Another music question.
Favorite genre of music?
There's not much I can say that I haven't already said in
previous responses to music-related questions. I like music that sounds good to me, and that's about it (There's really no way I can think of putting it that doesn't sound stupid.
). I just don't know enough about all the different music genres and what defines each one to be able to pigeonhole my musical preferences.
I suppose I could say that there are three basic kinds of songs or tunes that I enjoy: lively, bouncy music; slower, "soothing" music; and exciting, "epic" music.
Okay, my first question: can you forgive me for being so unresponsive lately? I'm sooooo very sorry about that. Between being obsessed with Super Mario Bros. and writing all sorts of fanfics, trying to keep my current job, trying to find an affordable apartment that allows pets (that one's been practically fruitless...looks like I might have to give up my ratties 
But at least my antlions can be passed as decorative bowls of sand...), and all sorts of other things, I have not been feeling very social at all, especially for the internet peoples... I hope you haven't been put off by my absence...
Of course I forgive you, Sparky.
I'll admit, it's been pretty lonely without you around, but I understand completely (I’ve had plenty of times where I just didn’t feel like socializing or was engrossed in an obsession too), and I can honestly say I hold you no ill will for it.
Sorry to hear about your problems in real life, and especially about your rats.
I wish you the best in finding an apartment that will accept them. (As for the antlions, won't you still have to smuggle ants into your apartment to feed them? :unsure:)
I do hope that, if you have the time and inclination, we’ll be able to pick up our abandoned conversations (Let me know if you need me to re-send you any e-mails or PMs, or remind you of threads in which I’m awaiting a response from you
). Put your real-life issues first, though. I don’t mind waiting longer.
Second question: I'm working on making another 'realistic' drawing, this one with Red Claw, Screech, Thud, and the two super-preds intended in the RP (Gigano and Stromer, I believe was the name for the Spinosaurus). Do you have any sources that can help me on scaling these characters accurately and/or have any pointers you might be willing to give me? 
Ooh, that picture sounds epic! :! Well, scaling isn’t one of my strong suits, but there’s plenty of scenes in the TV series showing the sharptooth trio together, so that shouldn’t be a problem, right? As for Gigano, we know he’s about the same size as Chomper’s parents, and Chomper claims that Red Claw is “the biggest sharptooth of all”, so that could mean that Gigano is actually slightly smaller than Red Claw. However, one possibility I just thought of is that Gigano is actually not a fully grown sharptooth (or at least he wasn’t at the time of LBT V): it could be that he was the sharptooth equivalent of an impulsive adolescent (more like a young adult). This could explain some of his behavior in LBT V (eating a bush because it smelled like the gang, managing to chomp down on his own tail, and taking on two angry parent sharpteeth: honestly, I’ve always thought that the guy seemed a few eggs short of a clutch), as well as why he was apparently smaller than Red Claw. Theoretically, Gigano could have experienced a late growth spurt since the events of LBT V (there’s good eatin’ to be had along the seaside
:), so that he has attained his adult size by the time in which the RP takes place, which would conceivably allow him to be as big asóor even slightly bigger thanóRed Claw. So I guess you’re free to make Gigano whatever size in relation to Red Claw that you want. (If you’re going for realism, though, keep in mind that
Giganotosaurus was only a few feet longer than
Tyrannosaurus: perhaps 40–43 feet compared to
T. rex’s 39–40 feet.)
Stromer the
Spinosaurus’s size is a little harder to ascertain. I guess you could look at screenshots from LBT XII showing him next to the gang, compare them to shots from the TV series showing the gang next to Red Claw, and estimate the two sharpteeth’s relative sizes, though there’s no guarantee that it would be accurate, considering that the character scaling in LBT is often inconsistent. Somehow I envision Stromer as being the biggest of the super-pred trio. It’s possible that Chomper only assumes that Red Claw is the largest sharptooth around because he has never seen Stromer’s kind, or even that Chomper’s use of the word “sharptooth” only refers to his own species (or just does not include
Spinosaurus because they look so different from other sharpteeth; even the gang asked “What is that thing?” when they saw Stromer for the first time). Even the real-life
Spinosaurus’s size is not known for certain, since only fragments of its skeleton are known. We don’t know how long its tail was, for instance:
this article provides a great visual representation of how this could affect
Spinosaurus’s total length. The respective lengths of the
Spinosaurus lengths in the drawing are stated to be 12, 14, and 16 meters (or 40, 46, and 53 feet). There’s also
this scale chart from Wikipedia showing the comparative sizes of
Tyrannosaurus,
Giganotosaurus,
Carcharodontosaurus, and
Spinosaurus (which is assumed here to be around 46 feet long). It should be taken with a grain of salt, though; it’s impossible to know whether
Spinosaurus had shorter legs or a shorter tail than are represented in the silhouette (More on the subject of Spino’s proportions later). And the author of
this article suggests that
Spinosaurus’s size has generally been overestimated, and that all of these mega-theropods were in about the same size range: about 42 feet long (give or take two to three feet). I should think that you would be safe with a conservative length of 45–46 feet for Stromer, 42–43 feet for Gigano, and 40–42 feet for Red Claw (remember that he
is supposedly a rather large
T. rex). But, like any animal, dinosaurs surely varied in size even as adults, so you can feel free to tweak those dimensions if you want.
This brings me to my next challenge: pointers on how to draw your dinosaurs realistically. Hoo-wee…three different species this time; four if you wanted tips on
Utahraptor as well. :blink:
Let me get
Utahraptor over with first, since I presume you’re more interested in info on the three mega-theropods. (Let me know if I am incorrect in this assumption.) Unfortunately,
Utahraptor ostrommaysorum is one of those dinosaurs that is only known from a few intriguing fragments, so there’s not much I can tell you about what it looked like. I
can tell you that it is believed to have belonged to the group of dromaeosaurids known as dromaeosaurines, which were more heavily built than their relatives the velociraptorines (e.g.,
Velociraptor and
Deinonychus). To my knowledge, the most complete known dromaeosaurine is its eponymous member,
Dromaeosaurus, but it lived roughly 50 million years later than
Utahraptor and probably wouldn’t make for a very accurate comparison.
This guy made a skeletal restoration of
Utahraptor a while back, but according to him it is inaccurate and should not be used as a reference for drawing this dinosaur. (I imagine there are worse places to start, but I still don’t feel quite right recommending it to you as a source. :unsure:)
This blog article (which I’m pretty sure I linked you to previously when I was telling you about
Archaeopteryx) contains an image that demonstrates the “do”s and “don’t”s of illustrating
Velociraptor, some of which you might be able to apply to
Utahraptor (see also my response to your third question, at least as far as feathers are concerned). The same blog author (who is also an artist) also wrote
this post regarding fact about dromaeosaurs that is rather ironic, given Screech and Thud’s LBT species name: raptors (
Utahraptor especially, in all likelihood) were not particularly well adapted for fast running. But then, it is currently thought that raptors in general were probably more like cats: adapted for short bursts of extreme power rather than prolonged chases. I would think that, like any big cat (and plenty of other animals that aren’t built for fast running but can still readily outpace your average human, such as rhinos, hippos, and grizzly bears), a dromaeosaur could move extremely fast when it wanted to; it just couldn’t keep going for very long. Anyway, the same page has an illustration of
Achillobator, a dromaeosaurine from Mongolia that approached
Utahraptor in size. I don’t know how much of the illustration is speculative, but it might be an okay reference for your realistic drawing of Screech and Thud.
Well…that was a little more info about
Utahraptor than I thought I would be able to provide. Anyway, on to the megatheropods:
Tyrannosaurus,
Giganotosaurus, and
Spinosaurus.
For a good overall guide to these three dinosaurs’ respective anatomies, here are three skeletal restorations, all done by the same person (who I understand to be a rather renowned and extremely knowledgeable paleoartist, so I consider him a trustworthy source):
Tyrannosaurus: skeletals based on both the specimen known as “
Sue” and the unusually big-headed individual called “
Stan” (Keep in mind that we do not know the actual genders of these specimens, or whether their physical differences are even related to gender.)
Giganotosaurus: The artist notes that one of the most commonly seen skull reconstructions of
Giganotosaurus is in fact inaccurate, so be sure to pay close attention to the skull in this image when drawing Gigano’s head.
Spinosaurus: The restoration on top shows the amount of skeletal material actually known from this dinosaur; as you can see, it’s not much.
A lot of my suggestions for accurately drawing
Tyrannosaurus,
Giganotosaurus, and
Spinosaurus applies equally to all three, so rather than describing each dinosaur separately, I’m going to alternate between them as I focus on different general aspects of their anatomy:
Body: From what I’ve heard,
Giganotosaurus was slightly bulkier than
T. rex (and probably wasn’t as fast or agile), whereas
Spinosaurus is apparently believed to have been more lightly built than either. This means that, in a head-to-head
Jurassic Park-style brawl,
Spinosaurus would be at a disadvantage due to its more delicate build (and specialized jaws that may not have been well suited for attacking large animals). In a more realistic hypothetical confrontation scenario, however, I strongly imagine that
T. rex or
Giganotosaurus would probably refuse to engage
Spinosaurus in a fight in the first place, because
Spinosaurus was simply so damn big and intimidating looking that no theropod in its right mind would consider it a remotely good idea to test whether this sail-backed behemoth’s combat prowess was in fact inferior to its own. (
See my dissertation on the absurd [IMHO] “
T. rex vs.
Spinosaurus” debate). This brings me to
Spinosaurus’s most distinctive characteristic: its sail. Many pictures you see of
Spinosaurus depict the sail as a simple half-disk affixed to the dinosaur’s back, supported by thin vertical rods, much like the sail of
Dimetrodon or the dorsal fin of some colossal fish. In fact,
Spinosaurus’s sail probably looked rather different.
This article contains a photo of the original
Spinosaurus sail material (which was later lost in a WWII bombing raid that destroyed the museum where the fossils were kept…yet another reason to hate Zotz-damn war <_<); as you can se, the spines were actually fairly broad, and most scientific restorations show them as being rather close together, which would suggest that the sail was more like a tall, narrow hump than a fin. In fact, I wouldn’t be surprised if the sail appeared as just a smooth, solid surface in the living animal, with the bony spines buried beneath the skin, as in
this illustration. Though much less extensive, the shoulder humps of
bison have similar-looking internal skeletal support. Granted, as
this article points out, bison shoulder humps are attachment points for muscles that support the head, which was almost certainly not the purpose of Spino’s sail.
Spinosaurus. Still, I would recommend drawing Stromer with a smooth humplike sail (See the “Soft tissue” section for an exemplary 3-D restoration and a few more relevant tips). As for the shape of the sail,
Spinosaurus’s relatives, such as
Suchomimus, had sails that extended all the way from their shoulders to partway down their tails; although these sails were lower than
Spinosaurus’s, evidently paleontologists believe that Spino’s sail would have been similarly extensive, and not just a simple semicircle affixed to the back of the torso as in some illustrations. There are already at least three image links in this post showing what the sail is apparently believed to have looked like, so I don’t think I need to elaborate any further.
Teeth: One aspect of accurate theropod illustration that I am perpetually unsure about is how to depict their teeth: exposed, like a crocodilian’s, or concealed by “lips”, like a lizard’s? On one hand, dinosaurs are more closely related to crocodilians, but unlike most dinosaurs, crocodilians live in aquatic habitats where don’t need to worry about their teeth drying out (that’s one argument I’ve heard, at least).
The author of
this article examines the various possible configurations of dinosaur “lips” and how they might have covered the teeth: like me, he’s apparently not an academically educated paleontology expert, but his knowledge of the field is well beyond mine, and even I have a hard time comprehending everything in his post. Personally, until more information on the subject becomes available to me, I’ll probably be drawing my theropods with moderate “lips”, with only the tips of the longer teeth protruding. (It might be safe to give Stromer more exposed teeth, considering the possibility that
Spinosaurus spent a good amount of its time up to its nostrils in water.) Mind you, reptile “lips” are not like mammalian lips: reptiles (including dinosaurs) have almost no facial musculature whatsoever, so they would not have been able to curl their lips back in a snarl. The equivalent threat display would probably consist of the dinosaur simply opening its mouth, as if to say ”I’mma bite you if you don’t back down!” This is pure speculation, but I imagine that the more threatening the display, the wider the gape; for example: closed mouth = “I’m submissive/I’m calm/You’re not bothering me”, slightly open mouth = “I’m a little worried you’re gonna hurt me/Careful, you’re cheesing me off”, and mouth wide open = “If you’re not running for the other side of Gondwana in three seconds you are DEAD MEAT!” However, I don’t know exactly how far any of these theropods could open their mouths (though if its relative
Allosaurus was anything to go by,
Giganotosaurus’s gape may have been pretty wide), so be careful not to dislocate your characters’ jaws. Also, don’t forget that theropod teeth were not uniform in size and shape: look closely at the teeth in the illustrations I’ve linked you to to get an idea of how to draw them accurately. Mind you, if you draw Red Claw and/or Gigano with their mouths closed, all of their upper teeth should be overlapping their lower teeth, so none of their lower teeth would be visible.
Spinosaurus, on the other hand, had a rosette of teeth in the bulbous section at the end of its lower jaw that, from the looks of things, would have overlapped the corresponding section of its upper jaw when its mouth was closed. (It’s worth remembering that spinosaur teeth were straighter and more conical than those of other theropods, much like the teeth of crocodiles.)
This illustration, based on a 2005 reappraisal of
Spinosaurus’s skull anatomy, should be a pretty good reference for the teeth, and the head in general.
Heads: Judging from what I consider to be the most accurate
Tyrannosaurus illustrations I have seen,
T. rex had two bony knobs directly above (and extending slightly behind) its eyes, with two relatively smooth, bar-like ridges extending about a third of the way down the snout in front of them. These bars seem to meet in the middle of the snout, and give way to a knobbly ridge that runs along the midline of the snout, ending slightly behind the nostrils.
Giganotosaurus seems to have had more of a short, blunt horn above and in front of the eye. Directly in front of each “horn” was a long, low ridge of very small, close-together bumps that extended about the same length along the snout as
T. rex’s ridge and “bar” ornaments combined (possibly even further). The ridges would never join, but they would run very close together, but much closer. Carnosaurs such as
Giganotosaurus are well known for having extremely narrow skulls, like giant axes, and are believed to have attacked large prey by opening their jaws wide and rapidly snapping them shut on the fleshy parts of their target’s bodies (such as the thighs and flanks), slicing off gigantic slabs of skin and flesh while avoiding breaking their teeth on the bones. Because their skulls were so narrow, I’m guessing their usual technique was to angle their jaws parallel with the sides of the prey’s body. Following that, I imagine the hunting carnosaur would wait for the prey to weaken a bit, then go in for another bite, repeating the process until the prey was dead and the hunter could dine leisurely.
Spinosaurus had a single small crest on the midline of its skull, just in front of its eyes. From the restorations I’ve seen, it was shaped like a slightly peaked semicircle, and seems to have had slight vertical ridges on its surface (almost like a mini version of its sail). It was probably slightly larger in life due to being covered with keratin, and some illustrations I’ve seen depict it as being softly serrated on top. Its nostrils were about midway between its eyes and the tip of its snout. An important thing to remember about dinosaur nostrils (which I remember telling you about before in your art thread): in life, the fleshy nostril openings of dinosaurs were small, and situated at the very front of the bony nostril openings, or nares. Don’t give your dinosaurs huge gaping nostrils. One fascinating theory about Spino’s facial anatomyóthough I am not entirely clear on how widely accepted it isóis that the end of its snout was pockmarked with tiny pits, similar to those found along the jaws of crocodilians, which are sensitive to changes in water pressure and allow them to detect prey swimming nearby (The proposed placement of the pits can be seen in
this drawing of Spino’s skull). Maybe one of
Spinosaurus’s hunting strategies was to stand in the water with its snout dipped beneath the surface (the high placement of its nostrils allowing it to breathe), patiently waiting for a fish to swim near. When that happened, it could rapidly twist its head and neck or dart its jaws forward to seize the fish. It’s also possible that it could have swum or waded deeper into the water, its head held at an angle so that its eyes and nostrils were exposed, but much of its mouth was underwater. In general,
Spinosaurus is believed to have been good at making swift, sharp, precision strikes at smaller prey. There’s even been one discovery of a spinosaur tooth embedded in the backbone of a pterosaur: the owner of the tooth could have been scavenging a dead pterosaur, but the more exciting possibility is is that it snatched the still-living pterosaur right out of the air (or ambushed it on the ground). The proportions of spinosaur jaws are apparently similar to those of gharials (though I can’t help thinking that they look a little more robust), which suggests that they wouldn’t have been very good for attacking large prey. However, it’s possible that
Spinosaurus was a canny scavenger, perhaps scaring other predators away from their kills, ripping open the bodies with its powerful arms and giant claws, and sticking its muzzle right into the body cavity, nosing around for the most nutritious innards without needing to pull out for air, thanks to its high-placed nostrils. It’s also been suggested that spinosaurs used their large hand claws to snatch or impale prey, though if you look at restorations, the arms don’t seem quite long enough to do that as effectively or as accurately as the jaws (I’m not even sure if
Spinosaurus would have been able to see its own hands that easily). It may have been able to use them to pick up and carry larger prey; some of the fish it probably hunted measured over six feet long.
Hands: When drawing theropod forelimbs, be sure to avoid the all-too-common mistake of “bunny hands syndrome”: drawing the hands pronated, with the arms folded up against the chest and the palms facing backward. No known theropod could hold its hands this way without dislocating its wrists: in general, they held their hands with the palms facing one another, as if poised to clap or holding an invisible basketball.
This is the best source I know for understanding the range of movement theropod arms had (I may have told you about all of this before, so forgive me if I am repeating myself).
T. rex, as we all know, had only two functional fingers, the second of which (the one on the bottom, if you’re looking at the hand from the side in the afore-described “clapping” pose) was slightly longer than the first. (It did have a vestigial third finger, but that was just a splint of bone that probably wasn’t even visible in life). Relative to its own body,
Giganotosaurus’s arms seem to have been about the same size as
T. rex’s, though the forearm appears to have been slightly stouter, with three fingers of relatively equal length whose claws were considerably longer than those
T. rex.
Spinosaurus (if related spinosaurs from which arm material is known are anything to go by) had much burlier arms. Its first finger was shorter than the other two, but bore an extremely long, curved claw that made its overall length (base to claw tip) about the same, if not slightly more. For all three of these dinosaurs, the first finger (the thumb) was angled forward slightly, while the other finger/s pointed more or less straight forward (at least, that’s how they appear when the hand is in profile; I’m guessing that the fingers curled inward somehat and the claws were more curved than you can see in the skeletals).
Soft tissue: Like any modern reptile, bird or mammal, dinosaurs weren’t just skin and a little muscle stretched over a skeleton: they had fat, and loose skin, and muscle tissue that would not be immediately evident from looking at attachment sites on bones, and just places with soft-tissue padding filling in spaces between bones. “Say no to shrink-wrapped dinosaurs!” as I saw one source put it.
(Though focusing mainly on sauropods,
these articles have some great images and pointers that relate to reconstructing appropriately fleshy dinosaurs.) So don’t draw dinosaurs with visible “windows” (fenestrae, if you want to be technical) in the skull: layer skin over them so that the dinosaur’s face is more or less a smooth surface. Ribs and vertebrae should not be easily distinguishable beneath the skin, and the base of Stromer’s sail should probably be merged with the sides of his body (sort of like if you pushed a CD up through a layer of stretchy fabric, as opposed to jamming the CD down into the back of a clay dinosaur). After all, animals’ vertebrae are generally not covered in form-fitting skin; they have flesh between the neural spines (the vertical bony projections on the midline of the vertebrae, which are extremely elongated in
Spinosaurus to form the sail) and the transverse processes (the paired bony projections that stick out from the sides of the vertebrae). Here’s
Here’s an image of two T-bone steaks (each of which is actually half of a cow’s lumbar vertebra and the meat around it) put back together. Outlined at the bottom is the actual shape of the complete vertebra: the “wings” are the transverse processes and the projection on top is the neural spine; as you can see, there’s plenty of back muscle bridging the gaps between them. And here’s
here’s a cross section of a cow’s entire torso, again with the vertebra outlined (though the transverse processes are not as long here), and
another image showing a cross-section of a human abdomen.
The article containing the latter two images points out that dinosaur (or at least sauropod) vertebrae were were not as deeply buried in the animals body as the vertebrae of mammals like cows or humans, and
Spinosaurus probably didn’t have a massive wall of meat between the top of its sail and its ribcage, but nonetheless, there probably wasn’t a sharp right angle between the base of the sail and the back. And be sure to give your dinosaurs broad, fleshy tails, like a crocodilian’s. If you look at the base of a croc’s tail, it’s actually wider than the hips. This is due to the caudofemoralis, a large slablike muscle that runs along the sides of the tail and connects to the thighbone via a tendon: the legs of reptilesóincluding dinosaursóare in fact largely powered by the tail muscles.
T. rex in particular is believed to have had an extremely muscular tail; it is believed to have been the fastest-running dinosaur of its size thanks to this.
This article is the best source I know regarding the caudofemoralis and why paleo-artists should take it into account when drawing dinosaur tails (At the bottom of the page is a good illustration of an accurately fleshy
T. rex. Here’s
Here’s an alternatively colored version on the artist’s DA account, and here’s
here’s another illustration by the same artist of a
T. rex in profile).
Here is one 3-D model of a
Spinosaurus done by an artist who, as far as I can tell, is trying to make it as accurate as possible (Both the artist and some of the commenters think that the base of the tail should be thicker than it already is). Now that’s one meaty-looking spinosaur!
(Honestly, though, I imagine that its bulk would make it look even more imposing and add to the sense of massiveness.) The same artist also has a 3-D model of
Tyrannosaurus. (No
Giganotosaurus, but it’s worth looking through this guy’s gallery just the same: he does some of the most awesome realistic paleo-art I’ve ever seen.)
Skin: Spinosaurus lived in a warm, humid climate (and may have been semi-aquatic as well), so I would make Stromer scaly. According to
one scientific paper I found,
Giganotosaurus’s habitat was more temperate, but there’s not much evidence as to what kind of skin it had, so you’d probably be safe drawing Gigano without feathers as well. From what I’ve been able to gather, the climate of Late Cretaceous Montana was subtropical, so adult
T. rex may not have needed a feathery coat either. I guess I would leave Red Claw scaly, too (See my response to your next question for more info on fuzzy tyrannosaurs.
)
And the main question in relation to that: Were Utahraptors feathered (I'm still convinced Screech and Thud are Utahraptors 
) ? I know their smaller relatives were almost certainly feathered primarily for regulating body temperature, but larger animals tend to be better at maintaining body heat without an insulating coat. So were Utahraptors big enough to forsake feathers or did they stay true to their family's feathery heritage 
?
Personally, I’d be inclined to put feathers on
Utahraptor, for a number of reasons. First, as you said, phylogenetic bracketing:
Utahraptor’s smaller, more basal relatives (e.g.,
Microraptor and
Sinornithosaurus) are definitively known to have been feathered (not just feathered, but fluffy all over, down to the tips of the toes and fingers and almost to the end of the snout) and there is evidence that its more derived relative
Velociraptor had feathers, too, so it’s almost certain that
Utahraptor had feathers at some point in its evolution, and it seems unlikely to me that it would lose them entirely.
Secondly, although it was indeed larger than any other dromaeosaur currently known, I don’t think
Utahraptor was so big as to not need an insulating coat. Its estimated weight is apparently around half a ton (1,000–1,100 pounds). That’s about the same weight as a grizzly bear, and yet grizzly bears get along just fine with a full coat of fur (and historically have lived in some rather hot climates, such as Mexico). And I should think that a
Utahraptor, with its long, slender limbs and tail, would have a lot more surface area than a grizzly, all the better to disperse excess body heat.
Thirdly, we have an extremely exciting fossil discovery (so exciting that I made
a post for it when I heard about it) that presents an argument in favor of big fluffy theropods:
Yutyrannus huali, a medium-sized (~30’ long) tyrannosaur that was covered in filamentous feathers up to 6 inches long, the largest confirmed feathered dinosaur known to date. Granted,
Yutyrannuss native climate is believed to have been fairly cool by Mesozoic standards, and I don’t know how
Utahraptor’s habitat compared. Still, it proves that “big theropod” does not necessarily equal “bald theropod”.
Now, this next line of reasoning isn’t really backed by any scientific sources or research; it’s largely speculation based on various things I know about feathers and thermoregulation: I can’t help but think that a large feathery animal would have an easier time keeping itself cool than a large furry animal, because of the structural differences between feathers and fur. The respective body coverings of both mammals and birds tend to come in two basic types that serve the same purposes: a short, soft, dense underlayer that provides insulation (underfur in mammals, down feathers in birds) and a long, coarse, waterproof layer that protects against the elements (guard hair in mammals, vaned feathers in birds). And for both kinds of animals, excess heat can be dissipated by fluffing out their coats, lifting their hairs or feathers to expose the skin and allow heat to escape. However, it would seem to me that feathers have an advantage over hairs insulation-wise because of their branching structure: not only does the vaned surface of a feather allow it to cover much more surface area than a hair, but a single feather can (to some extent, at least) serve both the insulatory and element-proofing roles by having fluffy branches at the base and vane-forming ones higher up.
Basically, my hypothesis is that a feathery animal (such as a dinosaur) could grow beyond the size where most mammals in the same climate would lose most of their hair, and still retain an insulating layer of feathers, because feathers, unlike hair, can continue to serve an insulating function even if they become sparser in order to keep an animal cool.
It’s rather confusing (even for me
) to explain where I’m coming from, so allow me to attempt to replicate my train of thought and how I came to this conclusion: A single feather covers much more skin than a single hair. > Feathers can be spaced farther apart than hairs (and fewer are needed overall) in order to adequately insulate a given area of skin. > Wider spaces between individual feathers means more bare skin is exposed when the animal fluffs out its coat, allowing the animal to dissipate more heat and cool itself more easily.
Here’s a photo I thought I’d share to help illustrate my point. This summer, when my family and I toured an emu ranch in Nevis, Minnesota, we had the opportunity to see a selection of feathers, skins, eggshells, and other artifacts from a variety of ratites (ostrich, rhea, and of course emu). Among these were a piece of an ostrich skin (the yellow object in
these photos*) and an emu skin (the large red-dyed object in both the above photos and
these ones). One thing I found striking was just how sparse the feathers on these birds (particularly the ostrich) really are. The little bumps on the skins where the feathers attach are farther apart than the hairs on your arm. Ostriches do in fact have large patches of bare skin underneath their wings and on their sides (as visible in
this picture, not taken by me), which are generally covered up when their wings are folded, but can be exposed when the ostrich needs to radiate excess heat. (That ostrich in the photo actually looks like it’s missing some feathers, judging from the goosebumpy patch on its leg; perhaps it’s been molting?) Emus also apparently have sparse or featherless patches on their underbellies, and they can thermoregulate by simply standing up when it’s hot, and sitting down when it’s cold.
It’s possible that some of the larger feathered dinosaurs had similarly placed bald spots that could be covered or exposed at will depending on the circumstances, so you could draw your
Utahraptors that way if you wanted. (Alternatively, you could just say that they have featherless patches but keep them hidden.
) I think it’s also safe to leave the legs unfeathered to at least some extent. As I recall, the ankle joint was the cutoff point for
Archaeopteryx’s leg feathers, while ratite feathers stop about halfway between the knee and ankle joint. You can decide for yourself whether you want to go with one of those configurations, or draw your
Utahraptors with completely featherless legs. You should probably
not omit feathers from the tail, head, or neck, and definitely not from the arms or back.
*Also visible in these photos:
(
1,
2) The huge white feather on the left of the first two photos is from an ostrich, the one in the middle is from a rhea, and the small beige-ish bifurcated feather on the right is from an emu.
(
3) An emu eggshell, sitting on top of two dyed skins from emu feet. Above is a stack of hides (with the feathers still attached) from emus of varying ages.
(
4) A whole dried emu foot (the “emu foot scepter”
).
Holy roly-poly star-nosed moley, THAT was one humongous post.
(
[size0]Imagine this guy with really huge, surprised looking eyes, like this: :blink:.)
