"Ectothermic dinosaurs"

[[][][]cordylus[][][]]

This was an old thread on Jptoys... what do you guys think of it?



"Only Kiezel on this forum perhaps has the scientific background to understand the original paper in the Public Library of Science:

biology.plosjournals.org/perlserv....al.pbio.0040248

but the gist of the research is that smaller dinosaurs were coldblooded; only the huge dinosaurs were able to maintain high body temperatures by virtue of their size (mass or inertial homeothermy). Which means that metabolically speaking dinosaurs were essentially cold-blooded, or at least non-internal-body-temperature-regulating reptiles, like crocodiles.

www.newscientist.com/article/dn95....-its-blood.html
www.eurekalert.org/pub_releases/2006-07/plos-maf070506.php

By the way, this study included Tyrannosaurus rex and Daspletosaurus and Gorgosaurus and Albertosaurus, so we can mercifully dispense with the dispiriting notion of tyrannosaurs needing feathers for insulation , unless one wants to argue that crocodile hatchlings have feathers too. The authenticity of Dilong's alleged fuzz should now be in even greater doubt than before

The authors don't mention this, perhaps in fear of incurring the cumulative wrath of the currrent generation of dino-bird paleos, but logically speaking this finding also is the final nail in the coffin (at least in my august opinion ) of the dino-bird hypothesis. Simply put, if birds were derived from dinosaurs, then we should expect that small dinosaurs were conclusively warm-blooded, since 1) no one disputes that birds are warm-blooded and 2) no one doubts that birds were derived from ancestors much tinier than Brontosaurus excelsus. If however small dinosaurs were themselves cold-blooded, then how could endothermic birds arise from them? The authors regrettably excluded the small dinosaur Shuvuuia from the analysis, in the mistaken belief that it was feathered.

I was right after all! Dinosaurs were reptiles and not overgrown chickens! Things are looking up "

...

[crazycrowman]

"but logically speaking this finding also is the final nail in the coffin"

?? What ? There is no nail at all. Sorry.
www.ucmp.berkeley.edu/diapsids/metabolism.html

"The authenticity of Dilong's alleged fuzz should now be in even greater doubt than before"

Should Archeopteryx be doubted as well ? And Caudipteryx ?
Seriously. I guess people who want dinosaurs to remain the way they wish they looked will do anything to those ends.

EVEN Fedducia and Martin have switched camps now. EVEN THEY concede that the Maniraptoria were feathered. The just think animals like the oviraptoridae and dromaeosaurids were all birds, that evolved alongside the other "dinosaurs".

"I was right after all! Dinosaurs were reptiles and not overgrown chickens! Things are looking up ""

Maybe things are looking up if you ignore evidence. Please, give it up already. If you like them without feathers, fine, but stop trying to attempt to "validate" that by ignoring science and "cherry picking" bits that you think support your claims.

[stoneage]

Your article says T-Rex is not a bird. Why then should we think it should have feathers. T-Rex became extinct and did not evolve into birds.

[tomhet]

Besides, Archaeopteryx and Caudipteryx have nothing to do with tyrannosaurids.

[Tyrannax]

Dec 10, 2008 2:52:03 GMT crazycrowman said:

"but logically speaking this finding also is the final nail in the coffin"

?? What ? There is no nail at all. Sorry.
www.ucmp.berkeley.edu/diapsids/metabolism.html

"The authenticity of Dilong's alleged fuzz should now be in even greater doubt than before"

Should Archeopteryx be doubted as well ? And Caudipteryx ?
Seriously. I guess people who want dinosaurs to remain the way they wish they looked will do anything to those ends.

EVEN Fedducia and Martin have switched camps now. EVEN THEY concede that the Maniraptoria were feathered. The just think animals like the oviraptoridae and dromaeosaurids were all birds, that evolved alongside the other "dinosaurs".

"I was right after all! Dinosaurs were reptiles and not overgrown chickens! Things are looking up ""

Maybe things are looking up if you ignore evidence. Please, give it up already. If you like them without feathers, fine, but stop trying to attempt to "validate" that by ignoring science and "cherry picking" bits that you think support your claims.

Completely true. They ignore major evidence, and pick out clues that tell us they were strictly reptiles.

[tomhet]

Dec 10, 2008 4:28:42 GMT Tyrannax said:

Completely true. They ignore major evidence, and pick out clues that tell us they were reptiles.

And where's the evidence that indicates that T-Rex was feathered?

[Tyrannax]

We've only found so many Tyrannosaur skeletons. Why base something like that on only a handful of specimen? Maybe it wasn't feathered as an adult, but Tyrannosaurus probably was feathered as a small juvenile.

[tomhet]

Again, where's the evidence? It was just speculation. But hey, nowadays everybody repeats mindlessly what the great Xu Xing says

Why does it excite people to hear that dinosaurs were feathered? I guess people who want dinosaurs to look the way they wish they looked will do anything to those ends.

[kuni]

::shrug:: Scientific consensus has shifted more to feathered right now, because of, well, all of the features on recent dino finds. I don't think it has anything to do with looks, at least for me -- I find feathered raptors a lot lamer than scaled ones, but that doesn't mean they weren't feathered.

(Slamming Xing is also not cool unless you've got a reason)

I will say that if Dilong is NOT a tyrannosauroid, then it does raise questions about feathers in the group. If it is, though, it's not unreasonable to think that T-Rex had feathers in the same way an elephant does (which is to say, very little).

[Tyrannax]

Having a closed mind doesn't help tomhet. Don't you think its even remotely possible for a large relative of modern day birds to have some sort of feather at some point in its life?

[tomhet]

They have a hard time classifying it but hey, who cares? Let's put feathers on a (possibly) related animal! I find that unscientific. Again, it's not only the looks (I admit I don't like them) it also has to do with the zeal people put in connecting dinosaurs with feathers. That's why the T-Rex 'proteins' disaster took place.

Xing has had business with Chinese fossil dealers, he got the other parts of Microraptor that way, I thought that was illegal or at least immoral?

Dec 10, 2008 5:07:48 GMT Tyrannax said:

Having a closed mind doesn't help tomhet. Don't you think its even remotely possible for a large relative of modern day birds to have some sort of feather at some point in its life?

We are closely related to apes but we are not completely covered with fur.

Heck, crocs are related to birds, but they don't have feathers.

[Tyrannax]

Describe the T-Rex protein disaster. I heard about this, but don't know much about it.

[stoneage]

Dec 10, 2008 5:07:48 GMT Tyrannax said:

Having a closed mind doesn't help tomhet. Don't you think its even remotely possible for a large relative of modern day birds to have some sort of feather at some point in its life?

Let me repeat there is no evidence that T-Rex is a relative of modern day birds. It went extinct there is no evidence of it evolving into anything else.

[tomhet]

Mary Schweitzer and Jack Horner said that they had found T-Rex soft tissue. Their protein 'study' determined that Rexy was closely related to chickens, but what they had found was slime

[therizinosaurus]

Dec 10, 2008 5:13:33 GMT stoneage said:

Dec 10, 2008 5:07:48 GMT Tyrannax said:

Having a closed mind doesn't help tomhet. Don't you think its even remotely possible for a large relative of modern day birds to have some sort of feather at some point in its life?

Let me repeat there is no evidence that T-Rex is a relative of modern day birds. It went extinct there is no evidence of it evolving into anything else.

Well, there is evidence it is a relative--since all land animals evolved from the same primitive sea creatures, we are all related. Humans are related to T-rex, and T-rex to birds, and cheetahs to turtles.

Just my two cents...

[Tyrannax]

Thanks tomhet, that summed it up. ;D

Then I guess evolution just crapped birds out. ;D

[stoneage]

Dec 10, 2008 5:18:10 GMT Tyrannax said:

Thanks tomhet, that summed it up. ;D

Then I guess evolution just crapped birds out. ;D

All that is being said is that T-Rex isn't the missing link to birds. Is there anyone else beside Tyrannax that things that T-Rex's evolved into birds. ;D

[kuni]

Dec 10, 2008 5:10:35 GMT @tomhet said:

Xing has had business with Chinese fossil dealers, he got the other parts of Microraptor that way, I thought that was illegal or at least immoral?

Not scientifically - better that science describe them than they sit with a private collector. (That being said, of course you want to go over those sorts of fossils with a fine-tooth comb, and by "comb" I mean of the CTscan variety )

I'm sick to death about Archeoraptor -- I mean, for the love of <deity>, it didn't even make it into a scientific publication before it was caught! That's pretty good!

[therizinosaurus]

No, but it was announced to the world in National Geographic.

[Tyrannax]

Dec 10, 2008 5:25:17 GMT stoneage said:

Dec 10, 2008 5:18:10 GMT Tyrannax said:

Thanks tomhet, that summed it up. ;D

Then I guess evolution just crapped birds out. ;D

All that is being said is that T-Rex isn't the missing link to birds. Is there anyone else beside Tyrannax that things that T-Rex's evolved into birds. ;D

Of course Tyrannosaurus isn't the missing link to birds, but he was related to them.