"Dinosaur Mummy" Has Skin Like Birds' and Crocodiles'

Friday, August 6, 2010



The skin of a 66-million-year-old duckbilled dinosaur pokes out of the soil at the Hell Creek formation in North Dakota in 2007. Advanced imaging and chemical techniques later revealed that the dinosaur had skin like that of birds or crocodiles, a July 2009 study says. [Photograph by Tyler Lyson, copyright NGS]

There's no evidence of goosebumps just yet, but a remarkably preserved dinosaur reveals that the prehistoric reptile had skin like that of birds and crocodiles, a new study says.

"This is the closest you're going to get to patting the animal," said excavation leader Phillip Manning, a paleontologist at Britain's University of Manchester.

Advanced imaging and chemical techniques revealed that the 66-million-year-old "mummified" duckbilled dinosaur had two layers of skin, as do modern vertebrates, including humans.

Such a discovery was possible because the dinosaur's skin fossilized before bacteria had a chance to eat up the tissue.

It is "absolutely amazing to be able to identify organic molecules from soft tissue that belonged to a beast that died over 66 million years ago," said Manning, whose work with the fossil was partially funded by the National Geographic Expeditions Council. (The National Geographic Society owns National Geographic News.)

"It's certainly in my top ten all-time fossils."

World-Class Dino

Tyler Lyson, a teenager at the time, discovered Dakota, as the fossil was later dubbed, in 1999 on his family's North Dakota property. (See photos of the "mummified" dinosaur.)

No one knows how the hippo-size animal died.

But scientists do know that the body was probably buried rapidly. The resulting low-oxygen environment and the apparent lack of disturbance to the site made Dakota a "world-class dinosaur" fossil, according to the new study, published July 1 in the journal Proceedings of the Royal Society B.

Building Blocks

With electron microscopes and x-rays, Manning discovered that Dakota had cell-like structures indicative of two-ply skin: a thin surface layer plus an underlying layer of dense connective tissues.

That's just like skin of modern birds and reptiles, which scientists believe are closely related to duckbilled dinosaurs.

Protein-recovery techniques used on the skin and a claw detected amino acids, the building blocks of proteins. Proteins themselves, complex molecules that degrade easily over time, were not found, however.

(Related: "Oldest Dinosaur Protein Found—Blood Vessels, More.")

But Manning did identify molecules that would have broken down proteins in Dakota's body.

That's like finding fragments of a broken vase instead of the intact vase, explained Thomas R. Holtz Jr., a vertebrate paleontologist at the University of Maryland.

"What's really nice" about the new research is this protein-recovery strategy. It's the first time the skin of such a big plant-eating dinosaur has been analyzed so deeply, said Holtz, who was not involved in the research.

That Dakota's skin resembles modern vertebrate skin is not surprising but nonetheless "comforting," Holtz added.

Beyond Bones

Understanding the exact environments that froze Dakota in time may help paleontologists better target future fossil hunts, lead study author Manning said.

"Who knows? The elusive dinosaur mummies of the fossil record might be more common," added Manning, also the author of the new book Grave Secrets of Dinosaurs: Soft Tissues and Hard Science.

There's even a chance that scientists could find a Tyrannosaurus rex—a major predator of duckbilled dinosaurs—in the same area, the University of Maryland's Holtz added.

The new discovery shows "that there is a lot more to paleontology than just looking at interesting skeletons," Holtz said.

If you're limited to bones, "you lose a lot of what you can find out about ancient creatures."

The Cuélebre

Thursday, July 8, 2010




The Cuélebre is the Spanish variety of dragon, specifically, from the regions of Asturias and Cantabria. Serpentine, winged and with colorful scales, the Cuélebre are immortal and obsessed with pretty, shiny objects. They hoard treasure and fairy-like blonde nymphs. The legend relating how the Cuélebre originated goes like this:

A beautiful but vain young woman disbelieves her family’s warnings against combing her hair as she admires her reflection in a pool of water. Unfortunately, a powerful water nymph living in the pool observes as she neglects her tasks in favor of this activity. Once the girl ruffles the surface of the water, as one of her hairs drops in, the nymph takes the opportunity to teach her a lesson. The nymph curses the girl; she grows huge, her hair is replaced by crests and her skin by scales, and she sprouts wings. In true fairytale fashion the maiden can only be returned to her original state by meeting a knight “who is so brave that he is not afraid of you and has a heart so pure that he finds you beautiful.” The Cuélebre hides in a cave by the sea and waits…

The Zmaj




The Zmaj comes from the Slavic country Slovenia and has much in common with other Slavic dragons – three heads that may grow back if decapitated, green scaly skin, and fire-spitting abilities. Its name, Zmaj, is a masculine version of the word for snake, which is usually feminine. The Zmaj can also be called by a much older name of murky origin, Pozoj. Slovenic dragons are generally similar in disposition to other European dragons and are featured in Christian stories of St. George as well as pre-Christian stories in which they are tricked into eating sulphur-containing gifts and thus defeated. The dragon of Ljubljana is a notable exception – it once protected the capital city and is depicted on its coat of arms.

The Níðhöggr




The Níðhöggr is a one-of-a-kind dragon that exists within Norse legend. It lives below a giant ash tree, the Yggdrasil or World Tree, which binds the nine worlds of Norse mythology together. Níðhöggr is usually translated as meaning Malice Striker (sometimes as Striker in the Dark) and lives up to his name as he viciously gnaws at the root of the World Tree that keeps him trapped above Hvergelmir, a seething cauldron, in Hel (the Nordic Hel is roughly equivalent to the English Hell). If Níðhöggr chews his way through the root of the World Tree it heralds the arrival of Ragnarök and the subsequent destruction of the world. The serpent-like Níðhöggr is described in the poem Völuspá as one who ‘sucks on the corpses of the dead.’

The Korean dragon




The Korean dragons are derived from the Chinese ones, are given very similar cultural status, and look much the same. Where the Chinese dragon has five toes and the Japanese three, the Korean has four – the dragons are said to have lost toes as they moved south. The Korean dragon has a long beard and no wings. Like other Asian dragons, the Korean variety was supposed to be peaceful and kind creatures that were strongly associated with water and agriculture. They are mostly said to live in watery places such as rivers, ponds, lakes, and oceans. Korean dragons differ from others in that history records them as being sentient and capable of understanding concepts like devotion, gratitude, and kindness.

Before a Korean dragon is a dragon it can be a creature called an imoogi. Depending on which account you read, imoogi are immature dragons that must live for 1000 years before becoming a dragon or, alternatively, cursed, hornless beings that are unable to become fully-fledged dragons.

The Yilbegän




The Yilbegän is more closely related to the Turkish and Slavic dragons of Europe than those of Eastern Asia; consequently it is portrayed as man-eating and ogre-like rather than gentle and kind, despite its Asian home. This reptilian dragon is depicted in the mythology of two ethnic groups living in Siberia – the Turkic peoples and the Siberian Tatars – as a polycephalous monster. In some legends the Yilbegän takes the form of a winged dragon or serpentine creature but in others he is a leviathan who rides an ox with 99 horns.

The Bakunawa



The Bakunawa is actually a deity that was represented as a serpentine dragon, according to Filipino mythology. He has two sets of wings, whiskers, a red tongue, and a mouth ‘the size of a lake.’ The Filipinos once thought that the Bakunawa lived in the sea at a time when the world had seven moons and that the dragons, being fascinated by their light, would rise out of the sky into the sky and consume the moons. Thus, the dragons were the cause of eclipses. To prevent the world from becoming dark the people would run out of their homes, taking their pots and pans, to make the most noise they could in order to scare the Bakunawa so they would stop eating the moons and give them the moonlight back. Interestingly, the name of the dragons, Bakunawa, can be translated as ‘moon eater’ or ‘man eater,’ the latter being atypical of Asian dragons.

The Naga




Naga is a wingless type of Indian dragon found in Hindu and Buddhist culture. Although the word Naga is often ambiguous the Mahabharata (an epic Sanskrit poem that is an important Hindu text) tells us that the Naga possess the traits of both snakes and humans. In Hinduism, the Naga are portrayed in similar fashion to the Chinese family of dragons, being natural spirits that are associated with water sources but can also be European-style guardians of immense treasure. Naga are also found in Buddhist tradition – as polycephalous (multi-headed) serpents that can magically transforms themselves into human shape. Like the Naga of Hindu legend, the Buddhist version prefers watery dwellings. They particularly like to eat frogs and drink milk.

Monster Moby Dick chomped on whales

Thursday, July 1, 2010


An artist's impression of the giant whale, which researchers say gripped large prey with its interlocking teeth. (MNHN/Nature)

Scientists have reported the discovery of an extinct predator sperm whale with jaws and teeth so huge it probably hunted other whales not less than half its size.

Named in honour of Herman Melville, the author of Moby Dick, Leviathan melvillei lived some 12 to 13 million years ago and was a 14-metre behemoth sharing top billing in the ocean food chain with giant sharks.

The prehistoric sperm whale gripped large prey with its interlocking teeth, inflicting deep wounds and tearing large pieces from the body of its victims, the researchers said.

Palaeontologists have long suspected that some such air-breathing monster once roamed ancient seas, but until now only a few gigantic teeth had turned up in the fossil record.

The new find in Peru's Pisco basin, reported in the British journal Nature, leaves no doubt that Leviathan existed, terrorising major marine fauna of the Miocene epoch.

Olivier Lambert of Belgium's Royal Institute of Natural Sciences and colleagues unearthed the animal's skull and jaw, lined top and bottom with teeth each as long and thick as a man's forearm.

"It must have eaten very large animals, and the most common prey at the site are baleen whales about seven or eight metres long. It was a super-predator," Mr Lambert said.

Present-day sperm whales are also formidable, deep-diving hunters.

But because their teeth are relatively small and restricted to the lower jaw, they use suction to ingest their prey, mainly squid.

Leviathan more closely resembles modern orcas, or killer whales - except it was three or four times as big.

Its tusk-like teeth must have been very robust and resistant in order to hang on to a mega-prey trying desperately to escape, Mr Lambert said.

"Baleen whales have hugely powerful tails, and when they struggle the tension would be enormous for the predator in whose jaws it has been caught," he explained.

Amphicoelias fragillimus

Monday, June 21, 2010


This elusive fossil was discovered by the famed paleontologist Edward Drinker Cope, the same man who competed with Othniel Charles Marsh in the infamous “Bone Wars”. Cope discovered many prehistoric fossils, but this one is, by far, the oddest. The only fossil that exists of it was a single vertebra fragment. It was 5 feet high, estimated to be 8.8 feet high if the entire fossil was intact. Compare that to your vertebrae. Yeah. Estimates vary, but they range from 131 to 196 feet in length, making it, by far, the longest creature ever, competing with the blue whale for being the heaviest creature ever (along with another, very elusive sauropd, Bruhathkayosaurus). But, as luck would have it, the fossil just disappeared. It vanished without a trace. Was it a hoax? A misconception? Or was it really the largest animal to ever walk the earth? Sadly, we will probably never know.

Deinocheirus


The only fossil of this dinosaur is a pair of arms. These arms look like they belonged to an ornithomimid but they were 8 feet long. This means that either Deinocheirus towered over the rest of the ornithomimids (and most theropods, since, regarding proportions, it would have been 40 feet long!) or it simply had very long arms for its body. The use of its arms is debated: some say it used them to tear apart large dinosaurs, others say that the claws were too blunt, so they were used as defensive weapons. Some have even said that Deinocheirus used its huge arms to climb trees, although this hypothesis is widely disregarded. Once again, the lack of a body leaves many questions unanswered.

Helicoprion


This bizarre fossil was originally thought to be an ammonite, as the fossil looked like a spiraling, circular shell. However, after some examination, it was revealed that is wasn’t a shell, but a spiraling set of shark teeth, a “tooth whirl”. Unfortunately, due to a lack of a body (cartilage does not fossilize as well as bone), so a guessing game began. It was guessed to be on the shark’s dorsal fin, tail, or even its snout. Thankfully, a skull of a related shark, Ornithoprion, was found to have a tooth-whirl on its lower jaw. The tooth whirl likely contained all of the shark’s teeth that it would use in its life: its older teeth would be moved away to make room for its newer, better teeth. This does not solve the problem yet, however! The tooth whirl was then placed on the tip of the lower jaw but it turns out that that would actually slow down the shark! Perhaps the most accurate representation is one where the tooth whirl existed deep in its mouth instead.

Stethacanthus


Sharks have lasted for over 400 million years. Although they have remained relatively unchanged throughout the fossil record, there are definitely some odd balls. This particular shark had an anvil-shaped dorsal fin, with small spikes on it, as well as having a very bizarre growth on its head. The fin could have been used for courtship or for defense.

Dunkleosteus


One of the scariest creatures ever to live in the ocean, this Devonian fish could grow up to 33 feet long, had an armored face, and likely had one of the strongest bites in history! It used a beak-like mouth instead of teeth to devourer its prey. It was one of the largest of the Placoderms, a group of armored fish that are now extinct.

Pterodaustro



This pterosaur had an unusual set of teeth, similar to the baleen of some whales. It almost certainly used these teeth to eat small, aquatic organisms, similar to the way a flamingo eats brine shrimp. Since flamingos get their pinkish hue from their diet, Pterodaustro might have been pinkish too.

Nyctosaurus


This genus of pterosaurs is the only one that does not have claws on its wings. Otherwise, most species looked quite average, similar to the famous Pterodon… until a new, currently unnamed species was discovered in 2003. The species had a huge, antler-like crest, larger than any other pterosaurs crest. Some speculated that there was a flap of tissue in between these antlers, like some other pterosaurs, which could have been used like a sail to enhance its flight. However, research shows that a crest that large would actually impair its flight, so it likely just had an odd set of antlers.

Sharovipteryx


Another gliding reptile, this Triassic critter glided similarly to Microraptor. However, Sharovipteryx had two “wings” on its hind legs and two small “wings” on its front legs. It might have used its wings while jumping from place to place on the ground. Some scientists think it was related to Pterosaurs, but its reversal of wings to its legs instead of arms questions this.

Tanystropheus


When I describe a long necked reptile, most people think of sauropods or even plesiosaurs. This Triassic reptile was neither of these. This reptile was 20 feet long, yet had a 10 foot long neck! Evidence indicates that this was a fish-eating reptile, since fossils of it have been found in mainly partially aquatic fossil sites and fish scales and Cephalopod tentacles have been found in their stomachs. They might have stayed on the beach, using their long necks to help them devour fish from the sea. It is also thought to have been at least semi-aquatic.

Longisquama


Living during the Triassic, Longisquama was a small, lizard like creature that appears to have had a series of long feathers on its back. This implies that birds might have not evolved from theropods, but lizard-like reptiles instead. Of course, things are not always what they seem. Some scientists think they are just specially modified scales. Others think that the fossil’s form is an optical illusion: that the feathers are just fern fronds. Due to the large amount of feathered dinosaur fossils, it seems that these two possibilities are more accurate.

Microraptor


Yet another bird-like dinosaur, this dinosaur had four wings (and a feathered tail), although it could not fly. Instead, it likely glided from place to place, kind of like a flying squirrel. It is likely that this creature is one of the most recent common ancestors between birds and dinosaurs, its gliding ability eventually evolving into flight. Unfortunately for the genus, one fossil was used in a forgery, along with a fossil of a primitive bird, Yanornis, to create a fake fossil that was said to be the ultimate missing link between birds and dinosaurs: Archeoraptor. Although it could have been caught before the public noticed, it was published in National Geographic before it could be peer reviewed. When it was exposed for the fraud it was quite embarrassing to the scientific community. There are two species of Microraptor.

Epidendrosaurus


Another bird-like dinosaur, this one belonged in the same family as Epidexipteryx. It is currently the earliest dinosaur known to have adapted for life in the trees, an important moment in the evolution of birds. More bizarrely, this dinosaur had an oddly long third finger, twice the length of the other ones. They may have been used to dig for insects.

Epidexipteryx



This bird-like dinosaur reveals an interesting part about the evolutionary history of birds. This member of the Scansoriopterygidae (“climbing wings”) had no flight feathers, but it did have four long tail feathers. These feathers were likely used in displays. Due to its age (It lived in China around 152 to 168 million years ago), it provides evidence that feathers evolved several million years before flight did (not surprisingly). It was also one of the smallest dinosaurs, reaching just 10 inches in height as an adult (not counting its feathers). That’s the size of a pigeon.

Therizinosauridaes


This family of strange, mysterious theropods was notable for their long necks and their large claws. However, unlike most other theropods, they were herbivores (or at least primarily). Some of them may have had feathers. The genus that the family is named after, Therizinosaurus, is actually only known from a few fossils, but its claws were quite large, likely reaching a meter in length.

Deinotherium


This genus of elephant-like creatures was not only huge, but they also had a pair of chin tusks. These odd tusks might have been used to dig up the soil to gain access to roots and vegetables. They also had a relatively short trunk compared to other Proboscideans. They ranged from 12-15 feet high, making them one of the largest mammals to ever walk on the earth.

Newly uncovered dinosaur had 'longest horns of all'

Saturday, May 29, 2010


The 72-million-year-old herbivore has two large horns above its eyes measuring up to 1.22 metres long. (The University of Utah: Lukas Panzarin)

US palaeontologists say they have unearthed a new species of dinosaurs standing some 1.8 metres tall and weighing up to 4.5 tonnes, with the longest horns of all.

The 72-million-year-old herbivore, now named coahuilaceratops magnacuerna, has two large horns above its eyes measuring up to 1.22 metres long - the largest of any other species, providing fresh insight into the history of western North America.

Scientists uncovered fossils belonging to both an adult and a juvenile of the rhino-sized tubby creature at the Cerro del Pueblo Formation in Coahuila, Mexico.

It measured about 6.7 metres long as an adult.

"We know very little about the dinosaurs of Mexico, and this find increases immeasurably our knowledge of the dinosaurs living in Mexico during the Late Cretaceous," said the study's lead author Mark Loewen, a palaeontologist with the Utah Museum of Natural History.

His team is to release a book next week detailing the find, which took place during expeditions in 2002 and 2003 in the Coahuila desert. The study was funded by the National Geographic Society and the University of Utah.

When dinosaurs lived in this corner of Mexico, it was a lush, humid estuary where ocean water mixed with fresh water from rivers, similar to the US Gulf Coast today.

Many dinosaur bones unearthed in the area are covered with fossilised snails and marine clams, indicating that the creatures lived close to the seashore.

The rocks in which the palaeontologists found coahuilaceratops contained large fossil deposits of jumbled duck-bill dinosaur skeletons.

According to the scientists, the dinosaurs likely died en masse in the area due to storms similar to present-day hurricanes.

During most of the Late Cretaceous Period, 97 to 65 million years ago, high global sea levels led to flooding of the central, low-lying portion of North America.

Ultimately, a warm, shallow sea emerged, stretching from the Gulf of Mexico to the Arctic Ocean and splitting the continent into eastern and western landmasses.

"We are confident that Mexican dinosaurs will be a critical element in unravelling the ancient mystery of this island continent," said Scott Sampson of the Utah Museum of Natural History.

- AFP

Paleothermometer to take dinosaurs' temperatures

Wednesday, May 26, 2010


New technology should shed light on whether dinosaurs were cold-blooded or warm-blooded (www.flickr.com: Diegosaurius Rex)

New technology developed by US researchers should shed light on whether dinosaurs were cold-blooded or warm-blooded animals.
California Institute of Technology (Caltech) researchers have unveiled what they say is the first method for direct measurement of the body temperatures of large extinct vertebrates using analyses of isotopes in animals' bones, teeth, and eggshells.
The findings were published in the early edition of the Proceedings of the National Academy of Sciences (PNAS).
"This is not quite like going back in time and sticking a thermometer up a creature's back end. But it's close," said researcher John Eiler, a geochemistry professor at Caltech.
To study changes in temperature regulation in extinct animals requires knowing what their body temperatures once were. The team's method looks at the concentrations of two rare isotopes - carbon-13 and oxygen-18.
"Heavy isotopes like to bond, or clump together, and this clumping effect is dependent on temperature," said lead author Robert Eagle, a Caltech postdoctoral scholar.
"At very hot temperatures, you get a more random distribution of these isotopes, less clumping. At low temperatures, you find more clumping."
After proving their method on living elephants and sharks, the team turned to the extinct.
They examined a 12-million-year-old fossil from a relative of the rhinoceros, as well as from a cold-blooded member of the alligator family tree.
"We found we could measure the expected body temperature of the rhino-like mammal, and could see a temperature difference between that and the alligator relative, of about six degrees centigrade," Dr Eagle explained.
"When we look at tooth enamel, for instance, what we get is a record of the head temperature of the animal when the tooth grew," Professor Eiler said.
But "if you want to know what his big-toe temperature was two years later, too bad."
With an accurate paleothermometer working, the researchers want to look further back at body temperatures of less-known vertebrates.
"Before mammals and birds, we have no good idea what physiology these ancient creatures had," Dr Eagle said.
Now it is the dinosaurs' turn to get a closer temperature look.
"We're looking at eggshells and teeth to see whether the most conspicuous dinosaur species were warm- or cold-blooded," Professor Eiler said.
-AFP

Sauropod dinosaurs

Sunday, April 25, 2010



Sauropod dinosaurs are familiar to most everyone. It is the group commonly called brontosaurs, and with such creatures as Brachiosaurus, it includes the largest animals that have ever lived on land. Like most all really huge animals inhabiting the landscape at a given time, the sauropods were herbivorous. They ate plants and only plants. They were big, and they were not necessarily friendly, but they were not necessarily ferocious either.

Larger size often conveys certain advantages. It stacks the deck in favor of bigger individuals in the competition with other members of the same species. Larger individuals can obtain the best space, resources, mates, and they may be better able to defend themselves. Thus increasing size through a biological lineage is a common trend in evolutionary history. This trend to evolve larger descendant species from smaller ancestors is known as Cope's rule.

The best-known sauropods are of gigantic proportions. The largest of the sauropods might have weighed as much as fifty, sixty, maybe even eighty tons. Most were probably in the twenty-to-thirty-ton range, still highly respect- able. Early in sauropod evolution there had to be even smaller ones, presumably, if the evolution of larger species followed Cope's rule. The dinosaurian ancestors of the known sauropods, the hypothetical first true sauropod, if we had a complete fossil record, would have been much smaller than the giants. Some or all of the evolutionary lineages leading to different species of sauropod giants became larger with geologic time until they went extinct.

The only animals that have ever surpassed the sauropod size record are the blue whales. They, of course, have an advantage because they live in seawater, which is a dense fluid that buoys up their massive bodies. If stranded on land, whales, even the smaller ones, will suffocate from being crushed under their own weight. The structure of their bodies cannot keep their weight off of their lungs.

The problems of supporting weight for any animal are much greater on land than those encountered in an aqueous medium, such as whales inhabit, but the problems are particularly difficult for those land-dwelling animals of exceptionally large size. Being such large animals as most of the sauropods are, shear bulk places a tremendous strain on them. One reason contributing to why sauropod dinosaurs were able to evolve into such large and heavy forms is that at some time in their early history they began to walk on four legs rather than two. Strange as it seems, dinosaurs started out walking, running, and standing on two legs. Bipedal locomotion is primitive for the group as a whole (and for many of the more familiar dinosaurs, such as Tyrannosaurus rex). In sauropods, dinosaurs specialized in obtaining large size, four legs provide a more stable foundation for body mass and double the number of pillars supporting the animal.

There are big ancillary problems associated with Cope's rule. The mass of an animal's body increases at a greater rate than the simple increase in a linear dimension. That means that an animal twice as long as another of the same shape and physical appearance will weigh more than twice the second animal's weight. Larger animals weigh proportionately, as well as absolutely, more than smaller animals. Therefore, if a sauropod lineage is to become gigantic, it must be able to support a spiraling increase in weight with each moderate increment in size. The strength of the bones must be great enough to hold up all that bulk, but if the bones are made bigger to be stronger, they will reach a point where they increase in weight faster than they increase in strength. There is the dilemma.

The solution is to evolve structural modifications in the shape and construction of bones so that they are both light and strong. Birds do it by having thin-walled, hollow bones. Pterodactyls do it the same way. From a paleontological point of view, such bones are fragile. That is why both these groups of flying reptiles are uncommonly preserved as fossils, and when they are, they are usually crushed.

#

Sauropod heads have a particularly nasty habit so far as field paleontologists are concerned. They are not often found. In life they must have been weakly attached to the end of the neck, because in death the head is quickly separated from the body. I cannot shake the image of a sauropod head rolling off like a soccer ball, but of course it was not like that. The light, thin bones of the head are as lightly built and as thin-walled as the vertebrae are. They are insecurely fastened to each other. As a dead sauropod rotted or was dismembered, the head separated from the neck, and the delicate bones became scattered and destroyed. The problem this makes for paleontologists is that many species of sauropods are known only from bones that come from the neck or farther back in the skeleton, and we have no idea what the head was actually like. Heads are known in only a fraction of the named sauropod species. In fact Apatosaurus, the real name of brontosaurus, suffered for decades with the wrong head until the mistake was caught and corrected.

Sauropod skulls that are known show quite a bit of diversity in their shapes. In all, the bony holes through which the nasal passages go appear excessively large. In life these accommodated, in addition to the air passages, tissue and blood vessels that have been considered speculatively at one time or another to control the temperature of blood flowing to the brain, to resonate the sounds uttered by the beast, or to facilitate a flexible proboscis. The issue is still open.

Some sauropods have long heads, others have heads that are almost incredibly blunt. Elongation of sauropod skulls seems to have evolved in at least two different ways. Brachiosaurus was described as having an absurd, toothy duck's bill. The front of the head is long because the bones that hold the teeth, called maxilla and premaxilla, are exaggerated into the shape of a duck's bill. The nasal bones, which support the nostrils, are looped high up and back, doming the skull. Other sauropods, such as Camarasaurus, have high heads, but the jaws are not drawn nearly so far forward as in Brachiosaurus and the nostrils are not so far back and up. Sauropods such as the familiar Apatosaurus and Diplodocus are different. Their nostrils are back and on the top of their heads, but the nasal bones are not looped and the bony opening in the skull for the nasal passage is much smaller. The skulls in Diplodocus and Apatosaurus are oblong-shaped, somewhat like lozenges. The jaws are long, but taper from the back of the skull to the snout gradually, rather than being drawn out into a duck's bill. And the teeth are restricted to the front part of the upper and lower jaws instead of continuing back along the sides of the mouth. In addition, the front of the jaws is squared off and blunt, rather than curving more gently to meet at the midline.

Jaws and teeth are particularly important when considering how the sauropod giants managed to obtain sufficient nourishment. Besides the variation in jaw shape discussed above, there is also variation among sauropod species in the shape of the teeth. Some sauropods, such as Brachiosaurus and Camarasaurus, have teeth with spoon-shaped crowns. Others, such as Diplodocus, have teeth that are shaped like pencils. They are little round cylinders. Both of these shapes of sauropod teeth, when multiplied by a mouthful of them, are adequate for plucking and nipping sprigs, twigs, fronds, and leaves, but they are not good for chewing them up. In addition, they are not held very strongly in their sockets, and they were replaced in life at frequent intervals by replacement teeth growing in from the roots. After a sauropod dies, the teeth very quickly fall out. Since neither tooth shape is adequate for a good, thorough chewing of the food, the teeth were used primarily to obtain food. The processing of it was done by gizzard stones, called gastroliths, that ground foodstuffs into a mash, after which it was most likely fermented by the action of microbes. The gastroliths are rocks that were selectively swallowed for the purpose. Birds and crocodiles do that now. It is not all that unusual in the world of animal digestion. There can be variation in the shape of teeth within certain species of sauropods. In Brachiosaurus, for instance, the teeth in the front of the mouth are more broadly spoon-shaped than those farther back. Still, even in the back of the mouth they are different from the pencil-shaped teeth found in Diplodocus, a shape that is much more simple and less variable because it is basically an uncomplicated cylinder. By comparison with other, more primitive dinosaurs, it seems most likely that the spoon-shaped teeth are less evolved and more akin to the shape of teeth in hypothetical ancestral sauropods. Pencil-shaped teeth evolved from the more primitive spoon-shaped form, but since one simple cylindrical shape looks pretty much like any other simple cylindrical shape, the possession of pencil-like teeth alone, when considered among all the species of sauropods, does not necessarily reflect a common ancestry. In other words, simple teeth may have evolved from more complex teeth more than once. 

Uncovered: How the 100-tonne Titanosaurs stalked Australia


Fossil bones from the largest dinosaurs ever known to walk Australia have been uncovered.

The remains of two Titanosaurs, nicknamed Cooper and George, were uncovered by farmers near the outback town of Eromanga in south-west Queensland state in 2005 and 2006.

Their remains were kept secret to allow investigation by dinosaur-hunting scientist

And scientists claim the discovery sheds new light on the country's prehistoric past.
Farmer Stuart MacKenzie said: "We were mustering cattle on motorbikes when we found fragments of the big one, Cooper.

"My 14-year-old son found the other one."

Fossilised leg bones showed the pair were 6-7 metres longer than the biggest sauropod dinosaur previously found in Australia, Queensland Museum Curator Scott Hocknull said.

The finding is likely to change understanding of how big dinosaurs grew in Australia, and their range across the country, with the latest discovery being further south than previous discoveries.

"The great thing about Australia is that there are always new things being found and it's all new to science. It's the tip of the iceberg," Hocknull said.

Titanosaurs, with their long necks and tails, were among the heaviest creatures to walk the earth, weighing up to 100 tonnes, and were one of the last sauropods of the Cretaceous Period.

They roamed Australia 98 million years ago, when the continent was greener and wetter, living on plants until prehistoric climate change saw their extinction.

They were named after the Titans of Greek myth and lived in mainly southern parts of the ancient supercontinent Gondwana.

Hocknull said Cooper's right humerus weighed 100 kilograms (220 pounds) and was a rare complete bone measuring 1.5 metres (5 feet) in length.

The two dinosaurs would have been at least 26 metres long, but may even have rivalled the largest dinosaur ever found, the 35-metre Argentinosaurus.

Fossil records in Australia are relatively rare because of the country's vast size and low population, which has hampered proper exploration by scientists.

"The fact is it is just not populated enough for people to find things. Almost all of the dinosaur discoveries are made by landowners, and the percentage that recognise they have found something different is pretty small," Hocknull said.

The latest findings could help scientists learn lessons about climate change and a generational drought currently being felt by Australians and blamed on global warming.

"If we don't know what happened to our animals and plants in the past, we cannot tell what happens in the future," he said.

Dimorphodon

Sunday, March 21, 2010



The Early Jurassic pterosaur, Dimorphodon, eats an early relative of the herring, Leptolepus. By Wayne D. Barlowe.

Mosasaur



A terrible reptile, but not a dinosaur, this Mosasaur devours a nautiloid of the Late Cretaceous seas. By William Parsons.

Australian dinosaurs


A group of Australian dinosaurs from various parts of the Early Cretaceous. They signify the radiations of dinosaurs into many types and to distant climes. In the foreground are two large Muttaburrasaurs, a Fulgotherium (herbivores), and behind them the ferocious Rapator. By Mark Hallett.

Extinction -Explanation

Thursday, February 18, 2010


Paleontologists generally divide extinctions into two categories. The first are the so-called background extinctions, isolated extinctions of species that occur in an ongoing fashion. The second type are called mass extinctions. The latter certainly have caught media and the public’s attention, and they appear to be something qualitatively as well as quantitatively different than background extinctions.

Background extinctions
Although background extinctions are less glamorous than mass extinctions, they are essential to biotic turnover: University of Tennessee paleobiologist M. L. McKinney has estimated that as much as 95% of all extinctions can be accounted for by background extinctions. Isolated species disappear from a variety of causes, including out-competition (the edge), depletion of resources in a habitat, changes in climate, the growth or weathering of a mountain range, river channel migration, the eruption of a volcano, the drying of a lake, the spraying of a pesticide, or the destruction of a forest, grassland, or wetland habitat. Dinosaur populations had a species’ turnover rate of around 2 million years per species. This means that each species lasted about 2 million years, before a new one appeared and the old one disappeared. 1 Although some dinosaur extinctions coincided with earlier mass extinction events (such as those at the Triassic–Jurassic and Cretaceous–Tertiary boundaries), most dinosaurs fell prey to background extinctions. By far the majority of favorite and famous dinosaurs – Maiasaura, Dilophosaurus, Protoceratops, Deinocheirus, Styracosaurus, Velociraptor, Iguanodon, Ouranosaurus, Allosaurus (to name a tiny fraction) – were the victims of background extinctions. The ultimate dinosaur extinction didn’t wipe out the total number of species accumulated over 160 million years, it killed only the latest-evolved representatives of the group (see Figure 13.1).

Mass extinctions
Mass extinctions involve large numbers of species and many types of species undergoing global extinction in a geologically short period of time. None of these has a truly precise definition, because there are no fixed rules for mass extinctions. Indeed, how do we know that there even were mass extinction “events” and how can we recognize them? A compilation of invertebrate extinctions through time (Figure B15.1.1) shows that, although extinctions characterize all periods (it is these that are termed background extinctions), there are intervals of time in which extinction levels are significantly elevated above background levels. Such intervals are said to contain the mass extinctions. Fifteen such intervals are recognized, of which five clearly towered above the others (Figure B15.1.1). The 15 mass extinctions are classified into “minor,” “intermediate,” and “major” mass extinctions, on the basis of the amount of extinction that took place above background. In the entire history of life, only one extinction qualifies as “major”; that is, the Permian–Triassic (commonly called Permo- Triassic) extinction. The remaining four of the Big Five – including dinosaur extinction – are considered to have been “intermediate.” The rest are considered “minor,” although undoubtedly not to the organisms that succumbed during them.


Dragon Roots

Tuesday, February 2, 2010


Researchers have long noticed the universality of dragon lore, and many have tried to explain why this monster is so common in world mythology. Both a Munich geology professor and American astronomer Carl Sagan have suggested that an ancient memory—carried in genes inherited from our mammalian ancestors—is responsible for an inborn fear of large reptiles. Prehistoric memories of dinosaurs seep from our subconscious into our impressions of the world, according to this theory, and turn old nightmares into legend.

These fears may have been confirmed in people’s minds whenever they accidentally uncovered fossilized dinosaur skeletons, seemingly real proof that such creatures existed. Some ancient saurians still live, however. The Komodo dragon, a lizard named after the Indonesian island where Westerners first learned of it in 1912, is the living creature that most closely resembles a traditional dragon. These carnivorous monsters may grow to more than 12 feet in length, and can eat large mammals such as goats. They are related to a fairly recently extinct Australian monitor lizard that could reach three times that length. Although they don’t breathe fire or fly, Komodo dragons still present a very formidable appearance and might easily provoke terror-stricken witness reports of dragons if encountered unexpectedly.

Author Peter Costello believes that human craft may have played a role equal to that of nature in reinforcing the idea of dragons. From the early to late Middle Ages, he says in The Magic Zoo, the custom of using giant, fluttering windsock dragons as battlefield banners spread from Asia to Europe. Each banner held a flaming torch to present the daunting illusion of a flying, fire-breathing dragon, and may have helped turn the tide of many medieval battles. At night, in the heat of battle, the billowing figures may have appeared real, and those who lived to tell the tale probably swore they battled dragons.

Tolkien’s dragons


Smaug by Angus McBride
By John D. Rateliff

There he lay, a vast red-golden dragon, fast asleep; a thrumming came from his jaws and nostrils, and wisps of smoke, but his fires were low in slumber. Beneath him, under all his limbs and his huge coiled tail, and about him on all sides stretching away across the unseen floors, lay countless piles of precious things, gold wrought and unwrought, gems and jewels, and silver red-stained in the ruddy light. —J.R.R. Tolkien The Hobbit

J.R.R. Tolkien’s contributions to fantasy in general and dragon-lore in particular are so great as to place him in a league of his own. The whole concept of the PC party (specialists of different backgrounds working together toward a common goal) derives from Tolkien’s “Fellowship of the Rings,” while his own particular “take” on all the major fantasy races — elves, dwarves, goblins, etc. — have become the common currency for a whole generation of successors. He is the most imitated fantasist of all time, and his masterly portrayal of Smaug, “the chiefest and greatest of all calamities,” is the standard by which all other fantasy dragons should be judged.

Whereas after Grahame the tendency had been to treat dragons as witty and cute, Tolkien restored the sense of them as deadly predators. All of Tolkien’s dragons — Smaug from The Hobbit, Glorund from The Silmarillion, the wily but not over-bold Chrystophlax Dives from Farmer Giles of Ham — are clever, unscrupulous, greedy, and exceedingly dangerous. They can be bargained with, but each is capable of wiping out a small army or good-sized town all by himself. Anyone who dares to talk with one of Tolkien’s dragons had better have an escape route planned if he does not want to become the creature’s next meal.

Furthermore, Tolkien’s dragons delight in mischief: rather than kill Turin, a brave but rash and not overly clever hero, Glorund convinces him to abandon the people who rely upon him and sends him on a fool’s errand, while Smaug sows the seeds of doubt in Bilbo’s mind that shortly afterward help wreck his friendship with the dwarves. People who listen to dragons are apt to fall under their enchantment (“Smaug had rather an overwhelming personality”), and any spark of greed inside them usually fares into full life. Sometimes this dragongreed is even contagious, transmitted by contact with treasure “over whom a dragon has long brooded” — as shown in the fate of Thorin Oakenshield and to a lesser extent that of Bilbo himself (whose secret theft of the Arkenstone was a thoroughly uncharacteristic act). Similarly, Fafnir’s treasure, the hoard of the Niebelungs, seems to bring disaster to all who possess or even lay claim to it, while Beowulf’s grieving countrymen wisely decline to take any of the dragon’s hoard after his death, instead placing it all on his pyre and burying what remains in his barrow.

Finally, Tolkien’s dragons are hard to kill. Smaug destroys Dale and the Kingdom Under the Mountain, sweeping aside all resistance, and that was when he was, in his own words, “young and tender.” Later in the book we’re given a vivid description of his attack on the mountainside and burning of Lake-Town. Had he not been slain by Bard’s expert shot with a special arrow to his one secret vulnerable spot, Tolkien speculated that Sauron might have later manipulated him into destroying Rivendell. [1] Likewise, Glorund destroys the elven city of Nargothrond, effortlessly scattering and destroying its battle-tried elven warriors, while other dragons help plunder the great hidden city of Gondolin. For his part, Chrystophlax shows great reluctance to melee with anyone armed with a sword of dragon-slaying like Giles’ Claudimorax (and no wonder), but when faced with the possibility of losing his whole hoard handily massacres the Little Kingdom’s assembled knighthood, then later effortlessly puts a second army to flight. It’s possible to slay one of the Great Worms, but only by careful planning and good luck.

[1] Unfinished Tales (1980), “The Quest of Gandalf’s point of view, telling us how the contrast to Bilbo’s narrative, this bit of “alter- Erebor,” contains a behind-the-scenes look at events appeared to the wizard and the alternate Hobbit” lets us learn more about the opening chapter of The Hobbit from dwarves. In addition to offering an amusing Gandalf’s motives and plans.

CAUDIPTERYX


Meaning: Wing tail
Time: Early Cretaceous
Size: 2 ft. 3 in.
Diet: Insects
Information: One of the small theropods that show distinctive bird features. It was very lightly built and had feathers on the wings and the tail. However, the wings were too small to allow it to fly. Here it is shown in the bottom, right of the picture.

The discovery of Caudipteryx led to many intensive studies on and debate over the relationship of birds and dinosaurs. The possible positions in the debate can be summarized as follows: Caudipteryx  is either a member of the Oviraptorosauria, or a bird, or both, and birds are either dinosaurs or they are not.

Because Caudipteryx has clear and unambiguously pennaceous feathers, like modern birds, and because several cladistic analyses have consistently recovered it as a nonavian, oviraptorid, dinosaur, it provided, at the time of its description, the clearest and most succinct evidence that birds evolved from dinosaurs. Lawrence Witmer stated: “The presence of unambiguous feathers in an unambiguously nonavian theropod has the rhetorical impact of an atomic bomb, rendering any doubt about the theropod relationships of birds ludicrous.”

However, not all scientists agreed that Caudipteryx was unambiguously non-avian, and some of them continued to doubt that general consensus. Paleornithologist Alan Feduccia sees Caudipteryx as a flightless bird evolving from earlier archosaurian dinosaurs rather than from late theropods. Jones et al. (2000) found that Caudipteryx was a bird based on a mathematical comparison of the body proportions of flightless birds and non-avian theropods. Dyke and Norell (2005) criticized this result for flaws in their mathematical methods, and produced results of their own which supported the opposite conclusion.

Other researchers not normally involved in the debate over bird origins, such as Zhou, acknowledged that the true affinities of Caudipteryx were debatable.

Arambourgiania

 

 


Meaning: Named after Camille Arambourg, who first described it in the 1950s
Time: Late Cretaceous
Size: 39 ft. 4 in. (13m)wingspan
Diet: Probably fish
Information: Scientists continue finding bigger and bigger pterosaur bones and announcing that this must have been the biggest animal that could possibly fly. The current record holder is Arambourgiania.
The biggest pterosaurs are not known from complete specimens, so all the figures you see on this subject are only estimates based on extrapolation from smaller, more complete finds. Currently, the record holders amongst pterosaurs (and, indeed, all volant animals) are the giant azhdarchids, enormous pterosaurs that existed across the world in the Cretaceous. The best known of these is Quetzalcoatlus nothropi from the Javelina Formation of Texas. Known from a stupendously big humerus and other fragmentary elements, the wingspan of this animal is estimated at 10 - 11 m with a shoulder height of 2.5 m when it stood on the ground.

However, other azhdarchids known from even scantier material hint at bigger animals. Arambourgiania philidelphae, a pterosaur known from a solitary neck vertebrae and scrappy wing elements from Jordan, may have achieved a wingspan of 11 - 13 m. However, Hatzagopteryx thambema is the current record holder for the largest pterosaur known: with only a few pieces of skull and a couple of scrappy limb elements, estimates for this critter put it between 12 - 14 m across the wings.

Death of the Dinosaurs

Wednesday, January 20, 2010



 

Dinosaurs: Giants of Patagonia (3D/2D)

Tuesday, January 19, 2010

bigImage

This documentary-style narrative focuses on the history, evolution and extinction of the dinosaurs. In larger-than-life fashion, audiences will explore a subject matter whose mystique and appeal are unquestioned.

Dinosaurs are amongst the most fascinating animals to have ever walked the Earth. We are captivated by their enormous size and intrigued by the fact that they disappeared millions of years ago. DINOSAURS 3D will take audiences on an unprecedented and unique 3D journey into the world of the largest known dinosaurs and, in the process, explore some of the great paleontological discoveries of modern time.

Done in close collaboration with the foremost scientists of the domain, the movie will show never seen before computer generated footage of the Giganotosaurus and the Argentinosaurus to name a few. At the moment of initiating this extraordinary project, one question comes to mind: "Is the giant screen big enough?"

Alternate Title(s): Formerly Dinosaurs of Patagonia