Dragons Guide

Pterosaurs

Pterosaurs (/?t?.rs(r)/, from the Greek , pterosauros, meaning "winged lizard", often referred to as pterodactyls, from the Greek , pterodaktulos, meaning "winged finger" /?t?.rd?k.t?l/) were flying reptiles of the clade Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period (228 to 65 million years ago). Pterosaurs were the first vertebrates to evolve flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the thorax to a dramatically lengthened fourth finger. Earlier species had long, fully-toothed jaws and long tails, while later forms had a highly reduced tail, and some lacked teeth.

Pterosaurs are sometimes referred to in the popular media as dinosaurs, but this is incorrect. The term "dinosaur" is properly restricted to a certain group of terrestrial reptiles with a unique upright stance (superorder Dinosauria), and therefore excludes the pterosaurs, as well as the various groups of extinct aquatic reptiles, such as ichthyosaurs, plesiosaurs, and mosasaurs.

Fossilised pterosaurs have been found in North America, South America, United Kingdom, Europe, Africa, Asia and Australia. The first pterosaur fossil was found by an Italian naturalist, Cosimo Collini, in 1784. The name "Ptero-dactyle" was first coined by Georges Cuvier in 1809 for a specimen recovered in Germany; however, due to the standardization of scientific names, the official name for this species became Pterodactylus, though the name "pterodactyl" continued to be popularly applied to all members of this first specimen's order.

A famous UK find was an example of Dimorphodon by Mary Anning, at Lyme Regis in 1828.

At least 60 genera of pterosaurs have been found, ranging from the size of a small bird to wingspans in excess of 10 meters (33 feet). Since the first pterosaur fossil was discovered in the late Jurassic Solnhofen limestone in 1784, twenty-nine kinds of pterosaurs have been found in those deposits alone. Most paleontologists now believe that pterosaurs were adapted for active flight, not just gliding as was earlier believed. The three dimensionally preserved skull of Anhanguera santanae, from the Santana Formation, Brazil.

Most pterosaur fossils did not preserve well. Their bones were hollow and, when sediments piled on top of them, the bones were flattened. The best preserved fossils have come from the Araripe Plateau, Brazil. For some reason, when the bones were deposited, the sediments encapsulated the bones, rather than crushing them. This created three-dimensional fossils for paleontologists to study. The first find in the Araripe Plateau was made in 1974.

The anatomy of pterosaurs was highly modified from their reptilian ancestors for the demands of flight. Pterosaur bones were hollow and air filled, like the bones of birds. They had a keeled breastbone that was developed for the attachment of flight muscles and an enlarged brain that shows specialised features associated with flight.

Pterosaur wings were formed by membranes of skin and other tissues, strengthened by various types of closely spaced fibers. The membranes attached to the extremely long fourth finger of each arm and extended along the sides of the body. A bone unique to pterosaurs, known as the pteroid, connected to the wrist and helped to support a membrane (the propatagium) between the wrist and shoulder. The pteroid might have been able to swing forward to extend this membrane,, although this is very debatable. In some later pterosaurs, the backbone over the shoulders fused into a structure known as a notarium, which served to stiffen the torso during flight, and provide a stable support for the scapula (shoulder blade).

There has been considerable argument among paleontologists about whether the wings attached to the hindlimbs as well. Fossils of the rhamphorhynchoid Sordes, the anurognathid Jeholopterus, and a pterodactyloid from the Santana Formation seem to demonstrate that the wing membrane did attach to the hindlimbs, at least in some species. However, modern bats and flying squirrels show considerable variation in the extent of their wing membranes and it is possible that, like these groups, different species of pterosaur had different wing designs. Indeed, analysis of pterosaur limb proportions shows that there was considerable variation, possibly reflecting a variety of wing-plans. Many if not all pterosaurs also had webbed feet, and although these have been considered to be evidence of swimming, they may have had an aerodynamic function.

There is no fossil evidence of feathers, but pterosaurs were unique among reptiles in that at least some of them were covered with hair, similar to but not homologous with mammalian hair. Pterosaur "hair" is not true hair as seen in mammals, but a unique structure that developed a similar appearance through convergent evolution. Although in some cases fibers in the wing membrane have been mistaken for hair, some fossils such as those of Sordes pilosus (the "hairy demon") do show the unmistakable imprints of hair on the head and body, not unlike modern-day bats, another example of convergent evolution. The presence of hair (and the demands of flight) imply that pterosaurs were warm-blooded ('endothermic').

A study of pterosaur brain cavities using X-rays has revealed extraordinary information about their habits. Studying fossil pterosaur skulls is extremely difficult because they are so delicate, but Lawrence Witmer at Ohio University in Athens and his colleagues used X-ray CT scans to build up 3D images of the brains of two species. One striking finding was that the animals (Rhamphorhynchus muensteri and Anhanguera santanae) had massive flocculi. The flocculus is a brain region that integrates signals from joints, muscles, skin and the balance organs.

The pterosaurs' flocculi occupied 7.5% of the animals' total brain mass, more than in any other vertebrate. Birds have unusually large flocculi compared with other animals, but these only occupy between 1 and 2% of total brain mass.

The flocculus sends out neural signals that produce small, automatic movements in the eye muscles. These keep the image on an animal's retina steady. Pterosaurs may have had such a large flocculus because of their large wing size, which would mean that there was a great deal more sensory information to process.

Pterosaur's hip sockets were oriented facing slightly upwards, and the head of the femur (thigh bone) was only moderately inward facing, suggesting that pterosaurs had a semi-erect stance. It would have been possible to lift the thigh into a horizontal position during flight as gliding lizards do.

There has been considerable debate in the past about whether pterosaurs moved about on the ground as quadrupeds or as bipeds. A large number of pterosaur trackways are now known, with a distinctive four-toed hind foot and three-toed front foot; these are the unmistakable prints of pterosaurs walking on all fours. It has been suggested that smaller pterosaurs with longer hindlimbs such as Dimorphodon might have walked or even run bipedally, in addition to flying, not unlike modern road runners. Other small pterosaurs such as Rhamphorhynchus may have scurried around on all fours. Larger pterosaurs with proportionately smaller hindlimbs and massive forebodies are generally thought to have moved about on all fours while on the ground. All known pterosaur footprints match the feet of pterosaurs adapted to wading and sifting for their food. Tracks that can be matched to soaring and tree-clinging pterosaurs are not known.

Pterosaurs are known to have been eaten by spinosaurs. In the 1 July 2004 edition of Nature, paleontologist Eric Buffetaut discusses an early Cretaceous fossil of three cervical vertebrae of a pterosaur with the broken tooth of a spinosaur embedded in it. The vertebrae are known not to have been eaten and exposed to digestion, as the joints still articulated.

Very little is known about pterosaur reproduction. A single pterosaur egg has been found in the quarries of Liaoning, the same place that yielded the famous 'feathered' dinosaurs. The egg was squashed flat with no signs of cracking, so evidently the eggs had leathery shells, as in modern lizards. The embryo's wing membranes were well developed, suggesting pterosaurs were ready to fly soon after birth. This is corroborated by very young animals found in the Solnhofen limestone beds, where they presumably flew to the middle of a lagoon, fell in and drowned. It is not known whether pterosaurs practised parental care, but their comparatively early flight capabilities suggest the young were not completely dependent on parents as most birds are.

A study of pterosaur eggshell structure and chemistry published in 2007 indicated that it is likely pterosaurs buried their eggs, like modern crocodile and turtles. Egg-burying would have been beneficial to the early evolution of pterosaurs, as it allows for more weight-reducing adaptations, but this method of reproduction also would have put limits on the variety of environments pterosaurs could live in, and may have disadvantaged them when they began to face ecological competition from birds. The alternative would be for the mother to retain the egg within the body until just prior to hatching, as some lizards do, but archosaurs are incapable of.

Megalania Prisca

Megalania is an extinct giant monitor lizard. It was one of the megafauna that roamed southern Australia, and appears to have become extinct around 40,000 years ago. It was once thought to belong to a distinct monotypic genus and called Megalania prisca, (Greek "great" + "roam", "in reference to the terrestrial nature of the great Saurian" (Owen, 1859)). Its placement as a valid genus remains controversial, with many authors preferring sinking the genus into Varanus (Molnar, 2004), which encompasses all living monitor lizards. The first aboriginal settlers of Australia would certainly have encountered living Megalania.

Lack of enough fossil material has made it very hard to determine the exact dimensions of Megalania . (Molnar, 2004). Conservative estimates place the length of the largest individuals at a little over 7 meters (23 ft), with a maximum conservative weight of approximately 1940 kg (4,268 lbs [Molnar, 2004]). Average sized specimens would have been a leaner, but still impressive, 320 kg (704 lbs). Megalania was the largest land-dwelling lizard to have ever lived, and a fearsome predator as well as a scavenger. Judging from its size, Megalania would feed mostly on medium to large sized animals, including any of the giant marsupials like Diprotodon along with other reptiles, small mammals, and birds and their eggs and chicks. It had heavily built limbs and body and a large skull complete with a small crest in between the eyes, and a jaw full of serrated blade-like teeth. Due to its size and similarities to the Komodo Dragon, a relationship between the two species has been suggested. In reality however, Megalania's closest living relative is the perentie, Australia's largest living lizard, not the Komodo Dragon.

There have been numerous reports and rumors of living Megalania in Australia, and occasionally New Guinea, as recently as the mid 1990s. Australian cryptozoologist Rex Gilroy has stated that Megalania is still alive today, and it is only a matter of time until one comes in. Aside from stories and eyewitness accounts, the only suggestion that Megalania might still be alive today is plaster casts of possible Megalania footprints that Gilroy made in 1979. However, this view is not accepted by most scientists, and it has been pointed out that supposed sightings of this lizard did not begin until after its initial discovery.

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Komodo Dragons

The Komodo dragon (Varanus komodoensis), also known as the Komodo Monitor, Komodo Island Monitor, Ora (to the natives of Komodo), or simply Komodo, is a species of lizard which inhabits the islands of Komodo, Rinca, Flores, Gili Motang, and Gili Dasami in central Indonesia.

A member of the monitor lizard family Varanidae, and the clade Toxicofera, the Komodo is the largest living species of lizard, growing to an average length of 2-3 metres (approximately 6.5-10 feet). This great length is attributed to island gigantism, as there are no carnivorous mammals to fill the niche in the islands that they live on, and the Komodo dragon's low metabolic rate. As a result of their great size, these lizards are apex predators, dominating the ecosystems in which they live.

Komodo dragons were only discovered by Western scientists in 1910. Their large size and fearsome reputation makes them popular zoo exhibits. In the wild their range has contracted due to human activities and they are listed as vulnerable by the IUCN. They are protected under Indonesian law and a national park, Komodo National Park, was founded in order to protect them.

In the wild, adult komodods usually weigh around 70 kilograms (154 pounds). Captive specimens often weigh more. The largest verified wild specimen was 3.13 metres (10 feet 3 inches) long and weighed 166 kilograms (365 pounds), including undigested food. Komodo dragons have a tail that is as long as the body, as well as about 60 frequently-replaced serrated teeth that may be 2.5 centimetres (1 inch) in length. Their saliva will frequently be blood-tinged, because their teeth are almost completely covered by gingival tissue and this tissue is naturally lacerated during feeding. This creates an ideal culture for the virulent bacteria that live in their mouths. It also has a long, yellow, deeply-forked tongue.

Komodo dragons' sense of hearing is not particularly acute, despite their visible earholes. They are able to see as far away as 300 metres (985 feet), but because their retinas only contain cones, they are thought to have poor night vision. Komodo dragons are able to see in color and have poor visual discrimination of stationary objects. They use their tongue to detect taste and smell stimuli, as with many other reptiles, with the vomeronasal sense using a Jacobson's organ, a sense that aids navigation in the dark. With the help of a favorable wind and their habit of swinging their head from side to side as they walk, they may be able to detect carrion from 4-9.5 kilometres (2.5-6 miles) away. Komodo dragons' nostrils are not of great use for smelling, as they do not have a diaphragm. They have no taste buds on their tongues, only a few in the back of the throat.

Their scales, some reinforced with bone, have sensory plaques connected to nerves that facilitate their sense of touch. The scales around the ears, lips, chin, and soles of the feet may have three or more sensory plaques.

Formerly, Komodo dragons were thought to be deaf when a study reported no agitation in wild Komodo dragons during whispers, raised voices, and shouts. This was disputed when London Zoological Garden employee Joan Proctor trained a captive monitor to come out to feed at the sound of her voice, even when she could not be seen.

Komodo dragons are found exclusively in Indonesia, on the islands of Komodo, Flores and Rinca and on several islands of the Lesser Sunda archipelago. They prefer hot and dry places, and typically live in dry open grassland, savanna and tropical forest at low elevations. As poikilotherms, they are most active in the day, although they do exhibit some nocturnal activity. Komodo dragons are largely solitary, coming together only to breed and eat. They are capable of running rapidly in brief sprints (up to 20 kilometres per hour [12.4 miles per hour]), are excellent swimmers (may dive up to 4.5 metres [15 feet]), and climb trees proficiently through use of their strong claws. To catch prey that is out of reach, they may stand on their hind legs and use their tail as a support. As Komodo dragons mature, their claws are used primarily as weapons, as their great mass makes climbing impractical.

For shelter, dragons dig holes that can measure from 1-3 metres (3-10 ft) wide with their powerful forelimbs and claws. Because of their large size and habit of sleeping in these burrows, Komodo dragons are able to conserve body heat throughout the night and minimize their basking period the morning after. Komodo dragons typically hunt in the afternoon, but stay in the shade during the hottest part of the day.

Komodo dragons are carnivorous. Although they eat mostly carrion, studies show that they also hunt live prey with a stealthy approach followed by a sudden short charge. When suitable prey arrives near a dragon's ambush site, it will suddenly charge at the animal and go for the underside or the throat. The lizard is able to locate its prey using its keen sense of smell, which can locate a dead or dying animal from a range of up to 9.5 kilometers (6 miles).

Komodo dragons have recently been discovered to produce a powerful venom, making the dragon one of the three lizard species to produce venom. In addition to the powerful venom, dragons also possess virulent bacteria in their saliva, of which more than 28 Gram-negative and 29 Gram-positive strains have been isolated. These bacteria cause septicemia in their victim; if an initial bite does not kill the prey animal and it escapes, it will commonly succumb within a week to the resulting infection. The deadliest bacteria in Komodo dragon saliva appears to be a very deadly strain of Pasteurella multocida, from studies performed with lab mice. Because the Komodo dragon appears immune to its own microbes, much research has been done searching for the antibacterial molecule in the hopes of human medicinal use.

Komodo dragons eat by tearing large chunks of flesh and swallowing them whole while holding the carcass down with their forelegs. The copious amounts of red saliva that the Komodo dragons produce helps to lubricate the food, but swallowing is still a long process (15-20 minutes to swallow a goat). To prevent itself from suffocating while swallowing, it breathes using a small tube under the tongue that connects to the lungs. The Komodo dragon's loosely articulated jaws, flexible skull, and expandable stomach allows it to eat up to 80 percent of its body weight in one meal. After eating, it drags itself to a sunny spot to speed digestion, as the food could rot and poison the dragon if left undigested for too long. Because of their slow metabolism, large dragons can survive on as little as 12 meals a year. After digestion, the Komodo Dragon regurgitates a mass of horns, hair, and teeth known as the gastric pellet, which is covered in malodorous mucus. After regurgitating the gastric pellet, it rubs its face in the dirt or on bushes to get rid of the mucus, suggesting that it, like humans, does not relish the scent of its own mucus.

The largest animals generally eat first, while the smaller ones follow a hierarchy. The largest male asserts his dominance and the smaller males show their submission by use of body language and rumbling hisses. Dragons of equal size may resort to "wrestling." Losers usually retreat, though have been known to have been killed and eaten by victors.

The dragon's diet is wide-ranging, and includes invertebrates, other reptiles (including smaller dragons), birds, bird eggs, small mammals, monkeys, wild boars, goats, deer, horses, and water buffalos. Young Komodos will eat insects, eggs, geckoes, and small mammals. Occasionally they have been known to consume humans and human corpses, digging up bodies from shallow graves to do so. It is thought that the Komodo dragon evolved to feed on the extinct dwarf elephant Stegodon that once lived on Flores.

The Komodo dragon has been observed intentionally startling a pregnant deer in the hopes of a miscarriage whose remains they can eat, a technique that has also been observed in large African predators.

Because the Komodo dragon does not have a diaphragm, it cannot suck water when drinking, nor can it lap water with its tongue. Instead, it drinks by taking a mouthful of water, lifting its head, and letting the water run down its throat.

Mating occurs between May and August, with the eggs laid in September. During this period, males fight over females and territory by grappling with one another upon their hind legs with the loser eventually being pinned to the ground. These males may vomit or defecate when preparing for the fight. The winner of the fight will then flick his long tongue at the female to gain information about her receptivity. Females are antagonistic and resist with their claws and teeth during the early phases of courtship. Therefore, the male must fully restrain the female during coitus to avoid being hurt. Other courtship displays include males rubbing their chins on the female, hard scratches to the back, and licking. Copulation occurs when the male inserts one of his hemipenes into the female's cloaca. Komodo dragons may be monogamous and form "pair bonds," a rare behavior for lizards.

The female will lay her eggs in the burrows in the ground, cut into the side of a hill or in the abandoned nesting mounds of the Orange-footed Scrubfowl (a moundbuilder or megapode), with a preference for the abandoned mounds. Clutches contain an average of 20 eggs which have an incubation period of 7-8 months. The female lies on the eggs to incubate and protect them until they hatch around April, at the end of the rainy season when insects are plentiful.

Hatching is an exhausting effort for the pups, who break out of their eggshells with an egg tooth that falls off after the job is done. After cutting out the hatchlings may lie in their eggshells for hours before starting to dig out of the nest. They are born quite defenseless, and many are eaten by predators.

Young Komodo dragons spend much of their first few years in trees, where they are relatively safe from predators, including cannibalistic adults, who make juvenile dragons 10 percent of their diet. When the young must approach a kill, they roll around in fecal matter and rest in the intestines of eviscerated animals to deter these hungry adults. Dragons take about three to five years to mature, and may live for up to 50 years.

There are recorded examples of parthenogenesis (reproduction without the contribution of a male), a phenomenon also known to occur in some other reptile species, such as Whiptail Lizards.

Flying Dragon

Draco volans, or the Flying Dragon, is a "flying" lizard that lives in the rainforests of Asia and the East Indies. They can also be found on rubber plantations. It can spread out folds of skin attached to its movable ribs to form "wings" that it uses to glide from tree to tree over distances upwards of 8 meters (25 feet). Its wings are brightly colored with orange, red and blue spots and stripes, and they provide camouflage when folded. The flying dragon can reach lengths as long as 19 - 23 cm. It feeds on arboreal ants and termites. During breeding season the female flying dragon will venture down to the forest floor and bury its 1-5 eggs in the soil.Its range is the Philippines to Malaysia and Indonesia. They have short sticky tongues that they use to eat the ants and termites with.

Sea Dragon

The leafy sea dragon, Phycodurus eques, is a marine fish related to the seahorse. It is the only member of the genus Phycodurus. These creatures are found around southern and western Australia and generally remain in shallow, temperate waters. Their name comes from their appearance, with long leaf-like protrusions coming from all over the body. These protrusions are not used for propulsion; they serve only as camouflage. The leafy sea dragon propels itself by means of a pectoral fin on the ridge of its neck and a dorsal fin on its back closer to the tail end. These small fins are almost completely transparent and difficult to see as they undulate minutely to move the creature sedately through the water, completing the illusion of floating seaweed.

Much like the seahorse, the leafy sea dragon's name is derived from its resemblance to another creature (in this case, a mythical creature). While not large by sea monster standards, they are very large for sea horses, growing at least 18 inches (45 cm). They feed on plankton and small crustaceans. Females deposit eggs on the tail of the male where they grow to maturity. They have become endangered through pollution and industrial runoff as well as collection by fascinated divers who are entranced by their unique appearance. In response to these dangers they have been officially protected by the Australian government.

A related species is the weedy sea dragon, which is multi-coloured and grows weed-like fins and can be much smaller than the leafy sea dragon. In the November 2006 issue of National Geographic magazine, marine biologist Greg Rouse is reported as investigating the DNA variation of the two sea dragon species across their ranges.

The leafy sea dragon is the official marine emblem of the state of South Australia. A biennial Leafy Sea Dragon Festival is held by the District Council of Yankalilla, South Australia. It is a festival of the environment, arts and culture of the southern Fleurieu Peninsula, with a theme of celebrating the leafy sea dragon. The inaugural festival in 2005 attracted over 7000 participants and visitors.

Sea dragons are protected by Australian law. Obtaining them is often an expensive and difficult process as they must be from captive bred stock, and exporters must prove their broodstock were caught before collecting restrictions went into effect, or that they had the correct licenses to collect them.

They are very fragile and unstable outside their natural habitats. Success keeping them has been largely in the public aquarium sector, due to funding and knowledge that would not be available to the average aquarium enthusiast.

Python

The Pythonidae are a family of non-venomous snakes found in Africa, Asia and Australia. Among its members are some of the largest snakes in the world. Currently, 8 genera and 26 species are recognized.

Adults range in size from 0.5 to 10 meters (1.5 to 33 feet) in length. One species, Python reticulatus, the reticulated python, holds the record for world's longest snake: 10 m (32 ft 9.5 in).

The Pythonidae are distinguished from the family Boidae (boas) by the fact that they have teeth on the premaxilla: a small bone at the very front and center of the upper jaw. Most species have rows of heat-sensing organs between the sublabial scales: labial pits. Although not as well developed as the loreal pits of the subfamily Crotalinae (pitvipers), these organs enable the snakes to detect objects that are hotter than the surrounding environment, and enable hunting to take place in total darkness, such as inside caves.

Some species exhibit vestigial bones of the pelvis and rear legs, which are externally apparent in the form of a pair of anal spurs on each side of the cloaca. These spurs are larger in males than females, and are used by the male to grip and/or stimulate the female during copulation. Male of certain species occasionally cause spur related injuries to each other during territorial combat, and though more likely to be incidental than intentional, some captured specimens have shown multiple episodes of scarring from such injuries.

Color patterns vary from striking to nondescript brown or olive. It usually reflects appropriate camouflage for the native habitat. Even within a given species, there may be enormous differences in coloration and pattern in different parts of the geographic range.

Found in subsaharan Africa, peninsular India, Myanmar, southern China, Southeast Asia and the Philippines southeast through Indonesia to New Guinea and Australia.

In the United States, a population of Burmese pythons, Python molurus bivittatus, has existed as an invasive species in the Everglades National Park since the late 1990s, which has damaged the local ecosystem. More than 300 have been removed. They are not native to the south Floridian marshlands, but have been deposited there by pet owners who no longer wished to care for them and also did not want to euthanize them. Scientists believe that the snakes are a grave threat to nearly every species of animal in the Everglades, including alligators. There have been several accounts of python versus alligator encounters there, including one in autumn 2005 between a 13-foot (4 m) python and a six-foot (1.8 m) alligator that proved fatal for both. The two were found with the alligator's body protruding from a tear in the snake's body.

Many species have been hunted aggressively, which has decimated some, such as the Indian python, Python molurus.

Ambush predators, they typically remain motionless in a camouflaged position and then strike suddenly at passing prey. They will generally not attack humans unless startled or provoked, although females protecting their eggs can be aggressive. Large adult specimens can kill people. Unsuspecting children can and have become prey and swallowed whole after being suffocated. Reports of attacks on human beings were once more common in South and Southeast Asia, but are now quite rare.

Prey is killed by a process known as constriction; after an animal has been grasped to restrain it, a number of coils are hastily wrapped around it. Then, by applying and maintaining sufficient pressure to prevent it from inhaling, the prey eventually succumbs due to asphyxiation. It has recently been suggested that the pressures produced during constriction cause cardiac arrest by interfering with blood flow, but this hypothesis has not yet been confirmed. As opposed to popular belief, prey is not crushed; even when constricting normal sized prey, sufficient pressure to break bones is almost certainly never applied.

Larger specimens usually eat animals about the size of a house cat, but larger food items are not unknown: some large Asian species have been known to take down adult Deer, and the African rock python, Python sebae, has been known to eat Gazelle. Prey is swallowed whole, and may take anywhere from several days or even weeks to fully digest. Despite their intimidating size and muscular power, they are generally not dangerous to humans.

Females lay eggs (oviparous). This sets them apart from the family, Boidae (boas), most of which bear live young (ovoviviparous).

Most species in this family are available in the exotic pet trade. However, caution must be exercised with the larger species as they can be dangerous; cases of large specimens killing their owners have been documented.

Bearded Dragon

Bearded dragons have broad triangular heads and flattened bodies, with adults reaching approximately 24 inches head-to-tail. When threatened or aroused, they will expand a spiny pouch under their jaw to make them appear larger. This pouch, especially in its expanded state, resembles a beard, lending the animal their name, this pouch will also turn black, also contributing to the "bearded look". Males are often slightly larger than females, with a larger head in proportion to their bodies, but females are often slightly more heavily set. Males also typically have darker "beards," and have two bulges just posterior to the cloaca, where only a single, medially-located lump is present in a female. Bearded dragons have a distinctive series of lateral spines (specialized scales) radiating horizontally from the head to the base of the tail. Their colour ranges from light tan to dark brown or green, depending on their native soil, often with highlights of black, or brilliant red or gold, and can change somewhat depending upon their internal condition. Some captive populations have been selectively bred for more brilliant red and gold colorations. As juveniles, they are semi-arboreal. As adults, they are mostly terrestrial, but will climb to bask and search for prey. Bearded Dragons occupy a large range of habitats from the desert to dry forests and scrublands.

All species are from Australia, but they have been exported worldwide and bred widely in captivity. In the wild, the various species are widely distributed throughout different regions of Australia. Bearded dragons live about 7 to 12 years with proper care.

Bearded dragons are opportunistic omnivores. Many Bearded dragon habitats are dry and sparsely vegetated, so food may often be difficult to find. As a result, Bearded dragons are capable of subsisting on a wide variety of food sources, including vegetation, some fruit like strawberries and apples. Vegetables such as carrots and some types of lettuce. Insects, spiders, meal worms, and the occasional small rodent or lizard. Their stomachs are large enough to accommodate large quantities of plant and animal matter. At a young age, Bearded dragon will tend not to eat as much vegetation as their adult counterparts. As a Bearded dragon ages it will eat more and more vegetables

Due largely to their animated, highly social behavior, mild temperament, ready willingness to breed in captivity, flexible diet and robust nature, Bearded dragons are popular among reptile enthusiasts as pets.

Bearded dragons are omnivorous, requiring both insects and vegetable food. A typical diet for captive Bearded dragons includes ample quantities of leafy greens and vegetables, and regular meals of feeder insects, such as crickets, roaches, silkworms, hornworms, butterworms and phoenix worms. The mealworm has a fairly hard chitin (exoskeleton) and is generally low in the "chitin to meat" ratio. The chitin is hard enough to compact Bearded Dragon's digestion system, and can lead to death. Superworms are a better choice for older lizards, especially after the insect molts. This is a general rule and does not need to inhibit ever feeding mealworms as a treat. A significant portion of the Bearded dragon's diet must consist of leafy greens. Dragons enjoy many types of readily available greens, including: collard greens, escarole, turnip greens, mustard greens, romaine lettuce, dandelion greens, beans, parsley, kale and carrot tops. It is also recommended that this portion of the dragon's diet be supplemented with a variety of finely diced fruits, vegetables and legumes. Feeding a mixture of these plants ensures a wider variety of nutrients, and variations in texture to aid digestion.

The staple insects in the pet Bearded dragon's diet are crickets, which are readily available at pet stores in a wide range of sizes for various ages of dragons. Other insects that may be offered include: silkworms, hornworms, butterworms, phoenix worms and roaches. Waxworms can be given as a treat, but no more then 3-4 a week in most cases as they are extremely fatty, and in some cases very addictive. The insects being offered should not be any larger than the space between the lizard's eyes to ensure safe digestion. Soft bodied worms are an exception to this rule but do not feed anything that seems too big to get down. Before being offered to the dragon, it is recommended that insects be fed for at least 24 hours in advance, or "gut-loaded" to increase their nutritional value. Commercial cricket foods for gut-loading are available, but many household food items may be used instead. Insects caught in the wild are not recommended, due to the increased risk of pesticide exposure and parasites, and fireflies are reportedly fatal to Bearded dragons. It is also highly recommended that any insects being fed to the lizard first be dusted with a phosphorus-free commercial calcium supplement, as Bearded dragons are susceptible to metabolic bone disease if their calcium and vitamin D3 requirements are not met.

A 20 gallon long aquarium is the bare minimum for a juvenile bearded dragon. For an adult the minimum is a 40 breeder, though this is small. Generally the minimum should be 2 ? their STL (Stretched Total ) length for the length, 1 ? the STL for the width and 1 ? the STL for the height, this will be about a 4' ? 2'? 2' for a large dragon. The cage should be at least 16" wide to avoid problems turning.

Bearded dragons like to bask on rocks, and they use the edges of rocks to shed their skin. It is important that there is at least one or two good "basking rocks" in the dragon's habitat. Only naturally formed medium to large rocks (such as those found in backyards, woods, etc) should be used, as electric or battery powered heating devices such as HotRocks can cause stomach burns and flesh tearing on bearded dragons and pretty much all basking reptiles, especially babies.

In addition to basking and shedding, the other reason for having at least one large rock in the dragon's habitat is to successfully simulate its natural habitat. Most bearded dragons come from desert environments, which get cooler by night. Bearded dragons need a rock they can burrow under to sleep for the night, to give them shade and coolness.

In addition to rocks, bearded dragons need things to hide, burrow, and play in. Holey logs, sold in pet shops, are ideal for this. Caves or shelters should not be put in with bearded dragons until they are full size. Juvenile bearded dragons tend to stay in their shelter and not come out, which means they would not get enough light for proper growth.

Bearded dragons also need proper lighting. A UVB light is needed, with two options being available. Fluorescent strip bulbs or mercury vapor bulbs. An example of a good brand of fluorescent bulbs is Repti-Sun 10.0, which needs to be 6-10 inches away. The Repti-Sun 5.0 needs to be 4-6 inches away, the Repti-Glo 8.0 that needs to be 4-6" away, and the Repti-Glo 10.0 that needs to be 6-10 inches away. These bulbs need to be replaced every 6 months. The owner should make sure to buy a strip bulb, not a compact. This is because the compacts wear out in about 1 month. Fluorescent bulbs need to be replaced every 6 months. For mercury vapor the two best are the T-rex UV heat and the Megray (reptileuv.com) They each are the same output and are 3-4x stronger than the best fluorescent. A 100 watt should be 10-12 inches away minimum, the 160 should be 16-18" minimum and the other wattages should be listed when you buy it. They last 6-12 months. All bulbs are cheaper online. Without a good UVB your dragon will develop MBD and not eat much.

For basking, Beardies need bright white light. If a colored bulb is used, they will eat less and seem sick.

Temperature is another important health factor. A dragon needs correct temperature to digest, so a good thermometer is essential. Analog, Round, stick-on, and other non-digital thermometers do not measure basking temperature properly and can be inaccurate by as much as 20 degrees. A digital thermometer with a probe or a tempgun are two recommended types. Temps need to be 95-110 during day and 60-80 at night (the higher end of this range for babies, the lower portion of the range for adult dragons).

Bearded dragons are known to be very docile and trusting, yet at the same time, outgoing and curious lizards. Their behaviour includes body language such as head bobbing and leg waving. Some owners have mimicked these behavioral patterns and have successfully aroused a mirrored response in their dragons.

Pogona vitticeps is the most docile and friendly of all lizard species which is why they make desirable pets. Unlike iguanas, monitors, water dragons, and the flightier lizards of the exotic pet trade, bearded dragons tend to enjoy human contact and to be handled by humans. They rarely bite, scratch, or otherwise attack a human. As a result, bearded dragons are a suitable reptile for younger children (always with proper supervision).

Basic rule of thumb is to never keep any dragons housed together. While they may stay friendly towards each other for a time, one will always get more food.Even though, they do enjoy to interact at non feeding times.

Due to domestication, beardies have exhibited rather distinctive colorations. These "designer" dragons display brilliant hues of pastel oranges, violets, and reds. The most popular morphs thus far has been the "sand fire" and "tiger" dragons. Much like designer dogs, the price tags of these customized pets are many times the price of "generic" ones. Currently, breeders are working towards and showing some progress of developing a green morph. Since breeding beardies is a relatively new area, it may take some time before that dream of a green dragon is fully realized.

They can have up to 50 eggs a month. Females have been known to eat the eggs that were not fertilized/stillborn

When provided with the proper habitat, temperatures, and UVB lighting, bearded dragons are hardy lizards. They are also pets who do their best to hide health problems when becoming ill (as do most reptiles). This is probably an instinctual behavior, since a sick dragon in the wild would probably not live long. The most common diseases they get are: mites, terminal ingestion, thermal burns, calcium deficiency, impaction, hypovitaminosis A, respiratory infections, dehydration, stomatitis, internal parasites, coccidia and other parasites, dystocia (egg binding), and MBD (Metabolic Bone Disease).

Frilled Dragon

The Frill-necked Lizard, or Frilled Lizard also known as the Frilled Dragon, (Chlamydosaurus kingii) is so called because of the large ruff of skin which usually lies folded back against its head and neck. The neck frill is supported by long spines of cartilage, and when the lizard is frightened, it gapes its mouth showing a bright pink or yellow lining, and the frill flares out, displaying bright orange and red scales. The frill may also aid in thermoregulation.

Adult frill-necked lizards may grow up to one metre in total length. They often walk quadrupedally when on the ground. When frightened they begin to run on all-fours and then accelerate onto the hind-legs. In Australia, the frill-necked lizard is also known as the "bicycle lizard" because of this behaviour. Males are significantly larger than females both as juveniles and when mature. The frill of the Australian frilled dragon is used to scare off potential predators as well as hissing and lunging. If this fails to ward off the threat, the lizard flees bipedally to a nearby tree where it climbs to the top and relies on camouflage to keep it hidden.

The lizard is found in southern New Guinea, as well as in the Kimberley region of Western Australia and across northern Australia. It primarily inhabits savanna woodlands, but may also be found in tropical to warm temperate forests, and where there is an open scrub or tussock grass understorey. It is semi-arboreal, and hunts in the trees for small arthropods (including caterpillars and cicadas), and on the ground for ants and termites, spiders, or small vertebrates (e.g. other lizards). The lizards are less active during the dry season (April-August)

The only reported predators are Morelia.

Frill-necked lizards breed in the early wet season from September to October. Adult males fight for mates, displaying their frills and biting each other. One to two clutches of 8-23 eggs are laid from early to mid-wet season from November to February. The eggs are laid in a nest 5-20 cm below ground, and usually in sunny areas. Incubation takes two to three months. Sex is partly temperature determined, with extreme temperatures producing exclusively females, and intermediate temperatures (29-35C) producing equal numbers of males and females. Their eggs are soft-shelled.

Chinese Alligator

The Chinese Alligator or Yangtze Alligator (Chinese: , Alligator sinensis) is one of two living species of Alligator, a genus within the family Alligatoridae. The Chinese Alligator is native only to China. It is smaller than the other Alligator species, the American Alligator, growing to an average of 1.5 m (5 ft).

While its appearance is very close and similar to its cousin the, American Alligator, it has few differences. One obvious difference is that the Chinese Alligator is quite small. Only attaining a length of 5 feet, they are known to grow to 7 feet, though it wasn't officially announced by that time. Unlike the American Alligator, the Chinese Alligator is fully armored, even the belly is armored in which only features on few certain crocodilians.

While it originally ranged through much of China, this species' wild habitat has been reduced to little more than a few ponds containing a small number of animals (<200 individuals, only approximately 50 of which are mature) along the lower Yangtze River in the provinces of Jiangsu, Zhejiang, and Anhui. Its population reduction has been mostly due to conversion of its habitat to agricultural use. Poisoning of rats, which the alligators then eat, has also been blamed for their decline. In the past decade, very few wild nests have been found, and even fewer produced viable offspring.

The Chinese alligator is listed as a CITES Appendix I species, which puts extreme restrictions on its trade and exportation throughout the world. It is IUCN Red Listed as a critically endangered species. Efforts are underway to reintroduce captive bred animals to suitable wild habitats, but thus far have not met with much success.

Chinese alligators are quite prolific in captivity, with estimates of the total captive population at over 10,000 animals, mostly in the Anhui Research Centre of Chinese Alligator Reproduction and the Madras Crocodile Bank, as well as numerous zoos.

This species is widely regarded as quite docile, but, as with any large crocodilian, it is capable of inflicting grievous bodily harm.

A rare alligator form exists within the cadre of animal forms belonging to Xingyi boxing. One source states the titular technique was inspired by the way an alligator can "float and swim well". It goes on to say "The alligators attribute is a combination of quietness, nimbleness, and a sudden, smooth, and quickly twisting force." The character used to represent alligator in this instance is Tuo (traditional Chinese: ?; simplified Chinese: ?), which is different from that regularly used to describe both the alligator and crocodile. Tuo is generally used to describe any number of large reptiles or water lizards.