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20090726

Reptile news and facts

For Horned Lizards, Horns Alone Do Not Make The Species ScienceDaily (July 21, 2009)


How do you recognize a new species? A thorough study of the million-year evolution of California's horned lizards, sometimes referred to as "horny toads," shows that when it comes to distinguishing such recently diverged species, the most powerful method integrates genetic, anatomical and ecological information.

In the study, published in the journal Proceedings of the National Academy of Sciences, researchers from the University of California, Berkeley, and the U.S. Geological Survey consider all these criteria to show that when the coast horned lizard (Phrynosoma coronatum) moved north from Baja California and spread throughout the state, it diverged into at least two new species.

"When you stack up all the data sets, they all support three species," said lead author Adam Leaché, a recent UC Berkeley Ph.D. recipient who is now a National Science Foundation bioinformatics postdoctoral fellow at UC Davis. "If you were to pick only one data set, you would get a different number of species. One lesson we learned about the speciation process is that you can't rely on one type of data to accurately track a species' history."

Aside from the oldest and original species, P. coronatum, found only in southern Baja California, the researchers identified a new species, P. cerroense, in central Baja and a third, P. blainvillii, whose range extends from northern Baja to Northern California. Within the third, wide-ranging species, the study's authors found enough genetic and ecological differences to suggest there are at least three distinct populations of P. blainvillii, each requiring separate management and protection.

The findings have implications for conservation efforts, because coast horned lizard populations are in decline from southern Baja California to Northern California due to several factors. Among these are loss of lowland habitat from agriculture and urbanization and the introduction of Argentine ants, which displace the more nutritious harvester ants, the favored diet of the lizards. The lizard is on the International Union for Conservation of Nature's Red List of Threatened Species, as are California's two other horned lizards, the desert and flat-tailed horned lizards.

"For decades, it has not been clear what might be useful conservation units within the declining horned lizards in coastal California. Our study finally gives some clarity and direction for conservation actions to follow," said co-author Robert Fisher, a research biologist at the U.S. Geological Survey in San Diego, Calif.

For over 100 years, scientists have been trying to distinguish species among coast horned lizards, with the number of recognized species ranging from 1 to 6 depending on the author. These prior studies were reliant almost entirely on morphology. But when it comes to recently diverged species like the coast horned lizard, where morphological differences are subtle, it can be difficult to distinguish species, according to co-author Jimmy McGuire, UC Berkeley associate professor of integrative biology.

"This sort of analysis is going to be necessary in order to tackle questions of recent speciation," McGuire said. "Lineages that have been separated for a long time are not controversial – we have no trouble distinguishing chimps from humans, for example – but it is trickier with species that are younger and thus less morphologically heterogeneous."

"This could have an impact on the number of species that we recognize on the planet, because many species are young like this," he added.

In particular, the number of species in California could be substantially underestimated because even well-studied groups like horned lizards are likely to be comprised of multiple cryptic species, McGuire said. Studies integrating diverse data sets and focusing on the question of gene flow between lineages will almost certainly result in the discovery of many new species, he added.

Over the course of millions of years, populations of horned lizards migrating northward have separated and diverged from one another, producing an array of genetic lineages all along the western coast of North America that are adapted to unique ecological niches, according to the study.

"The genetic differences between the populations of horned lizards in California are striking – nobody could have predicted this high degree of differentiation simply by looking at the physical differences between the lizards," Leaché said.

Given enough time and continued environmental protection for the lizards to persist for the long-term, it's likely that the California horned lizards, like those in Baja California, will also evolve more dramatic physical differences through natural selection.

Leaché and McGuire, as well as the other UC Berkeley coauthors of the paper – Michelle S. Koo, Carol L. Spencer and Theodore J. Papenfuss – are affiliated with the campus's Museum of Vertebrate Zoology.

The study was funded by the National Science Foundation, The Nature Conservancy, California Department of Fish and Game, California Department of Parks and Recreation, Metropolitan Water District, U.S. Fish and Wildlife Service and U.S. Department of Defense.

University of California - Berkeley. "For Horned Lizard, Horns Alone Do Not Make The Species." ScienceDaily 21 July 2009. 26 July 2009 /releases/2009/07/090721163115.htm>.


horned lizard eating ants (video)

feeding horned lizards (video)


20090704

(Reptile news) Obesity Clues From Research On How Burrowing Frogs Survive Years Without Food


Obesity Clues From Research On How Burrowing Frogs Survive Years Without Food

Source: ScienceDaily (June 29, 2009)

Many species of animals go through a period of torpor to conserve energy when resources are scarce. But when it comes to switching to energy-saving mode, the champion by far among vertebrates is the burrowing frog (Cyclorana alboguttata), which can survive for several years buried in the mud in the absence of any food or water.

How do they accomplish this feat? A team of scientists at the University of Queensland have discovered that the metabolism of their cells changes radically during the dormancy period allowing the frogs to maximise the use of their limited energy resources without ever running on empty.

This discovery could prove to have important medical applications in the long term. "It could potentially be useful in the treatment of energy-related disorders such as obesity", explains Ms. Sara Kayes who will present her findings at the Society of Experimental Biology Annual Meeting in Glasgow on the 29th June 2009.

When the operation efficiency of the mitochondria, the tiny "power plants" of the cell, was measured during the dormancy period, it was found to be significantly higher compared to that observed in active animals. This trick , known as mitochondrial coupling, allows these frogs to be extremely efficient in the use of the limited energy stores they have by increasing the total amount of energy obtained per unit consumed, allowing them to easily outperform other species whose energy production efficiency remains essentially the same even when they happen to be inactive for extended periods.

If this is such an efficient way to use energy resources during dormancy, how come that it is not more widespread in the animal kingdom? The researchers speculate that a potential drawback may be the increased production of reactive oxygen species, which may in turn lead to oxidative stress. Since these small molecules are believed to cause most of the damage during periods of re-awakening, increasing mitochondrial coupling does not seem to be a particularly good idea for animals that tend to exhibit short periods of spontaneous arousal during the dormancy period, in some cases even daily.

Burrowing frogs, on the other hand, are believed to remain deeply asleep during the entire period of dormancy. Furthermore, being cold-blooded, they don't have the need to maintain a basal level of heat production, minimizing their energy needs.

Society for Experimental Biology (2009, June 29). Obesity Clues From Research On How Burrowing Frogs Survive Years Without Food. ScienceDaily. Retrieved July 3, 2009, from http://www.sciencedaily.com­ /releases/2009/06/090629081133.htm

visit original article.

20090703

(Reptile News) Boy Or Girl? In Lizards, Egg Size Matters

Boy Or Girl? In Lizards, Egg Size Matters
ScienceDaily (June 22, 2009)

Whether baby lizards will turn out to be male or female is a more complicated question than scientists would have ever guessed, according to a new report published online on June 4th in Current Biology. The study shows that for at least one lizard species, egg size matters.

"We were astonished," said Richard Shine of the University of Sydney. "Our studies on small alpine lizards have revealed another influence on lizard sex: the size of the egg. Big eggs tend to give girls, and small eggs tend to give boys. And if you remove some of the yolk just after the egg is laid, it's likely to switch to being a boy, even if it has female sex chromosomes; and if you inject a bit of extra yolk, the egg will produce a girl, even if it has male sex chromosomes."

In many animals, the sex of offspring depends on specialized sex chromosomes. In mammals and many reptiles, for instance, males carry one X and one Y chromosome, while females have a pair of X chromosomes. In contrast, animals such as alligators depend on environmental cues like temperature to set the sex of future generations.

The new findings add to evidence that when it comes to genetic versus environmental factors influencing sex determination, it doesn't have to be an either/or proposition. In fact, Shine and his colleagues earlier found in hatchlings of the alpine-dwelling Bassiana duperreyi that extreme nest temperatures can override the genetically determined sex, in some cases producing XX boys and XY girls. His group had also noticed something else: large lizard eggs were more likely to produce daughters and small eggs to produce sons.

Despite the correlation, Shine said he had assumed that the association was indirect. In fact, his colleague Rajkumar Radder conducted studies in which he removed some yolk from larger eggs, more likely to produce daughters, to confirm that assumption.

"We were confident that there would be no effect on hatchling sex whatsoever," Shine said. "When those baby boy lizards started hatching out, we were gob-smacked."

Shine thinks there will be much more to discover when it comes to lizard sex determination.

"I suspect that the ecology of a species will determine how it makes boys versus girls, and that our yolk-allocation effect is just the tip of a very large iceberg," he said.

The authors include Rajkumar S. Radder, University of Sydney, Australia; David A. Pike, University of Sydney, Australia; Alexander E. Quinn, University of Canberra, Australia; and Richard Shine, University of Sydney, Australia.

Cell Press. "Boy Or Girl? In Lizards, Egg Size Matters." ScienceDaily 22 June 2009. 2 July 2009 /releases/2009/06/090604124015.htm>.

20090629

Reptile News

Ancient reptile tracks unearthed
source: BBC News


The earliest evidence for the existence of reptiles has been found in Canada.

The 315 million-year-old fossilised tracks give an insight into a key milestone in the history of life, when animals left water to live on dry land.

The footprints suggest reptiles evolved between one and three million years earlier than previously thought.

They were found by UK scientist Dr Howard Falcon-Lang in fossil-rich sea cliffs at New Brunswick. "The discovery was pure luck," he said.

"As I walked along remote sea-cliffs at the end of a long day in the field, I passed a recent rock fall.

"One large slab of rock was covered with hundreds of fossil footprints! The Sun was low in the sky and I probably wouldn't have seen them if it hadn't been for the shadows," the University of Bristol researcher explained.


Diverse ecology

The ancient trackway gives an insight into a time when vertebrates were evolving through amphibians to reptiles.

The origin of reptiles, in particular the appearance of eggs protected by a shell, allowed four-legged animals to avoid having to go back into water to lay eggs, heralding life on dry land.

"The evolution of reptiles was one of the most important events in the whole history of life," Dr Falcon-Lang told BBC News.

"That paved the way for the diverse ecology that we have on our planet today."

Scientists believe the tracks preserved in sandstone were left by reptiles gathering around a watering hole on river plains that were dry for at least part of the year.

List of suspects

Using a bit of biological detective work, Dr Falcon-Lang and colleagues in the UK and Canada tracked down the likely maker of the footprints.

We can be confident the footprints are older than the skeletons
Howard Falcon-Lang

"There were only a few species capable of making prints like this around at the time so we came up with a shortlist of suspects," said Professor Mike Benton, also of the University of Bristol, who co-authored the study.

"However, the prints showed that the hands had five fingers and scales, sure evidence they were made by reptiles and not amphibians."

The most likely contender was a lizard-like reptile named Hylonomus lyelli after the 19th Century geologist Sir Charles Lyell.

Until now, the oldest evidence for reptiles was thought to be skeletal fossils of the creature found in 1859 by William Dawson.

Dr Falcon-Lang said the new material was found in the same general region of an area of rock formation known as Joggins but at a level almost a kilometre below Dawson's discovery.

"Consequently we can be confident the footprints are older than the skeletons," he said.

"The most likely track-maker was the Hylonomus lyelli reptile we know from the slightly later remains at Joggins," he added.

The results of the study are published in the Journal of the Geological Society of London.


Original content with pics at BBC NEWS

20090623

reptile fact.

Water Snake Startles Fish So They Flee Into Its Jaws

— Forget the old folk tales about snakes hypnotizing their prey. The tentacled snake from South East Asia has developed a more effective technique. The small water snake has found a way to startle its prey so that the fish turn toward the snake's head to flee instead of turning away. In addition, the fish's reaction is so predictable that the snake actually aims its strike at the position where the fish's head will be instead of tracking its actual movement.

"I haven't been able to find reports of any other predators that exhibit a similar ability to influence and predict the future behavior of their prey," says Kenneth Catania, associate professor of biological sciences at Vanderbilt University, who has used high-speed video to deconstruct the snake's unusual hunting technique.
His observations are published the week of June 15 in the online early edition of the Proceedings of the National Academy of Sciences.
Catania, who is the recipient of a MacArthur "genius" award, studies the brains and behavior of species with extreme specializations. He was attracted to the tentacled snake because it is the only snake that comes equipped with a pair of short tentacles on its nose and he was curious about their function.
"Before I begin a study on a new species, it is my practice to spend some time simply observing its basic behavior," Catania explains. The snake forms an unusual "J" shape with its head at the bottom of the "J" when it is fishing. Then it remains completely motionless until a fish swims into the area near the hook of the "J." That is when the snake strikes.
The snakes' motions take only a few hundredths of a second and are too fast for the human eye to follow. However, its prey reacts even faster, in a few thousandths of a second. In fact, fish are famous for the rapidity of their escape response and it has been extensively studied. These studies have found that many fish have a special circuit in their brains that initiates the escape, which biologists call the "C-start." Fish ears sense the sound pressure on each side of their body. When the ear on one side detects a disturbance, it sends a message to the fishes' muscles causing its body to bend into a C-shape facing in the opposite direction so it can begin swimming away from danger as quickly as possible.
Catania is the first scientist to study this particular predator-prey interaction with the aid of a high-speed video camera. When he began examining the movements of the snake and its prey in slow motion, he saw something peculiar. When the fish that the snake targets turn to flee, most of them turn toward the snake's head and many literally swim into its jaws! In 120 trials with four different snakes, in fact, he discovered that an amazing 78 percent of the fish turned toward the snake's head instead of turning away.
Next, the biologist noticed that the first part of its body that the snake moves is not its head. Instead, it flexes a point midway down its body. Using a sensitive hydrophone that he put in the aquarium, he confirmed that this body fake produces sound waves intense enough to trigger the fish's C-start response. Because these sound waves come from the side opposite the snake's head, this reflex action drives the fish to turn and swim directly toward the snake's mouth.
"Once the C-start begins, the fish can't turn back," Catania says. "The snake has found a way to use the fish's escape reflex to its advantage."
As he studied the snake's actions even closer, he made an even more remarkable discovery. When it strikes, the snake doesn't aim for the fish's initial position and then adjust its direction as the fish moves – the way most predators do. Instead it heads directly for the location where it expects the fish's head to be.
"The best evidence for this is the cases when the snake misses," says Catania. "Not all the targeted fish react with a C-start and the snake almost always misses those that don't react reflexively."
Catania's next step will be to determine whether this predictive capability is hard-wired or learned. To do so, he hopes to obtain some baby snakes that have just hatched and videotape their first efforts to catch prey.
The research was supported by a grant from the National Science Foundation.


Vanderbilt University. "Water Snake Startles Fish So They Flee Into Its Jaws." ScienceDaily 18 June 2009. 23 June 2009 .

20090619

Illegal Trade In Vietnam's Marine Turtles Continues Despite National Ban

Marine turtles are vanishing from Viet Nam’s waters and illegal trade is largely to blame says a new study by TRAFFIC, the wildlife trade monitoring network.


An assessment of the marine turtle trade in Viet Nam, launched to mark World Turtle Day found that large marine turtles are now virtually absent from Viet Nam’s waters except for Green Turtles around the Con Dao Islands National Park.

A government-owned souvenir shop found selling illegal turtle products was a potent symbol of how a national ban on turtle products enacted in 2002 has been undermined by a lack of enforcement.

Traders in all Viet Nam’s coastal localities reported that catches of local marine turtles, especially Hawksbill Turtles, were becoming rare, and even the few caught were smaller than in previous years.

“Without effective enforcement of the laws, the future for marine turtles in Vietnamese waters looks very bleak.” says Tom Osborn, Acting Director of TRAFFIC’s Greater Mekong Programme.

A 2002 TRAFFIC study found that trade in marine turtles had extended into a large-scale wholesale export market and a Ministry of Fisheries report estimated the combined take across the entire Vietnamese coastline at 4,000 marine turtles annually. (read more at science daily)

World Wildlife Fund. "Illegal Trade In Vietnam's Marine Turtles Continues Despite National Ban." ScienceDaily 16 June 2009. 18 June 2009 /releases/2009/05/090530173402.htm>.



save the marine turtles (video)


20090618

Responsible Reptile Owners


This leads to problems for both humans and ultimately the reptiles themselves. More often than not, people purchase reptiles for the wrong reasons. They often purchase on impulse or because they think it will make them look cool amongst their friends.

Your decision to purchase any reptile must not be taken lightly. A reptile in captivity depends on its owner completely. Unable to care for itself, it is at the mercy of the caregiver and without the proper care, can lead to health problems and even death.

To neglect responsibility as an owner can mean torture for your newly acquired reptile. If you think a reptile is incapable of emotion, maybe you should refrain from acquiring any pet. Remember, there is still the element of pain and suffering to be considered should it be neglected.

Any living being deserves the right to obtain the best care possible, especially one held in captivity. The environment you provide your reptile must closely resemble the natural area in which they are found in the wild.

If you decide to give your pet away or sell because it was not right for you, please make sure the person receiving the reptile has proper knowledge of what it takes to care for and shelter the animal.

Reptiles make fascinating pets. The experience can be rewarding and educational. The responsibility lies in the hands of the owner. If you want a fulfilling and long lasting experience as a reptile owner, take the time and make the effort to learn about what's involved before you purchase or accept a reptile.

Why do snakes stick out their tongues???

Snakes don't sting or use their forked tongues as weapons. The tongues are perfectly harmless.

A snake sticks out its tongue to collect data for its Jacobson's Organ, an organ strategically located in front of the roof of the snake's mouth that functions as a chemical receptor. Each and every time the snake flicks out its forked tongue, it snares chemical particles in the air, which latch onto, or dissolve in, the moisture of the snake's tongue. Once the snake reels in its tongue, it inserts the tips of the forked tongue into the two awaiting openings of the Jacobson's organ where the particles, especially those of animal body odors, are identified, analyzed, and acted upon.

For the male snake, the tongue is both a sensory organ, and a sensual organ. The tongue plays a vital role in snake courtship and reproduction, as the male snake's jerking body motions and rapidly flicking tongue either charm the female snake, or render her unresponsive. In either instance, by sticking out their tongues, snakes ensure the survival of the species.




20090617

Whats the difference between a Toad and a Frog?


As the legend goes, each frog is just a prince waiting for the kiss of his princess. The toad, on the other hand, has a somewhat less attractive connotation: They are dark, squatty, lumpy-looking creatures that spread warts. Many people actually think frogs and toad are two separate species, and some are convinced that frogs are amphibians and toads are their reptile cousins. Despite a recent surge of interest in frogs and toads, misconceptions still abound.

The word "frog" is a general term. Toad is more specific. All toads are frogs but not all frogs are toads. For example, the Colorado River toad is a frog, and the green tree frog is not a toad. If this is still a little confusing, think of this. Your cuddly kitten may have very little in common with the lion, the King of the African jungle, but they both belong to the Felidae or "cat" family.

Amphibians are divided into three distinct orders: Frogs, salamanders and caecilians.

Toads and Frogs in Terrarium setup (video)
Difference between Toads and Frogs (video)

Reptiles, Cold Blooded?

Are Reptiles Cold Blooded? and why?

well, reptiles are called cold blooded but theyr blood is not actually cold, they just cant heat themselfs up on theyr own.
When reptiles need to warm themself up , they just lay down in the sun until they are heated enough.
When they need to cool down they just stay in the shade.
Reptiles actually need this to survive

Reptiles , are they really Monsters?


Some people might ask us Reptile keepers why we would want to keep these little Monsters, then they would start to ask us why we wont just stay with the usual cute fluffy kind of pet, like a Hamster , a cat or a dog?

Because its my style, everybody has their own likes and dislikes. Like if i like Rock and another guy likes Hip Hop, theres nothing wrong abouthaving different taste .
Then there are people who call them Monsters just because they heard bad news about it, and think the same thing will happen to every reptile keeper. So why would we keep "Monsters" even know they can kills us. ??


Well first of all i wouldnt call them Monsters, and if, they would be the cutest Monsters i know. A reptile can look scary to some people, i understand they do look tough and agressive, but are actually interesting to watch and take care of and there are alot of reptiles that are friendly and not dangerous or anything. For example the Bearded Dragon Lizard in my experience always enjoy having theyr owner around, always enjoy a sit on your nap, they usually dont bite and are not so hard to keep, just make sure to get UVB Lights or they might and most probably will become handicaped or even Die!! Another one is the Leopard Gecko, they are pretty beautiful in colours, can cost just as much as bearded Dragons or even more depending on what morph and how the colours are. Leopard Geckos also make a great pet for a beginner reptile keeper, they live for many years, and if you tread them right they will never bite you. A last example is the Blue tongued skink, easy to keep, will eat anything, and they normally dont bite at all.
So if someone is scared of the danger or from getting a litle bite on your finger, just try keeping one of the reptiles in my example.

Well many reptiles can be dangerous and agressive, but only depending on which kind of reptiles and what instincts they got. If its a Huge Flesh eating Reptile, it could see you as prey or as an intruder depending on how the keeper handles them. Someone with experience can tame reptiles like Snakes and Crocodiles, but it'd still be a lil risky depending on the size . But even the Tamest Snake or other killer-reptile could freak out and be on the loose when suddenly showned to others, its theyr instinct , suddenly being surrounded by a bunch of people they dont know they might sometimes behave weird or even strike.
Some reptiles like the Iguana have instinct to protect them from predators, so if not tamed they can be agressive and defensive when grown up, they make nasty bites and they can hit you very hard with theyr tail. But a well tamed iguana can be a very friendly pet, always peacefully lying around and sometimes follow theyr owners around a little. During Mating season, a green iguana
will turn Orange in colour, during this season the Iguana should be left alone alot, cause during mating season iguanas are very agressive and it might bite the owner even a really tame iguana could bite his owner during the season.

Still think they are monsters? i just think it depends on the owner!
A good pet keeper, will get a good reptile!
A Bad pet keeper, wil get a bad reptile!
kinda like Karma!



Post by: reptiles101.blogspot.com

20090616

Reptile News

Snakes Use Friction And Redistribution Of Their Weight To Slither On Flat Terrain



Snakes use both friction generated by their scales and redistribution of their weight to slither along flat surfaces, researchers at New York University and the Georgia Institute of Technology have found. Their findings, which appear in the latest issue of the Proceedings of the National Academy of Sciences, run counter to previous studies that have shown snakes move by pushing laterally against rocks and branches.

"We found that snakes' belly scales are oriented so that snakes resist sliding toward their tails and flanks," said the paper's lead author, David Hu, a former post-doctoral researcher at NYU's Courant Institute of Mathematical Sciences and now an assistant professor of mechanical engineering at Georgia Tech's George W. Woodruff School of Mechanical Engineering. "These scales give the snakes a preferred direction of motion, which makes snake movement a lot like that of wheels, cross-country skis, or ice skates. In all these examples, sliding forward takes less work than does sliding sideways."

The study's other co-authors were Jasmine Nirody and Terri Scott, both undergraduate researchers at NYU, Michael Shelley, a professor of mathematics and neural science and the Lilian and George Lyttle Professor of Applied Mathematics at Courant.

The study centered on the frictional anisotropy—or resistance to sliding in certain directions—of a snake's belly scales. While previous investigators had suggested that the frictional anisotropy of these scales might play a role in locomotion over flat surfaces, the details of this process had not been understood.

To explore this matter, the researchers first developed a theoretical model of a snake's movement. The model determined the speed of a snake's center of mass as a function of the speed and size of its body waves, taking into account the laws of friction and the scales' frictional anisotropy. The model suggested that a snake's motion arises by the interaction of surface friction and its internal body forces.

To confirm movement as predicted by the model, the researchers then measured the sliding resistance of snake scales and monitored the movement of snakes through a series of experiments on flat and inclined surfaces. They employed video and time-lapse photography to gauge their movements.

The results showed a close relationship between what the model predicted and the snakes' actual movements. The theoretical predictions of the model were generally consistent with the snakes' actual body speeds on both flat and inclined surfaces.


New York University. "Snakes Use Friction And Redistribution Of Their Weight To Slither On Flat Terrain." ScienceDaily 9 June 2009. 16 June 2009 /releases/2009/06/090608182435.htm>.



20090615

Did you know ?

Komodo Dragons Even More Deadly Than Thought: Combined Tooth-venom Arsenal Key To Hunting Strategy Source: Sciencedaily




A new study has shown that the effectiveness of the Komodo Dragon bite is a combination of highly specialized serrated teeth and venom. The authors also dismiss the widely accepted theory that prey die from septicemia caused by toxic bacteria living in the dragon's mouth


Using sophisticated medical imaging techniques, an international team led by Dr Bryan Fry from the University of Melbourne have revealed that the Komodo Dragon (Varanus komodoensis) has the most complex venom glands yet described for any reptile, and that its close extinct relative Megalania was the largest venomous animal to have lived.

The work will be published in the next issue of the journal Proceedings of the National Academy of Sciences.

"These large carnivorous reptiles are known to bite prey and release them, leaving the prey to bleed to death from the horrific wounds inflicted. We have now shown that it is the combined arsenal of the Komodo Dragon's tooth and venom that account for their hunting prowess," said Dr Fry from the Department of Biochemistry and Molecular Biology, Bio21 Institute at the University of Melbourne.

"The combination of this specialized bite and venom seem to minimise the Dragon's contact with its prey and this allows it to take large animals."

Komodo Dragons are native to the islands of Indonesia, with adult males weighing over 100kg, and exceeding 3 metres in length. They have around 60 highly serrated teeth which are frequently replaced during their lifetime.



The researchers conducted a comprehensive study of the Komodo Dragon bite, employing computer techniques to analyze stress in a dragon's jaws and compare them to those of a crocodile. The dragons were found to have much weaker bites than crocodiles, but magnetic resonance imaging (MRI) of a preserved dragon head revealed complex venom glands and specialised serrated teeth which create deep lacerations for entry of the venom.

"We believe that the dragon is able to weaken and immobilize their prey with a venomous bite that increases the damage done by their long serrated teeth," said Dr Fry.

The researchers located and surgically excised the glands from a terminally ill dragon at the Singapore Zoo, and used mass spectrometry to obtain a profile of the venom molecules. The team also analysed which toxin genes were expressed in the dragon's venom gland.

The effects of venom were also tested by the team and found to be similar to that of the gila monster and many snakes which cause a severe loss in blood pressure by widening blood vessels, thereby inducing shock in a victim. These findings may explain the observations by Dr Fry and others that Komodo Dragon prey become still and unusually quiet soon after being bitten. Bitten prey also bleed profusely, consistent with the team's discovery that the venom was also rich in toxins that prolong bleeding.

The researchers also examined fossils of the Dragon's giant extinct relative Megalania (Varanus priscus). From similarities in skull anatomy they determined that this seven metre lizard would have used a similar venom and bite system, making it the largest venomous animal to have ever lived.



Komodo Dragon (video)
Komodo Dragons with Hatchlings (video)

Reptile News

Sea reptile is biggest on record
source: , BBC News


A fossilised "sea monster" unearthed on an Arctic island is the largest reptile of its type known to science, Norwegian scientists have announced.

The 150 million-year-old specimen was found on Spitspergen, in the Arctic island chain of Svalbard, in 2006.

The Jurassic-era leviathan is one of 40 sea reptiles from a fossil "treasure trove" uncovered on the island.

Nicknamed "The Monster", the immense creature would have measured 15m (50ft) from nose to tail.


And during the last field expedition, scientists discovered the remains of another so-called pliosaur which is thought to belong to the same species as The Monster - and may have been just as colossal.

The expedition's director Dr Jorn Hurum, from the University of Oslo Natural History Museum, said the Svalbard specimen is 20% larger than the previous biggest pliosaur - another massive pliosaur from Australia called Kronosaurus.

"We have carried out a search of the literature, so we now know that we have the biggest [pliosaur]. It's not just arm-waving anymore," Dr Hurum told the BBC News website.

"The flipper is 3m long with very few parts missing. On Monday, we assembled all the bones in our basement and we amazed ourselves - we had never seen it together before."


Pliosaurs were a short-necked form of plesiosaur, a group of extinct reptiles that lived in the world's oceans during the age of the dinosaurs.

A pliosaur's body was tear drop-shaped with two sets of powerful flippers which it used to propel itself through the water.

"These animals were awesomely powerful predators," said plesiosaur palaeontologist Richard Forrest.


"If you compare the skull of a large pliosaur to a crocodile, it is very clear it is much better built for biting... by comparison with a crocodile, you have something like three or four times the cross-sectional space for muscles. So you have much bigger, more powerful muscles and huge, robust jaws.

"A large pliosaur was big enough to pick up a small car in its jaws and bite it in half."

"There are a few isolated bones of huge pliosaurs already known but this is the first find of a significant portion of a whole skeleton of such a giant," said Angela Milner, associate keeper of palaeontology at London's Natural History Museum

"It will undoubtedly add much to our knowledge of these top marine predators. Pliosaurs were reptiles and they were almost certainly not warm-blooded so this discovery is also a good demonstration of plate tectonics and ancient climates.


"One hundred and fifty million years ago, Svalbard was not so near the North Pole, there was no ice cap and the climate was much warmer than it is today."

The Monster was excavated in August 2007 and taken to the Natural History Museum in Oslo. Team members had to remove hundreds of tonnes of rock by hand in high winds, fog, rain, freezing temperatures and with the constant threat of attack by polar bears.

They recovered the animal's snout, some teeth, much of the neck and back, the shoulder girdle and a nearly complete flipper.

Unfortunately, there was a small river running through where the head lay, so much of the skull had been washed away.

A preliminary analysis of the bones suggests this beast belongs to a previously unknown species.


Unprecedented haul

The researchers plan to return to Svalbard later this year to excavate the new pliosaur.

A few skull pieces, broken teeth and vertebrae from this second large specimen are already exposed and plenty more may be waiting to be excavated.

"It's a large one, and has the same bone structure as the previous one we found," said Espen Knutsen, from Oslo's Natural History Museum, who is studying the fossils.

Dr Hurum and his colleagues have now identified a total of 40 marine reptiles from Svalbard. The haul includes many long-necked plesiosaurs and ichthyosaurs in addition to the two pliosaurs.

Long-necked plesiosaurs are said to fit descriptions of Scotland's mythical Loch Ness monster. Ichthyosaurs bore a passing resemblance to modern dolphins, but they used an upright tail fin to propel themselves through the water.

Richard Forrest commented: "Here in Svalbard you have 40 specimens just lying around, which is like nothing we know.

"Even in classic fossil exposures such as you have in Dorset [in England], there are cliffs eroding over many years and every so often something pops up. But we haven't had 40 plesiosaurs from Dorset in 200 years."

The fossils were found in a fine-grained sedimentary rock called black shale. When the animals died, they sank to the bottom of a cold, shallow Jurassic sea and were covered over by mud. The oxygen-free, alkaline chemistry of the mud may explain the fossils' remarkable preservation, said Dr Hurum.

The discovery of another large pliosaur was announced in 2002. Known as the "Monster of Aramberri" after the site in north-eastern Mexico where it was dug up, the creature could be just as big as the Svalbard specimen, according to the team that found it.

But palaeontologists told the BBC a much more detailed analysis of these fossils was required before a true picture of its size could be obtained......

pliosaur Fossil (video)



20090614

Welcome to Reptiles101


Here on Reptiles101 , you can find information on different reptiles as well as Mammals and Fishes, along with videos and caresheets for every animal posted. The information was collected from the internet and as well as some of the pics, our videos and caresheets are all links to external websites.



please enjoy! :)

20090612

Reptiles














Reptiles, or members of the class Reptilia, are air-breathing, cold-blooded amniotes that have skin covered in scales or scutes as opposed to hair or feathers. They are tetrapods (having or having descended from vertebrates with four limbs) and lay amniote eggs, whose embryos are surrounded by the amnion membrane. Modern reptiles inhabit every continent with the exception of Antarctica, and four living orders are currently recognized:

The majority of reptile species are oviparous (egg-laying) although certain species of squamates are capable of giving live birth. This is achieved, either through ovoviviparity (egg retention), or viviparity (offspring born without use of calcified eggs). Many of the viviparous species feed their fetuses through various forms of placenta analogous to those of mammals with some providing initial care for their hatchlings. Extant reptiles range in size from a tiny gecko, Sphaerodactylus ariasae, that grows to only 1.6 cm (0.6 in), to the saltwater crocodile that may reach 6 m in length and weigh over 1,000 kg. The science dealing with reptiles is called herpetology.