Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

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

11.10.2005


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.

David Williamson | EurekAlert!
Further information:
http://www.unc.edu

More articles from Studies and Analyses:

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>