Dinosaurs Breathed Like Birds

[dhuusa_deer]

Birds evolved from dinosaurs, most paleontologists agree. But there are big questions about just how similar the large dinosaurs really were to today's eagles and hawks.

Experts still argue whether dinosaurs were hot-blooded, agile and active like the cunning predators in "Jurassic Park" or, as scientists at U.C. Berkeley phrase the old conventional view, "sluggish and stupid."

A new study finds an important bird trait embedded in dinosaur bones that argues for the more nimble view.

Big meat-eating dinosaurs had a complex system of air sacs similar to the setup in today's birds, according to an investigation led by Patrick O'Connor of Ohio University. The lungs of theropod dinosaurs -- carnivores that walked on two legs and had bird-like feet -- likely pumped air into hollow sacs in their skeletons, as is the case in birds.

"What was once formally considered unique to birds was present in some form in the ancestors of birds," O'Connor said.

The study, funded in part by the National Science Foundation, is detailed in the July 14 issue of the journal Nature.

Theory takes flight

For more than three decades, scientists have seriously pondered the idea that birds are today's dinosaurs. The theory was put on solid footing in 1996 with the discovery of a well preserved, small and feathered dinosaur named sinosauropterx.

Other studies have since suggested that while an adult T. rex likely had scales, its young may have been covered in downy feathers.

Yet paleontologists had long thought that dinosaurs were cold-blooded, like reptiles. A reptile's simple heart puts only low amounts of oxygen in its blood -- not the right mix in the recipe of flight.

Modern computerized tomography (CT) scans of dinosaur chest cavities five years ago found the apparent remnants of complex, four-chambered hearts more like mammals and birds.

Earlier this year, rare soft tissue of a T. rex showed its blood vessels were similar to those of an ostrich.

Meanwhile, sketchy evidence in recent years had suggested dinosaur bones might contain air cavities. Still, some experts contended dinosaurs breathed more like crocodiles.

In the new study, O'Connor and his colleague, Leon Claessens of Harvard University, examined Majungatholus atopus, a recently discovered primitive theropod that is several yards long. They found cavities in its vertebral bones similar to those found in birds.

They found that "the pulmonary system of meat-eating dinosaurs such as T. rex in fact shares many structural similarities with that of modern birds," Claessens said.

Warm or cold?

A bird's air sacs, distributed throughout its body, cause air to pass through the lungs twice, creating a very efficient respiration system.

The superior breathing apparatus, along with their complex hearts, increases bird metabolism and makes them warm-blooded, meaning they generate internal heat that controls their body temperature.

Reptiles are cold-blooded, relying on the environment and their behavior to regulate body temperature.

Though the dinosaur breathing system was not likely identical to living birds, "it's nothing like the crocodile system as we know it," O'Connor said.

The newfound similarities do not necessarily mean dinosaurs were warm-blooded, however. While that debate continues, O'Connor speculates that the blood of the long-gone beasts was probably somewhere between warm and cold.

[Hydra]

Dhuuso_Dheere, According to your comment in another thread, you would follow spinoza's concept of God if atheism wasn't an option for you, Why is that? Do you also know how his definition of God differs from that of Islam if you know the concept of God in islam? Sorry if your topic was strictly for dinasours having breathed like birds.

[FULL_MOON]

Finally you did something useful other then disregarding allah swt, Btw interesting article saxiib, Keep it up Dhuuse deer .
.
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بارك, جعله مقدس, رسم إشار

[dhuusa_deer]

Hydra,

"According to your comment in another thread, you would follow spinoza's concept of God if atheism wasn't an option for you, Why is that?"

Many reasons.

I said 'Spinoza's God' for specific reason. The 'God' of Pantheism, which is Spinoza's God, is ungodlike. Many Pantheist don't even use the word 'God' to describe their supreme being. The name God is has universal meaning across many denominations in stark contrast to the meaning of Pantheist's 'God'.

Spinoza's God (S-God) is part of ALL the natural laws of the universe. His existance 'necessitates' the 'creation' or existance of our universe. Since natural laws of the universe are extension of S-God, and S-God exits, its given that our universe must come into existance too. S-God didn't not have free will and one day decided to 'create' our universe from nothing. Our universe was 'created' or formed in compliance with and becuz of the natural laws of the universe.

These natural laws of the universe govern everything from living to non-living. From biological to chemical to physical. Everything that 'is' is as the result of the actions of these natural laws. We come to know these natural laws to be invariant. We know this from looking in deep space at other galaxies which obey the same laws as ours. We also know this from looking back in history (looking into deep space), billions of years ago, in which these invariant natural seemed to be at work. Therefore, its reasonable to say that these invariant natural laws existed prior the formation of our universe and will probably exist after our universe dies.

One appealing concept to me about S-God is, unlike other Gods, its personal God. S-God doesn't have human-like emotions like anger, hate, fear and prejudice. S-God doesn't have hell or heaven, in his eyes no one is good or bad, right or wrong. S-God can't bend, change or alter invariant natural laws. S-God doesn't have favourites, no one can claim to be suprior becuz they 'believe' in S-God, as S-God doesn't reward worship.

There are no religious texts sent down by S-God, no prophets. S-God never communicated with us. His only contact with us is through these invariant natural laws.

Lastly, knowing more about these invariant natural laws will get us closer to knowing the truth about 'God'. Once we find a unified theory explaining the ALL natural laws, the holy grail of modern physics and cosmology, we would, as Stephen Hawkin put it 'know the mind of God'.

To me all of this makes sense and don't have any philosophical problems with it, other than not seeing the need for a 'God'.

"Do you also know how his definition of God differs from that of Islam if you know the concept of God in islam?"

The God of Islam, like that of all other monotheistic faiths (Judaism, christianity and Zoroasterism), is omnipotent, omnipresent, omnisceince and benevolent. The God of Islam has human emotions like anger, sadness and happiness. Demands worship and rewards it. Those that don't, go to hell. Has heaven and hell in the after world. Some humans are suprior in his view becuz they believe.

In my view all this sounds human invention. Laden with projections of human fears, desires, hopes and prejudices.

[PragmaticGal]

That's really interesting. But I think dinosaurs share some features with reptiles that would make them not entirely endothermic.

[PragmaticGal]

DD,

Why use the term "God", when it is already associated with a certain entity that is quite unlike Spinoza's "God"? Isn't that just confusing the issue?

[dhuusa_deer]

[quote="PragmaticGal"]DD,

Why use the term "God", when it is already associated with a certain entity that is quite unlike Spinoza's "God"? Isn't that just confusing the issue?[/quote]

I know, that is why I said Spinoza's God. Many believers in such deity don't use the term 'God' at all, just call it Nature or Supreme being or whatever.

Most scientist's who say they believe in 'God' like Einstien, Hawking, mean they believe in Spinoza's God. I agree its confusing and loosely used.

[dhuusa_deer]

PragmaticGal,

Are you an atheist?

[PragmaticGal]

[quote="dhuusa_deer"]PragmaticGal,

Are you an atheist?[/quote]

Yes.

[dhuusa_deer]

[quote="PragmaticGal"][quote="dhuusa_deer"]PragmaticGal,

Are you an atheist?[/quote]

Yes.[/quote]

And one more question. Are you student of science? If yes, what do you take?

[PragmaticGal]

[quote="dhuusa_deer"][quote="PragmaticGal"][quote="dhuusa_deer"]PragmaticGal,

Are you an atheist?[/quote]

Yes.[/quote]

And one more question. Are you student of science? If yes, what do you take?[/quote]

I am a biologist.

[dhuusa_deer]

[quote="PragmaticGal"][quote="dhuusa_deer"][quote="PragmaticGal"][quote="dhuusa_deer"]PragmaticGal,

Are you an atheist?[/quote]

Yes.[/quote]

And one more question. Are you student of science? If yes, what do you take?[/quote]

I am a biologist.[/quote]

That is nice to hear. I'm taking biochemistry, going into my third year, this coming year.

Are you still studying or done your studies?

[gurey25]

"Meanwhile, sketchy evidence in recent years had suggested dinosaur bones might contain air cavities. Still, some experts contended dinosaurs breathed more like crocodiles.
"
Air cavities? does that mean they were lighter than we thought.

and guys DD and Pragamticgirl there is something called PM.

[PragmaticGal]

I'm done my undergrad studies. Doing my PhD in genetics. What school do you attend? We (our lab) collaborates w/ a few researchers at U of T.

[dhuusa_deer]

gurey25

"Air cavities? does that mean they were lighter than we thought."

In theory yes. I have personally dissected pigeons, who like all other birds, have air sacks. Nine in total. These air sacks are filled with air while in flight, making them weigh less than when on land. They are similar to lipid filled livers of sharks, which reduce the density of sharks when under water.