are highly endangered. Turtles are ectothermsanimals commonly called cold bloodedmeaning that their internal temperature varies according to the ambient environment. The Red Turtle Free Download' title='The Red Turtle Free Download' />The upper shell of the turtle is called the carapace. The lower shell that encases the belly is called the plastron. The carapace and plastron are joined together on. Songs. Songs annotated with an blue asterisk include guitar chords. Songs with a red asterisk include lyrics in Cherokee. The music for all songs listed here. 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 other reptiles, birds, and mammals. Like other amniotes, turtles breathe air and do not lay eggs underwater, although many species live in or around water. Turtle, tortoise, or terrapin. The word chelonian is popular among veterinarians, scientists, and conservationists working with these animals as a catch all name for any member of the superorder Chelonia, which includes all turtles living and extinct, as well as their immediate ancestors. Chelonia is based on the Greek word chelone tortoise, turtle another relevant word is chelys tortoise,89 also denoting armor or interlocking shields 1. Latin word testudo tortoise. Turtle may either refer to the order as a whole, or to particular turtles that make up a form taxon that is not monophyletic. The meaning of the word turtle differs from region to region. In North America, all chelonians are commonly called turtles, including terrapins and tortoises. In Great Britain, the word turtle is used for sea dwelling species, but not for tortoises. The term tortoise usually refers to any land dwelling, non swimming chelonian. Most land dwelling chelonians are in the Testudinidae family, only one of the fourteen extant turtle families. Terrapin is used to describe several species of small, edible, hard shell turtles, typically those found in brackish waters, and is an Algonquian word for turtle. Some languages do not have this distinction, as all of these are referred to by the same name. For example, in Spanish, the word tortuga is used for turtles, tortoises, and terrapins. A sea dwelling turtle is tortuga marina, a freshwater species tortuga de ro, and a tortoise tortuga terrestre. Anatomy and morphology. The largest living chelonian is the leatherback sea turtle Dermochelys coriacea, which reaches a shell length of 2. Freshwater turtles are generally smaller, but with the largest species, the Asian softshell turtle Pelochelys cantorii, a few individuals have been reported up to 2. This dwarfs even the better known alligator snapping turtle, the largest chelonian in North America, which attains a shell length of up to 8. Giant tortoises of the genera Geochelone, Meiolania, and others were relatively widely distributed around the world into prehistoric times, and are known to have existed in North and South America, Australia, and Africa. They became extinct at the same time as the appearance of man, and it is assumed humans hunted them for food. The only surviving giant tortoises are on the Seychelles and Galpagos Islands and can grow to over 1. The largest ever chelonian was Archelon ischyros, a Late Cretaceous sea turtle known to have been up to 4. The smallest turtle is the speckled padloper tortoise of South Africa. It measures no more than 8 cm 3. Two other species of small turtles are the American mud turtles and musk turtles that live in an area that ranges from Canada to South America. The shell length of many species in this group is less than 1. Neck retraction. Turtles are divided into two groups, according to how they retract their necks into their shells something the ancestral Proganochelys could not do. The Cryptodira retract their necks backwards while contracting it under their spine, whereas the Pleurodira contract their necks to the side. Head. Most turtles that spend most of their lives on land have their eyes looking down at objects in front of them. Some aquatic turtles, such as snapping turtles and soft shelled turtles, have eyes closer to the top of the head. These species of turtle can hide from predators in shallow water, where they lie entirely submerged except for their eyes and nostrils. Near their eyes, sea turtles possess glands that produce salty tears that rid their body of excess salt taken in from the water they drink. Turtles have rigid beaks and use their jaws to cut and chew food. Instead of having teeth, which they appear to have lost about 1. Carnivorous turtles usually have knife sharp ridges for slicing through their prey. Herbivorous turtles have serrated edged ridges that help them cut through tough plants. They use their tongues to swallow food, but unlike most reptiles, they cannot stick out their tongues to catch food. Shell. The upper shell of the turtle is called the carapace. The lower shell that encases the belly is called the plastron. The carapace and plastron are joined together on the turtles sides by bony structures called bridges. The inner layer of a turtles shell is made up of about 6. In most turtles, the outer layer of the shell is covered by horny scales called scutes that are part of its outer skin, or epidermis. Scutes are made up of the fibrous proteinkeratin that also makes up the scales of other reptiles. These scutes overlap the seams between the shell bones and add strength to the shell. Some turtles do not have horny scutes for example, the leatherback sea turtle and the soft shelled turtles have shells covered with leathery skin instead. The rigid shell means that turtles cannot breathe as other reptiles do, by changing the volume of their chest cavities via expansion and contraction of the ribs. Instead, they breathe in two ways. First, they employ limb pumping, sucking air into their lungs and pushing it out by moving the limbs in and out relative to the shell. Secondly, when the abdominal muscles that cover the posterior opening of the shell contract, the pressure inside the shell and lungs decreases, drawing air into the lungs, allowing these muscles to function in much the same way as the mammalian diaphragm. A second set of abdominal muscles face the opposite way and when they contract they expel air under positive pressure. The shape of the shell gives helpful clues about how a turtle lives. Most tortoises have a large, dome shaped shell that makes it difficult for predators to crush the shell between their jaws. One of the few exceptions is the African pancake tortoise, which has a flat, flexible shell that allows it to hide in rock crevices. Most aquatic turtles have flat, streamlined shells, which aid in swimming and diving. American snapping turtles and musk turtles have small, cross shaped plastrons that give them more efficient leg movement for walking along the bottom of ponds and streams. The color of a turtles shell may vary. Shells are commonly colored brown, black, or olive green. In some species, shells may have red, orange, yellow, or grey markings, often spots, lines, or irregular blotches. One of the most colorful turtles is the eastern painted turtle, which includes a yellow plastron and a black or olive shell with red markings around the rim. Tortoises, being land based, have rather heavy shells. In contrast, aquatic and soft shelled turtles have lighter shells that help them avoid sinking in water and swim faster with more agility. These lighter shells have large spaces called fontanelles between the shell bones. The shells of leatherback sea turtles are extremely light because they lack scutes and contain many fontanelles. It has been suggested by Jackson 2. Mystery Thriller Cartoons Michael Jackson`S Halloween there.