Dinosaurs may have been a fluffy lot ~~ now they tell us....

THE popular image of Tyrannosaurus rex and other killer dinosaurs may have to be changed as a scientific consensus emerges that many were covered with feathers.

Most predatory dinosaurs such as tyrannosaurs and velociraptors have usually been depicted in museums, films and books as covered in a thick hide of dull brown or green skin. The impression was of a killer stripped of adornment in the name of hunting efficiency.

Gareth Dyke, a palaeontologist of University College Dublin, will tell the BA Festival of Science being held in the city that most such creatures were coated with delicate feathery plumage that could even have been multi-coloured. Fossil evidence that such dinosaurs were feathered is now “irrefutable”.

“The way these creatures are depicted can no longer be considered scientifically accurate,” he said. “All the evidence is that they looked more like birds than reptiles. Tyrannosaurs might have resembled giant chicks.”

The latest visualisation suggests that parts of Walking with Dinosaurs, the acclaimed BBC series, cannot be seen as scientifically valid. Similar criticisms might also be levelled at the Hollywood blockbuster Jurassic Park.

The Natural History Museum in London, which has a popular exhibition of robot dinosaurs, conceded this weekend that some of its permanent displays may have to be adapted to reflect the new findings.

The feather revelation follows a series of discoveries in fossil beds at Liaoning in northeast China where a volcanic eruption buried many dinosaurs alive. It also cut off the oxygen that would otherwise have rotted them away.

Some theropod (“beast-footed”) dinosaurs were preserved complete with feathery plumage. Theropod is the name given to predatory creatures that walked upright on two legs, balanced by a long tail.

The feathered finds include an early tyrannosaur, a likely ancestor of Tyrannosaurus rex, two small flying dinosaurs and five other predators. Feathers are thought to have evolved first to keep dinosaurs warm and only later as an aid to flight.

Such finds are significant in linking dinosaurs to modern birds. Most palaeontologists accept that birds are descended from dinosaurs but there is fierce debate over how this happened. At the Dublin conference, Dyke will present new evidence suggesting that dinosaurs evolved the ability to fly and that some even developed all four limbs into wings.

From six years ago (still on the hard drive, of course):

Another Dino with ‘Feathers'
by Kenneth Chang
May 26 1999
Scientists opposed to the idea that birds descended from dinosaurs see otherwise. The filament impressions, says Larry Martin of the University of Kansas, are probably left behind by connective tissue fibers beneath the skin. "I think it's pretty clear they're not homologues of feathers," Martin says. "They have no features of feathers." Martin has argued that two other reported "feathered dinosaurs" — which clearly have modern-looking bird feathers — are actually flightless birds, not dinosaurs. Luis Chiappe of the Natural History Museum of Los Angeles County dismisses Martin's hypothesis that the impressions are merely tendons and ligaments. "The only ones having these types of things are the therapods," he says. "Is that a coincidence? I don't think so. These structures that most of us regard as protofeathers are showing up in a number of therapod lineages. I would bet they would also be in creatures like a T. rex." That feathers haven't been seen in any T. rex fossils doesn't mean Chiappe has already lost his bet. Stuff like skin, scales and feathers rarely fossilize, and, Currie says, if tyrannosaurs had feathers, they likely shed them as they grew into adults.

What a lucky break for Chiappe et al -- there was no fossil evidence for it, which just means that as adults, they no longer had it. Heads he wins, tails you lose. :')

The link was extinct, so I located a similar page:

Fossils Challenge Bird Origin
by Paul Recer
June 22, 2000
The fossil of a small lizard-like, flying reptile with a complex set of feathers challenges the theory that birds evolved from dinosaurs, a new study says.

Researchers say the feathered reptile lived 225 million years ago, proving that feathered animals evolved millions of years before the appearance of the dinosaurs that most experts say are the ancestors of modern birds.

The fossil has been called Longisquama and is thought to be an archosaur, a member of a reptile group that later gave rise to dinosaurs, crocodiles and birds. The first known bird, Archeopteryx, appeared about 145 million years ago, some 75 million after the date for Longisquama.

"Here you've got an animal that isn't a bird and it isn't a dinosaur, and yet it has feathers,'' said Nicholas R. Geist, paleobiologist at Sonoma State University and co-author of a study appearing Friday in the journal Science.

"It is going to be a major monkey wrench in the theory about the dinosaurean origin of birds,'' he said. "It is going to cause some people to take a real good second look at their data.''

However, Jacques Gauthier of Yale University, an expert on the evolution of dinosaurs, said that Longisquama is a poorly preserved specimen that is important only "if you allow your imagination to run wild.''

"There is a huge body of data that show birds evolved from dinosaurs,'' said Gauthier. "This (the Longisquama study) is way over the top.''

Gauthier said that a single specimen is not enough to dismiss a theory that is supported by many studies that point to the dinosaur ancestry of birds, including evidence that some dinosaurs had feathers.

The Longisquama fossil includes the head, forelegs and part of a torso of a lizard-like animal. Along its back are a series of appendages that Geist and his co-authors say are feathers.

Longisquama was found in Kyrgyzstan, in central Asia, in 1969, and was stored for years in a drawer in Moscow. The specimen provoked little interest until it was included as part of a traveling exhibition and spotted at a shopping mall in Kansas by Oregon State University paleontologists John Ruben and Terry Jones, co-authors of the study in Science.

Ruben and Jones said they identified the appendages on the back of the small fossil as feathers and began a long study of the small critter.

Jones said that the feathers along the back of Longisquama are fully developed and very "birdlike.''

"The skeleton is also very birdlike,'' said Jones. "It has a birdlike head, shoulders and a wishbone. The wishbone is almost exactly like that of Archeopteryx.''

Geist said the feather structure of Longisquama was well preserved in hardened mud because the animal apparently sank to a lake bottom after it died.

He that Longisquama probably had muscle control of the feathers and that it used them to glide from trees. The animal was not able to achieve true flight as do modern birds, said Geist.

"These feathers emerge from a follicle the way feathers do in modern birds,'' said Geist. "They had a quill-like structure that was hollow.''

Geist said that feathers are very complicated structures and that it is unlikely that feathers would have evolved twice -- once among the early reptiles and then later among the dinosaurs.

Ruben said that other researchers have identified dinosaurs as having feathers and as being birdlike. But he said two of the most birdlike dinosaurs, Bambiraptor and Velociraptor, lived 70 million years after the earliest known bird.

Longisquama, however, he said, lived at the right time and had the feathers that suggest it could have been an evolutionary ancestor of birds.

Jones said that the feathers on Longisquama are so well developed that it is likely that the first feathers appeared on reptiles many generations before Longisquama came along.

But Gauthier said the study is going to have little effect on the theory that birds evolved from dinosaurs, an idea that can be traced back through the work of hundreds of scientists over many decades.

Accepting a Longisquama as the first bird "would be like saying suddenly that humans are not primates or even mammals,'' said Gaiter. He said more evidence than Longisquama would be needed to disprove a theory that has been long accepted by the majority of paleobiologists.

Birds and dinos had a common ancestor. The dinos and the ancestor are extinct. Birds are still around.

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