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T-PEKC — Tyrannosaurus rex
Published: 2013-08-05 13:27:27 +0000 UTC; Views: 11613; Favourites: 177; Downloads: 0
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Description
Tyrannosaurus rex. Staring. Right. At. You. Peacefully.This reconstruction is part of an artwork that is currently in progress (working title "Tyrannosaurus rex and neighbours" or alternatively "One Hell of a Creek"). Hopefully it will be done by the end of the week. No promises though. It's going to be heavily detailed piece, with 4 other archosaurs in it, so I'm gonna take my time with it.
Uploading this now, because I will need separate (cropped out) image of T. rex either way.
References: Various skeletal drawing by Scott Hartman
Carr, T. D. (1999). Craniofacial ontogeny in Tyrannosauridae (Dinosauria, Coelurosauria).- Journal of Vertebrate Paleontology 19, 3, pp. 497–520.
Medium: Ink
Done: 2013
Related content
Comments: 100
I noticed one oddity. Most of your drawings without background, face turned to the right. Wonder what that means? Isn't it telling that the artist is right-handed or left-handed? I prefer to draw dinosaurs with the faces to the left, and I'm right-handed.
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Funny enough, I'm right handed and I also prefer to draw creatures and characters facing the right. Thankfully I can draw characters facing the left just fine as well, even though it's takes a little getting used to.
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The oddity that you noticed is true. I am left-handed and for me it comes naturally to depict dinosaurs, when I am drawing them in lateral view, in their right profile with head pointing in the same direction. I suppose this is an artefact from the times I was working mostly with pencil - when drawing dinosaurs from left to right I was smudging the graphite and destroying details, a problem that necessitated planning of what detail to draw first and what second. When working with paints, whether it is watercolors or acrylics, I am trying to depict more dinosaurs with their left side visible.
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Clear. I'm glad my fears were confirmed.
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There is no way t-rex was covered in feathers. The bigger the animal is, the more it's body absorbs heat. Animals can not live with too much heat on their bodies. That is why elephants have almost no fur, unlike smaller animals like lions and tigers. And t-rex was larger than an elephant lived on an Era when it was so hot that the South Pole was a forest, so t-rex would not survive being covered in feathers. So t-rex was definitaly NOT covered in feathers, but it could have some feathers on it's back and/or on the back of it's neck... and maybe some feathers on it's tail and/or on it's arms. But we can not be sure about it, by the time being.
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Surface Area/Volume ratio, you nimrod. Do you understand that? That a T. rex (Yes, fucking T. rex, not "t-rex") has a far greater surface area:volume ratio than an Elephant? Do you know what those implications mean? I'm assuming not, otherwise you wouldn't have tried to use that excuse to hold dear your childhood memory of T. rex. A greater surface area = greater release of energy. What about fucking Giraffes, they're fucking huge and they have fur, why don't you look at that, instead of Elephants? And feathers do not work like fur, and stop pretending it does. Feathers can achieve both the retention and release of heat. You can pretend like you know what you're talking about, but anyone who knows what they're talking about can easily tell you are parroting information you couldn't understand by someone else who couldn't understand the same information.
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Sorry, but feathers sometimes work like fur. Protofeathers are almost like fur and both trap heat.
And about Giraffes: really? Giraffes are very slim and they even do not have a huge amount of fur, while elephants and even rhinos are almost naked and even with those giant ears, elephants have difficulties in keeping themselves cool.
And as far as I know, many birds that live in cold climates have larger amounts of feathers that birds that live in cooler climates.
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Protofeathers are not like fur. Fur is far more dense than protofeathers and has a significantly different structure. Feathers are far better at heat shielding than fur (A paper that looks at Emu's, who live in a hot climate with a thick and dark coat of feathers), and are also capable of releasing heat effectively, while being able to insulate the body when need be. The Giraffe example was to drill in your head how surface area:volume works and how Elephants are a terrible analogy to T. rex. T. rex's surface area:volume is far more comparable to a Giraffe than to an Elephant, and a T. rex is still likely more efficient at releasing heat with its post-cranial pneumaticity showing evidence of air sacs. You're bringing in an orange as a point against apples, I hope you realize this now.
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Elephants are a good analogy due to body mass. Animals with bigger body masses tend to retain more heat, and dinosaurs clearely had a warm-blooded metabolism (or at least more close to warm blood), wich means that t-rex would release an amount if heat ptoportional to it's body surface area, BUT it would have to produce heat proportional to it's mass.
Feathers are different than fur? Alright. Both are good in trapping heat, so IN THIS CASE it makes almost no difference.
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It is like you didn't even read my comment...
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Oh, I did.
Otherwise I would even answer it.
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Not even sure why I expected you to, since you're still speaking about this mythical beast called "t-rex".
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aaaaand it's mostly nekku now.
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Those are some pretty bold statements and sligthly presumptuous assumptions you got there. Is there any chance you can back up any of those with scientific references, you know ... something like papers, conference/symposium abstracts, books, or else; or you are just repeating what you have seen others saying times and times again? Because, and I will be bluntly honest here, your post is showing that you fail to understand the grounds of the arguments you are making. Not to mention that everything you have said as criticism to the idea of feathered tyrannosaurs has been rebutted like million times already. I will present just one example of erroneous understanding of the science behind some the arguments you are making - the problem of dense insulation (be it feathers or fur) in large bodied endothermic animals is NOT because the body is ABSORBING more heat, but because the low body surface to body mass ration makes it difficult to RELEASE the EXCESSIVE HEAT generated by the metabolic processes and reactions in the organism. Simply put the body overheats because it produces more heat than its surface can emit into the environment. Truth is that in reality it is more complex than that, because there are many other factors in play.
If you are interested in actually learning something, then I will gladly enter a in discussion of the tyrannosaurids' integument and provide scientific papers to back up my claims, my interpretations and my artistic decisions. But that's only in case you are willing to approach the problem scientifically. If this is not the case and your comment was prompted by your urge to defend what popular media like Jurassic Park thinks Tyrannosaurus rex looked like, or your personal preferences for scaly beasts, then I am sorry to say it, but I don't think to waste even a minute discussing the matter with you.
In the end of my post, I want to direct you to a handy guide of how are species binomials properly abbreviated. The guide is here -> chrismasna.deviantart.com/art/… . The take home point is that there is no such thing as "t-rex". It's T. rex.
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"the problem of dense insulation (be it feathers or fur) in large bodied endothermic animals is NOT because the body is ABSORBING more heat, but because the low body surface to body mass ration makes it difficult to RELEASE the EXCESSIVE HEAT generated by the metabolic processes and reactions in the organism" this makes almost no difference to me, and you just destroyed your own art. You just mentioned that large bodies make it difficult to release excessive heat, and, as I said before, t-rex was larger than an elephant lived on an Era when it was so hot that the South Pole was a forest.
"If this is not the case and your comment was prompted by your urge to defend what popular media like Jurassic Park thinks Tyrannosaurus rex looked like, or your personal preferences for scaly beasts, then I am sorry to say it, but I don't think to waste even a minute discussing the matter with you." STRAW MAN FALLACY DETECTED: I never said that t-rex could not have any feather, I said that he could not be COVERED on it. In Jurassic Park, the frog DNA may have caused a mutation, preventing feathered dinosaur species from developing actual feathers.
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"this makes almost no difference to me, ...
A comment like this one makes crystal clear two things: 1) as I suspected you completely fail to understand the science behind the arguments you are making in defense of your views; and 2) you don't really care about the science side of things. Since science is integral to the process of creating paleoart, I simply can not discuss anything paleoart related with someone who refuses to acknowledge the difference behind absorbing and releasing heat. Nor I can take criticism from such person. I will be welcoming a discussion with you if you manage to cite your sources and put together a coherent argument without just repeating what others have said before.
and you just destroyed your own art.
No. Not at all. What I did was merely stating some widely known science fact and explaining to you what the actual argument against feathers in large bodied coelurosaurians is all about. My comment was meant to correct your completely inaccurate statement on why large bodied animals can't have dense feather covering (your claim was that large body absorbs more hear). If you did carefully read the rest of my comment, you would had probably seen that I said while this is the basic argument, there are other factors at play and things are much more complex. For one, the body plan of dinosaurs is different than that of large mammals, a difference which probably was of importance for how internal heat was emited from the different parts of the body. Another difference between the dinosaurs and mammals is the existence of avian-style pulmonary system with air-sacks in the former, something which surely has effect on how the animal cooled down. Then there are behavioral mechanism which the animal may have used to lower its temperature. The problem is that none of this additional factors have been thoroughly tested by paleontologists, but this does not mean that I, or any other paleoartist, should ignore them and their implications when reconstructing extinct animals, like Tyrannosaurus rex.
t-rex was larger than an elephant lived on an Era when it was so hot that the South Pole was a forest.
First, again, there is not such thing as t-rex. It is T. rex. If you are going to discuss paleoart with paleoartist or paleontologist at least try to get familiar with basic scientific terms and concepts involved. How to abbreviate species names is one of these concepts. Second, you keep telling how hot was the Earth during the Maastrichtian age of the Late Cretaceous, which is showing me that you know little for the climate during that time. While as a whole Cretaceous global temperatures were higher than modern day ones, there was a cooling trend which started sometime around the beginning of the Maastrichtian age. Also, temperatures were not equal all over the globe - as is the case today local climates could have substantially differed based on locality. Add to that the fact that Tyrannosaurus rex was spread from the north parts of Laramida all the way down to the south, so you have species which different populations inhabited areas with more or less different climate condition. Close to the North Polar circle, where we know dinosaurs were present, temperatures occasionally were below 0 degrees Celsius during the polar winter, which by the way forced animals to spent months living in cold polar night. If you are so interested I can provide you with scientific papers dealing with paleoclimatology so you can see the paleotemperatures for yourself. The idea that the planet was tropical paradise at mid- to high-latitudes during the Maastrichtian times is oversimplified and not correct.
STRAW MAN FALLACY DETECTED: I never said that t-rex could not have any feather, I said that he could not be COVERED on it.
I really think that you need to consider what your views that Tyrannosaurus rex "could have some feathers on it's back and/or on the back of it's neck... and maybe some feathers on it's tail and/or on it's arms" mean in broader context and in the context of criticizing that particular artwork of mine.
Anyway, if it is going to be of any consolation for you, I want to say that if I was to draw T. rex right now, I would have drawn it differently. There are some things in this reconstruction which I do not like and think that they may be done much better.
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Once again the fallacy of the straw man: I said that your correction of the heat problem would not make a too much fifference if I understood well. I indeed misunderstood this heat problem in the first time, but now I know the truth (but even though the results of my last thought were almost equal).
And if these avian pulmonar sacks really existed in t-rex, would it really make a huge difference? It would be only on the chest area, but what about the rest of the body?
And elephants also have another "weapon": african elephants use their long ears to refresh themselves, even though they still being almost furless.
And about the different regions: you are right about the North Pole, but AS FAR AS I KNOW, no t-rex skeleton was found there. If we someday find it we will most likely have two different t-rex subspecies. You see: lions in Kenya have smaller manes due to the hotter climate (masai lions), while south african lions have huge manes (kruger lions).
PS: I was not only crictizing your art, but saying in what areas t-rex could have feathers (if it had). And thanks for correcting me about the heat problem.
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Once again the fallacy of the straw man: I said that your correction of the heat problem would not make a too much fifference if I understood well.
It makes difference in that it properly described the science behind the argument you were making, something which you are acknowledging yourself now. That part was not intended to overthrown your argument. I did provide counter-arguments afterwards: that one has to consider things like body plan, air-sack system, and even behavior, before blidnly following the argument for small body surface area to body mass (or volume) ratio.
You keep using elephants and other large mammals as an example, but the these mammals make really poor comparison with large bodied dinosaurs. You may ask why? It is because their body plans are markedly different and that difference is of importance when considering the body surface area:body mass ratio and its implications. Large mammals, like your so favorite elephants, are build like bricks. They have compact body, with short neck and short tail. Such body plan creates difficulties in efficiently dissipating internal heat due to the small body surface for an animal that big. On the other side dinosaurs, like Tyrannosaurus for example, had really long tails, proprotionally longer necks and large heads. They had higher body surface area:body mass ratio (the body had more surface to dissipate internal heat) than an elephant of the same body mass. This automatically means that if you have a Tyrannosaurus and an elephant with the same body mass, the dinosaur is going to dissipate/lose heat quicker (more efficiently) than the mammal. That's why it is bad to compare large dinosaurs to large mammals by directly applying the body surface area:body mass ratio without considering additional factors.
Also, don't forget that the distal parts of very long limbs or other long body parts (tail) which are far from the torso (which usually contains the bulk of the animal) are prone to losing heat quicker. Have you noticed that finger tips and toe tips are usually the first things to freeze when exposed to cold weather? I don't know about you, but to me it seems like long tails not only increased body surface area but could have helped in the dissipation of some extra heat.
And if these avian pulmonar sacks really existed in t-rex, would it really make a huge difference? It would be only on the chest area, but what about the rest of the body?
Air-sacks were not restricted only the the chest area.
And about the different regions: you are right about the North Pole, but AS FAR AS I KNOW, no t-rex skeleton was found there.
There are T. rex fossils (really, stop with that "t-rex" nonsense) found in Canada (Frenchman Formation) in areas which back in the Maastrichtian were positioned at 58 degrees north latitude (Mclver, 2002; www.nrcresearchpress.com/doi/a… ). Some studies give mean annual temperatures for these areas (Frenchman Formation) of 12-14 degrees Celsius (Bamforth et al, 2014; www.sciencedirect.com/science/… ). While such mean annual temperatures in combination with paleofloral data are interpreted as representative for subtropical to warm-temperate climate (Bamfort et al, 2014), the mean annual temperatures in the environment inhabited by Yutyrannus were just a 2-4 degrees Celsius lower (Amiot et al, 2011; www.pnas.org/content/108/13/51… ). At northern latitudes of 75-85 degrees, some studies estimate mean annual temperatures of 5 degrees Celsius (Spicer and Parrish, 1990; jgs.lyellcollection.org/conten… ).
Specifically for the southerly located Hell Creek formation, some recent studies on plant megafossils from eastern Montana provided mean annual between of 7-11 degrees Celsius (Arens, 2014; specialpapers.gsapubs.org/cont… ). Other studies show a cooling trend in Hell Creek during the last 300 000 years of the Maastrictian, which saw mean summer temperatures drop with 8 degrees Celsius (Tobin et al, 2014; geology.gsapubs.org/content/42… ).
Do you still think that Tyrannosaurus lived in tropical paradise throughout the year? I urge you to take your own Google research and see what kind of climate characterize modern areas with mean annual temperatures of 12-14 degrees Celsius, and what kind of weather conditions are recorded there. Even if temperatures back in the Maastrichtian were not low enough to allow the formation of lasting snow covering during winter, but it is pretty that showing was possible and temperature occasionaly dropped pretty low (this implies mostly to higher latitudes of course).
Of course non-Tyrannosaurus tyrannosaurids like Albertosaurus and Gorgosaurus are known to have inhabited even higher latitudes with even harsher conditions.
PS: I was not only crictizing your art, but saying in what areas t-rex could have feathers (if it had). And thanks for correcting me about the heat problem.
But see, you ARE criticizing the art. Every piece of paleoart is a depiction of a hypothesis. If you criticize the science behind the hypothesis, then you are criticizing the artistic decisions made on the base of that hypothesis. Personally, I do not have any problem with constructive criticism. In fact I actually admire it and hope to receive it when I post art. But only when this criticism is well though out, properly constructed and the author is citing sources for its claims.
but it could have some feathers on it's back and/or on the back of it's neck... and maybe some feathers on it's tail and/or on it's arms. But we can not be sure about it, by the time being.
I am sorry but such distribution does not make much sense to me. Could you provide some anatomica, ecological, or behavioral examples/evidence of why that's more probable then reconstruction with more extensive feathering?
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So it seems we have two t-rex subspecies here.
Some t-rex skeletons were found in west US, in areas that even nowadays have cool climate, so they would have similar climate on an Era that had a forest looking South Pole.
And, if I understood well, these are temperatures recorded TODAY. And t-rex should have lived on a forest looking environment (not a tropical paradise like Bahamas).
And this distribution does make sense: t-rex could have feathers in these areas to show sexual maturity, for example.
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So it seems we have two t-rex subspecies here.
Nothing I have said implies that there are two subspieces of T. rex. (Also, do you keep using that inaccurate abbreviation "t-rex" just to troll? It is fucking annoying dude. The proper abbreviation of the binomial Tyrannosaurus rex isT. rex). To my knowledge no one has ever proposed that this taxon had subspecies, let alone test this hypothesis properly. The word you are looking for is not "subspecies", but "population".
Some t-rex skeletons were found in west US, in areas that even nowadays have cool climate, so they would have similar climate on an Era that had a forest looking South Pole.
Having forests in Antarctica does not mean that you can't have show fall and low temperatures in the northern hemisphere, you know? Please read more about paleoclimates.
And, if I understood well, these are temperatures recorded TODAY. And t-rex should have lived on a forest looking environment (not a tropical paradise like Bahamas).
Dude, just go back and read the paper's abstract I provided links to. The temperatures mentioned are paleotemperatures estimated on the base of oxygen isotopes in the fossils/rocks, or via analysis of plant fossils.
And this distribution does make sense: t-rex could have feathers in these areas to show sexual maturity, for example.
How this makes sense is beyond me. If you knew anything about dinosaurian integument you would have understand that.
Now, if you excuse me, I have better things to do than wasting my time in this discussion. Have a nice day.
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What I am saying is that in the Mezozoic Era, the simple fact that Antartica was a forest proves that the temperature was higher in that Era.
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It is like I am talking to the wall here. Yes, global temperature during the Maastrichtian were higher than today. Yet local annual mean temperatures were not necessarily uniformly high. Some parts of the planet were still cold enough to see snow fall. Parts of T. rex's habitat had temperature similar to these in modern day mid-latitudes which experience cold winters.
Just read the frackin' papers dude!
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Yeah, parts. Congratulations for getting your head around the concept that climate and weather conditions are not uniform across the planet.
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It seems you misunderstood me.
Well, t-rexes that lived more to the north (Canada) could probably have more feathers than southern ones (if these kast ones really had feathers). It would be more like two subspecies of t-rex.
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Why would such a big animal have so much of its body covered by feathers in a warm-temperate climate? Tyrannosaurus rex was on the leage of modern elephants and they lose almost all their fur when they become adults.
I understand small theropods, and younglings, having a good feather cover, but for 6 tons dinosaurs it seems paleoartists add them only for looks .
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Elephants come from aquatic ancestry. They're also built like bricks and radiate less heat than tyrannosaurids, which had more surface. Feathers can also cool the animal down to some extent and so far we don't know the true advancement state of tyrannosaurid feathers. Having bald, elephant-like skin wouldn't be beneficial to an animal that would, essentially, overheat and get burned.
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We neither know yet if dinosaurs were true homeoterms or just inertial homeoterms.
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Archosaurian ancestry indicates endothermic animals, for both suchians and ornithodirans. It'd mean that we'd have dinosaurs losing the trait secondarily.
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Endothermy on basal suchians is not a fact, just an inference from indirect evidence. And living crocodilians losing the trait is not a problem for you, then?
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Why should it be? They thrive with it incorporated into their livestyles. It's there, working. Only remnants of their more active ancestry are, iirc, their advanced hearts. What is there to suggest that theropods wheren't endothermic then?
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I remember reading about the isotopic ratio on their bones not corresponding with the expected for endotherms, but I could be mistaken.
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This is an excellant drawing. But i think that is way to much plumage for an adult T Rex. Get rid of most of those feathers and you would have a superb drawing. Right know it just looks way to cuddly.
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I still do not dig large tyrannosaurs with dense, body-covering plummage.
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Isn't Yutyrannus enough to make it possible?
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Nope, Yutyrannus was far smaller (especially in weight) and lived in a far colder climate.
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-sigh- How did T.rex lose all the feathering if all it's ancestors had it, them? Size is no excuse.
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How did cetaceans lose their fur?
How did large tropical and sub-tropical elephants lose their fur?
How did that ugly pink-skinned apes lose their fur?
How did naked mole rats lose all their fur?
Furthermore, we have absolutely no proof of feathers on tyrannosaurines, large because we have little to no skin impressions of them.
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I hope I won't have to explain to you that feathers are not fur. This deviation should clarify, although it is about deinonychosaurs and not Tyrannosaurus rex, your arguments seem exactly like these: www.deviantart.com/art/Mammals… .
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Dromaesaurids aren't equal to tyrannosauines, tyrannosauroids are in fact among the most basal branches of coelurosaurs, emerging as early as in the middle jurassic, some 165 million years ago and thus probably lacked any of the more advanced forms of feathers apparent in more modern clades like Dromaeosaurids or Ornithomimids. In fact, their "stage 1" protofeathers are in their function much, much closer to fur than to modern feathers (modern feathers actually help to radiate heat). Furthermore, comparing Dromaesaurids, which reached at most 7m length and 500 kg of weight to the 13m long, 6-9 tons heavy T. rex, which furthermore lacked one pair of significant limbs, which with their large surface-to-volume ratio help with radiating heat, is more than flawed.
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Although comparing more advanced coelurosaurs to Tyrannosaurus rex is flawed, comparing to modern mammals is much worse. And even if it wasn't flawed, no mammal yet known has lost the fur by sheer size - elephants have semiaquatic ancestors, and cetaceans are mostly marine. Unless there is something indicating early tyrannosauroids had an aquatic lifestyle, it would be evolutionarily useless for T.rex's ancestors to lose their protofeathers, and thus they would have kept them, even if as sparsely as modern pachyderms.
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So, you are basically saying that losing fur/feathers is extremely hard, from an evolutionary perspective, while re-gaining fur, provided one of the species' ancestors had it, is extremely easy?
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I don't think I ever said re-gaining fur is easy, because it's not. Both re-gaining fur and feathers is hard, while completely losing feathers is also extremely hard.
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Then why do Mammoths (Mammuthus), which include extremely furry species like Mammuthus primigenius, have fur, while members of their sister taxon, Elephas, which consists solely of the Asian Elephant E. maximus, have lost most of their hair? Even within the genus Mammuthus there were apparently vast differences in the extent of their fur, and they did so in the extremely short time of about 6 to 5 million years. It's a real shame these animals have gone extinct.
Sure, mammals and dinosaurs are two pair of shoes, but a decrease of plummage was probably the easiest way for a large tyrannosaur to deal with eventual overheating, as they did not possess any large appendixes (that we know of). And slowing down the entire metabolism might not be the best way for a predator, either.
I really hope we find some "real" skin impressions from large tyrannosaurines someday.
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