Anatomy and morphology The tortoise has a variety of sizes. Even so, the sea turtle (turtle) has a size larger than his brother on land and in freshwater.
Chelonian largest sea turtle, sea turtle that is backed fur (leatherback sea turtle) giant, which reaches 200 cm shell length and weight can reach over 900 kg. Freshwater turtles are generally smaller, but the biggest species of turtles-turtles (tortoises cartilaginous) in Asia, Pelochelys cantorii, which was reported by some people has a length of up to 200 cm (Das, 1991). Other large turtle is the common Snapping Turtle, Chelydra serpentina, Chelonian North America's largest, which has a shell up to 80 cm long and weighing about 60 kg.
Tortoise (tortoise) of the genus Geochelone, Testudo, and more widespread throughout the world in ancient times, and now widely available in North and South America, Australia, and Africa. They became extinct along with the emergence of humans, who suspected that humans hunt for food. Giant tortoises that still survive until today there are in the Seychelles and Galápagos Islands and can grow to more than 130 cm long, and weighs about 300 kg.
Chelonian greatest of all time is Archelon ischyros, a sea turtle that lived at the end of the Cretaceous age are known magnitude can reach up to 4.6 m.
The smallest turtle is the speckled tortoises padloper from South Africa. The turtles only have a length not more than 8 cm and weighing about 140 g. Two species of small turtles are mud turtles and musk turtles Americans who live in the area that runs between Canada to South America. Shell length of many species in this group is less than 13 cm.
The neck is doubled
Turtles were divided into two groups, according to how they pull their necks into the shell (something that can not be done by an ancient species Proganochelys): the Cryptodira, which can draw their necks and folded it under his spine, and Pleurodira, which to fold their neck to the side.
Head
Most turtles that spend most of his life on the mainland have eyes that always look down on any object in front. Some freshwater turtles, such as the common tortoise and turtles-turtles, have eyes closer to the top of the head. Species of turtles can hide from predators in shallow water where they drown in the water all over his body except the eyes and nostrils. Sea turtles have glands near the eyes that produce salty tears that serves to remove excess salt from their bodies taken from the water they drink.
The tortoise has a privilege in the form of night vision capability due to great large number of stem cells in their retinas. Turtles have color vision with a wealth of cone subtypes with sensitivities between almost Ultraviolet (UV-A) to Red. Some tortoises have the ability to 'catch prey' which is very bad, so usually it becomes prey for predators that hunt prey that can move quickly. However, turtles are carnivores can quickly move the head to bite suddenly.
Turtles have a wide mouth that sturdy. Turtles use jaws to cut and chew food. As a replacement tooth, upper and lower jaw on the turtles covered by a row of hard bone.Carnivorous turtles usually have a bone in the form of a sharp knife for slicing prey.Herbivorous turtles have bones that ends like a saw to cut up plants that hard. Tortoises use their tongue to help chew food, but they can not, unlike most reptiles, stuck out his tongue to catch food.
Shell
Tortoise shell top is called the carapace. Bottom shell is bound called Plastron. Carapace and Plastron connected on the sides of the turtles by bone structures called bridges.Lining the inside of the turtles - turtles made of about 60 bones that include the portion of the spine and ribs, which means that the turtle can not crawl out of the shell. In most turtles, the outer layer of shell covered by hard scales called scute which is part of the outer skin, or epidermis. Scute is made of fibrous protein called keratin that also form the scales of other reptiles. Scute is growing beyond the layers between the shell bones and add strength shell. Some turtles do not have a hard scute. For example, leather-backed turtles and turtles-turtles who have skin-covered shell scute scute smooth and not harsh.
Form of tortoise shell gives helpful clues about how the turtle lives. Most tortoises have a large shell-shaped dome that makes it difficult for predators to crush the shell between the teeth-fangs. One of the few exceptions is the pancake tortoise shell Africa that has a flat which makes it flexible and can hide among the splinter of stone. Most aquatic turtles have flat, grooved shell which assist in swimming and diving. Musk turtles and tortoises have Plastron American alligator-shaped and small crosses which provide a more efficient leg movement for walking along the bottom of ponds and rivers.
Tortoise shell color can vary. Shell generally brown, black, or dark green. In some species, the shell has signs of red, orange, yellow, or gray and these signs can be spotted, striped, or random spots. Salah satu dari turtles of the most colorful adalah painted turtle has shell Plastron yellow and black or dark green with red bintiki around the edges.
Tortoises, which live in the plains, have a heavier shell. In contrast, turtles and aquatic turtles-turtles have lighter shells that help her to not drown in the water and swim at a faster rate. These lighter shells have a large empty space, called fontanelles between the shell bones. Shell on the turtle-backed hair is very light because they have little scute and filled many fontanelles.
Leather and leather turnover
As mentioned above, the outer shell layer is part of the skin, each scute (or plate) on the shell is a modified scales. Shell is composed of skin with scales that are smaller, just like any other reptile skin. Aquatic turtles and Terrapin does not change skin in one-time process, as is done by a snake, but continually, in small pieces. When located within a scope akuaria, small sheets of dead skin can be seen in the water (sometimes looks like a piece of thin plastic) when it was crusty, even when the animal rubbed its body on a piece of wood or stone. Tortoises also changed its skin, but a large number of dead skin can be accumulated into thick pieces that give protection to parts of the body outside the shell.
Scute the shell was never changed, and, the longer accumulate, become increasingly thick shell. By counting scute circle formed by the older and smaller in the upper younger scute and larger, allowing us to estimate the age of a tortoise, if we know how many scute which is produced in a year. This method is less accurate, because most of the growth rate is not constant, but also because some of scute sometimes fall from the shell.
Limb
Tortoises have short legs. Tortoises are known for having a slow motion, this is because the shell is domed and weight but also because the crawl gait inefficiencies that they have, with legs that stretch to one another, unlike the straight-legged lizards each another directly under the body, as well as in mammals.
Turtles are amphibians who normally have limbs similar to the tortoise's foot was unless they have a membrane finger and usually have long nails. These turtles swim using all four legs in the same way as dogs who were swimming, with the legs on the right side and left side alternately rocking body. Freshwater turtles are much more rare than the swimming freshwater turtles are small, and very large species, such as alligator turtle, rarely swim, much like walking along the bottom of a lake or river. As well as the lining of the feet, freshwater turtles also have very long nails, used to help in climbing the edge of the river and float to the top, where they enjoy sunbathing. Freshwater turtles has more male long nails, and this is used to stimulate the female during mating. Although most freshwater turtles have webbed feet fingers, some freshwater turtles, such as pig snout turtle, has a true paddle-shaped feet, with fingers that are attached form a paddle and small nails.These species swim in the same manner as that of turtles (see below).
Turtle almost entirely aquatic and have a paddle-shaped feet (Flipper) instead of legs.Turtles "fly" in water, using up and down movement of the foot paddle to create thrust front, the hind legs are not used for swimming but may be used for balancing. Compared with freshwater turtles, sea turtles rarely rises to the mainland, and usually only to hatch alone. Male turtles normally never leave the ocean, while the females have to ride to the mainland to incubate eggs. They move very slowly, dragging their bodies with foot oar.Foot paddle behind them are used to dig holes and fill them back eggs with sand when the eggs are hatched.
Ecology and life history
Although many types of turtles that live under water, all water turtles and land is the air-breathing reptiles with lungs, and must rise to the surface on at regular intervals to refill his lungs with fresh air. They also can spend almost all his life on dry land. Aquatic respiration in freshwater turtles in Australia are now being studied. Some species have large cloacal holes filled by many projections are shaped like a finger. These projections, called "papillae", have an abundant blood supply, and serves to increase the surface area of the cloaca. Water turtles can filter oxygen contained in water using these papillae, almost as much as fish use gills to breathe.
Turtles are animals that lay eggs like other reptiles, where the eggs were soft and fluffy.
The eggs of the largest species are round, while the eggs of other species is elliptical.Albumennya white and contains a different protein from the eggs of birds, which causes the embryo will not harden when cooked. Turtle egg contains almost all the yolk. In some species, temperature determines whether an embryo in the egg will develop into male or female: higher temperatures lead to female embryos, a lower temperature causes the embryo male sex. A large number of the eggs stored in pits and buried by mud or sand.The eggs were then covered and left to be incubated alone. When the baby turtles were born, they find their own way to reach the waters. The tortoise is not a species in which the parent is caring for her children.
Turtles lay eggs on dry sandy beaches, and the presence of eggs was very threatened by coastal development and egg hunts. Young turtles are also not raised by its mother.
Tortoise takes many years to reach breeding age. Sometimes the turtles only breed every few years or more.
Researchers recently discovered that the organs of the turtle is not becoming more and more not working, unlike most other animals. It has been found that the liver, lungs and kidneys in centenarian tortoise function better with age. This has inspired genetic researchers to begin research on turtle genome for genes that produce long-lived.
Turtle, tortoise or Terrapin?
Although the word "turtle" widely used to describe all members of the Order Testudines, in general, we also see certain members described as "Terrapin", "tortoise", or "sea turtles".Precisely how these alternative names are used, depending on the type of English used.
• Bristish Home usually describes these reptiles as a "turtle" when they live in the sea; "Terrapin" when they live in freshwater or brackish water, or "tortoise" when they live on land. However, there are exceptions to this where common names are used in America or Australia meluar, such as 'Fly River Turtle'.
• American Home uses the word "turtle" for the whole turtle species, no matter where one habitat, although the "tortoise" is also used to describe accurately the turtles that live on land. Marine species is more specific with the word "sea turtles". While the word "Terrapin" clearly used for the turtles that live in brackish water such as diamond-back Terrapin (Diamondback Terrapin), Malaclemys Terrapin; word "Terrapin" in this case taken from the Algonquian vocabulary for this animal.
• Australian Home uses the word "turtle" for marine and freshwater species and the "tortoise" to mainland species.
To avoid confusion, the word "chelonian" is more popular among veterinarians, researchers, and conservationists who work on these animals, as the names of all members of the Order Testudines. This is based on the ancient Greek χελώνη (chelone, the new Greek χελώνα), meaning tortoise.
Taxonomy
List of Testudines Family
Suborder Paracryptodira (extinct)
Suborder Cryptodira
• Family Chelydridae (alligator turtle)
• Family Meiolaniidae (extinct)
• Chelonioidea superfamily (sea turtles)
• Family Protostegidae (extinct)
• Family Thalassemyidae (extinct)
• Family Toxochelyidae (extinct)
• Family Cheloniidae (green sea turtles and their relatives)
• Family Dermochelyidae (Turtle-backed hair)
• Kinosternoidea superfamily
• Family Dermatemydidae (River Turtles)
• Family Kinosternidae (mud turtles)
• Family Platysternidae (big-headed turtles)
• Testudinoidea superfamily
• Family Haichemydidae (extinct)
• Family Lindholmemydidae (extinct)
• Family Sinochelyidae (extinct)
• Family Emydidae (pond turtles / tortoise Brazil)
• Family Geoemydidae (leaf turtles, Asian box turtles)
• Family Testudinidae (tortoise)
• Trionychoidea superfamily
• Family Adocidae (extinct)
• Family Carettochelyidae (Tortoise pig snout)
• Family Trionychidae (Labi-turtles)
Suborder Pleurodira
• Family Araripemydidae (extinct)
• Family Proterochersidae (extinct)
• Family Chelidae (long neck tortoise Austro-American)
• Pelomedusoidea superfamily
• Family Bothremydidae (extinct)
• Family Pelomedusidae (Tortoise sideneck Afro-American)
• Family Podocnemididae (Yellow Spoturtleted T)
Excerpted from Wikipedia, translated by member Cheloniafreak rx ..
http://www.reptilx.com/rxforum/viewtopic.php?f=45&t=3990
