A turtle video recorded June, 2013
What should you do if you see one crossing your path?
Just a turtle and a dog video
Turtle (wiki)
Turtles are reptiles of the order Chelonii or Testudines characterised by a special bony or cartilaginous shell developed from their ribs and acting as a shield.[3] 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 220 million years ago, making turtles one of the oldest reptile groups and a more ancient group than lizards, snakes or crocodiles. Of the many species alive today, some are highly endangered.
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 other reptiles (including birds) and mammals. Like other amniotes, turtles breathe air and do not lay eggs underwater, although many species live in or around water.
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 turtles 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 are thought to have exceptional night vision due to the unusually large number of rod cells in their retinas. Turtles have color vision with a wealth of cone subtypes with sensitivities ranging from the near ultraviolet (UV A) to red. Some land turtles have very poor pursuit movement abilities, which are normally found only in predators that hunt quick-moving prey, but carnivorous turtles are able to move their heads quickly to snap.
Turtles have rigid beaks, and use their jaws to cut and chew food. Instead of having teeth, the upper and lower jaws of the turtle are covered by horny ridges. 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.
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.
Ecology and life history
Although many turtles spend large amounts of their lives underwater, all turtles and tortoises breathe air, and must surface at regular intervals to refill their lungs. They can also spend much or all of their lives on dry land. Aquatic respiration in Australian freshwater turtles is currently being studied. Some species have large cloacal cavities that are lined with many finger-like projections. These projections, called papillae, have a rich blood supply, and increase the surface area of the cloaca. The turtles can take up dissolved oxygen from the water using these papillae, in much the same way that fish use gills to respire.
Like other reptiles, turtles lay eggs which are slightly soft and leathery. The eggs of the largest species are spherical, while the eggs of the rest are elongated. Their albumen is white and contains a different protein from bird eggs, such that it will not coagulate when cooked. Turtle eggs prepared to eat consist mainly of yolk. In some species, temperature determines whether an egg develops into a male or a female: a higher temperature causes a female, a lower temperature causes a male. Large numbers of eggs are deposited in holes dug into mud or sand. They are then covered and left to incubate by themselves. Depending on the species, the eggs will typically take 70–120 days to hatch. When the turtles hatch, they squirm their way to the surface and head toward the water. There are no known species in which the mother cares for her young.
Sea turtles lay their eggs on dry, sandy beaches. Immature sea turtles are not cared for by the adults. Turtles can take many years to reach breeding age, and in many cases breed every few years rather than annually.
Researchers have recently discovered a turtle’s organs do not gradually break down or become less efficient over time, unlike most other animals. It was found that the liver, lungs, and kidneys of a centenarian turtle are virtually indistinguishable from those of its immature counterpart. This has inspired genetic researchers to begin examining the turtle genome for longevity genes.
A group of turtles is known as a bale.
Systematics and evolution
The first proto-turtles are believed to have existed in the late Triassic Period of the Mesozoic era, about 220 million years ago, and their shell, which has remained a remarkably stable body plan, is thought to have evolved from bony extensions of their backbones and broad ribs that expanded and grew together to form a complete shell that offered protection at every stage of its evolution, even when the bony component of the shell was not complete. This is supported by fossils of the freshwater Odontochelys semitestacea or "half-shelled turtle with teeth", from the late Triassic, which have been found near Guangling in southwest China. Odontochelys displays a complete bony plastron and an incomplete carapace, similar to an early stage of turtle embryonic development. Prior to this discovery, the earliest-known fossil turtles were terrestrial and had a complete shell, offering no clue to the evolution of this remarkable anatomical feature. By the late Jurassic, turtles had radiated widely, and their fossil history becomes easier to read.
Their exact ancestry has been disputed. It was believed they are the only surviving branch of the ancient evolutionary grade Anapsida, which includes groups such as procolophonids, millerettids, protorothyrids, and pareiasaurs. All anapsid skulls lack a temporal opening, while all other extant amniotes have temporal openings (although in mammals the hole has become the zygomatic arch). The millerettids, protorothyrids, and pareiasaurs became extinct in the late Permian period, and the procolophonoids during the Triassic.
What should you do if you see one crossing your path?
Just a turtle and a dog video
Turtle (wiki)
Turtles are reptiles of the order Chelonii or Testudines characterised by a special bony or cartilaginous shell developed from their ribs and acting as a shield.[3] 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 220 million years ago, making turtles one of the oldest reptile groups and a more ancient group than lizards, snakes or crocodiles. Of the many species alive today, some are highly endangered.
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 other reptiles (including birds) and mammals. Like other amniotes, turtles breathe air and do not lay eggs underwater, although many species live in or around water.
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 turtles 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 are thought to have exceptional night vision due to the unusually large number of rod cells in their retinas. Turtles have color vision with a wealth of cone subtypes with sensitivities ranging from the near ultraviolet (UV A) to red. Some land turtles have very poor pursuit movement abilities, which are normally found only in predators that hunt quick-moving prey, but carnivorous turtles are able to move their heads quickly to snap.
Turtles have rigid beaks, and use their jaws to cut and chew food. Instead of having teeth, the upper and lower jaws of the turtle are covered by horny ridges. 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.
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.
Ecology and life history
Although many turtles spend large amounts of their lives underwater, all turtles and tortoises breathe air, and must surface at regular intervals to refill their lungs. They can also spend much or all of their lives on dry land. Aquatic respiration in Australian freshwater turtles is currently being studied. Some species have large cloacal cavities that are lined with many finger-like projections. These projections, called papillae, have a rich blood supply, and increase the surface area of the cloaca. The turtles can take up dissolved oxygen from the water using these papillae, in much the same way that fish use gills to respire.
Like other reptiles, turtles lay eggs which are slightly soft and leathery. The eggs of the largest species are spherical, while the eggs of the rest are elongated. Their albumen is white and contains a different protein from bird eggs, such that it will not coagulate when cooked. Turtle eggs prepared to eat consist mainly of yolk. In some species, temperature determines whether an egg develops into a male or a female: a higher temperature causes a female, a lower temperature causes a male. Large numbers of eggs are deposited in holes dug into mud or sand. They are then covered and left to incubate by themselves. Depending on the species, the eggs will typically take 70–120 days to hatch. When the turtles hatch, they squirm their way to the surface and head toward the water. There are no known species in which the mother cares for her young.
Sea turtles lay their eggs on dry, sandy beaches. Immature sea turtles are not cared for by the adults. Turtles can take many years to reach breeding age, and in many cases breed every few years rather than annually.
Researchers have recently discovered a turtle’s organs do not gradually break down or become less efficient over time, unlike most other animals. It was found that the liver, lungs, and kidneys of a centenarian turtle are virtually indistinguishable from those of its immature counterpart. This has inspired genetic researchers to begin examining the turtle genome for longevity genes.
A group of turtles is known as a bale.
Systematics and evolution
The first proto-turtles are believed to have existed in the late Triassic Period of the Mesozoic era, about 220 million years ago, and their shell, which has remained a remarkably stable body plan, is thought to have evolved from bony extensions of their backbones and broad ribs that expanded and grew together to form a complete shell that offered protection at every stage of its evolution, even when the bony component of the shell was not complete. This is supported by fossils of the freshwater Odontochelys semitestacea or "half-shelled turtle with teeth", from the late Triassic, which have been found near Guangling in southwest China. Odontochelys displays a complete bony plastron and an incomplete carapace, similar to an early stage of turtle embryonic development. Prior to this discovery, the earliest-known fossil turtles were terrestrial and had a complete shell, offering no clue to the evolution of this remarkable anatomical feature. By the late Jurassic, turtles had radiated widely, and their fossil history becomes easier to read.
Their exact ancestry has been disputed. It was believed they are the only surviving branch of the ancient evolutionary grade Anapsida, which includes groups such as procolophonids, millerettids, protorothyrids, and pareiasaurs. All anapsid skulls lack a temporal opening, while all other extant amniotes have temporal openings (although in mammals the hole has become the zygomatic arch). The millerettids, protorothyrids, and pareiasaurs became extinct in the late Permian period, and the procolophonoids during the Triassic.
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