Feathers In Tyrannosaurids

[Tyrannoraptor]

Ok, this topic might have been discussed before elsewhere, but I didn't find the thread (if it exists), so I'm making a new one.

I'm interested in the theory about Tyrannosaurids (especially T. rex) having some kind of feathers. As far as I know no conclusive evidence in support of this theory have been found so far. In fact, the fossilized impressions of the skin of large Tyrannosaurids seem to suggest that their skin was much like we pictured it basically since the discovery of the first dinosaurs - mosaic scales, reptile-like.

But the fact is that in order to fully prove/disprove the theory of large Tyrannosaurids being covered in feathers at least partially, impressions of the whole (or at least most of) surface of their skin would have to be found, and so far nothing like that has been found.

I'm gonna go with the theory that large Tyrannosaurids didn't need feathers, at least not as adults, as they would not need such insulation, the bulks of their bodies alone should be enough to sustain constant temperature over the colder nights, while during a hot day such insulation could prove itself to be more of a disadvantage.

However, I do think it is totally plausible that SOME parts of their bodies (smaller areas) could be covered with feathers or protofeathers for display purposes. Then again, there is no definite proof for this yet, so I'm gonna assume they were featherless, until proven otherwise.

What are your opinions on this matter? Discuss

edit: I'm not advocating any of these two (feathered/not feathered) theories, I doubt T. rex having feathers would ruin the animal for me

Edited November 9, 2011 by Tyrannoraptor

[Auspex]

I think that many theropods may well have grown dermal integuments of some description, but they would not have resembled what we think of as "feathers", since such have complex structures not needed by a flightless animal. The genetic predisposition among the theropods toward feather-like structures was well established by the late Cretaceous, and if growing them proved to be advantageous, they would have been grown.

[grampa dino]

They had feathers, they could fly and when Bar B-Q they taste like chicken

They also did not roar but they clucked, like chickens :bbq:

[tracer]

why do i have hairs on the dorsal surface of the skin over the middle phalanges of all my fingers except the index fingers? and don't say it has anything to do with "dermal integuments" because i already decided i'm not going to go look that up...

on that other thing, none of the big lizards i've met so far had feathers, but i do think folks should keep digging until they find out the answers to all that kind of stuff.

p.s. - just found this - but i can't support the hypothesis cuz one time when i was young and impetuous i briefly rode an ephelant wearing shorts (me, not the ephelant) and it's longish, wiry hairs irritated my legs semi-dramatically to the point where it almost distracted me from the fact that i was riding an ephelant. so why'd it have those hairs if it was all thermo-regulated from being massive?

p.p.s. - OMG - i just had an epiphany! tyrannosaurids shed their filamentacious protohairfeathers in the summer, and that's when most of them got stuck in mud and drowned during the summer floods from glacial melts, so the fossils reflect a seasonal anomaly.

[Tyrannoraptor]

True, if the fearher-like structures (I wasn't thinking about those structures being true feathers) would prove to be advantageous in some way or another I think there would be reason for dinosaurs to evolve such structures, good point. So far nearly all the evidence for such structures come from the dinosaurs from the coelurosauria clade (and as recently discovered from some ornitischian dinosaurs also), which seems fairly logical as this is the clade of theropods that supposely gave rise to birds.

Tracer - that thought had occured to me too. Elephants are covered in hair, but of course to a far lesser degree than, let's say, lions. Of course, in large tyrannosaurid dinosaurs those feather-like structures could be secondarily lost (I believe an evidence in support of this theory would come from a Gorgosaurus skin impression, as the skin looked smooth, like in cases of modern birds which secondarily lost their skin on some parts of their bodies), but only if there was a reason fo them to be lost. Since the evidence we have for now (for large tyrannosaurids) shows they had bare, scaly skin at least on some parts of the body, I'll go with the featherless theory (or perhaps baing covered with primitive, feather-like structures to the same degree as elephants are covered in hair).

Hopefuly the future would bring some hard evidence in support of either of these theories.

I'm laughing at the thought of seing a T. rex fly. Think about what would happen when it would land on a tree branch

[BisonJim]

I doubt they had feathers on their head. Lacking decent forearms, like a vulture, and sticking their face in their food, like a vulture, they were probably bald, like a vulture. Also, unlike a vulture or feather-headed bird of prey such as an eagle, T.rex didn't have a hooked beak which allows for a certain distance to be maintained between the face and the food. T.rex actually had to get her face into her work. I would think feathers would be a hindrance. If she had them anywhere, I could see them on the back and shoulders but not elsewhere. Just guessing, though.

[Diplotomodon]

I would imagine that they had feathers when they were hatchlings, but started losing them as juveniles. When you got to large sizes, the need for feathers probably wasn't as great (of course, then Concavenator comes along and screws it all up )

[RCFossils]

Dilong paradoxus is an early Cretaceous theropod believed to be one of the earliest tyrannosaurs. Several specimens have been found in the Yixian Formation of NW China and at least one example had protofeathers preserved around sections of its body. These would have most likely been for insulation.

[Tyrannoraptor]

Dilong paradoxus is an early Cretaceous theropod believed to be one of the earliest tyrannosaurs. Several specimens have been found in the Yixian Formation of NW China and at least one example had protofeathers preserved around sections of its body. These would have most likely been for insulation.

Yep, I've read about this dinosaur. It wasn't as large as T. rex, but it could serve as an evidence that the ancestors of Tyrannosaurus rex indeed had feathers (as we don't know for sure if Dilong was in direct evolutionary line of T. rex, but we can assume that other early tyrannosaurids had protofeathers too). It's interesting.

BisonLatifrons - I agree, feathers on its snout would cause nothing but trouble to T. rex. The animal would have a really hard time trying to clean up all the blood. So if it did have feathers I'd say that its head was still bare/scaly.

Some may oppose the thought of a feathered (or plummaged) T. rex because it wouldn't look "cool" anymore. But what matters is that we have the correct picture of how the animal really look like instead of how we think it should look like. So while I think that Tyrannosaurus rex (along with other large tyrannosaurids) was (largely) featherless, I keep an open mind about the matter.

[NelsonFL]

hmm, I just though of something, do we have any evidence that a T-Rex roared other than Hollywood? We have reptiles now that hiss, growl, and squeak, but no roaring.

[Tyrannoraptor]

hmm, I just though of something, do we have any evidence that a T-Rex roared other than Hollywood? We have reptiles now that hiss, growl, and squeak, but no roaring.

Actually I don't think we have any evidence about ANY dinosaur being able to vocalize, not just T. rex (maybe except for one dinosaur, but I need to look that up again). I was going to make another thread about that (I might make one later)

[ghost1066]

Well alligators roar all through breeding season so why would a T. Rex not be able to? Just a thought.

[32fordboy]

Isn't there cranial evidence Parasaurolophus could vocalize? Also, when it comes to "the big fella", I disregard any evidence of earlier Tyrannosaurs having feathers as evidence of Tyrannosaurus having feathers.

I have heared mammal paleontologists say there is a growing concensus the genre Mammuthus and Elephas are one and the same. Elephas is still around and isn't very hairy compared to Mammuthus primigenius, which is known to have had very thick hair. The point is: characteristics of one species, much less genus, shouldn't be considered as evidence for another, at least in my opinion.

I can agree that if Trex had protofeathers, it would have been soft and light at a very young age. I think if they had protofeathers as adults, it would have been much like todays' elephants as far as coverage goes. I still prefer a featherless Trex.

One man's opinion, of course.

EDIT: isn't there new evidence of quills on an Asian Tyrannosaur's back and tail, like a Psittacosaurus? Awe, where did I see that....?

Edited November 10, 2011 by 32fordboy

[Tyrannoraptor]

I was referring to Phil Senter's research. In short, he came to a conclusion that dinosaurs probably didn't have the ability to produce sound via vocal chords. He found that larynx in crocodiles and syrinx in birds likely evolved independently from one another, which could mean that the last common ancestors of crocodiles and dinosaurs (who as we know gave rise to birds) didn't have any organ for vocalisation, and that the lack of clavicular air sacs in dinosaurs (except from Aerosteon), which would be neccessary for vocalisation, means that dinosaurs couldn't vocalize.

Parasaurolophus had a resonant chamber in his crest, it could produce sound that way without having a larynx or syrinx.

I don't know, they had to produce sound in some way or another in my opinion. We just might never find out in what way exactly.

Well, about Mammuthus and Elephas - mammoths needed their thick hair coating because of harsh, cold climate, so this might not be the best comparison, but I see your point, and I agree. The ancestors having feathers doesn't mean T. rex must have had feathers too. So far the evidence we have (skin impressions from large tyrannosaurids) point in the other, featherless direction. I prefer featherless T. rex too, but in case of evidence for rex being covered with feathers/protofeathers comes up it wouldn't be a huge disappointment for me, I'd get adjusted to the idea

And for a feathered Tyrannosaur from Asia, are you referring to Dilong? In that case it was just a smaller theropod, one of the early Tyrannosaurs.

Edited November 10, 2011 by Tyrannoraptor

[32fordboy]

Not too sure if it was Dilong or not.

I think the comparison between Mammoths and Asian elephants fit the bill just right. The point here has little to do with climate conditions and more to do with the extreme variation between two very closely related animals to fill a certain need. It's my fault for not pointing that out. Animals all evolve to fill their needs, regardless of what their cousins needed, which was the point. While smaller Tyrannosaurs may have favored protofeathers, the big ones may have not.

Of course, I don't care either way, either...I just don't like how all of a sudden big-names like Nat Geo are giving him a huge main of feathers and passing it off as if it is fact when what little evidence we have (logic is all we've got at this point, really) points the other direction. It's just misleding to non-paleo people.

[32fordboy]

Good thread, by the way. It doesn't hurt to re-evaluate the facts every now and then, especially since new fossils are always turning up.

[Tyrannoraptor]

Good thread, by the way. It doesn't hurt to re-evaluate the facts every now and then, especially since new fossils are always turning up.

Thanks, I thought it would be an interesting topic for discussion, and perhaps people (myself included) could learn something new from it. It's always interesting to hear different points of view.

I saw your point about mammoths and elephants the first time, but now it's even clearer. And all this sudden influx of articles that treat T. rex as a feathered dinosaur (one of the reconstructions shows the animal being fully covered in what looks like true feathers from snout to tail, which I find extremely unlikely) is bothering me too, especially because they are treating it as a fact, as you pointed out. It can be very misleading for the general public, as not everyone has been pulled into researching dinosaurs or palaeontology in general as much as we have been. Rather than as fact, Tyrannosaurus rex being covered in primitive feathers should be mentioned as a possible theory.

[Auspex]

Even within Class Aves, there is a vast range of designs for the syrinx. The complexity, or lack thereof, was and is used to classify relationships between families, with the more complex considered to be the more derived. The selective pressure for the development of a complex syrinx is certainly behavioral, and I see no reason to think that there would have been less variety among the dinosaurs.

[BisonJim]

I must strongly agree with the point about our relative ignorance and the pontificating-as-fact that is seen in many media, like Nat Geo. It seems to be a combination of scientists giving their views and editors trying to make more extreme copy for sales, and so the water cooler crowd can impress each other with knowledge they pick up from something other than a tabloid.

It galled me to see an article about a stash of white Clovis points that was found, and the huge point they made about the point's color, and the stash, made them ceremonial points, as opposed to practical points. They found trace evidence of blood on them but the mere fact they were white, and had been stashed, meant they had to be ceremonial. It was almost a mystery as to how the blood got on these sacred white points that, of course, would never have actually been used for something so mundane as a killing food.

No one ever argued the case that, yeah, duh, the entire act of living and hunting and killing and butchering and eating on a practical, day to day basis was probably itself ceremonial. Most indigenous people will tell you that. The color of the points and the stash could very well have been fortuitous. They found a good source of white rock for making points. They stashed them and never came back for some reason. Some guy finds them 10,000 years later and applies our view of the world to the color of a rock.

T. rex with feathers won't be a fact until it's proven. In the meantime, we can speculate, but to sell it as fact is a disservice.

[ashcraft]

The important point about t-rex ancestors having feathers, is that it allows for the possibility for t-rex to have had feathers. Feathers have only evolved once, and if a t-rex ancestor had lost the ability to grow them, it would be highly unlikely for t-rex to regain that ability.

It is like teeth in birds. Their ancestors had teeth, but lost the ability to grow them. No birds since have had a functional mouth full of choppers.

Further research does not support what I said about the hoatzin having teeth, don't know where I got that idea.

I believe the Hoatzin has an egg tooth,, but I believe they only have one, and as I recall, they retain many "primitive" reptile characteristics, they are to birds what platypi are to mammals.(Perry not withstanding). Auspex, please correct me if I am wrong.

Brent Ashcraft

Edited November 10, 2011 by ashcraft

[Auspex]

The Hoatzin was declared primitive early on because it has "primitive" characteristics (particularly when young). It is now not viewed as an ancient species, but as a modern re-expression of genetic predispositions that serve a useful function in it's specialized lifestyle.

[Tyrannoraptor]

Even within Class Aves, there is a vast range of designs for the syrinx. The complexity, or lack thereof, was and is used to classify relationships between families, with the more complex considered to be the more derived. The selective pressure for the development of a complex syrinx is certainly behavioral, and I see no reason to think that there would have been less variety among the dinosaurs.

Good point here. Dinosaurs were just as diverse as modern groups, and at least for some groups we can assume they were pretty social animals. And there must have been some communications between the members of a certain group, whether vocal or not. An organ for vocalization would be very useful in this case, so the need for evolving such an organ was certainly there. And since the diversity between various dinosaur species was so great we should have a wide array of sounds produced by different species. I don't really see a reason why dinosaurs wouldn't evolve an organ for this purpose. I'm not an expert though, no matter how much I am interested in these things, it's just what I think.

Wow, I looked up the Hoatzin bird, and I must say, that thing even looks ancient! It's easy to imagine the earliest birds looking a lot like it.

Edited November 10, 2011 by Tyrannoraptor

[ashcraft]

The Hoatzin was declared primitive early on because it has "primitive" characteristics (particularly when young). It is now not viewed as an ancient species, but as a modern re-expression of genetic predispositions that serve a useful function in it's specialized lifestyle.

From what I read, I don't think we have heard the last on its evolution, since they can't seem to find a close relative. Very interesting animal, regardless.

Brent Ashcraft

[Tyrannoraptor]

Bump

The discovery of Yutyrannus (http://en.wikipedia....wiki/Yutyrannus) seems to help in spreading the idea of large Tyrannosaurs being feathered. It was a breakthrough discovery, but I'm not sure this means all Tyrannosaurs must have been feathered. Yutyrannus also lived in a cooler climate, so there might have been use in feathers as insulation, but perhaps there was no need for that at the end of the Cretaceous?

My interest in this had been revitalized lately, as I'm deciding what should my T. rex head reconstruction be covered in: feathers or scales. I'll base it on this drawing of the skull, which is also my own work:

edit: re-uploaded the pic

Edited July 28, 2012 by Tyrannoraptor

[Carcharodontosaurus]

Here is a database of feathered dinosaurs: http://z13.invisionfree.com/Hell_Creek/index.php?showtopic=19

It mentions that Tyrannosaurus shows some evidence of feathers. Mind you, a T.rex with feathers would still be quite terrifying in the same way that a Titanis walleri is terrifying.