[_ Old Earth _] "Avian Respiratory Systems" Originated in Dinosaurs

[Barbarian]

Bird-like respiratory systems in dinosaurs -- A recent analysis showing the presence of a very bird-like pulmonary, or lung, system in predatory dinosaurs provides more evidence of an evolutionary link between dinosaurs and birds. First proposed in the late 19th century, theories about the animals' relatedness enjoyed brief support but soon fell out of favor. Evidence gathered over the past 30 years has breathed new life into the hypothesis. O'Connor and Claessens (2005) make clear the unique pulmonary system of birds, which has fixed lungs and air sacs that penetrate the skeleton, has an older history than previously realized. It also dispels the theory that predatory dinosaurs had lungs similar to living reptiles, like crocodiles.

The avian pulmonary system uses "flow-through ventilation," relying on a set of nine flexible air sacs that act like bellows to move air through the almost completely rigid lungs. Air sacs do not take part in the actual oxygen exchange, but do greatly enhance its efficiency and allow for the high metabolic rates found in birds. This system also keeps the volume of air in the lung nearly constant. O'Connor says the presence of an extensive pulmonary air sac system with flow-through ventilation of the lung suggests this group of dinosaurs could have maintained a stable and high metabolism, putting them much closer to a warm-blooded existence. "More and more characteristics that once defined birds--feathers, for example--are now known to have been present in dinosaurs, so, many avian features may really be dinosaurian," said O'Connor. A portion of the air sac actually integrates with the skeleton, forming air pockets in otherwise dense bone. The exact function of this skeletal modification is not completely understood, but one explanation theorizes the skeletal air pockets evolved to lighten the bone structure, allowing dinosaurs to walk upright and birds to fly.
http://people.eku.edu/ritchisong/birdrespiration.html

 

[KevinK]

Weren't the dinosaurs basically big birds? Most dinos were like modern reptiles, and birds are like specialized reptiles. For example, feathers are little more than specialized scales. (I realize I'm not using scientific language, putting it more in common speech. But my gross generalizations must have some validity, and I'm still agreeing with your basic assertions.)

 

[Barbarian]

Weren't the dinosaurs basically big birds? Most dinos were like modern reptiles, and birds are like specialized reptiles.

Dinosaurs, especially the theropod dinosaurs from which birds almost certainly evolved, were very unlike modern reptiles. They had high metabolic rates, evidenced by their skeletons, showing active lifestyles, and by Haversian canals in their bones. Many of them were feathered, and as you see, had bird-like respiratory systems. A growing number of scientists agree with you, grouping birds and dinosaurs together apart from reptiles, in the same way that many scientists group mammals and advanced thecodonts as a group, apart from reptiles.

For example, feathers are little more than specialized scales. (I realize I'm not using scientific language, putting it more in common speech. But my gross generalizations must have some validity, and I'm still agreeing with your basic assertions.)

There is some evidence that scutes (scales found on dinosaurs and birds) are derived from feathers. Other kinds of scales probably did not. Genetic manipulation can turn scutes into feathers in many cases. It appears that feathers are indeed modified scales.

 

[Barbarian]

Scutes and feathers turn out to have the same chemical structure and are controlled by the same genes. And the same protein that when missing in birds, results in webbed feet, mediates the conversion of scales to feathers.

 

[brother Paul]

Avian fossils predate the Archaeopteryx model by nearly 100,000 years....

grouping birds and dinosaurs together apart from reptiles

This is one more example of what the perpetrators of the theory over fact do. When reality begins to reflect opposition to the imposed Mantra, they wiggle the definition of terms (like they did with "species"). Dinosaur MEANS large or giant lizard and refers expressly to reptiles.

Birds are not and never were "Dinosaurs" nor are they reptiles. Dinosaurs however ARE all reptiles. Just because the deceptive ones work hard to change the plenary meaning of terms does not make the switcheroo now "truth"....

More propaganda technique only reveals the subtle dishonesty and intent....

We see this in what progressive politicians and their rhetoricians did with the word "choice" (now a politically sensitive buzzword euphemised to produce a defensive response). Webster defines it as

choice
noun \ˈchȯis\
Simple Definition of choice

• : the act of choosing : the act of picking or deciding between two or more possibilities
  
  
• : the opportunity or power to choose between two or more possibilities : the opportunity or power to make a decision
  
  
• : a range of things that can be chosen

but NOW it is a term wherein the choice of the individual is denied by law, the choice of the father is denied by law, and now the same crowd under their redefinition of "choice" is pushing to kill full term babies when they are birthing. The rhetoric says any who oppose this are "against freedom of choice".

Well here we have one of many examples of the same crafty deception for a political purpose. We KNOW Dinosours are reptile and means huge reptiles and now because a bunch with degrees publicly say so (appeal to authority) and declare consensus (argumentum ad populum) they now want Birds to be included so as to support and convince of the predetermined theory....

Sick minded devils if you ask me....genuinely objective scientists should see through this but sadly as the matrix goes many are being sucked in....Anatomical structural similarity does not necessitate that one BECAME the other...it is a prime non-sequitur

 

[Ph8th]

similarity comes from common a Creator. Age is based on assumption.
peter

 

[brother Paul]

Everybody quickly ignore the attempt at further brainwashing and look up the terms Dinosaur in any reputable dictionary or encyclopedia NOW! Then look up Reptile....then look up Avian...then look up Bird...and do it quick the diversions are about to flow.....Please....walk in the truth and may God bless.

Paul

 

[Barbarian]

Avian fossils predate the Archaeopteryx model by nearly 100,000 years....

Feathered flying dinosaurs predated birds by a very long time. We don't know how old Arachaepteryx is as a genu. It was fragile and we have found few fossils. But as you learned earlier, transitionals are not usually the direct ancestors of later forms. They are usually on a different branch, descended from the actual ancestor.

Barbarian observes:
grouping birds and dinosaurs together apart from reptiles

This is one more example of what the perpetrators of the theory over fact do.

Remember, it can't be a theory until it's based on facts.

When reality begins to reflect opposition to the imposed Mantra, they wiggle the definition of terms (like they did with "species"). Dinosaur MEANS large or giant lizard and refers expressly to reptiles.

The classification is due to the fact that theropod dinosaurs are more closely related to birds than to other reptiles. This group was highly energetic, with a endothermic metabolism ,as evidenced by the Haversian canals in their bones, an avian respiratory system, and feathers. A further confirmation is that when a bit of dinosaur heme was found intact in a T-Rex bone, it turned out to be more like that of birds than like that of other reptiles.

The theropods and birds evolved into a very different kind of animal than other reptiles.

Birds are not and never were "Dinosaurs" nor are they reptiles.

They have many characteristics of dinosaurs, such as feathers, scutes, a pneumatized bone respiratory system, and so on. It's pointless to deny.

Dinosaurs however ARE all reptiles.

Which is like saying "thecodonts are all reptiles." But they have characteristics found only in mammals, and used to classify mammals.

Just because the deceptive ones work hard to change the plenary meaning of terms does not make the switcheroo now "truth"....

See above. We know that many, or all advanced theropods had the traits used to identify an organism as a bird. A few had all the traits of a bird. Honesty would require an admission of these facts.

(bunny trail on abortion deleted)

Well here we have one of many examples of the same crafty deception for a political purpose. We KNOW Dinosours are reptile and means huge reptiles and now because a bunch with degrees publicly say so (appeal to authority) and declare consensus (argumentum ad populum)

Note that I demonstrated that birds and dinosaurs form a group without once making such a claim. Indeed, if you go back and look, you will find only evidence cited. Honesty would require your admission of this fact. We'll discuss the evidence for the evolution of mammals from thecodonts, next.

 

[Barbarian]

Everybody quickly ignore the attempt at further brainwashing and look up the terms Dinosaur in any reputable dictionary or encyclopedia NOW!

Using a common dictionary for scientific terms is a bad idea. However, let's see what a reputable source like Encyclopedia Britannica says:

The debate over the origin of birds centres on whether birds descended directly from thecodont reptiles about 230 million years ago (during the Triassic Period) or from a later lineage, the carnivorous theropod dinosaurs. This debate has been long-standing and divisive. At the beginning of the 21st century, the pendulum has swung decisively toward the theropod ancestor hypothesis—that today’s birds are feathered dinosaurs. This hypothesis is supported by analyses of shared characteristics (synapomorphies) combined with improved samples of early bipedal theropods.

The origin of feathers
Feathers are complex and novel evolutionary structures. They did not evolve directly from reptilian scales, as once was thought. Current hypotheses propose that they evolved through an invagination of the epidermis around the base of a dermal papilla, followed by increasing complexity of form and function. They evolved before birds and even before avian flight. Thus, early feathers functioned in thermal insulation, communication, or water repellency, but not in aerodynamics and flight. Among extinct life-forms, feathers are no longer considered a unique and diagnostic characteristic of birds. Feathers with modern features were present in a variety of forms on a variety of theropod dinosaurs. At least nine Cretaceous dinosaurs had featherlike structures. The details of some are questionable, but some, such as those of Sinornithosaurus and other basal dromaeosaurs, bear a resemblance to modern pennaceous feathers. Feathered dinosaurs did not survive the end of the Cretaceous Period, but birds did, and then they flourished.
http://www.britannica.com/animal/bird-animal/Evolution-and-paleontology#toc49228

This is actually pretty good, but it does not include the research showing that feathers and scutes (scales found on dinosaurs and birds) are genetically and chemically the same as feathers. Indeed, scutes can be made to produce feathers.

And there are a lot more feathered dinosaurs/early birds now known.

 

[Barbarian]

correction; should be mammals evolving from therapsids.

 

[Jacks Bratt]

Using a common dictionary for scientific terms is a bad idea. However, let's see what a reputable source like Encyclopedia Britannica says:

The debate over the origin of birds centres on whether birds descended directly from thecodont reptiles about 230 million years ago (during the Triassic Period) or from a later lineage, the carnivorous theropod dinosaurs. This debate has been long-standing and divisive. At the beginning of the 21st century, the pendulum has swung decisively toward the theropod ancestor hypothesis—that today’s birds are feathered dinosaurs. This hypothesis is supported by analyses of shared characteristics (synapomorphies) combined with improved samples of early bipedal theropods.

The origin of feathers
Feathers are complex and novel evolutionary structures. They did not evolve directly from reptilian scales, as once was thought. Current hypotheses propose that they evolved through an invagination of the epidermis around the base of a dermal papilla, followed by increasing complexity of form and function. They evolved before birds and even before avian flight. Thus, early feathers functioned in thermal insulation, communication, or water repellency, but not in aerodynamics and flight. Among extinct life-forms, feathers are no longer considered a unique and diagnostic characteristic of birds. Feathers with modern features were present in a variety of forms on a variety of theropod dinosaurs. At least nine Cretaceous dinosaurs had featherlike structures. The details of some are questionable, but some, such as those of Sinornithosaurus and other basal dromaeosaurs, bear a resemblance to modern pennaceous feathers. Feathered dinosaurs did not survive the end of the Cretaceous Period, but birds did, and then they flourished.
http://www.britannica.com/animal/bird-animal/Evolution-and-paleontology#toc49228

This is actually pretty good, but it does not include the research showing that feathers and scutes (scales found on dinosaurs and birds) are genetically and chemically the same as feathers. Indeed, scutes can be made to produce feathers.

And there are a lot more feathered dinosaurs/early birds now known.

The origin of feathers? How do they even dare try to predict this bogus diagram of stages when it happened millions of years ago.

This is such speculative assumptive dreaming.

 

[brother Paul]

Birds! And some are bird and reptile crushed together....birds are not and never were reptiles...any alleged reliable source that is influenced by the hocus pocus propaganda technique of redefining terms to fit the imagined possibility should no longer be considered reliable. As Shakespeare once said the sun is not the moon and the moon is not the sun (no matter how many insist it is)...

 

[Barbarian]

The origin of feathers? How do they even dare try to predict this bogus diagram of stages when it happened millions of years ago.

Because we can test that idea in existing organism. Turns out that scutes (scales found on birds and dinosaurs) can be induced to form feathers instead. And it happens that way. Also, scutes and feathers are mediated by the same genes and are composed of the same form of keratin unlike other scales.

It all depends on evidence.

 

[Barbarian]

Birds! And some are bird and reptile crushed together....

You're probably thinking of the dinosaur/bird hoax played on National Geographic. Scientists advised them to hold off publishing until the find was vetted. They went ahead and published, and were then embarrassed. They weren't crushed together; someone clumsily faked them by fitting slabs together. Turns out, the dinosaur in that fraud was an important new fossil in itself.

birds are not and never were reptiles...

More precisely, birds evolved from dinosaurs. We know this from genetic data, fossil transitionals, and of course that dinosaur heme that turned out to be birdlike. Oh, and the fact that the avian respiratory system evolved first in dinosaurs.

 

[brother Paul]

When you say evidence you mean spin....scales are entirely formed in the epidermis....totally different

 

[Barbarian]

When you say evidence you mean spin....

Nope. Evidence. For example, scales can be induced to form feathers.

In one way, this is not terribly surprising, as Alan Brush has shown that bird scutes, scutellae, claw sheaths, beak sheaths, and scales around the eyes are of the same chemical composition as feathers and are controlled by the same genes!
` The reticulae have been shown to be identical to those of crocodiles, both in composition and their location in the DNA. However, crocodiles also have scutes, which have almost the same chemical composition as bird scutes.
` Each time they infected a chick with the inhibitor virus at 15-18 days, at least some of the scutes developed into feathers in varying degrees, ranging from a thickening of the edge of the scute (like a follicle, I gather), to short, fat feathers, to long, thin feather filaments.

` The feathers developed the barbs characteristic of normal feathers, though there were a lot more of them.
` Unsurprisingly, the pebbly reticulae did not develop into feathers, as these scales are, according to Brush, more reptillian in various ways. Though Dhouaily, Hardy and Sengel (1980) were able to convert reticulae into feathers after treating them with retinoic acid, they were much more successful with the other two types of scales - keep in mind, I don't think this conversion had that much to do with development.
` Clearly, scutes and feathers are much more strongly linked than the reptilian scales, reticulae being chemically and genetically different. Now, dinosaurs such as Tyrannosaurus also had scutes - in fact armored dinosaurs were actually covered in modified scutes. And we know that more primitive tyrannosaurs and related dinosaurs had feathers.
http://seequine.blogspot.com/2005/05/dinosaurs-and-their-descendents-4-how.html

scales are entirely formed in the epidermis....totally different

So you see, the process can be observed in modern birds by inhibiting some of the genes that have evolved since then.