Feathered dinosaur theory won't fly

Feathers are flying once again over a fossil which is the cornerstone of 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 eater was covered with a down of fibre-like structures that, its Chinese researchers claimed, were primitive feathers.

Although the "feathers" were clearly not capable of flight, their existence provided key backing for a theory first aired in the 1970s that birds evolved from dinosaurs. This once outlandish notion has become mainstream.

But a new study, published by a team led by South African academic Prof Theagarten Lingham Soliar at the University of KwaZulu Natal, claims that the alleged branched structures that were proclaimed as early feathers are the remains of collagen fibres that reinforced a frill that ran down the dinosaur's back from head to tail as well as the skin.

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

He stressed in the paper that "the wider question of whether or not birds originate from dinosaurs does not concern the present study." But he added: "Because of the shabby methods of the original investigations of protofeathers by many of the same workers connected with other aspects of palaeontology, it does leave a cloud over the general reliability of such studies."

The evidence comes from a recently discovered specimen of Sinoauropteryx, also found in the same Yixian Formation at Liaoning, that Prof Lingham Soliar has studied under a high powered microscope.

"The fibres show a striking similarity to the structure and levels of organisation of dermal collagen," the kind of tough fibers found on the skin of sharks and reptiles today.

The fibres have an unusual "beaded" structure, but this most likely was caused by a natural twisting of these strands, and creasing caused by dehydration, when the dinosaur died and its tissues started to dry. "These are degraded fibres (probably collagen) pure and simple and nothing whatsoever to do with feathers or their origin in any form or manner," said Prof Lingham Soliar.

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, they suggest in the Proceedings of the Royal Society B.

The birds from dinosaurs theory is based on the idea that small, specialised theropod dinosaurs and carnivorous, bipedal dinosaurs with three toed feet gained an advantage by growing feathers leading to three highly contentious theories.

First, that feathers developed from a novel 'protofeather, rather than scales, second, that they originated for retaining heat, with the implications that body heat was generated internally in reptiles, and third, that such feathers, primarily unconnected with flight, eventually enabled the ancestor of birds to fly from the ground up, defying gravity.

The more reasonable theory of the evolution of flight, bearing in mind that the structures associated with flight would have been very poorly developed at first, was that birds took to the trees for safety, said Prof Lingham-Soliar.

From there, it was a relatively small step to developing gliding skills and then the ability to fly. The first known bird is Archaeopteryx, which lived around 150 million years ago.

The general consensus of palaeontologists remains that birds did indeed evolve from dinosaurs, and that most people support this view.

However, Prof Lingham Soliar said: "My view is that we leave mob rule out of good science otherwise we would still believe in blood-letting as a cure for disease, numerology of the pyramids, the flat earth theory and the sun going round the earth. "

News Release

For immediate use Oct. 10, 2005 -- No. 477

Latest study: scientists say no evidence exists that therapod dinosaurs evolved into birds

By DAVID WILLIAMSON

UNC News Services

CHAPEL HILL -- No good evidence exists that fossilized structures found in China and which some paleontologists claim are the earliest known rudimentary feathers were really feathers at all, a renowned ornithologist says. Instead, the fossilized patterns appear to be bits of decomposed skin and supporting tissues that just happen to resemble feathers to a modest degree.

Led by Dr. Alan Feduccia of the University of North Carolina at Chapel Hill, a team of scientists says that as a result of their new research and other studies, continuing, exaggerated controversies over "feathered dinosaurs" make no sense.

"We all agree that birds and dinosaurs had some reptilian ancestors in common," said Feduccia, professor of biology in UNC’s College of Arts and Sciences. "But to say dinosaurs were the ancestors of the modern birds we see flying around outside today because we would like them to be is a big mistake.

"The theory that birds are the equivalent of living dinosaurs and that dinosaurs were feathered is so full of holes that the creationists have jumped all over it, using the evolutionary nonsense of ‘dinosaurian science’ as evidence against the theory of evolution," he said. "To paraphrase one such individual, ‘This isn’t science . . . This is comic relief.’"

A report on the team’s latest research appears in the Journal of Morphology published online Monday (Oct. 10). Other authors are Drs. Theagarten Lingham-Soliar of the University of KwaZulu-Natal in South Africa and Richard Hinchliffe of the University College of Wales.

Using powerful microscopes, the team examined the skin of modern reptiles, the effects of decomposition on skin and the fossil evidence relating to alleged feather progenitors, also known as "protofeathers."

They found that fossilized patterns that resemble feathers somewhat also occur in fossils known not to be closely related to birds and hence are far more likely to be skin-related tissues, Feduccia said. Much of the confusion arose from the fact that in China in the same area, two sets of fossils were found. Some of these had true feathers and were indeed birds known as "microraptors," while others did not and should not be considered birds at all.

"Collagen is a scleroprotein, the chief structural protein of the connective tissue layer of skin," he said. "Naturally, because of its low solubility in water and its organization as tough, inelastic fiber networks, we would expect it to be preserved occasionally from flayed skin during the fossilization process."

Although a few artists depicted feathered dinosaurs as far back as the 1970s, Feduccia said the strongest case for feathered dinosaurs arose in 1996 with a small black and white photo of the early Cretaceous period small dinosaur Sinosauropteryx, which sported a coat of filamentous structures some called "dino-fuzz."

"The photo subsequently appeared in various prominent publications as the long-sought ‘definitive’ evidence of dinosaur ‘feathers’ and that birds were descended from dinosaurs," he said. "Yet no one ever bothered to provide evidence -- either structural or biological -- that these structures had anything to do with feathers. In our new work, we show that these and other filamentous structures were not protofeathers, but rather the remains of collagenous fiber meshworks that reinforced the skin."

Belief in the existence of the "dino-fuzz feathers" caused some scientists to conclude that they served as insulation, and hence dinosaurs were warm-blooded.

The researchers also examined evidence from five independent, agreeing studies involving structural and genetic analyses related to the "tridactyl," or three-fingered, hand, which is composed of digits 1, 2 and 3 in dinosaurs, Feduccia said. That is the most critical characteristic linking birds to dinosaurs. They found that embryos of developing birds differed significantly in that bird wings arose from digits 2, 3 and 4, the equivalent of index, middle and ring fingers of humans. To change so radically during evolution would be highly unlikely.

"If birds descended from dinosaurs, we would expect the same 1, 2 and 3 pattern," he said.

Current dinosaurian dogma requires that all the intricate adaptations of birds’ wings and feathers for flight evolved in a flightless dinosaur and then somehow became useful for flight only much later, Feduccia said. That is "close to being non-Darwinian."

Also, the current feathered dinosaurs theory makes little sense time-wise either because it holds that all stages of feather evolution and bird ancestry occurred some 125 million years ago in the early Cretaceous fossils unearthed in China.

"That’s some 25 million years after the time of Archaeopteryx, which already was a bird in the modern sense," he said. Superficially bird-like dinosaurs occurred some 25 million to 80 million years after the earliest known bird, which is 150 million years old."

Feduccia said the publication and promotion of feathered dinosaurs by the popular press and by prestigious journals and magazines, including National Geographic, Nature and Science, have made it difficult for opposing views to get a proper hearing.

"With the advent of ‘feathered dinosaurs,’ we are truly witnessing the beginnings of the meltdown of the field of paleontology," he said. "Just as the discovery a four-chambered heart in a dinosaur described in 2000 in an article in Science turned out to be an artifact, feathered dinosaurs too have become part of the fantasia of this field. Much of this is part of the delusional fantasy of the world of dinosaurs, the wishful hope that one can finally study dinosaurs at the backyard bird feeder.

"It is now clear that the origin of birds is a much more complicated question than has been previously thought," Feduccia said.

The UNC scientist is the author of more than 150 papers and six major books, including The Age of Birds, which Harvard University Press published in 1980 and The Origin and Evolution of Birds, published by Yale University Press in 1996.

Among other discoveries, Feduccia found by a careful examination that Archaeopteryx, the earliest known bird and one of the world’s most famous fossils, could fly. Previously, many scientists thought the animal to be an Earth-bound dinosaur.

He determined its flying ability by observing that the fossil’s feathers had leading edges significantly shorter than their trailing edges, which is characteristic of all modern flying birds. The edges of feather of birds incapable of flight, such as ostriches, are symmetrical.

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Note: Feduccia can be reached at (919) 962-3050 (w), (252) 438-6545 this weekend or (919) 942-3377 after Sunday afternoon (Oct. 9). feduccia@bio.unc.edun News Services contact: For art, contact David Williamson at (919) 962-8596 (w) or 732-2991 (h).

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