All Your Guessing Games


What? Another All Your Yesterdays mention?

Sorta.

Nuh uh -- not that easy!You remember when I asked you all what this might be? Someone got the right answer, although I’d love to speculate how they came about it. I have a clue, and it might be for the sake of perversity, or because I’m a predictable schmo (read: Yiddish, “I’m an idiot”).

See, I wanted to take some time and work out a possible speculation myself, but those guys at Irregular Books have done this with their own book, and whilst some drawings were made, the total thrust of things was sidetracked and instead, I went a tad over into fantasy. The use of a loaded term in this realm might annoy people, maybe provoke a rolled eye or three, but it helps. It helps because, ultimately, it is. Dinosaur reconstruction isn’t “fantasy” in the sense of 50 foot mumakil or TOHO’s Gojira franchise and the wonderfully silly, campy and adventourous spin-offs (I might temporize and call it “science fantasy” instead, as it has a basic science premise behind it, but otherwise these are fantasies in modern(ish) times, as much as Gaiman’s works are).

So, as Mickey Mortimer accused me earlier when I revealed the previous Guessing Game’s answer of Masiakasaurus knopfleri, I went and took a notable animal and “hid” it underneath plausible flesh. This is if anything a response to Mickey’s accusation. It tells me (and you) that there is truth in the argument, even when you don’t intend it. It also helps you frame how outrageous you might get while staying “plausible.”

Not that long ago, I was also in a discussion on what it might be to hide away an incredibly noticeable skull behind flesh. I was even asked once if I felt this particular animal was lipped or not. I have been curious about the answer, because while it is possible, I did not have the tools to assess it. I still do not. But I felt an excercise was in order.

So what is it? Well, what do you think it could be? Seems obvious it’s a dinosaur. A theropod one at that, and reasonably close to birds. Feathers and everything? Some suggested Eoraptor. That’s actually a nice answer, and one I didn’t expect, but it’s not correct: I wouldn’t think Eoraptor lunensis would have pennate feathers. If not that, then closer to birds. Well, putting several facts together, you might arrive at my answer:

1. I really like oviraptorosaurs (duh).

2. There are some strange oviraptorosaurs.

3. I am fascinated by the evolution of tooth loss.

4. I don’t apparently think there are “lips” in oviraptorosaurs (well, most of them).

5. I actually think many dinosaurs were a lot more ordinary looking than you might imagine. That is, I’d like to hope people don’t think of dinosaurs looked as outrageously as possible, but more or less “normal.”

I’ve you’ve seen one theropod head, then, you’ve seen ‘em all. There would be slight distortions in proportions, relative size of the eye, head to body, etc. But it’s all more or less the same. When fine bone details change, the underlying structure doesn’t This helps explain how many bird heads look so similar despite often drastic cranial disparity underlying it, or the muscle patterns of the jaw, wing, or neck being diagnostic despite similar relations. Applying this principle across dinosaurs means that a noasaurid wouldn’t look very different from a typical “raptor” head — until it opened its mouth. The shapes of an elmisaur ankle are diagnostic to them, but you’d never know the details from a fleshed specimen, and the same is true for most birds, whose tarsal morphologies can be used to diagnose subgroups among typically-lauded “species.” But these structures relate to the overlying tissues in the same general way, and they can tell you how “thick” a “knee” might be in a thicknee, how much a jugal bone relates to the line of the jaw, or position of the muscles attaching to the mandible. Regardless of the size or number of holes in the skull, the structure underneath all that flesh is basically the same, and so the head is basically the same. Skulls don’t really lie, but head shape and features related to it aren’t as dependent on skull-features as many might think.

So my argument then is that making your animal look like the concept of that animal that is most known is pushing it too far. You’re trying too hard. You probably wouldn’t see the high cheekbones in Nigersaurus; nor would you see the gap in the “gap-snouted” Dilophosaurus, Coelophysis, Baryonyx (incl. Suchomimus), and Spinosaurus. The humongous external bony naris of Jobaria is pretty noticeable, as it is in Camarasaurus, but visible from the fleshed head? Probably not. If you’ve got a flange of bone that sticks into the orbit to support the eyeball, it wouldn’t be noticeable. Skulls aren’t shrink-wrapped, and because of this, teeth aren’t visible. Oh, sure, in crocodilians you can see the teeth when the jaws closed, and there are no “lips.” But crocs may not need them. There are tissue conservation aspects that mayb be at play: crocs employ a LOT of neurosensory tissue to the multitude of facial electrosensory organs that help them hunt. They don’t even have facial scales anymore; it’s all skin. “Lips” — as we might imagine them on sauropsids rather than synapsids, the line stemming towards crocs, birds, lizards, snakes, and turtles rather than to mammals — might just get in the way, and they can ill-afford that development when the need is not there, given they are aquatic hunters. So, one might speculate, feeding into my thesis that virtually all terrestrial (at least) sauropsid tetrapods have “lips” until proven otherwise (including early birds), one can just suggest that the lips I show up there are hiding something noticeable.

Got it yet? The clues are dripping so far.

Fine.

Incisivosaurus gauthieri (or Protarchaeopteryx gauthieri, if you prefer, but it matters little).

UntitledFullsmThis is actually inspired by the “lipped” lepidosaurs Uromastyx and the tuatara. I even went further and speculated before about the rather unassuming “life” appearance of rhynchosaurs for this reason. Both of these taxa have beak-like features on the tips of their jaws, including a sharpened blade in portions, but retain a full extra-oral fleshy integument, complete with scales (which I’ve omitted here — that’s all bare skin). A large pair of teeth in both are the first premaxillary teeth, and they are noticeable when the jaw opens … yet there is no indication of them when the jaw shuts. We might apply this more readily were it not for the need to identify dinosaurs by their oddity, rather than by their commonality.

Oh, yes, there’s also something in that image about feeding behavior and use of the teeth, for processing large seeds or hard-rind fruits. Like parrots, the eternal comparison to oviraptorosaurs. The tongue doesn’t hurt the the comparison, but I am sad to say it is among the least fact-based aspects of this entire illustration, as such a tongue would require a large, bony basihyal, and frankly the hyoid apparatus of dinosaurs doesn’t fossilize well.

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11 Responses to All Your Guessing Games

  1. Mickey Mortimer says:

    The issue is you don’t actually draw the restorations in proportion to the known fossils. The only known specimen of Incisivosaurus for instance, has a much shorter snout (compared to height right in front of the eye) with a different outline than either individual. So sure, some Incisivosaurus individuals might have looked like your version, but you might as well say any drawing is an undiscovered individual/taxon, which eliminates most of the point of guessing. If you disagree, I’d like to see the Incisivosaurus type overlaid on your drawing.

    • Jaime, hope you don’t mind but I took the liberty of testing this… Micky, you’re right that it doesn’t quite jibe with the actual skull. The difference is a little more subtle than I expected, though still noticeably more “robust” looking.

      https://docs.google.com/file/d/0Bz2zp1zbdZeuNk9RZmJ1MlBtWFU/edit?usp=sharing

      • Mickey Mortimer says:

        Well there you go. Note too that while your second overlapped example seems close, it’s only because there are huge lips. Yet in Jaime’s picture with two heads, the open-mouthed one has minimal lips based on the visible teeth, yet the same snout depth as the close-mouthed individual. It would also leave the jaws technically open 5 degrees while the mouth was closed, which doesn’t happen in life as far as I know. So clearly that wasn’t Jaime’s intent.

        • The open-mouthed version should have a slightly deeper jaw. This is because the opening of the mouth and distention of the oral tissues is slightly decoupled from the bony jaw. The through distends or tightens depending on the hyolingual muscles. The throat clenches and the feathers might splay depending on neck stretching. In other words, not much difference in general. And yes, the teeth are smaller, but as I note in my earlier reply to you this is meant to suggest a “corrected” older animal. I am implying the holotype of this taxon is not an adult.

      • Absolutely not minding at all. But please refer to my reply to Mickey.

    • It has never been my purpose to draw a skull, find someway to assume the skull is in perfect condition — and discard the issue that the skull is exactly the same shape and proportion as any other specimen of that individual that lived or might be found, and that the specimen is of the only age that will ever be found or even true at any size. Even Matt’s adjustment, deepening the head, wouldn’t have resulted in any difference. I could have drawn the skull perfectly from a reconstruction produced by others (as I did with Masiakasaurus) and I still think you’d have nitpicked it — as you did with Masiaka.

      But that’s the point. The illustration is not an overlay of fleshy outline to skull shape. It extends the flesh from the bony outline, and this often forces a projection of the tissues beyond skull limits. I actually needed to pull the nostrils further back to keep it in line with the general position of the bony nares. Quite a lot of anatomical restroations of dinosaurs take skull outlines and simply pretend those outlines are flesh, or marginally extend equally in all outer margins the “scales” or whatever. This is not how it works with other sauropsids; it’s not even how it works with crocs. This might be most demonstrable with mammals, but it is useful with lizards and snakes alone. It is unlikely any dinosaur had closely-adhering, thin flesh, no fatty layers, even if unscaled. You don’t just take a skull and wrap skin like Saran wrap around it. You should never really see the definition of the skull or any portion of it. And that’s what this illustration is about. You are meant to have your expectations defied.

      As I said in this post, I did this illustration to be deliberately obfuscating, and it worked … for some. I didn’t even muck the skull design up when it was mocked in earlier sketches, though getting the skull too short can be explained away by noting the specimen in question may not be fully grown. We’d expect a shorter, shallower skull as a result.

      • Mickey Mortimer says:

        Ah, so the answer is “hypothetical older individual of Incisivosaurus”. I think that proves my point nicely.

        Your choice to use hypothetical individuals largely negates the purpose of your game. It’s true that everything covered in feathers will have a larger outline that hides skull shape, that soft tissue in the throat can hide structure posterior to the dentary symphysis and that soft crests can hide skeletal morphology as well. This is indeed historically underappreciated and neat, but your “gotcha” only works if soft tissues are hiding something we’re familiar with. If you have a head that’s fairly unrecognizable, it gets your point across when you then reveal you built it over the Velociraptor holotype skull we’ve all seen a million times. But if it’s supposed to be your idea of what an adult Bambiraptor would look like, then I don’t even know what the bones look like underneath. No one could be expected to guess a shrink-wrapped restoration based on skill, so the fact we can’t guess the realistic version is unsurprising.

        • The game is that I can fit the skull into an outline. The guesses ranged from in and around the origin of Dinosauria to an actual hit on the creature shown. This wide variance would likely be possible had I made the snout that much deeper to befit the holotype. However, what seems problematic for me is that you seemed to rely on your responses overly on specific specimens, and I’ll tell you:

          If you were to see the heads of Tsaagan mangas, Velociraptor mongoliensis, Velociraptor osmolskae (and were it valid, Linheraptor exquisitus) you’d not be able to tell one from the other. We are already running into discriminating these taxa on the basis of deep, fine, and few osteological details, so the task of discriminating them in the flesh could be either harder or easier. But on the basis of a defeathered specimen of each, I’d guarantee you couldn’t tell them apart.

          You, Mickey, rely overly TOO much on specimens as they are, rather than how they represent consequences of time. It would be akin to using the holotype of Velociraptor mongoliensis to say that MPC-D 100/25 represented a distinct species or even genus because of the lack of the distinct kink in the snout, the one that led so many to depict V. with that strong upturned schnoz. Specimens become distorted through time, and become less representative of their species. It is through the multitude of variation we can determine constancy. So, like Horner, I am prone to wonder that all the variation of ceratopsian skulls from the Hell Creek are variations on a theme, and that theme is improperly split amongst taxa; and that maybe, he’s right on Pacycephalosaurus. But based on the current sample, we shouldn’t just say one way or the other. So, too, anything else.

          And yes, it shouldn’t be unsurprising that concealed in flesh, many animals’ most distinctive features can very well be invisible. Imagine telling oviraptorids apart — the ones without all the head crests? But it is surprising, as the reactions I’ve received attest. You can understand, logically, what I say and show makes sense, and what it represents is reasonable; that for the most part velociraptorines and gorgosaurs and many crestless hadrosaurs were all pretty much identical to one another at skin-level. Add in color and region and you get variation, but we can’t know this for now. So all we are left with is to draw distinction on the basis of these extreme features, to draw them out somehow and let our logic and reason falter for the sake of distinctiveness.

          Gosh, imagine all the ornithischians that were identical to one another save for fine details of this or that bone and their teeth, but were truly as diverse in color and habit as all the varieties of African antelope? or sciuromorphan rodents? or chiclid fishes? Or on the flipside, all the varieties of dog are so diverse, but in contrast are each the same “subspecies”? It’s boggling.

  2. It is a bit of an issue I’ve had with illustrating extinct cetaceans. Thanks to the really thick layers of blubber and other integument, most cetaceans look identical behind the eyes with the exception of very minor shape differences in the fins and flukes. Unless there are extreme differences in rostral anatomy, reconstructions of most fossil cetaceans are just going to look like a bottlenose dolphin or minke whale.

  3. Alessio says:

    Great post, and i totally agree about skull structures not showing when the animal was alive… By the way, what do ya think about Pachycephalosaurs snouts? They bore a beak, lips, or what else?
    (i’m in a pachycephalosaur mood, lately, who knows why)

  4. Pingback: Something About Overbites | The Bite Stuff

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