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ktrianta

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Intersting article on Dinosaurs and Birds.

Not likely to have evolved from dinosaurs to birds as is the current belief.

http://cas.bellarmine.edu/tietjen/images/lung_structure_and_ventilation_i.htm


Lung Structure and Ventilation in Theropod Dinosaurs and Early Birds

John A. Ruben, Terry D. Jones, * Nicholas R. Geist, W. Jaap Hillenius

Reptiles and birds possess septate lungs rather than the alveolar-style lungs of mammals. The morphology of the unmodified, bellowslike septate lung restricts the maximum rates of respiratory gas exchange. Among taxa possessing septate lungs, only the modified avian flow-through lung is capable of the oxygen-carbon dioxide exchange rates that are typical of active endotherms. Paleontological and neontological evidence indicates that theropod dinosaurs possessed unmodified, bellowslike septate lungs that were ventilated with a crocodilelike hepatic-piston diaphragm. The earliest birds (Archaeopteryx and enantiornithines) also possessed unmodified septate lungs but lacked a hepatic-piston diaphragm mechanism. These data are consistent with an ectothermic status for theropod dinosaurs and early birds.

J. A. Ruben, T. D. Jones, N. R. Geist, Department of Zoology, Oregon State University, Corvallis, OR 97331-2914, USA.
W. J. Hillenius, Department of Biology, College of Charleston, Charleston, SC 29424, USA.
* To whom correspondence should be addressed. E-mail: jonest@bcc.orst.edu
 
ktrianta said:
Intersting article on Dinosaurs and Birds.

Not likely to have evolved from dinosaurs to birds as is the current belief.

http://cas.bellarmine.edu/tietjen/images/lung_structure_and_ventilation_i.htm


Lung Structure and Ventilation in Theropod Dinosaurs and Early Birds

John A. Ruben, Terry D. Jones, * Nicholas R. Geist, W. Jaap Hillenius

Reptiles and birds possess septate lungs rather than the alveolar-style lungs of mammals. The morphology of the unmodified, bellowslike septate lung restricts the maximum rates of respiratory gas exchange. Among taxa possessing septate lungs, only the modified avian flow-through lung is capable of the oxygen-carbon dioxide exchange rates that are typical of active endotherms. Paleontological and neontological evidence indicates that theropod dinosaurs possessed unmodified, bellowslike septate lungs that were ventilated with a crocodilelike hepatic-piston diaphragm. The earliest birds (Archaeopteryx and enantiornithines) also possessed unmodified septate lungs but lacked a hepatic-piston diaphragm mechanism. These data are consistent with an ectothermic status for theropod dinosaurs and early birds.
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Why?
 
On the other hand - there was a bird with claws in China - Confuciusornis. (gets confusing don't it).
http://en.wikipedia.org/wiki/Bird_evolution

Another way to look at it :topic
Ever heard of the "thippeny problem"? - like when we went metric in 1966, there was no problem with the big coins, 2/- became 20c, 1/- became 10c, 6d became 5c, etc - but then the huge debate whether 3d became 2c or 3c etc. Hours and hours went into pondering this quandary ...

and lo and behold, the 2c is (also) becoming - or rather has already become extinct. :eek: :2twocents

... bird species are currently going extinct at a far greater rate than any possible speciation or other generation of new species. The disappearance of a population, subspecies, or species represents the permanent loss of a range of genes.
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PS But try telling Cardinal Pell that man has anything to do with that ...
 

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ktrianta said:
1. The earliest birds ...
2. lacked a hepatic-piston diaphragm mechanism.
3. These data are consistent .. for theropod dinosaurs and early birds.
Click to expand...
1. if they're wrong, the earliest birds couldn't give a damn about worms.
2. if we have hepatic-piston diaphragms, does that mean we're evolved from the model T?

PS. The early bird gets the worm, but the second mouse gets the cheese :2twocents
 
ktrianta said:
Read the paper. The link is there and it explains it.

Basically to do with differences in anatomical structure.
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Couldn't you give a summary in your own words :confused:

There is nothing there to suggest that it's a myth.

Explain your claim.

There are millions of observations supporting evolution, and precisely none suggesting otherwise.
 
spooly - just so you know the creationists are having wet dreams about this article. (Just don't mention "peer review", OK?)
 
spooly74 said:
That link is broken.
If you can't even explain in your own words, don't bother appealing to authority.
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Science News Share Blog Cite Print Email BookmarkDiscovery Raises New Doubts About Dinosaur-bird Links
ScienceDaily (June 9, 2009) ”” Researchers at Oregon State University have made a fundamental new discovery about how birds breathe and have a lung capacity that allows for flight – and the finding means it's unlikely that birds descended from any known theropod dinosaurs.


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See also:
Plants & Animals
Birds
Zoology
Bird Flu Research
Fossils & Ruins
Early Birds
Dinosaurs
Paleontology
Reference
Archaeopteryx
Lung
Feathered dinosaurs
Gun dog
The conclusions add to other evolving evidence that may finally force many paleontologists to reconsider their long-held belief that modern birds are the direct descendants of ancient, meat-eating dinosaurs, OSU researchers say.

"It's really kind of amazing that after centuries of studying birds and flight we still didn't understand a basic aspect of bird biology," said John Ruben, an OSU professor of zoology. "This discovery probably means that birds evolved on a parallel path alongside dinosaurs, starting that process before most dinosaur species even existed."

These studies were just published in The Journal of Morphology, and were funded by the National Science Foundation.

It's been known for decades that the femur, or thigh bone in birds is largely fixed and makes birds into "knee runners," unlike virtually all other land animals, the OSU experts say. What was just discovered, however, is that it's this fixed position of bird bones and musculature that keeps their air-sac lung from collapsing when the bird inhales.

Warm-blooded birds need about 20 times more oxygen than cold-blooded reptiles, and have evolved a unique lung structure that allows for a high rate of gas exchange and high activity level. Their unusual thigh complex is what helps support the lung and prevent its collapse.

"This is fundamental to bird physiology," said Devon Quick, an OSU instructor of zoology who completed this work as part of her doctoral studies. "It's really strange that no one realized this before. The position of the thigh bone and muscles in birds is critical to their lung function, which in turn is what gives them enough lung capacity for flight."

However, every other animal that has walked on land, the scientists said, has a moveable thigh bone that is involved in their motion – including humans, elephants, dogs, lizards and – in the ancient past – dinosaurs.

The implication, the researchers said, is that birds almost certainly did not descend from theropod dinosaurs, such as tyrannosaurus or allosaurus. The findings add to a growing body of evidence in the past two decades that challenge some of the most widely-held beliefs about animal evolution.

"For one thing, birds are found earlier in the fossil record than the dinosaurs they are supposed to have descended from," Ruben said. "That's a pretty serious problem, and there are other inconsistencies with the bird-from-dinosaur theories.

"But one of the primary reasons many scientists kept pointing to birds as having descended from dinosaurs was similarities in their lungs," Ruben said. "However, theropod dinosaurs had a moving femur and therefore could not have had a lung that worked like that in birds. Their abdominal air sac, if they had one, would have collapsed. That undercuts a critical piece of supporting evidence for the dinosaur-bird link.

"A velociraptor did not just sprout feathers at some point and fly off into the sunset," Ruben said.

The newest findings, the researchers said, are more consistent with birds having evolved separately from dinosaurs and developing their own unique characteristics, including feathers, wings and a unique lung and locomotion system.

There are some similarities between birds and dinosaurs, and it is possible, they said, that birds and dinosaurs may have shared a common ancestor, such as the small, reptilian "thecodonts," which may then have evolved on separate evolutionary paths into birds, crocodiles and dinosaurs. The lung structure and physiology of crocodiles, in fact, is much more similar to dinosaurs than it is to birds.

"We aren't suggesting that dinosaurs and birds may not have had a common ancestor somewhere in the distant past," Quick said. "That's quite possible and is routinely found in evolution. It just seems pretty clear now that birds were evolving all along on their own and did not descend directly from the theropod dinosaurs, which lived many millions of years later."

OSU research on avian biology and physiology was among the first in the nation to begin calling into question the dinosaur-bird link since the 1990s. Other findings have been made since then, at OSU and other institutions, which also raise doubts. But old theories die hard, Ruben said, especially when it comes to some of the most distinctive and romanticized animal species in world history.

"Frankly, there's a lot of museum politics involved in this, a lot of careers committed to a particular point of view even if new scientific evidence raises questions," Ruben said. In some museum displays, he said, the birds-descended-from-dinosaurs evolutionary theory has been portrayed as a largely accepted fact, with an asterisk pointing out in small type that "some scientists disagree."

"Our work at OSU used to be pretty much the only asterisk they were talking about," Ruben said. "But now there are more asterisks all the time. That's part of the process of s
 
Timmy said:
spooly - just so you know the creationists are having wet dreams about this article. (Just don't mention "peer review", OK?)
Click to expand...

What does this have to do with creationists?

Just because the dino to bird evolution is the current popular model, does not mean that it is above criticism does it???
 
ktrianta said:
What does this have to do with creationists?

Just because the dino to bird evolution is the current popular model, does not mean that it is above criticism does it???
Click to expand...

OK, I'll mention it - peer review. Check it out, or, keep clutching at those straws!
 
Timmy said:
OK, I'll mention it - peer review. Check it out, or, keep clutching at those straws!
Click to expand...

These studies were published in The Journal of Morphology, and were funded by the National Science Foundation. Is that Peer reviewed enough for you????????
 
ktrianta said:
These studies were published in The Journal of Morphology, and were funded by the National Science Foundation. Is that Peer reviewed enough for you????????
Click to expand...

I am quite satisfied, it is you needing to read the reviews. But all we have seen from you is a claim, a refusal to discuss it in your own words, and a huge slab of cut and paste.
 
ktrianta said:
What does this have to do with creationists?
Click to expand...

Creationists are like the opposition party in politics- they will grab any opportunity they can, no matter how irrelevant, to criticize and deride the people in power (or in this case the accepted truth of evolution) to try and make themselves look more appealing. Even though they would be incapable of producing as good a solution were they in a position where it was demanded of them.
 
Timmy said:
I am quite satisfied, it is you needing to read the reviews. But all we have seen from you is a claim, a refusal to discuss it in your own words, and a huge slab of cut and paste.
Click to expand...

Timmy,

You have the links, read them and come to your own conclusions. I doubt that you even know what peer review is.

By the way, where does it say I have to explain anything in my own words? I have referred to the links and if you bothered to read them, then it is pretty clear that the research shows that the whole dino to bird evolution thing just does not hold water.

If i explained it in my own words, you would have just criticised me for lack of support, until i provided support, and even then when that happens, because it may be your pet belief that ie being challenged you would then just claim that the article was not peer reviewed without even knowing what you are talking about.
 
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