Disclaimer: I consider myself a game developer. That's someone who is a better programmer than most artists and a better artist than most programmers. That may not be saying much. As such, my qualifications to speak on artistic processes may be suspect. My process is one of constant learning and continual development (i.e., trial and error). And technical difficulties. And feathered rex. But even before all that, Paleoart, the subject of this post, must begin with a lengthy decision making process.
Modeling a dinosaur pits artistry against accuracy. Which is more important, popularity or plausibility? Perception or reality? Art or science? For the paleoartist, science is of utmost importance. A paleoartist strives to depict prehistoric life according to the latest scientific findings. A paleoartist should only take artistic liberties to address questions unanswered by science. When it comes to dinosaurs however, and Tyrannosaurus Rex in particular, there are plenty of unanswered questions. The most pressing question is whether or not to depict Tyrannosaurus Rex with feathers, and if with, how?
The Case Against Feathers
It Was Hot
The Late Cretaceous, the period in which Tyrannosaurus rex lived, featured a relatively warm climate. It was notable for an abundance of volcanic activity and lack of glaciation. The assumption that Tyrannosaurs rex evolved (or retained) feathers for insulation therefor doesn't necessarily track with what we know about the general characteristics of its geologic period. Moreover, Tyrannosaurus was likely a gigantotherm and wouldn't need feathers for insulation.
In a hot climate an insulating integument is a liability. It's difficult to make the case that such a burden would serve as honest signaling. Colorful displays can be achieved without feathers. While there are plenty of terrifically tinctured Tropical birds, their feathers serve a primary purpose of flight. Since Tyrannosaurus rex couldn't fly, would be able to display without feathers, and typically would not need insulation, it's hard to make the case that feathers would be of benefit (even as a liability).
No Direct Evidence
It's important to recognize that nothing in the fossil record directly indicates Tyrannosaurus rex had feathers. In fact, there's some evidence seemingly to the contrary. A Tyrannosaurus rex specimen nicknamed "Wyrex" evinces mosaic scales. No feathers. Too scaly. As I've said, I'm still learning how to art. This was just an early "sketch."
The Case For Feathers
Why Not Tyrannosaurs?
In the absence of direct evidence, all arguments in favor of a feathered rex rely on inference. In the case of Tyrannosaurs rex, the assumption that it had feathers is inferred from the fossils of a closely related tyrannosauroid, Yutyrannus huali. Specimens of Yutyrannus illustrate feathery filaments over various parts of its body, suggesting that the coverage may have been complete. Feathers good for the goose, therefor, may be good gander dander too.
This inference relies on several suppositions, including, but not limited to the following:
- Previous paleontologists weren't looking for feather imprints and may have missed them
- We know little about the preservation of feathers (e.g., favorable circumstances and probability)
- The location of imprinting materials doesn't necessarily correlate to the imprint's position (i.e., a skin impression next to a tail bone needn't necessarily have been made by the tail)
Because We Say So
All is not lost for paleophiles who favor a feathered rex. Better than evidence, the notion that T. rex had feathers has consensus. And so, "no self-respecting dinosaur aficionado would draw a T. rex without at least some feathery covering."
Scientific Questions of Type, Color, and Coverage
Should the paleoartist choose to feather their Tyrannosaur, the next question is then, "what type of feathers should be communicated?" According to the paleontologists who discovered Yutyrannus, the feathers "...are too densely packed for it to be possible to determine whether they are elongate broad filamentous feathers (EBFFs) like those seen in the therizinosauroid Beipiaosaurus, slender monofilaments, or compound filamentous structures." The paleoartist is free to choose from among feather types.
The second question regards color. There have been recent revelations about the possible pigment of dinosaur plumage. Fossilized melanosomes have been found in several remains and suggest that the associated specimens wore varying bands of brown and black. Every dinosaur discovery comes with a caveat however; Smithsonian paleontologist Hans Dieter-Sues cautions against making "direct inferences concerning coloration because the coloration on many present-day animals quickly changes after death as the color pigments degrade chemically." Once again the paleoartist has lots of leeway.
The third and final question facing the paleoartist concerns coverage. On this point there is very little agreement. Wyrex suggests a complete lack of coverage. Yutyrannus specimens suggest complete or nearly complete feather coverage. Not surprisingly, paleoart depicts Tyrannosaurus feathers anywhere and everywhere, and then again lacking in those same places. Any claims of scientific authority governing these choices should be met with skepticism.
More Art Than Science
It's worth repeating that a paleoartist should only take artistic liberties to address questions unanswered by science. But with so much unanswered, depicting Tyrannosaurus rex quickly becomes more art than science. With every valid argument having an equally valid counter-argument, much of the portrayal can (and does) rely on personal preference.
The Case Against Feathers
While Tyrannsaurus rex had to contend with the harsh and unforgiving environment of the late Cretaceous, its depictions must adapt to survive an even harsher environment: the internet. Here, feathers may be an even greater liability than they would have been in the hot climate of the Cretaceous. Trolls, the natural predator of featheryTRex.jpg, were raised on the movie monster version of Tyrannosaurus. They will attack anything that doesn't fit their preconceived and potentially flawed notion of what dinosaurs should look like.
The Case For Feathers
Artistically, feathery rex is a relatively unexplored frontier. There's lots of room for artistic expression. There's even the potential to establish a new Tyrannosaurus archetype, all while retaining paleoartistic credentials. These are compelling reasons to feather the dinosaur king, and among those that I chose to feather mine.
Artistic Questions of Type, Color, and Coverage
I've chosen to feather my rex with slender monofilaments. Other feather types didn't seem to read right. Monofilaments, on the other hand, achieve a sleek and bird-like silhouette. Initially I wanted to apply alpha planes at the feather/scale borders. Unfortunately I was unable to get them to mesh with the mesh so as to seem seamless. I plan to experiment further. If anyone has alpha plane tips and tricks, please let me know.
I've chosen to countershade my feathered rex, contrasting a pale underbelly with a dark, bespeckled back. The notion that some dinosaurs exhibited countershading derives from a study published in Current Biology. Again, the idea was to demonstrate to the viewer a scaled-up bird reminiscent of those in their yard. I think for most people familiarity equals plausibility.
Many artists try to combine literal interpretations of the Wyrex specimen with inferences from Yutyrannus fossils. This pairing of mis-matched premises neglects the fact that nature abhors ass-less chaps. Very few animals Porky Pig it. I've chosen instead to match inferences from Yutyrannus with inferences from modern day birds. My Tyrannosaurus is part ostrich and part vulture: bare legs and bare head. The artistic reasoning for a bald head and bare legs was that it would remind viewers, at least partially, of their beloved Tyrannosaurus rex of Jurassic Park fame. I think for most people familiarity equals likability. The psuedo-scientific explanation for the bald head is that it would serve the same functions as a vulture's. It would be more hygienic when scavenging and allow for heat-dumping.
Tyrannosaurus rex had lips. Depictions of crocodile-like toothy overbites are patently wrong. Also, it is reasoned that T. rex's forelimbs typically faced inwards (not forwards) and had a limited range of motion.
Speaking of motion, when animating a Tyrannosaurus Rex it is important to note that it was not eminently agile. This is because of rotational inertia. "To reduce rotational inertia, theropods may have run with an arched back and tail, an S-curved neck and forelimbs held backwards against the body."
I've made it a point to include all these considerations in my reconstruction. As new facts are unearthed, I intend to update my model accordingly.
A paleoartist strives to depict prehistoric life according to the latest scientific findings. His work is as much research as it is rendering. Artistic liberties should only address those questions that are unanswered by science. In the case of Tyrannosaurus rex, there's plenty of room for artistic interpretation. Nonetheless, every choice should be carefully reasoned and include some supporting evidence. I'm mostly pleased with my depiction. Further experimentation (especially with alpha planes) will be necessary to better achieve my goals.
Postscript: You can follow the struggle beginning here. If you're interested in making the transition from gameartist to developer, please consider my textbook. The feathered rex depicted above will feature in a reboot of the realLive app: https://www.youtube.com/watch?v=YIpR46EpOj8 Follow me on Twitter, @nickelcitypixel, for crowdfunding updates. Your support means the world to me. Thanks for reading!