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Post by foxilized on Sept 6, 2009 17:33:18 GMT
Yeah, It could also serve as a clothes line.
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Post by fleshanthos on Sept 11, 2009 14:23:05 GMT
Steggo Thagomizer
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Post by sepp on Sept 12, 2009 8:45:29 GMT
I prefer the idea that the thagomizer on a stegosaurus' tail was more horizontal than pointing up. it makes sense in my head that a stegosaurus would have had a much more powerful blow swaying its tail from side to side, than pulling it straight up at a predator to get the spikes to impale. (impaling makes sense. they probably did not use the thagomizer to gently massage their attackers' aching shoulders ;D)
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Post by stoneage on Sept 13, 2009 20:45:43 GMT
I prefer the idea that the thagomizer on a stegosaurus' tail was more horizontal than pointing up. it makes sense in my head that a stegosaurus would have had a much more powerful blow swaying its tail from side to side, than pulling it straight up at a predator to get the spikes to impale. (impaling makes sense. they probably did not use the thagomizer to gently massage their attackers' aching shoulders ;D) Discoveries of articulated stegosaur armor show that, at least in some species, these spikes protruded horizontally from the tail, not vertically as often depicted. A study by McWhinney show spike damage that indicates it was used as a defensive weapon. Can I claim my prize now? J/K ;D
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Post by sepp on Sept 13, 2009 22:02:24 GMT
^ hooray!
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Post by Horridus on Sept 14, 2009 19:23:54 GMT
Certainly would make more sense for the animal to be swinging its tale side-to-side - much simpler than what it would otherwise have to do. Rather like the ankylosaurs and their tail clubs, really...
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Post by fleshanthos on Sept 15, 2009 3:05:47 GMT
Is there any evidence for vertical mounting in wounds found?
I had always wondered if there was any justification for that mounting at all, or if it was another bullnuts story given to us by the same people who claimed they were nothing but slow moving lizards who brainlessly gummed mushy marsh plants all day long.
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Post by foxilized on Oct 10, 2009 6:19:44 GMT
I do agree the idea of side-to-side movement of the tail with horizontal spines, makes much more sense. But If we consider for a moment the stego really had the spines in vertical postiion, I can imagine a reason. I am imagining the technique of attack of a big carnosaur and that would be get the jaws closer to the victim as he can, and the rest of the body could easily been far away. I mean, an Allosaurus stretching the neck as much as he can, to be sure the only part near the victim is the Jaws, and the vulnerable rest of the body is far away. I don't believe the predators would have jumped onto their preys berserker-style, without care (as lot of movies has shown). That is way too dangerous, knowing how many spines and dangerous denfenses the dinosaurs skins had. In the case of the Stego, it's clear he was some kind of porcupine so being too closer was too risky, and a broken bone or a big wound is not worthy for a predator, no matter how hungry. SO, if the predator attack only with the head, there's no sense a side-to-side defensive movement as the legs of the predator are too far away. The only way to hit the head of the predator is down-to-up. As the predator is way taller than the stego, the attack would come from up-to-down. Now, I totally ignore if the stego had in the bone tails the hability of a movement like that. If not, then it's weird as they had vertical spines with no possibility of movement. Other possibility, though, could have been they actually had side-to-side movement with vertical spines, though NOT TOTALLY VERTICAL, but with an INCLINATION OUTWARDS. Side-by-side movement with these inclined spines could have done really serious damage as they could stick really deeply. Of course, that would imply the predators to be very close to the stego, something I doubt, because who could be so crazy of coming really close to that living armour?? The only vulnerable part of the stego was the tiny head. Surely a good bite there would break the head into pieces. But of course the predator NEEDS to go close to the head and surely the stego is not going to make it easy. Surely the stego, when attacked, turned around and showed the tail and the spines, when attacked. The theory of the plates of the back having big SPOTS, like eyes, would help to confuse the predator and made harder to find the actual head. Modern animals use that technique of confusion with false eyes to look bigger and fool the possible predator. But probably was nothing of that and the real thing was something I can't even imagine.
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Post by kevin on Oct 11, 2009 13:59:14 GMT
The main problem I see with the plates as defensive weapons is that they are quite thin and fragile, and filled with blood vessles. Have we ever found stego plates with predation damage or such? My understanding is that they would have broken if used too harshly....
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Post by stoneage on Oct 11, 2009 15:16:15 GMT
The main problem I see with the plates as defensive weapons is that they are quite thin and fragile, and filled with blood vessles. Have we ever found stego plates with predation damage or such? My understanding is that they would have broken if used too harshly.... Yes they found a neck plate with an Allosaurus bite taken out of it. And Allosaurus had a relatively weak bite unlike T-rex. They weren't for defense but for display.
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Post by foxilized on Oct 11, 2009 21:20:39 GMT
Hm, there was any big Jurassic predator with strong bite?
If not, the plates in the back in vertical could have been served as defense as these coming up-to-down bites would find the plates instead of flesh. No need of being too tough as the jaws of the predators of that time weren't that strong...
I think the stego had to be extremely flexible, more than usually depicted, because he had no defense in the flanks otherwise. If he could move the tail side-by-side movement (with horizontal spikes) -which is actually the version I feel more realistic- that way he could have defended his flanks.
Was the spine any flexible, what does the bones suggest?
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Post by Horridus on Oct 11, 2009 21:24:52 GMT
Hm, there was any big Jurassic predator with strong bite? Nothing like the tyrannosaurs, they were pretty unique (and not a little bit weird).
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Post by Griffin on Oct 11, 2009 22:41:25 GMT
What about Torvosaurus?
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Post by Horridus on Oct 11, 2009 23:02:57 GMT
Is there any evidence that it had a particularly strong bite? Stronger than the allosaurs maybe, but I thought foxilized was responding to stoneage's comment about there not being any predator around able to crush bone. It was pretty much only the tyrannosaurs that had the 'pulverising' teeth and huge jaw muscles necessary for the job.
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Post by foxilized on Oct 12, 2009 0:17:23 GMT
Anyway I tend to prefer the idea of the plates not being a true armor, but a psychological defense. These had veins... which is truly interesting! Why not a "chamaleon" (or sepia) like feature, which can change colour and tone of the plates depending of how the animal feels? When attacked, they change to an agressive colour to scare, when in matting session, they turn beutiful and eye-catching, and so... Go figure you are an Allo so d**n hungry you are gonna try to hunt a young unexperienced (but still highly dangerous) Stego. You go close enough to him to bite but not enough to be hit by the Stego's defenses (you are hungry but not stupid). Then the Stego turns and suddenly shows a highly agressive colour in the plates, maybe even changing every second like neon lights, big spots like eyes appearing and dissapearing... you feel dizzy... you don't know where to bite... SUDDENLY! YOU FEEL THE SMASH OF THE SPIKED TAIL OF THE STEGO!
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Post by kevin on Oct 13, 2009 11:33:54 GMT
I took stoneage's point to be that we have bite evidence on plates matching an allo's mouth. Since the allo's bite was relatively weaker, the plates had to be pretty fragile to sustain damage from said allo bite, indicating they were not designed for defensive purposes. No need for bone crushing abilities. Think of them as a row of fancy potato chips or some such, that break and snap when stressed......
Hmmm, as for changing colors and patterns like that, what if it were a system similar to the abilities of squid--pretty psycodellic when aroused...
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Post by Horridus on Oct 13, 2009 14:46:53 GMT
I took stoneage's point to be that we have bite evidence on plates matching an allo's mouth. Since the allo's bite was relatively weaker, the plates had to be pretty fragile to sustain damage from said allo bite, indicating they were not designed for defensive purposes. Well yes, AND that there was no tyrannosaur-like predator around able to crush bone, therefore the plates must have been particularly weak. Which is what I was getting at.
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Post by bucketfoot on Oct 13, 2009 14:55:16 GMT
I took stoneage's point to be that we have bite evidence on plates matching an allo's mouth. Since the allo's bite was relatively weaker, the plates had to be pretty fragile to sustain damage from said allo bite, indicating they were not designed for defensive purposes. Well yes, AND that there was no tyrannosaur-like predator around able to crush bone, therefore the plates must have been particularly weak. Which is what I was getting at. Not quite. Torvosaurus (an Abelisaurid as I recall - someone correct me if I am wrong) was bigger than the standard Allosaurus and had - lookswise, the strongest skull with the thickest teeth of any Theropod until TRex (if the reconstructions I've seen are correct) In any event the plates are too flimsy to serve as defense against an Allosaur as well. Sexual display, plus a tool for making the animal appear bigger and more menacing - those to me are the likeliest uses for it.
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Post by Horridus on Oct 13, 2009 14:57:35 GMT
Not quite. Torvosaurus (an Abelisaurid as I recall - someone correct me if I am wrong) was bigger than the standard Allosaurus and had - lookswise, the strongest skull with the thickest teeth of any Theropod until TRex (if the reconstructions I've seen are correct) I've heard it was a megalosaur with pretty standard theropod dentition. Not that it really matters either way if Allosaurus could take chunks out of the plates.
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Post by Griffin on Oct 13, 2009 15:58:44 GMT
I did an illustration of Torvosaurus for a friend of mine on the JPtoys forum and from looking at the photos of bones I was working off of it really confused me as to how much the dental structure made it look like a tyrannosaurid. This animal def could have done some serious damage. I'm surprised its not seen as often in Jurassic reconstructions considering the fact that it appears to be nastier than Allosaurus. I wish I knew more about it. From what I know I believe it is indeed a Megalosaur though. www.twoguysfossils.com/images/pic_torvosaurus_skeleton.jpgDoes anyone know a lot about Torvosaurus? It did coexist with Stegosaurus right?
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