Dinosaurs: New Findings & Theories

[ramonmercado]

Feathers fly over key evidence in the rise of dino-birds



Birds fly over the sea after sunset. Palaeontologists have fired a broadside over a fossil which is the cornerstone evidence to back the theory that birds descended from dinosaurs.


Palaeontologists have fired a broadside over a fossil which is the cornerstone evidence to back the theory that birds descended from dinosaurs.

The row focuses on Sinosauropteryx, a fossil found in 1994 by a farmer in Liaoning province, northeastern China, a treasure trove of the Early Cretaceous period some 130 million years ago.

About the size of a turkey, the long-tailed meat-eating dino was covered with a down of fibres that, its Chinese researchers claimed, were primitive feathers.

That claim had the effect of a thunderclap.

Although the "feathers" were clearly not capable of flight, their existence dramatically supported a theory first aired in the 1970s that birds evolved from dinosaurs. As a result, a once-outlandish notion has become the mainstream concept for the ascent of Aves, as birds are classified.

But a new study, published by a team led by South African academic Theagarten Lingham-Soliar at the University of KwaZulu-Natal, sweeps away the proto-feathers claim.

The two-branched structures, called rachis with barbs, that were proclaimed as early feathers are quite simply the remains of a frill of collagen fibres that ran down the dinosaur's back from head to tail, they say.

The evidence comes from a recently discovered specimen of Sinoauropteryx, also found in the same Yixian Formation at Liaoning, that Lingham-Soliar put to the scrutiny of a high-powered microscope.

"The fibres show a striking similiarity to the structure and levels of organisation of dermal collagen," the kind of tough elastic strands found on the skin of sharks and reptiles today, the investigators say.

The fibres have an unusual "beaded" structure, but this most likely was caused by a natural twisting of these strands, and a clumping together caused by dehydration, when the dinosaur died and its tissues started to dry.

The tough fibres could have been either a form of armour to protect the small dinosaur from predators, or perhaps had a structural use, by stiffening its tail.

The first known bird is Archaeopteryx, which lived around 150 million years ago.

What is missing are the links between Archaeopteryx and other species that would show how it evolved. But fossil record is frustratingly small and incomplete and this is why debate has been so fierce.

The birds-from-dinos theory is based on the idea that small, specialised theropod dinosaurs -- theropods are carnivorous, bipedal dinos with three-toed feet -- gained an advantage by developing plant-eating habits, growing feathers to keep warm and taking to the trees for safety.

From there, it was a relatively small step to developing gliding skills and then the ability to fly.

Lingham-Soliar's team do not take issue with the theory itself.

But they are dismayed by what they see as a reckless leap to the conclusion that Sinoauropeteryx had the all-important "protofeathers", even though the this dinosaur was phylogenetically far removed from Archaeopteryx.

The evidence in support of the primitive feathers lacked serious investigation, Lingham-Soliar says.

"There is not a single close-up representation of the integumental structure alleged to be a protofeather," Lingham-Soliar says damningly.

Given that the evolution of the feather is a pivotal moment in the history of life, "scientific rigour is called for."

The study appears on Wednesday in Proceedings of the Royal Society B, a journal of the Royal Society, Britain's de-facto academy of sciences.


http://www.physorg.com/printnews.php?newsid=99114780

 

[ramonmercado]

Tracks suggest dinos could swim

The shape of the scratch marks suggested the beast was swimming
Ancient footprints have provided compelling evidence that some dinosaurs were able to swim, scientists report.
The 15m (50ft) trackway that reveals one animal's underwater odyssey was discovered in the Cameros Basin in Spain, once a vast lake.

The S-shaped prints suggest the beast clawed at sediment on the lake floor as it swam in about 3m (10ft) of water.

The marks are about 125 million years old, dating to the Early Cretaceous, the team writes in the journal Geology.

They were left by a large, bipedal, carnivorous dinosaur.

"We came across them about three or four years ago," explained Dr Loic Costeur, a palaeontologist at the University of Nantes, France, and a co-author of the paper.

"The Cameros Basin has thousands of walking footprints from diverse dinosaur fauna, but when we saw these it was obvious straightaway that this was a swimming dinosaur."

Immediately obvious

The underwater trackway, which is well-preserved in sandstone, is made up of 12 consecutive prints each consisting of two to three scratch marks.

"The footprints are really peculiar in their shape and morphology - they are not at all like walking footprints," Dr Costeur told the BBC News website.

"In walking footprints, you can recognise the shape of the foot; but here it is not at all the case: it is sets of grooves on the sediment surface.


The marks were made about 125 million years ago

"You get the idea that the animals' body was supported by water as it was scratching the sediment."

Ripple marks around the track suggested the dinosaur was swimming against a current, attempting to keep a straight path, the team said.

Further investigation of the well-preserved track revealed more about the beast's swimming style.

"The dinosaur swam with alternating movements of the two hind limbs: a pelvic paddle swimming motion," said Dr Costeur.

"It is a swimming style of amplified walking with movements similar to those used by modern bipeds, including aquatic birds."

For many years, the question of whether dinosaurs were able to swim remained unanswered.

Investigations into dinosaur anatomy and ecology suggested it was possible, but very little hard evidence existed documenting this behaviour.

But Dr Costeur described the find as "extremely exciting" and said it provided the first compelling evidence that dinosaurs were able to swim.

"The trackway at La Virgen del Campo opens the door to several new areas of research," said Costeur.

"New biomechanical modelling will increase our understanding of dinosaur physiology and physical capabilities, as well as our view of the ecological niches in which they lived."


http://news.bbc.co.uk/2/hi/science/nature/6687129.stm

 

[ramonmercado]

T. rex was 'slow-turning plodder'

T. rex had a big bite but it was no sprinter


T.rex animation
A Tyrannosaurus rex would have had great difficulty getting its jaws on fast, agile prey, a study confirms.
A US team has used detailed computer models to work out the weight of a typical "king of the dinosaurs", and determine how it ran and turned.

The results indicate a 6 to 8-tonne T. rex was unlikely to have topped 40km/h (25mph) and would take a couple of seconds to swivel 45 degrees.

The researchers report their findings in the Journal of Theoretical Biology.

They build on previous work detailing the biomechanics of the famous dinosaur, but add in new refinements.

"We've now got a pretty good estimate of its weight - over which there's been some controversy," lead author Dr John Hutchinson explained.

"We've shown there's no way it could weigh 3-4 tonnes as some people have suggested. It had to have weighed 6-8 tonnes," the scientist, who undertook the work at Stanford University, California, told BBC News.

Slowcoach dino

The team's computer modelling system estimated the centre of mass position and the inertia (resistance to turning), which have ramifications for how T. rex would have stood and moved and what it would have looked like.

As well as predicting the dinosaur's likely body mass and top speed (25-40km/h or 15-25mph), the computer calculations gave the team an idea of the turning ability of a T. rex. This has never been done before.

The study indicates the animal would have changed direction incredibly slowly because of its massive inertia, taking more than two seconds to make a quarter-turn.

The species certainly could not have pirouetted rapidly on one leg, as popular illustrations have sometimes pictured it, and other large dinosaurs, doing.

More agile prey would have given the slip to a marauding T. rex quite easily, it seems.

The researchers believe their work will help palaeontologists build up a more realistic picture of how the large dinosaurs lived.

"These were big clunky things - T. rex and the animals it probably preyed on. We have to slow down our view of that ecosystem," said Dr Hutchinson, who is currently lecturing in biomechanics at the Royal Veterinary College in the UK.

"It wasn't like the Serengeti today where everything is done at top speed."

Dr Paul Barrett, of London's Natural History Museum, commented: "This is another finding that undermines the kind of idea of T. rex as a super-predator.

"The main reason for that being it was a lot slower than we used to think it was; but it has this huge mouth filled with 60-odd, 30cm-long teeth, so it was still a formidable animal."

http://news.bbc.co.uk/2/hi/science/nature/6720461.stm

 

[ramonmercado]

Big Dinosaurs Heard Only Low-Pitch Sounds, Experts Suggest
Scott Norris
for National Geographic News

June 8, 2007
Large dinosaurs' hearing was more sensitive to booms and thuds than squeaks and whistles, new research says.

Dinos such as Brachiosaurus and Allosaurus probably could hear the deep-toned sounds of other dinosaurs' footfalls from miles away, researchers say.

But these massive reptiles may have had little or no hearing at higher sound frequencies—suggesting that the squeals of a smaller animal facing a Tyrannosaurus rex may have literally fallen upon deaf ears.

The theory of how dinosaurs may have perceived sound comes from studies of hearing in birds, which are widely believed to be dinosaurs' closest living relatives.

(Related: "'Feathered' Dinosaur Was Bald, Not Bird Ancestor, Controversial Study Says" [June 1, 2007].)

"We know a lot about hearing in birds," said acoustics researcher Robert Dooling of the University of Maryland, College Park.

"Big birds hear better at low frequencies, and small birds hear better at high frequencies."

Dooling's latest work, in collaboration with two German scientists, suggests the relationship between size and hearing extends from tiny songbirds to the 75-ton (68-metric-ton) Brachiosaurus.

That's because the inner ear structure of all archosaurs—the group of related species that includes dinosaurs, birds, and crocodiles—is basically identical, the experts say.

"What makes this whole thing work is that the ears of dinosaurs and birds are all scale models of one another," Dooling said.

The scientist presented his team's findings this week at the annual meeting of the Acoustical Society of America in Salt Lake City, Utah.

Close Correlations

The size of an auditory organ called the basilar papilla in the inner ear of birds is closely correlated with birds' overall body size, Dooling said.

Knowing this, the researchers gave different bird species hearing tests by training them to peck at a key for a food reward in response to sound.

From this the team established the sound frequencies at which birds hear best, and the high-frequency limit to their hearing.

Comparing more than 30 bird species, Dooling's team found a set of close correlations between basilar papilla length, frequency of optimal hearing, and the highest tone a species could detect.

Based on these relationships, the hearing capacity of most bird species can be accurately predicted from body size alone, Dooling said.

German collaborators Otto Gleich of the University of Regensburg and Geoffrey A. Manley at the Technical University of Munich added to Dooling's research.

They used fossils to determine the average basilar papilla length of Archaeopteryx—a feathered reptile thought to be a prehistoric cousin to modern birds—along with those of two species of dinosaur.

(Related news: "Dino-Era Bird Flew With Four Wings, Study Says" [September 28, 2006].)

For all three ancient creatures, the relationship between the size of the hearing organ and overall body size fit the same pattern shown by modern birds.

The researchers concluded that large dinosaurs may have had little or no hearing at sound frequencies to which the human ear is optimally attuned.

"You wouldn't expect a dinosaur of yesterday to be able to hear a bird of today," lead author Dooling said.

Lawrence Witmer, of Ohio University, has also studied the inner ear structure of dinosaurs. He called the new study "outstanding."

"I think [Dooling's team] is exactly right," Witmer said.

"My own data—not just from the inner ear but also other parts of the auditory system—fully support their contention that dinosaurs emphasized low-frequency hearing."

"Infrasound"

Knowing what dinosaurs could hear provides clues to their behavior, the experts say.

No one knows what types of sounds dinosaurs made, but their vocal abilities may have evolved to fit their hearing.

"Archosaurs in general are pretty vocal animals, and it's quite conceivable that dinosaurs vocalized in the low frequencies they could hear best," Dooling said.

He also noted that low-frequency "infrasound," which is inaudible to humans, can travel great distances.

Elephants are thought to hear infrasound vibrations produced by the strides of other elephants far away.

(Read: "Elephants 'Hear' Warnings With Their Feet, Study Confirms" [February 16, 2006].)

Larger dinosaurs could probably do the same, Dooling said, perhaps monitoring each other's movements over wide areas.

In general, Ohio University's Witmer cautions experts against making too many nuanced assumptions about dino behavior, since many details are simply lost to the sands of time.

"But careful studies like this one," he said, "reveal that we can indeed learn more than we had thought possible."

http://news.nationalgeographic.com/news ... -hear.html

 

[ramonmercado]

http://www.sciencedaily.com/releases/20 ... 112847.htm


Source: University of California - Berkeley
Date: June 11, 2007

Agonized Death Throes Probable Cause Of Open-mouthed, Head-back Pose Of Many Dinosaur Fossils
Science Daily — The peculiar pose of many fossilized dinosaurs, with wide-open mouth, head thrown back and recurved tail, likely results from the agonized death throes typical of brain damage and asphyxiation, according to two paleontologists.


The earliest feathered dinosaur, Archaeopteryx (plumage not shown). Drawn from specimen at Humboldt Museum, Berlin. The skull is about six inches long. (Credit: Image courtesy of University of California - Berkeley) A classic example of the posture, which has puzzled paleontologists for ages, is the 150 million-year-old Archaeopteryx, the first-known example of a feathered dinosaur and the proposed link between dinosaurs and present-day birds.

"Virtually all articulated specimens of Archaeopteryx are in this posture, exhibiting a classic pose of head thrown back, jaws open, back and tail reflexed backward and limbs contracted," said Kevin Padian, professor of integrative biology and curator in the Museum of Paleontology at the University of California, Berkeley. He and Cynthia Marshall Faux of the Museum of the Rockies published their findings in the March issue of the quarterly journal Paleobiology.

Dinosaurs and their relatives, ranging from the flying pterosaurs to Tyrannosaurus rex, as well as many early mammals, have been found exhibiting this posture. The explanation usually given by paleontologists is that the dinosaurs died in water and the currents drifted the bones into that position, or that rigor mortis or drying muscles, tendons and ligaments contorted the limbs.

"I'm reading this in the literature and thinking, "This doesn't make any sense to me as a veterinarian,'" said lead author Faux, a veterinarian-turned-paleontologist who also is a curatorial affiliate with Yale University's Peabody Museum. "Paleontologists aren't around sick and dying animals the way a veterinarian is, where you see this posture all the time in disease processes, in strychnine cases, in animals hit by a car or in some sort of extremis."

Faux and Padian argue in Paleobiology that the dinosaurs died in this posture as a result of damage to the central nervous system. In fact, the posture is well known to neurologists as opisthotonus and is due to damage to the brain's cerebellum. In humans and animals, cerebellar damage can result from suffocation, meningitis, tetanus or poisoning, and typically accompanies a long, slow death.

Some animals found in this posture may have suffocated in an ash fall during a volcanic eruption, consistent with the fact that many fossils are found in ash deposits, Faux and Padian said. But many other possibilities exist, including disease, brain trauma, severe bleeding, thiamine deficiency or poisoning.

"This puts a whole new light on the mode of death of these animals, and interpretation of the places they died in," Padian said. "This explanation gives us clues to interpreting a great many fossil horizons we didn't understand before and tells us something dinosaurs experienced while dying, not after dying."

Also, because the posture has been seen only in dinosaurs, pterosaurs and mammals, which are known or suspected to have had high metabolic rates, it appears to be a good indicator that the animal was warm blooded. Animals with lower metabolic rates, such as crocodiles and lizards, use less oxygen and so might have been less traumatically affected by hypoxia during death throes, Padian said.

Padian acknowledged that many dinosaur fossils show signs that the animal died in water and the current tugged the body into an arched position, but currents cannot explain all the characteristics of an opisthotonic pose. By studying a large number of fully articulated fossil skeletons, he and Faux were able to distinguish animals that underwent post-mortem water transport, a non-biological or abiotic process, from those with the classic "dead-bird" posture, which they interpret to be the result of biological processes.

Faux, who also works as a disaster veterinarian from her home in Lewiston, Idaho, set out to test other post-mortem processes - rigor mortis, which is the temporary stiffening of muscles after death; and the drying of muscles, tendons and ligaments - that some paleontologists credit with creating the opisthotonic posture. She obtained badly injured birds -owls, falcons and red-tailed hawks - that had been euthanized at a raptor recovery center and watched them for 8-10 hours, checking periodically to see if they moved during the process.

"In horses and smaller animals, rigor mortis sets in within a couple of hours, so I just looked to see if they were moving or not," Faux said. "And they weren't moving. They were staying in whatever position I'd left them in. I thought, 'If birds aren't doing it, and I'd never observed a horse doing it, then why would dinosaurs be doing it?'"

The idea that drying causes muscles or tendons to contract asymmetrically also didn't make sense, she said, based on her veterinary experience and an experiment she conducted with two euthanized red-tailed hawks, which she dried for two months set them in Styrofoam peanuts to dr. Most joints have counterbalancing muscles that dry the same way, she said, so there was no reason to expect that the muscles would turn a joint during drying. She found no post-mortem movement. She also pinned beef tendons as they dried, and though they shrank a bit, they did not shrink enough even to dislodge the pins. Given these observations, it is hard to imagine how shrinking tendons or muscles could drag a heavy creature into a different position, the researchers noted.

Padian pointed out, too, that all opisthotonic dinosaurs are very well preserved, meaning they evidently did not sit out in the open for long, or scavengers would have quickly scattered the bones. So, he wondered, how could they have been exposed long enough to dry out?

The only explanation that makes sense, they concluded, is central nervous system damage. The cerebellum is responsible for fine muscle movement, controlling, for example, the body's antigravity muscles that keep the head upright. Once the cerebellum ceases to modulate the behavior of the antigravity muscles, Faux said, the muscles pull at full force, tipping the head and tail back, contracting the limbs and opening the mouth.

Padian and Faux urge reanalysis of many fossil finds, referring, for example, to a mass death uncovered in Nebraska in the early 20th century. They argue that cerebellar dysfunction explains the opisthotonic posture of the numerous camel-like fossils better than does the common explanation - that the animals died in a stream and were washed into an eddy or backwater.

The authors also point to a fossil of Allosaurus, a T rex-like animal, that displayed bone lesions suggestive of a bacterial infection that also can lead to meningitis, a disease that can produce opithotonus. The authors point out that their explanation of the opisthotonic posture in dinosaurs and other animals provides a way to assess the role played by microbes in evolution, whether through disease or through other processes such as algal blooms - so-called "red tides" - that can suffocate aquatic animals.

This example and others "suggest that reevaluation may be in order for an untold number of paleoenvironments whose story has been at least partly explained on the basis of the death positions of many of their fossil vertebrates," the authors write in their Paleobiology paper.


Note: This story has been adapted from a news release issued by University of California - Berkeley.

 

[ramonmercado]

Fossil traces deep dinosaur roots

Its bone structure and light form suggest it moved swiftly

Scientists have described a new primitive dinosaur species, Eocursor parvus, which lived in the Late Triassic - about 210 million years ago.
Unearthed in South Africa's Free State, the creature appears to have been a small, agile plant-eater.

The team tells a Royal Society journal that Eocursor sheds light on the early evolution of the Ornithischia.

This important group included the well known herbivororous dinosaurs Triceratops and Stegosaurus.

The fossil specimen was first identified in 1993 but only recently appraised.

It is by far the most complete example of a Triassic ornithischian known, comprising skull and skeletal material, including bones of the backbone, arms, pelvis and legs.

Gripping hands

In its day, Eocursor would have been little bigger than a fox. Its bone structure and light form suggest it moved swiftly.


The specimen provides new information on an uncertain time
The scientists say the creature provides the earliest evidence for the origins of many skeletal characteristics seen in the ornithischian group, including the backward-pointing pelvis.

A comparison has been done across a wide range of specimens and this indicates that Late Triassic ornithischians were really quite rare. The group then diversified in the subsequent early Jurassic, filling empty herbivorous niches following mass extinctions of other creatures.

"We know ornithischians were a very successful and important group of plant-eating dinosaurs that first appeared 220 million years ago, in the late part of the Triassic Period," explained Dr Richard Butler, a palaeontologist at the Natural History Museum, London, UK.

"Eocursor is a very small and primitive dinosaur that would have eaten plants with its leaf-shaped teeth and had an unusually large, grasping hand. The lower leg bones are very long, suggesting it would have been able to run fast on its hindlegs to escape from predators."

The name Eocursor comes from the Greek eos, meaning "dawn" or "early", the Latin cursor meaning "runner" and parvus meaning "little"

Gap filler

"The earliest dinosaurs we know are about 228 million years old, so this one is only just a bit younger than that," commented Dr Paul Barrett, a NHM researcher unconnected with the new study.

"The fossil record for early meat-eating dinosaurs is slightly better; and for some of the other plant-eaters, we also have not-too-bad a record. But for the ornithischians, we have almost nothing; so in that sense, this is a major find," he told BBC News.

The assessment is reported in Proceedings of the Royal Society B: Biological Sciences.

The research team included co-workers at the Iziko South African Museum in Cape Town and the University of Cambridge, UK.


http://news.bbc.co.uk/2/hi/science/nature/6744955.stm

 

[ramonmercado]

Prehistoric Gliding Lizard Discovered in U.S.
Stefan Lovgren
for National Geographic News

June 12, 2007
Two hundred and twenty million years ago long-necked lizards spread their ribs and glided on winglike membranes through North American forests, according to a new discovery.

Two fossils of the animal, called Mecistotrachelos apeoros ("soaring, long-necked"), were excavated at a quarry on the Virginia-North Carolina state border.


The lizard has a much longer neck than the few other gliding reptiles that have been found dating back to the Triassic period (about 250 to 200 million years ago).

(See a picture of another gliding reptile, from 144 million years ago.)

"This is a very different form of gliding reptile from what we've seen before," said Nick Fraser, a vertebrate paleontologist at the Virginia Museum of Natural History who discovered the fossils.

The study is reported in the latest issue of the Journal of Vertebrate Paleontology.

Protorosaurs

Among the gliding reptiles that have previously been found from the Triassic era are two specimens called Icarosaurus and Kuehneosaurus, which were found in New Jersey and the United Kingdom, respectively.

Like the newfound species, these animals had elongated ribs, which supported gliding membranes—similar to modern-day Draco lizards found in Southeast Asia.

A third gliding reptile from the Triassic period is called Sharovipteryx (previously known as Podopteryx, or "foot wing").

Unlike the others, Sharovipteryx's main flight membrane was stretched between long back legs rather than its very short front limbs.

"We're not sure where [Mecistotrachelos apeoros] falls into things, but probably within a group of long-extinct reptiles called protorosaurs."

Protorosaurs were part of an order of diverse, predatory reptiles that lived as far back as 280 million years ago.

Study co-author Paul Olsen, a paleontologist at New York's Columbia University, sees the diversity of gliding mechanisms among prehistoric lizards as an indication of a golden age of species diversity.




Picture: "Ancient Gliding Beast" Changes Mammal History (December 12, 2006)
Dino-Era Bird Flew With Four Wings, Study Says (September 28, 2006)

The newfound form of lizard "wing," he said is "emblematic of our growing knowledge of land animal diversity during the Late Triassic.

"We now know the Late Triassic was a time of stunning diversity all to itself, a high point before the fall—the mass extinction near the Triassic-Jurassic boundary," Olsen said.

The new study was partly funded by the National Geographic Society's Committee for Research and Exploration. (National Geographic News is part of the National Geographic Society.)

Flat Rock

Fraser found the first fossil back in 1994, but was unable to figure out what it represented because of its poor condition.

A second fossil, discovered by Fraser eight years later, faintly showed a tail and a neck. But the second fossil was also in too poor a condition to prepare.

Instead, the descriptions of the lizard had to be based entirely on CT scans performed at Pennsylvania State University.

Even that proved problematic.

The second fossil was "a strange object to CT scan because of its flat shape," said Tim Ryan, a research associate at Penn State's Center for Quantitative Imaging.

"CT scanners don't particularly like flat, oblong things. They much prefer cylindrical sorts of objects," Ryan added.

"It was a test of the scanner and our ingenuity that we were able to get decent data from it."

The scanning revealed the bones of the lizard, and the scientists were able to reconstruct what the animal looked like.

Robust Ribs

Study leader Fraser said the gliding lizard's elongated neck would seem to complicate its flying ability.

"The neck was about 2 inches [5 centimeters] long, which is really long given the [length] of the animal"—only about 10 or 11 inches (25 or 28 centimeters).

"Presumably it held its neck straight forward while gliding," Fraser added.

The lizard also had unusual feet, which were preserved curled up in a grasping posture.

"We think that tells us something about its lifestyle—that this was an arboreal animal that scurried up trees while foraging for insects on the way, before gliding onto neighboring trees," Fraser said.

Another interesting feature is that the first two to three of the animal's elongated ribs are very thick.

"If you are a glider, you want to keep your bone structure as light as possible, so it's quite unusual to have this thickened rib there," Fraser said.

"We think that it had pretty good musculature attached to those ribs … and that it had much more control over where it went than the other Triassic gliders."


http://news.nationalgeographic.com/news ... izard.html

 

[Graylien]

So - was the T-Rex fast or slow then? The article referenced above refers to it as a "slow-turning plodder". But - invoking shades of Brass Eye - the BBC excitedly goes with the headline: T. Rex Would Outrun Footballer, and refers to it as a "fast predator". Same news, different spin.

T. rex 'would outrun footballer'
By Liz Seward


Tyrannosaurus rex would have been able to outrun a footballer, according to computer models used to estimate running speeds of dinosaurs.

The work used data taken directly from dinosaur fossils, rather than referring to previous work on modern animals.

The University of Manchester study published in Proceedings of the Royal Society B, shows T. rex had a top running speed of 8m/s (18mph).

The fastest dinosaur was a small, bipedal and carnivorous species.

This animal, called Compsognathus was about the size of a chicken, and could run at 18m/s (40mph).

The only modern bird to equal this speed is the ostrich. By comparison, an athlete in a 200m sprint can reach a top speed of 12 metres per second (27 miles per hour).

T. rex's speed of 8m/s (18mph) is fractionally quicker than the average professional footballer.

Predator and prey

The work so far has focused on carnivorous dinosaurs.

Co-author Dr Bill Sellers, from the University of Manchester, said: "One of the things that people argue about is why did they need to move as fast as they did - what are they chasing after.


"We're now doing some work on Hadrosaurus which is assumed to be one of the things that T. rex would prey upon because there have been fossils found with bite marks on their backs.

"What we find is that we're getting really quite high speeds for these animals as well, which makes perfect sense. If you're a fast predator you're probably chasing fast prey that you want to catch."

Not like us

The model is the first to attempt to build a picture of how a dinosaur would move, without basing it on modern animal models.

"There is no animation input, it's a fully dynamic model. We predict the movements of these animals but we don't base it on any existing animal movements.

"So the only input to the model is basically what we know from the fossil record about the shape of the animal," said Dr Sellers.

"It [the computer model] is much less biased by what we think about how these animals ought to have moved. We have this expectation that they ought to move like humans or ostriches, and of course they didn't.

"They don't look very much like humans or ostriches, so they would have moved like dinosaurs, this seems to be a much better way of achieving that."

'Educated guess'

There is one area where the researchers have had to make an educated guess, which is the muscle strength and density.

"The muscles that don't fossilise we get from information from what we know about modern animals," Dr Sellers told the BBC News website.

"It's all anatomical information that goes into the model and then the computer itself chooses the best way of activating the muscles in the model to maximise the speed of the animal."

Using their dinosaur modelling techniques the team also modelled humans and ostriches and compared their results with measured values. They are confident in their approach.

Future plans

In the future, Dr Sellers and his team hope to produce 3D simulations of dinosaurs which will allow them to explore the full range of motions the reptiles were capable of.

"At the moment computers aren't quite big enough for all the things we want to do with the model. It takes a long time to get the animal to learn to walk. The next step is to move into 3D."

They are currently working with animators on a dinosaur model which "because it uses the musculoskeletal model as the starting point, anything we get the animal to do, it could actually do."

source

Incidentally, I'd very much like to see a T-Rex outrun a footballer. And then eat him.

 

[ramonmercado]

I'd rather see a T-Rex run amok during a cricket test.

 

[OneWingedBird]

the videolink for the running dinosaurs has a jurrasic park style velociraptor in it... i thought the actual velociraptor was more like the actual size of a chicken :?

something more like an allosaur might have filled that sort of size niche...

 

[Graylien]

For those of you who would like to see T-Rex outrun a dinosaur, the Mail have created a state-of-the art digital composite of the scene here. It seems that the T-Rex's footballer of choice would be David Beckham.

 

[lawofnations]

the videolink for the running dinosaurs has a jurrasic park style velociraptor in it... i thought the actual velociraptor was more like the actual size of a chicken :?

something more like an allosaur might have filled that sort of size niche...

According to Mrs Lawofnations (who should know these things) a Velociraptor was larger than a chicken - about the size of an alsatian, with added tail.

Deinonychus was about the size of the velociraptors in Jurassic Park.

As for reports on dinosaurs on the BBC... don't get me started. My wife's research suggesting that the dinosaur fossil record is about two thirds complete got transformed by the BBC into "only 500 dinosaur species left to find" which are not the same things!

 

[ramonmercado]

A new twist on the old asteroid theory. They claim even the Moon was bashed by shards from the same collision.

Space pile-up 'condemned dinos'

The collision would have occurred in the asteroid belt


Enlarge Image

A colossal collision in space 160 million years ago set the dinosaurs on the path to extinction, a study claims.
An asteroid pile-up sent debris swirling around the Solar System, including a chunk that later smashed into Earth wiping out the great beasts.

Other fragments crashed into the Moon, Venus and Mars, gouging out some of their most dominant impact craters, a US-Czech research team believes.

Its study, based on computer

modelling, is reported in the journal Nature.

"We believe there is a direct connection between this break-up event, the asteroid shower it produced and the very large impact that occurred 65 million years ago that is thought to have wiped out the dinosaurs," Dr Bill Bottke from the Southwest Research Institute, Boulder, Colorado, US, told BBC News.

Rock swarm

A number of studies have considered what appears to have been an increase in asteroid strikes on Earth in the last 100-200 million years - something like a doubling over the long-term norm.

Dr Bottke and his colleagues have attempted to show that this surge was probably triggered by the catastrophic disruption of a 170km-wide rock in the asteroid belt between Mars and Jupiter about 160 million years ago.

The mountainous object's break-up - induced by a collision with a space rock under half its size - resulted in the cluster of fragments visible today and known as the Baptistina family, they say.


It is thought the dinosaurs could not cope with the impact's effects


Enlarge Image

The researchers have modelled the evolution of this cluster and concluded that it would have lost many of its original members to the inner Solar System.

The analysis shows, the team says, that one large shard from the break-up probably created the 85km-wide Tycho impact crater on the Moon 108 million years ago.

But even more likely, they contend, is that a still larger fragment dug out the 180km-wide Chicxulub crater off what is today the Yucatan Peninsula of Mexico.

This is the impact scar many scientists link to the Cretaceous/Tertiary Mass Extinction, which saw the dinosaurs disappear into the fossil record.

'Inevitable' outcome

"The [Baptistina] break-up event took place very close to what one might describe as a 'dynamical superhighway', a way for objects to escape the asteroid belt - and many of them did so," explained Dr Bottke.

"These fragments began to wander the region where the Earth and Moon are located; and in fact, so many escaped that it became almost inevitable that some of the larger pieces were going to hit the planets of the inner Solar System."


The Chicxulub crater has left its mark on Mexico


Enlarge Image

Chemical analysis of projectile material connected to the Chicxulub event is also said to tie its impactor to the type of rocks that make up the Baptistina family.

Philippe Claeys and Steve Goderis from the Free University of Brussels, Belgium, write a commentary on the research in Nature.

They say that unless a rogue comet came from the outer edge of the Solar System ("a rather unlikely event"), the Baptistina asteroid family remains a likely source for the Chicxulub impactor.

"It is a poignant thought that the Baptistina collision some 160 million years ago sealed the fate of the late-Cretaceous dinosaurs well before most of them had evolved," they write.

Dr Bottke's colleagues on the study were David Vokrouhlicky and David Nesvorny.


http://news.bbc.co.uk/2/hi/science/nature/6980468.stm

 

[ramonmercado]

Another interesting theory. You can have them and running or smaller and flying.

Height or flight? Fossil answers some questions about evolution of flight in dinosaurs, raises others



A dinosaur fossil unearthed in the Gobi Desert of Mongolia shows that miniaturization, a hallmark of bird origins and a necessary precursor of flight, occurred progressively in primitive dinosaurs. Credit: F. Ippolito, American Museum of Natural History


Paleontologists have long theorized that miniaturization was one of the last stages in the long series of changes required in order for dinosaurs to make the evolutionary “leap” to take flight and so become what we call birds. New evidence from a tiny Mongolian dinosaur, however, may leave some current theories about the evolution of flight up in the air.

A team of researchers including Dr. Julia Clarke, assistant professor of paleontology at North Carolina State University with a joint appointment at the North Carolina Museum of Natural Sciences, studied the new dinosaur species Mahakala omnogovae and its relationships to other small meat-eating dinosaurs including birds.

They found that small size was held in common among early species within the two dinosaurian lineages most closely related to birds and was evolved well before the ability to fly. Further, the dinosaurs within each lineage did not get uniformly smaller as time went on; in fact, in some lineages dinosaurs’ size increased by a factor of three.

Their results are published in the Sept. 7 edition of the journal Science.

What we know as extant or modern-day birds trace their lineage back to membership in a clade, or group of dinosaurian species that share many similar physical traits, known as Paraves.

Within Paraves are two other branches besides that leading to birds. The new study indicates that while the species on the bird branch stayed small, the two other branches showed pronounced trends toward increases in size over time. One of these secondarily large groups includes Velociraptor, familiar to fans of the Jurassic Park movies.

The Mahakala specimen measures approximately 70 centimeters (28 inches) long and the researchers believe the fossil is from a young adult of the species, not a juvenile. Other characteristics identify Mahakala as a member of Dromaeosauridae, a group that also contains larger species such as Velociraptor.

“This specimen shows that dinosaurs evolved small size earlier than we previously thought,” Clarke says. “And even more interesting is the fact that in a couple of these lineages closely most related to birds, dinosaurs didn’t stay small – they got much larger. So we now see some competing trends within very closely related groups over the same time interval in the Cretaceous period.”

If miniaturization of dinosaurs occurred well before the origin of flight, then this raises other questions about the ways that paleontologists have traditionally explained trends in the early history of birds.

“We had closely linked smaller size in dinosaurs including birds to flight, changes in growth strategy and metabolism: They got progressively smaller, grew faster, and flew,” Clarke adds. “Now we see that small size occurs well before many other innovations in locomotion and growth strategy. It forces us to look at the ways we were explaining trends within this part of Dinosauria, and to question our previous assumptions about causal factors in, and timing of, the acquisition of attributes seen in living birds.”

Source: North Carolina State University
http://www.physorg.com/printnews.php?newsid=108307836

 

[lawofnations]

As for reports on dinosaurs on the BBC... don't get me started. My wife's research suggesting that the dinosaur fossil record is about two thirds complete got transformed by the BBC into "only 500 dinosaur species left to find" which are not the same things!

So who told the BBC how many species of dinosaurs actually existed? Do they have special access to God?

As liscence fee payers I think we should be told...

As luck would have it she's just written a blog entry and mentions what happened in it:

I'm still living down the "only 500 dinosaurs left to be discovered" comment attributed to me in 2004. Waaaay back in 2003 I had a poster at GSA, on Estimating the completeness and congruence of the dinosaur fossil record: phylogenetic approaches. You'll see the text of the abstract. Just after the conference I gave an interview to the Wash U Record, and Dinosaur fossil record compiled, analysed was the result, albeit several months later. Now I'm pretty sure that I said that if the new discoveries merely filled the gaps and didn't push back the divergence dates for any of the clades I used, then another 500 species would probably fill up the gaps in the fossil record. And to his credit, Tony Fitzpatrick did say "there might be 500 or more yet to be discovered" (although you'll notice some parts where he quoted straight from the abstract!).

Now you and I know that all it takes is one Upper Triassic neosauropod, and the whole thing collapses, leaving palaeontologists looking for all the missing data between the Upper Triassic and the Middle Jurassic. So yeah, on the basis of pushing 800-900 genera, with the analysis as it stood back in 2003 (it's changed now, so this figure is no longer valid) putting the dinosaur fossil record at about 67% "complete", another 400-500 genera could fill the gaps. But they won't. And in fact we will never find all the dinosaurs - it just won't happen. There must have been millions - they were the dominant terrestrial animals for nearly 200 million years.

But then the BBC got hold of it, and rather than bothering to interview me, or even ask me for a couple of soundbites, they rehashed Tony's interview, quoted me only where Tony had quoted me, and then said "Up to 500 dinosaur groups may remain undiscovered... The figure of 500 may seem a lot, but this is a maximum possible value"! See what they did there? From me saying to Tony that there could be 500 or more to be discovered, the BBC translated it as no more than 500. Minimum to maximum in the space of one anonymous BBC science writer.

 

[rynner2]

As luck would have it she's just written a blog entry and mentions what happened in it:

Of course, from that information, I can find out your wife's name, your name, your address and credit card numbers and all your passwords, etc...

But I'm a nice man, so I won't do that if you send £1000 to rynner, c/o Lloydstsb, rynnerville, UK...

(Yes, perhaps we do need a site safety officer here... 8) )

 

[ramonmercado]

Well they are 290 million year old reptile prints so I guess they belong here.

Oldest Identifiable Footprints Found
Ker Than
LiveScience Staff Writer
LiveScience.com
Wed Sep 12, 6:20 AM ET


Two reptile-like animals living 290 million years ago are the oldest creatures to have their footprints positively identified after a fortuitous discovery allowed scientists to match fossils to preserved trackways.


Fossils of Diadectes absitus and Orobates pabsti were recently found in the Tambach Formation in central Germany. Nearby and in the same sediment layer, scientists found well-preserved footprints made by creatures that plodded through the region's soft sediments long ago. The footprints turned out to be a match for the fossil animals.


The work, detailed in the latest issue of the Journal of Vertebrate Paleontology, marks the first footprints of the Paleozoic Era, a time before the dinosaurs that lasted from 540 to 240 million years ago, to be associated with the animals that made them. It could also force scientists to rethink how the ancient creatures moved.


Because of the exceptional preservation of the Tambach skeletons, scientists were able to match them to the nearby footprints. The two species were among the first four-legged plant eaters on land and have no close living relatives.


"Fossils don't usually include really good feet," said study team member David Berman of the Carnegie Museum of Natural History in Pittsburgh. "It's rare that we get feet with all the toe and wrist and ankle bones [intact]."


O. pabsti is a completely new species that has never been described before. "It's a new genus and species," Berman told LiveScience.


The new findings could allow scientists to partially recreate the migration patterns of these long-extinct creatures. "It is not necessary to find the skeleton of a creature at a certain locality to state that this animal has lived there," said Sebastian Voigt, a trackway expert from the Freiberg University of Mining and Technology in Germany.


The work could also lead to a rethinking of how some of the first land creatures stood and walked. Mammals tend to have legs and limbs that drop vertically from the pelvis to the ground, while those of reptiles tend to extend away from the body horizontally before turning back downward. The new reptiles had a "mammalian" arrangement for their limbs.


"We know from the trackways that these animals had their feet planted almost under their body," Berman said, "whereas in textbooks, they give them a sprawling gait as if the limbs are extended out from the body considerably. This just isn't true. You look at the trackway and you see that the footprints are very close to the midline of the body."

Footprints

 

[lawofnations]

As luck would have it she's just written a blog entry and mentions what happened in it:

Of course, from that information, I can find out your wife's name, your name, your address and credit card numbers and all your passwords, etc...

True - but then again neither of us are trying to hide our real names (mine is on my profile here!), in fact doing so would be a hindrance (doubly so for her career - journals don't accept papers under a pseudonym). To be on the safe side I'll send you the money though - it's in my Northern Rock account...

 

[ramonmercado]

Hmm, looks interesting. Lets await further results.

Amazing find of dinosaur 'mummy'

Scientists now think these dinosaurs were more muscular than previously thought


Enlarge Image

Fossil hunters have uncovered the remains of a dinosaur that has much of its soft tissue still intact.
Skin, muscle, tendons and other tissue that rarely survive fossilisation have all been preserved in the specimen unearthed in North Dakota, US.

The 67 million-year-old dinosaur is one of the duck-billed hadrosaur group.

The preservation allowed scientists to estimate that it was more muscular than thought, perhaps giving it the ability to outrun predators like T. rex.

The researchers propose that the dinosaur's rump was 25% larger than had previously been thought. This probably meant more muscle mass and therefore greater acceleration, giving it a greater chance of evading meat-eating dinosaurs in hot pursuit.

Depth and structure

While it has been dubbed a dinosaur "mummy", the dinosaur is actually fossilised into stone.

But unlike the collections of bones found in many museums, this hadrosaur came complete with fossilised skin, ligaments, tendons and possibly some internal organs, according to researchers.

"It's unbelievable when you look at it for the first time," said palaeontologist Phillip Manning from the University of Manchester, UK.


The scales are still visible on the fossilised skin
"There is depth and structure to the skin. The level of detail expressed in the skin is just breathtaking."

Dr Manning said there was a pattern of banding to the larger and smaller scales on the skin.

Because it has been fossilised researchers do not know the colour of the skin. But looking at it in monochrome shows a striped pattern. He noted that in modern reptiles, such a pattern is often associated with transitions between different skin colours.

The fossil was found in 1999 and is now nicknamed Dakota. It is being analysed in the world's largest CT scanner, operated by the Boeing corporation.

The machine usually is used for space shuttle engines and other large objects. Researchers hope the technology will help them learn more about the fossilised insides of the creature.

The reptile had no chest cavity, suggesting it had been partially eaten by predators before being "mummified" in unusual conditions: acidic, waterlogged sediments collected around the dinosaur, triggering the rapid deposit of minerals and trapping organic molecules before they decayed.

http://news.bbc.co.uk/2/hi/science/nature/7124969.stm

 

[ramonmercado]

Another piece on the mummified dinosaur.

A mummified dinosaur

Dec 6th 2007
From The Economist print edition

Dinosaur bones are fairly rare fossils, but compared with what is shown in this picture, they are as common as muck. It is a piece of dinosaur skin (or, rather, its petrified transmutation). It belongs to a fossil hadrosaur (a type of herbivorous dinosaur) that lived 67m years ago in what is now Hell Creek, North Dakota. The first bones of the animal were discovered in 1999 by Tyler Lyson, now a graduate student at Yale, but then a schoolboy. A full-scale expedition to recover it has, however, only recently been mounted. The fossil's state of preservation is remarkable. Besides skin, various ligaments and tendons have been found, and the specimen is now undergoing examination in the industrial equivalent of a hospital body scanner, at a Boeing workshop in California, to see if any internal organs have been petrified, too.


http://www.economist.com/science/Printe ... d=10250315

 

[rynner2]

Science: dinosaur find in Dorset
Last Updated: 12:01am BST 20/05/2008

Anna Grayson tells the story of a remarkable find on the Dorset coast

The most complete dinosaur skeleton ever found in Britain is about to go on display - evidence of a species unique to Britain that perished in a devastating flood.

The first piece was retrieved from a beach in Dorset in 2000 by David Sole, a former solicitor turned professional fossil collector. "There was a lump of rock about two foot by one foot lodged in fine-shingle sand, and I sensed there was something unusual about it," he recalls.

Further investigation showed that what looked like a chunk of limestone was packed with bone. Over the following months and years, other fragments were found embedded in neighbouring pieces of limestone - the last, containing a small piece of foot, by an amateur in 2005.

After daily soaking in very dilute acetic acid - not even as strong as the vinegar used on chips - the stone revealed, bit by bit, a whole skeleton. The creature, the experts discovered, was a 195 million-year-old Scelidosaurus, the earliest of the armoured dinosaurs.

"It has heavy spines all over its body, with two goat-like horns on the back of the skull forming a kind of ruff with its neck armour. This leads to the inference that this specimen was likely to have been a mature male," explains Dr Tim Ewin of Bristol City Museum and Art Gallery, where the beast will be shown to the public from next month.

Until now, this particular species had appeared in just a single band of rock from another outcropping near Lyme Regis - and certainly not in such detail.

Unusually, the almost-complete skeleton was articulated, meaning that each bone was linked and in its correct place. Equally striking were the long, thin tendons that supported the animal's huge stomach, which still stretched from the backbone - and the fact that the creature's gullet contained a discoloured area, with the remains of its last meal.

The location of the find was puzzling, however. The rocks of Lyme Regis were all formed under open sea, yet dinosaurs were landlubbers. Apart from a Jurassic shipwreck, what could have caused one to be preserved at sea?

Part of the answer lies in our prehistoric geography. During the Jurassic era, southern Britain was a series of low-lying islands separated by seas. As Dr Ewin points out, islands are often home to species, such as the modern-day Komodo dragon, that are found nowhere else.

"It could be that Scelidosaurus only lived on one island, a few miles away from Lyme Regis, which would explain why the species has not been reported anywhere else. We began to wonder if we were looking at a family group that was washed off the island by a sudden tsunami, similar to what we saw on Boxing Day 2004."

There is corroborating evidence for a Jurassic tsunami in the form of rapidly dumped boulders that have been found in Scotland. But there is a further mystery - trapped within the animal's jaw are two crocodile teeth.

Could it be that the Scelidosaurus died protecting its family - the smaller, less complete skeletons found earlier - from crocodile attack? Ewin thinks not: the teeth are inside the jaw and not embedded on the outside.

"Plant-eating dinosaurs frequently swallowed stones to help them break down the coarse vegetation of the time in their stomachs, and it occurred to me that this species might have swallowed crocodile teeth instead of stones. Crocodiles always shed teeth, and they would have been easy to find on the island. They would have boosted dietary calcium, which would have been needed to make all that bony armour."

But the crocodile teeth are in the mouth, not the stomach. So Ewin looked again at the supposed "last meal" in the gullet.

"It was all very fine, and with no recognisable chunks of plant material. I then thought that maybe this material was not on its way down, but digested material on its way up - dinosaur vomit. The crocodile teeth would have been ejected from the stomach as part of that process. Vomiting often occurs on the point of drowning, and I fear that is what must have happened."

So it seems that this family, members of a unique species of British dinosaur, was indeed swept away to sea in a terrifying flood, along with the plant debris and mud that preserved them - until almost 200 million years later, when a modern storm revealed their burial place on that Dorset beach.

http://www.telegraph.co.uk/earth/main.j ... set120.xml

 

[ramonmercado]

Climate change gave dinosaurs a lucky break
by Jeff Hecht

Dino

The dinosaurs got lucky. Before they finally came to dominate Earth life in the Jurassic period, they were perpetual also-rans to their crocodilian cousins. But then the climate gave them a helping hand.

Near the start of the Triassic period, 250 million years ago, the archosaurs, or "ruling reptiles", split into two major groups: the dinosaurs and a group called crurotarsans, whose only living descendants are the crocodiles.

Palaeontologists had long thought that the more successful dinosaurs dominated the last 30 million years of the Triassic, but in recent years they have found that many of the fossils originally thought to be dinosaurs were actually similar-looking crurotarsans.

Now new research challenges the idea that dinosaurs had some evolutionary advantage over their croc rivals.

Climate catastrophe
Analysing data for the 30 million years of the Triassic that the two groups lived side by side, Steve Brusatte and Mike Benton at the University of Bristol, UK, found they evolved at essentially the same rate. Moreover they also found that the crurotarsans also developed a much broader range of body types than the dinosaurs.

An observer comparing the two groups in the late Triassic would have expected the crurotarsans to eventually dominate, says Brusatte, now at the American Museum of Natural History in New York.

Yet all the crurotarsans bar the crocodiles were wiped out 200 million years ago, when rapid climate change caused a mass extinction. Dinosaurs "pretty much got lucky" and sailed through to dominate ecosystems for another 135 million years, he says.

It's an example, Brusatte adds, of how evolution doesn't really record "progress" – the winners may just have luck on their side.

Journal reference: Science (DOI: 10.1126/science.1161833)

Dinosaurs - Learn more in our comprehensive special report.
http://www.newscientist.com/channel/life/dinosaurs

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Weblinks

Stephen Brusatte, University of Bristol
Brusatte

Crurotarsans, Wikipedia
http://en.wikipedia.org/wiki/Crurotarsi

 

[ramonmercado]

Hopes that Australian dinosaur find is new species

http://www.physorg.com/printnews.php?newsid=140762767

Australian scientists were hopeful Tuesday that two tonnes of bones found in the country's northeast are the remains of a new species of dinosaur.

A two-week dig in the west of Queensland state has uncovered bones in an area which three years ago yielded the fossilised remains of a late Triassic period herbivore dubbed Matilda.

Amateur paleontologist David Elliott, from the Australian Age of Dinosaurs Institute which organised the dig, said the new bones were considered as too small to belong to 20-metre (66-foot) long Matilda.

Elliott said the chances the new bones -- estimated to be up to 98 million years old -- were from a new species was "very, very likely simply because of the rarity of Australian dinosaurs".

"There is very little in the way of Australian dinosaurs that have been scientifically described and because of the isolation of Australia... most Australian fauna are very different to others around the world," he said.

"All of the dinosaurs that have been discovered around Australia have been different from other ones around the world and it's almost certain that this will be the same and we have what appears to be a different species.

"You can't say for absolute certain but we're very, very excited about it and we're hopeful that that is what it is," he told AFP.

Elliott said that scientists would examine the bones and it would be up to eight months before any final conclusion on the type of animal was made.

 

[ramonmercado]

In search of Thingummyjigosaurus
There are errors in almost half the names given to dinosaurs.

Rex Dalton


Megalosaurus. At least that's what we've been told...Dorling Kindersley RFOne hundred and thirty-five years of questionable judgments, some driven by a lust for headlines, have left dinosaur nomenclature in disarray, according to two new studies.

The studies find that of 1,401 names given to dinosaurs species from 1824 to 2004, about 16 per cent of names were duplicates, and 32 per cent embodied errors of some other sort.

"It is a bit scary," says Michael Benton, a palaeontologist at the University of Bristol, England, who is author of the studies. A first discussion of the results is published today in the Royal Society's Biology Letters1, and a longer analysis will be published in December in Paleobiology2.

The high error rate is not just a problem for fossil hunters; it is a warning that scientists should take extra precautions when identifying new species as they assess modern biodiversity, too, says Benton. "We need to be sure species lists are properly vetted, so incorrect information isn't used in formulating policies."

Quest for glory
The fact that there are errors is not surprising. As Mark Goodwin, a palaeontologist at the University of California at Berkeley, says, "If you are in the trenches, dinosaur taxonomy and systematics will always be a work in progress." But the extent of the problems is a shock. "We knew there was an issue, but no one did the work of seeing how bad it was," says Peter Makovicky, a palaeontologist at the Field Museum in Chicago.

As more public money came to be used for exploration projects, Benton notes there was a growing risk that funding-agency and journal pressures might lead to unnecessary naming of genera or species. Concerned these factors "may be distorting" the field, Benton began making a catalogue about four years ago.

But despite these pressures, Benton noted that the scientific process has addressed the publication shortcomings through literature corrections, which he called "heartening."

These corrections eliminated duplications — called synonyms, or aliases — and other errors, such as a lack of sufficient fossil material, an undiagnostic description, or the use of a name already assigned to something else.

The hall of fame
For his studies, Benton completed a list of the top 30 dinosaur namers of all time, of whom half are still alive. For the top five, the percentage of names that have held up varies from 14 per cent to 64 per cent.

“We knew there was an issue, but no one did the work of seeing how bad it was.”
Peter Makovicky
The Field Museum
At the top of the list is Othniel Marsh, who in the nineteenth century vied with Edward Drinker Cope to be America's king of the dinosaurs. Marsh named 80 dinosaurs from 1870 to 1899; 23 of those names are still valid, says Benton, giving a success rate of 29 per cent.

At number four on the list is Dong Zhiming, a Chinese scientist now semi-retired to Yunnan. He named 42 dinosaurs from 1973–2004, with 27 of those still valid (64 per cent).

The most prolific dinosaur namer still active is Xu Xing, who like Dong is associated with the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing of the Chinese Academy of Sciences. Xu sports a perfect record: 24 species named from 1999–2006, with all still valid. His rate of three namings per year is unmatched.

Much of Dong's early work was done when there was pressure on Chinese scientists to discover new species, and when international exchange and access to high-quality, peer-reviewed journals was limited. For all that, his 27 properly named species is the highest total ever achieved.

In contrast, Xu studied and collaborated at some of the finest US institutions, benefited from China's recent major research funding increases, and had ready access to top journals.

References
Benton, M. J. Biol. Lett. doi:10.1098/rsbl.2008.0402 (2008)
Benton, M. J. Paleobiology, 34, 4, 516-533 (2008)

http://www.nature.com/news/2008/080917/ ... .1111.html

 

[ramonmercado]

Researcher finds tiny dino in world of giants
By Jeffrey Jones

CALGARY, Alberta, Sep. 23, 2008 (Reuters) — A Canadian researcher has discovered what is believed to be North America's smallest dinosaur, a 70-million-year-old chicken-sized beast that was also unusual for its diet of insects.

Nick Longrich, a palaeontology research associate in the Department of Biological Sciences at the University of Calgary, announces the discovery of North America's smallest dinosaur in Calgary September 23, 2008. The dinosaur is 70 million years old, the size of a chicken, is called Albertonykus borealis and looks like an animal created by "Dr. Seuss.". REUTERS/Todd Korol

Called the Albertonykus borealis, the odd-looking creature had bird-like features including slender legs, jaws like pincers and stubby arms with big claws.

Its bones were excavated near Red Deer, in fossil-rich Alberta, in 2002 among about 20 Albertosaurus remains, and went unnoticed.

The dinosaur is a newly discovered member of the family Alvarezsauridae, from which fossils had previously been dug up only in South America and Mongolia, said Nick Longrich, paleontology research associate at the University of Calgary.

The find is evidence that the dinosaurs migrated to Asia from the bottom part of the western hemisphere, Longrich said.

His research on the Albertonykus is published in the journal Cretaceous Research.

"Most of the dinosaurs we know about -- things like Tyrannosaurus, giant carnivores, or Triceratops, big herbivores -- are large. This thing is very small, about 2-1/2 feet (two-thirds of a meter) long and we think it's doing something very different: we think it might have actually been an insectivore," he said.

It was not made for digging, like moles. Its features were not unlike those of anteaters, and Longrich said it appears it tore into logs so it could feast on termites or beetles.

"This is a dinosaur doing what we didn't have a lot of evidence of them doing before," he said.

He said it may have been prey for such other dinosaurs as Albertosaurus and Velociraptors, those that could catch the speedy little beast.

"(The find) tells us a little bit about how these dinosaurs were dispersing through the environment, and I think one of the things that it also emphasizes is that there's a lot more waiting to be discovered," Longrich said.

(Editing by Peter Galloway)

http://www.newsdaily.com/stories/tre48m ... -science/#

 

[ramonmercado]

America's Smallest Dinosaur Uncovered
http://www.sciencedaily.com/releases/20 ... 104414.htm

An illustration of Albertonykus borealis. (Credit: Nick Longrich)

ScienceDaily (Sep. 25, 2008) — An unusual breed of dinosaur that was the size of a chicken, ran on two legs and scoured the ancient forest floor for termites is the smallest dinosaur species found in North America, according to a University of Calgary researcher who analyzed bones found during the excavation of an ancient bone bed near Red Deer, Alberta.

"These are bizarre animals. They have long and slender legs, stumpy arms with huge claws and tweezer-like jaws. They look like an animal created by Dr. Seuss," said Nick Longrich, a paleontology research associate in the Department of Biological Sciences. "This appears to be the smallest dinosaur yet discovered in North America."

Called Albertonykus borealis, the slender bird-like creature is a new member of the family Alvarezsauridae and is one of only a few such fossils found outside of South America and Asia. In a paper published in the current issue of the journal Cretaceous Research, Longrich and University of Alberta paleontologist Philip Currie describe the specimen and explain how it it likely specialized in consuming termites by using its small but powerful forelimbs to tear into logs.

"Proportionately, the forelimbs are shorter than in a Tyrannosaurus but they are powerfully-built, so they seem to have served a purpose," Longrich said. "They are built for digging but too short to burrow, so we think they may have been used to rip open log in search of insects."

Longrich studied 70 million-year-old bones that were collected on a dig led by Currie at Dry Island Buffalo Jump Provincial Park in 2002 where the remains of more than 20 Albertosaurus sarcophagus individuals were found. Albertosaurs are a type of tyrannosaur. The bones were placed in storage at the Royal Tyrrell Museum and Longrich came across them while trying to compare Albertosaurus claws to another dinosaur species.

"This is the oldest and most complete dinosaur of its kind known from North America and it provides evidence that these dinosaurs migrated to Asia through North America," he said.

Longrich, who specializes in studying dinosaur-era ancestors of birds, completed his PhD at the University of Calgary under the supervision of zoology professor Anthony Russell. In September 2006 Longrich argued that that earliest known ancestor of birds, a feathered creature called Archaeopteryx, likely flew with wings on all four limbs after examining fossils originally collected in Germany in 1861.

"You can really find amazing things if you just keep looking at fossils we already have sitting in museum collections," he said. "The number of dinosaur discoveries is actually accelerating because we just keep digging up more material to work with."


--------------------------------------------------------------------------------

Journal reference:

Longrich et al. Albertonykus borealis, a new alvarezsaur (Dinosauria: Theropoda) from the Early Maastrichtian of Alberta, Canada: implications for the systematics and ecology of the Alvarezsauridae. Cretaceous Research, August 2008; DOI: 10.1016/j.cretres.2008.07.005
Adapted from materials provided by University of Calgary.

 

[ramonmercado]

Photos & full story at link.

PHOTOS: Meat Eating Dino had Birdlike Breathing System

Birdlike Dinosaur Found in Argentina (September 29, 2008)
Dino

September 29, 2008--This newly found South American dinosaur may have had flesh-ripping teeth, but it had the lungs of a bird, scientists announced Monday.

Found in Mendoza Province, Argentina, Aerosteon riocoloradensis lived 85 million years ago during the Cretaceous period.

The elephant-size dinosaur's breathing system may help scientists better understand the evolution of avian lungs and air sacs. In birds, bellows-like sacs pump air through the lungs.

The find offers the first evidence of air sacs in dinosaurs, said Paul Sereno, the project's lead researcher and a National Geographic explorer-in-residence.

 

[ramonmercado]

Another piece on Dinos lucky breaks.

Dinosaurs survived 2 mass extinctions and 50 million years before taking over the world and dominating ecosystems
http://www.physorg.com/printnews.php?newsid=141994803


A herd of primitive carnivorous dinosaurs (Coelophysis, foreground) is enveloped by a sandstorm, while a large carnivorous crocodile-like archosaur (Postosuchus) and several early sauropodomorph dinosaurs lurk in the background. This reconstructed scene is taken from Steve Brusatte's new book Dinosaurs which is advised by Mike Benton and will be published in October 2008 by Quercus Publishing, London.
Click here to enlarge image


Reporting in Biology Letters, Steve Brusatte, Professor Michael Benton, and colleagues at the University of Bristol show that dinosaurs did not proliferate immediately after they originated, but that their rise was a slow and complicated event, and driven by two mass extinctions.


"The sheer size of dinosaurs like Tyrannosaurus makes us think there was something special about these animals that preordained them for success right from the beginning," Brusatte said. "However, our research shows that the rise of dinosaurs was a prolonged and complicated process. It isn't clear from the data that they would go on to dominate the world until at least 30 million years after they originated."

Importantly, the new research also shows that dinosaurs evolved into all their classic lifestyles – big predators, long-necked herbivores, etc. – long before they became abundant or diversified into the many different species we know today.

Brusatte added: "It just wasn't a case of dinosaurs exploding onto the scene because of a special adaptation. Rather, they had to wait their turn and evolved in fits and starts before finally dominating their world."

Dinosaurs originated about 230 million years ago and survived the Late Triassic mass extinction (228 million years ago), when some 35 per cent of all living families died out. It was their predecessors dying out during this extinction that allowed herbivorous dinosaurs to expand into the niches they left behind.

The rapid expansion of carnivorous and armoured dinosaur groups did not happen until after the much bigger mass extinction some 200 million year ago, at the Triassic-Jurassic boundary. At least half of the species now known to have been living on Earth at that time became extinct, which profoundly affected life on land and in the oceans.

Historically the rise of the dinosaurs has been treated as a classic case in which a group evolves key features that allow it to rapidly expand, fill many niches, and out-compete other groups. But Professor Benton said the story isn't so simplistic: "We argue that the expansion of the dinosaurs took up to 50 million years and was not a simple process that can be explained with broad generalizations."

Source: University of Bristol

 

[ramonmercado]

Pterosaurs couldn't soar, says expert
http://www.physorg.com/printnews.php?newsid=142086647

A reproduction of the Thalassodromeus sethi, a specimen of pterosaur is seen at the Museum of Natural History in Rio de Janeiro. A Japanese researcher has put paleo-biologists in a flap by suggesting pterosaurs -- the winged lizards beloved of toymakers and dino movies -- were unable to fly, New Scientist says.


A Japanese researcher has put paleo-biologists in a flap by suggesting pterosaurs -- the winged lizards beloved of toymakers and dino movies -- were unable to fly, New Scientist says.


Katsufumi Sato of the University of Tokyo carried out an unusual study on the Crozet Islands, in the southern Indian Ocean, to test flying ability among large sea birds.

He attached accelerometers the size of AA batteries to the wings of 28 birds from five large species, including the wandering albatross, the world's biggest flying bird.

Albatrosses fly by riding shifting winds, thanks to wings spanning 3.5 metres (11.4 feet) whose shape can be varied to exploit each draft.

When there is no wind, or if the wind blows at a constant speed, the bird can only stay aloft by flapping its wings, otherwise it is forced down by gravity and air resistance.

In a months-long experiment, Sato's instruments showed that the seabirds had two flapping speeds -- fast for taking off, and slow, for keeping aloft when the wind dies, New Scientist says.

The bird's flapping speed is limited by its muscle strength, and the speed decreases for heavier birds that have longer wings, Sato found.

According to Sato's calculations, animals heavier than 40 kilos (88 pounds) would be unable to flap fast enough to fly in zero winds.

A wandering albatross is fine, as it weighs 22 kilos (44 pounds) -- but the news is terrible for pterosaurs. Large ones would be unable to stay aloft, by this benchmark.

The largest pterosaur specimen found, Quetzalcoatlus northropi, had a wingspan of 11-12 metres (35.75-39 feet) and its weight is estimated to be in the order of 100 kilos (220 pounds).

Sato presented his results at a Biologging Science Symposium in Stanford University, California last month.

He has run into flak from pterosaur fans who are convinced that their creatures were "dynamic soarers" like the albatross and could sustain active flight and not just glide.

Differences in anatomy, physiology and environment must be taken into account when comparing the two sets of flyers, they say, according to the New Scientist report.

 

[feen5]

You wonder why and how people like that get funding. It sounds like that old chestnut that bees should not be able to fly when they clearly can.