Allosaurus vs Stegosaurus

[Godzillasaurus]

It´s also entirely likely the Allosaurus that bit it was a juvenile or subadult, because over 80% of Cleveland lloyd Allosaurus-specimens are (and that´s subadults such as <60cm femur lenght, not "big-al-type non-fully-growns")

But that doesn't mean the stegosaurus couldn't be juvenile or sub-adult as well.

It is not about being simply ripped off. it is about the combination of cutting and pulling forces that could first weaken the fibrous support structures enough to then rip it off (as I wrote, given the right circumstances, not in every case).

Of course, but the ripping-out of important tissue and musculature would probably already have killed the herbivore before its head gets ripped off, especially if its spine was damaged.

Which applies to the neural arches or spines of many animals even if their centra are far thicker. You´d be surprised of how lightly constructed (which doesn´t equal being weak, but makes the walls more prone to external forces such as the compression or shear induced by a bite or slash) and thin-walled even Sauropod vertebrae are.

Allosaurus would still be much better off with its slashing and ripping techniques, however, as that was obviously what its jaws and teeth were designed to do in the first place. I wouldn't imagine that a hatchet-bite would case much actually bone damage in itself, as the allosaurus' jaws would be coming only from up above and would not actually close around the actual structure itself. Remember, the hatchet-bite is the most probable way that allosaurus attacked a prey animal's back and neck regions, and it would more often than not tear out good amounts of important tissue and cause major blood loss. But even if actual bone damage is possible in this kind of event, it would still be very superficial.

I was, again, referring to WHAT a bite would damage (a bite to the skull would probably just be torn back until it encounters the right kind of tissue, ie the skull base and neck), not that it would necessarily puncture the skull (which, I think, depends entirely on the size of the combatants, I presume at average it would rather not happen).

I see

Either way an Allosaurus´ bite packs enough cutting power and force to cause not just severe and deadly exanguination, but also spinal trauma if it bit a neck like Stegosaurus´ (or, to name a different example, Camptosaurus) in the right place.

But still, as both you and I already said, spinal damage would be attributed more towards tissue, ligament, and tendon damage as opposed to actual vertebral damage. And the "force" aspect of this would also rely more on the allosaurus' impressive neck musculature and overall strength, as that is what fundamentally powers the hatchet-bite in the first place. Its bite force was obviously very superficial.

They have powerful necks that augment their bites, and neural arches are thin, plus vertebrae don´t have to be broken, they can also be dislocated by an impact or separated by pulling.

Definitely

So, are they resistant, or aren´t they?



Of course that´s not a thick bone, neither is whatever it might have to break in otrder to cause fatal damage to a Stegosaurus´ neck (Neural arches are not really thick or large). You sound as if I proposed Allosaurus biting Stegosaurus´ sacrum or pubis or femur in half.

I think I might have worded that post awkwardly. I was first talking about adult/mature dorsal plates as being thicker and more resistant to forces than juvenile or sub-adult plates (obviously), so the stegosaurus not being fully grown yet could have been the reason why they, in that specific event, were pierced so easily. And then I went off saying how stegosaur plates were still relatively thin and fragile (even in mature specimens), so an allosaurus actually managing to penetrate the entire structure as a whole did not mean much when compared to its inability to pierce much denser and/or thicker bony structures with ease (ie skulls).

In other words, allosaurus was simply not designed for causing major bone damage, so the penetration of stegosaur plates is "strange". It is also completely likely that the damage done to the stegosaurus' dorsal plates was the effect of smaller, less forceful pulling methods (while the theropod was clamping down on it), as the knife-like shape and serrations of the theropod's teeth could slowly wear down a bony structure that way. As I already said, allosaur bite forces were relatively weak, and stegosaur dorsal plates would be in a very awkward position to effectively damage with a hatchet-bite, so the slow but sure wearing down of it was more than possible. This event may sound unusual, but it is entirely possible.

So what is so similar about Stegosaur and Ankylosaur osteoderms, and what does it matter if there´s no functional inference to draw from it?

Both structures were bony thyreophoran dorsal structures and they were not actually part of the actual spine itself. They were very different in appearance and function, but they were still relatively similar.

[creature386]

Dec 7, 2013 20:40:35 GMT 5 Godzillasaurus said:

It´s also entirely likely the Allosaurus that bit it was a juvenile or subadult, because over 80% of Cleveland lloyd Allosaurus-specimens are (and that´s subadults such as <60cm femur lenght, not "big-al-type non-fully-growns")

But that doesn't mean the stegosaurus couldn't be juvenile or sub-adult as well.

Theropod isn't denying that. He was just saying the Allosaurus could've been a juvenile too (that's why he wrote "also" in his post).

[theropod]

But that doesn't mean the stegosaurus couldn't be juvenile or sub-adult as well.

Of course not, but if both are juveniles that's no different from both being adult (unless inexplicably Allosaurus developed a potent bite much earlier compared to the thickening of Stegosaurus spines)

Of course, but the ripping-out of important tissue and musculature would probably already have killed the herbivore before its head gets ripped off, especially if its spine was damaged.

Of course, it would be dead either way. As I wrote, I merely used this as a kind of thought experiment for demonstration.

Allosaurus would still be much better off with its slashing and ripping techniques, however, as that was obviously what its jaws and teeth were designed to do in the first place. I wouldn't imagine that a hatchet-bite would case much actually bone damage in itself, as the allosaurus' jaws would be coming only from up above and would not actually close around the actual structure itself. Remember, the hatchet-bite is the most probable way that allosaurus attacked a prey animal's back and neck regions, and it would more often than not tear out good amounts of important tissue and cause major blood loss. But even if actual bone damage is possible in this kind of event, it would still be very superficial.

Not too superficial to cause severe damage to the structure as a whole.

I don't think in the event of a neck bite on Stegosaurus (on a relatively light, flexible, mobile and nimble structure) it would use a lot of "hatchetting", the prolongued stopping time due to the would take much of its efficiency.
Bring (both) the jaws down on the neck, hold on, pull back (perhaps also ventrally, but not exclusively)-that's fully sufficient.

A powerful depressor action makes more sense on a region that has a greater inertia and is thus less mobile, where it naturally has to go deeper (ie. cut into or through ribs, large muscles or the abdominal walls and inner organs), and that won't transform that much of the strike's momentum into its own (ie. flanks, tail/neck base, abdomen, tigh).

But still, as both you and I already said, spinal damage would be attributed more towards tissue, ligament, and tendon damage as opposed to actual vertebral damage.

Yes of course, that's undoubtedly the main type of damage jaws like those of allosaurus would do.
Still it doesn't mean it's the only kind.

And the "force" aspect of this would also rely more on the allosaurus' impressive neck musculature and overall strength, as that is what fundamentally powers the hatchet-bite in the first place. Its bite force was obviously very superficial.

yes, that's again right. I wasn't thinking of it crushing anything, just slashing through smallish bones in the process of biting something (which is also performed by sharks, eg when biting off human legs)

They have powerful necks that augment their bites, and neural arches are thin, plus vertebrae don´t have to be broken, they can also be dislocated by an impact or separated by pulling.

Definitely

I think I might have worded that post awkwardly. I was first talking about adult/mature dorsal plates as being thicker and more resistant to forces than juvenile or sub-adult plates (obviously), so the stegosaurus not being fully grown yet could have been the reason why they, in that specific event, were pierced so easily.

Was it pierced "so easily"? We don't have a lot of information on this case, and I cannot even acess the relevant part in The Carnivorous Dinosaurs (can you?)

And then I went off saying how stegosaur plates were still relatively thin and fragile (even in mature specimens), so an allosaurus actually managing to penetrate the entire structure as a whole did not mean much when compared to its inability to pierce much denser and/or thicker bony structures with ease (ie skulls).

I did not suggest that. I suggested that, no matter whether it actually did serious damage to the skull bone, it would certainly inflict very serious trauma, realistically leading to quick death, anyway.

In other words, allosaurus was simply not designed for causing major bone damage, so the penetration of stegosaur plates is "strange".

Or perhaps it is as stated by Hone & Rauhut 2009, and as can be observed on extant species of similar size and comparable morphology, such as sharks, just normal, even for an not therefor adapted animal, to bite through small bones.
This isn't the only incedent of an Allosaurus inflicting notable marks on bones. Remains of Camarasaurus (an ilium) and other sauropods (eg. Apatosaurus limbbones) sometimes show quite prominent ghashes (and you have to keep in mind these are truly huge and massive bones, so it means something).
Of course that's not the primary purpose of Allosaurus' dentition, which, of course, doesn't mean it was completely incapable of it either. Nobody would suggest T. rex or even a crocodile were completely incapable of tearing flesh, would they?

It is also completely likely that the damage done to the stegosaurus' dorsal plates was the effect of smaller, less forceful pulling methods (while the theropod was clamping down on it), as the knife-like shape and serrations of the theropod's teeth could slowly wear down a bony structure that way. As I already said, allosaur bite forces were relatively weak, and stegosaur dorsal plates would be in a very awkward position to effectively damage with a hatchet-bite, so the slow but sure wearing down of it was more than possible. This event may sound unusual, but it is entirely possible.

you don't have to tell me that, I know it. No matter how it did that, whether it was by a sudden, forceful strike at an odd angle, or by classic biting and subsequent sawing, it still managed to cause quite some damage to that plate.
What I'd like to add is that we don't actually know what kind of plate that was. My guess is that it's pretty far anteriorly, in which case it was simply bitten through because it was in the way of and destroyed by a bite aimed at the neck. In that case, we can probably say at least the anteriormost few plates wouldn't be major obstacles.

And the scenario I was referring to applied to structures at not that inconvenient an angle for it to strike, bite, or pull at.

Both structures were bony thyreophoran dorsal structures and they were not actually part of the actual spine itself. They were very different in appearance and function, but they were still relatively similar.

Two osteoderms with different function (ie. non-analogous ones) are hardly that similar.

[Godzillasaurus]

Bring (both) the jaws down on the neck, hold on, pull back (perhaps also ventrally, but not exclusively)-that's fully sufficient.

Although a hatchet-bite would still be much more efficient due to its quick downward force jerk and intense perpendicular spinal damage.

yes, that's again right. I wasn't thinking of it crushing anything, just slashing through smallish bones in the process of biting something (which is also performed by sharks, eg when biting off human legs)

But sharks also do have a much greater mechanical advantage with this technique due to their much wider and shorter jaws than that of allosaurus (meaning their most effective dentition is located at the front of the mouth). Allosaurus had longer jaws, and their side teeth were the longest and "most deadly", so the theropod would need to utilize backward ripping techniques to sever small bones.

I did not suggest that. I suggested that, no matter whether it actually did serious damage to the skull bone, it would certainly inflict very serious trauma, realistically leading to quick death, anyway.

That is the dependent factor though of the amount of force brought upon the skull.

Or perhaps it is as stated by Hone & Rauhut 2009, and as can be observed on extant species of similar size and comparable morphology, such as sharks, just normal, even for an not therefor adapted animal, to bite through small bones.
This isn't the only incedent of an Allosaurus inflicting notable marks on bones. Remains of Camarasaurus (an ilium) and other sauropods (eg. Apatosaurus limbbones) sometimes show quite prominent ghashes (and you have to keep in mind these are truly huge and massive bones, so it means something).

The gashes, however, only really imply that allosaurus was capable of doing SOMETHING to large bones, not necessarily damaging them majorly. As you said, carnosaur jaws and dentition were not designed for this, so any sort of damage done does not necessarily imply that such damage could be used to cripple an opponent.

Two osteoderms with different function (ie. non-analogous ones) are hardly that similar.

Well it is all a matter of perception, and it is not really necessary to discuss here. Oh well, that puts that argument to rest

[theropod]

Although a hatchet-bite would still be much more efficient due to its quick downward force jerk and intense perpendicular spinal damage.

On many regions of the body, undoubtedly a strike or other form of employing strong ventroflexive force would be a very effective way of driving the jaw deep into the animal. On the neck, I think this would not be effective, since the neck has little inertia and accordingly most of the strike´s energy would be converted into kinetic energy, ie. it would blow out without a lot of actual tissue damage.
But on the neck of a Stegosaurus, such an attack is not needed since there isn´t a big bulk of tissue that has to be severed anyway-the teeth have to cut a relatively thin sheet of musculature, since the vital structures are in pretty close proximity to the surface. Thus a traditional bite with mandibular involvement is enough. Perhaps some dowward-jerking would be involved, but not very extreme.

I think what you call "hatchet bite" would be primarily suited for massive and relatively immobile body regions, where the whole force of the blow is used for slashing deep into the flesh.

But sharks also do have a much greater mechanical advantage with this technique due to their much wider and shorter jaws than that of allosaurus (meaning their most effective dentition is located at the front of the mouth).

That´s hogwash. The bite is always strongest in the back of the toothrow, and Sharks are no exception to this.
What´s important here is the actuall force, and we know both sharks and Allosaurids could apply great forces over their teeth in perpendicular and mesiodistal directions. This is what they are very similar in, thus the related effects of their bites likely are as well.
Thus, s striking and/or pulling bite by an Allosaurid could slash through and sever muscles, tear out chunks of flesh, and saw through (relatively) small bones in the process. THat´s what sharks can do and what Hone & Rauhut acknowledge many non-tyrannosaurid theropods were aloso capable of.

Besides, Allosaurus of has a pretty high mechanical advantage (probably just owing to its moderate jaw lenght).

The gashes, however, only really imply that allosaurus was capable of doing SOMETHING to large bones, not necessarily damaging them majorly.

The ghashes give us evidence of the amount of damage they could do to bone. How much that was relative to a large bone is not relevant since here I´m not talking about a Camarasaurus ilium, but merely neural arches and ribs (of a far smaller animal than a Camarasaurus).

As you said, carnosaur jaws and dentition were not designed for this, so any sort of damage done does not necessarily imply that such damage could be used to cripple an opponent.

Where have I ever been talking about that?

All I suggested was a bite to the neck would cause massive trauma not just to the soft tissue but also the spine, some small bones logically being no exception or major obstacle, becauese they aren´t either in modern predators.

[Godzillasaurus]

That´s hogwash. The bite is always strongest in the back of the toothrow, and Sharks are no exception to this.

I know that, that is not what I was referring to. Sharks, due to their much shorter jaws and surplus amount of teeth at the very front of the jaw, would be much more able to dispatch prey more quickly due to the rapid side-to-side movement of their heads. Allosaurus would need to strike and then pull back due to its more elongated jaws and recurved teeth, which would still be deadly nonetheless, but it would be a much slower process.

Besides, Allosaurus of has a pretty high mechanical advantage (probably just owing to its moderate jaw lenght).

Again, I was talking about mechanical advantage in a different way than vertical force

Where have I ever been talking about that?

Earlier in this thread

[theropod]

I know that, that is not what I was referring to. Sharks, due to their much shorter jaws and surplus amount of teeth at the very front of the jaw, would be much more able to dispatch prey more quickly due to the rapid side-to-side movement of their heads. Allosaurus would need to strike and then pull back due to its more elongated jaws and recurved teeth, which would still be deadly nonetheless, but it would be a much slower process.

Why is a side-to-side movement quicker than a pull? It has the same effect (slicing, primarily of soft tissue) and works the same way (moving the teeth in a mesiodistal plane).

Again, I was talking about mechanical advantage in a different way than vertical force

Any reason why pulling (which we know Allosaurus had the right musculature for) should have a lower mechanical advantage than lateral shaking?

Where have I ever been talking about that?

Earlier in this thread
[/quote]
I have not talked about a crippling, bone-sawing bite anywhere (ie. one that would severely damage a limb-bone, the jaws or a defensive structure like a horn, tail or spike). Of course an Allosaurus bite could be crippling, but by cutting muscles and tendons.

Severing a neck or cutting a throat doesn't qualify as "crippling", it is, very simply, a killing bite.

[Godzillasaurus]

Why is a side-to-side movement quicker than a pull? It has the same effect (slicing, primarily of soft tissue) and works the same way (moving the teeth in a mesiodistal plane).

Great whites have triangular dentition that is designed for slicing in two ways. Allosaurus, on the other hand, had recurved dentition that, although still very deadly (and serrated and knife-like in shape), would have required it to strike the prey animal again after pulling back.

Any reason why pulling (which we know Allosaurus had the right musculature for) should have a lower mechanical advantage than lateral shaking?

Reasons that I stated above.

I have not talked about a crippling, bone-sawing bite anywhere (ie. one that would severely damage a limb-bone, the jaws or a defensive structure like a horn, tail or spike). Of course an Allosaurus bite could be crippling, but by cutting muscles and tendons.

I said that you stated the fact that allosaurus was ill-adapted for damaging bone and skeletal material (specifically vertebrae and skulls) earlier and that severing important tissue, ripping out musculature, and simple blood-loss were what allosaur dentition was designed for (which is, of course, correct). You said that near the beginning of the thread after it "boomed".

Severing a neck or cutting a throat doesn't qualify as "crippling", it is, very simply, a killing bite.

Lol ok.

[theropod]

Great whites have triangular dentition that is designed for slicing in two ways. Allosaurus, on the other hand, had recurved dentition that, although still very deadly (and serrated and knife-like in shape), would have required it to strike the prey animal again after pulling back.

Only if more than one sawing action would even be necessary.
This whole thing happens very quickly in the analogy I used, it's not as if it was shaking its prey for minutes, it strikes and quicker than you can follow the action it already has a gaping hole in it.
It won't look much different in an Allosaurus attack, it will strike, pull, and what is in the way of its teeth will be cut, unless it is a large bone of the sort I'm not talking about anyway. The recurved tooth shape will be an advantage for catching a lot of tissue in the bite.

Reasons that I stated above.

But that's not mechanical advantage you are talking about. Mechanical advantage is about how efficiently force is transmitted.

I said that you stated the fact that allosaurus was ill-adapted for damaging bone and skeletal material (specifically vertebrae and skulls) earlier and that severing important tissue, ripping out musculature, and simple blood-loss were what allosaur dentition was designed for (which is, of course, correct). You said that near the beginning of the thread after it "boomed".

Sorry, I must have misunderstood you in the first place.
Anyway, the bones I was referring to were large and robust ones, ie. there are a lot of bones in an animal's body that do not qualify for this category.

[Godzillasaurus]

Quote: Only if more than one sawing action would be necessary

I feel that this would only be the case if the initial impact (as in the event of a hatchet bite) created enough spinal damage and laceration damage in itself.

Sorry, I am having some issues with my ipad right now. I will need to create multiple posts

[Godzillasaurus]

Dec 12, 2013 17:28:42 GMT 5 theropod said:

Great whites have triangular dentition that is designed for slicing in two ways. Allosaurus, on the other hand, had recurved dentition that, although still very deadly (and serrated and knife-like in shape), would have required it to strike the prey animal again after pulling back.

Only if more than one sawing action would even be necessary.
This whole thing happens very quickly in the analogy I used, it's not as if it was shaking its prey for minutes, it strikes and quicker than you can follow the action it already has a gaping hole in it.
It won't look much different in an Allosaurus attack, it will strike, pull, and what is in the way of its teeth will be cut, unless it is a large bone of the sort I'm not talking about anyway. The recurved tooth shape will be an advantage for catching a lot of tissue in the bite.

Reasons that I stated above.

But that's not mechanical advantage you are talking about. Mechanical advantage is about how efficiently force is transmitted.

I said that you stated the fact that allosaurus was ill-adapted for damaging bone and skeletal material (specifically vertebrae and skulls) earlier and that severing important tissue, ripping out musculature, and simple blood-loss were what allosaur dentition was designed for (which is, of course, correct). You said that near the beginning of the thread after it "boomed".

Sorry, I must have misunderstood you in the first place.
Anyway, the bones I was referring to were large and robust ones, ie. there are a lot of bones in an animal's body that do not qualify for this category.

In reply to your plight about bone damage:

I can definitely see allosaurus causing slight damage to considerably thinner skeletal structures (ie. neural arches), but the net damage done to the entirety of the vertebrae would be very subtle if anything

[theropod]

You're underestimating the damage bites can do even what they are not specialized in. Remember that video of the crocodile disemboweling the zebra? Or the GWS with the dolphin bitten in half in its stomach?

A small bone (as per Hone & Rauhut, and as demonstrated by sharks) can be severed quite easily. Of course this does not apply to large, weight bearing structures like vertebral centra or limb-bones, where it automatically gets increasingly difficult and risky for the teeth due to the resistance, but everything from neural arch to rib is quite endangered from any bite.

I should add that a secondary bite in the event of unsufficient damage wouldn't be much of an issue for an Allosaurus, it has a light and maneuverable skull built for quick attacks and will most likely use its claws to secure its prey if the need exists.
But whether this is necessary is not related to how much damage the initial phase of the bite would do, I'm talking about the sawing action, which will inevitably slash through the tissues-if it doesn't, the prey won't be released from the grip-unless there is a big bone that either causes teeth to dislodge/break, or lets them scratch it and slide off due to its girth.
A bone that's not resistant enough can be broken and/or sliced by this motion.

[Godzillasaurus]

A small bone (as per Hone & Rauhut, and as demonstrated by sharks) can be severed quite easily. Of course this does not apply to large, weight bearing structures like vertebral centra or limb-bones, where it automatically gets increasingly difficult and risky for the teeth due to the resistance, but everything from neural arch to rib is quite endangered from any bite.

The ribs would be a stretch here, as the positioning of the allosaurus' jaws when biting an animal's flanks would not allow for very much power to be exerted whether it be through biting or utilizing the rostrum in a similar way to the hatchet-bite. But yes, smaller structures could be easily damaged.

You're underestimating the damage bites can do even what they are not specialized in. Remember that video of the crocodile disemboweling the zebra? Or the GWS with the dolphin bitten in half in its stomach?

I was talking about severely damaging the vertebrae in their entirety, which you agreed on.

I should add that a secondary bite in the event of unsufficient damage wouldn't be much of an issue for an Allosaurus, it has a light and maneuverable skull built for quick attacks and will most likely use its claws to secure its prey if the need exists.
But whether this is necessary is not related to how much damage the initial phase of the bite would do, I'm talking about the sawing action, which will inevitably slash through the tissues-if it doesn't, the prey won't be released from the grip-unless there is a big bone that either causes teeth to dislodge/break, or lets them scratch it and slide off due to its girth.
A bone that's not resistant enough can be broken and/or sliced by this motion

True

[theropod]

The rib-point rather applies to animals with a different morphology from Stegosaurus (which has a deep and laterally only lightly convex body), eg a theropod, whose flanks are generally in a more favourable position and shape for such a bite. Whether it could bite through the ribs of a Stegosaurus is, again, size dependant, but I think generally Allosaurus would prefer the abdominal region or or tigh which is easier to bite.

Btw I think the body shape of Stegosaurus offers some notable advantages in this regard;
-sides flat, tricky to bite and require wide gape
-acess to more convex dorsum obstructed by the largest plates

It´s not impervious to attack, but it isn´t easy to severely damage it in these regions either. The neck is it´s weak spot and a predator´s best chance imo.

[Godzillasaurus]

The rib-point rather applies to animals with a different morphology from Stegosaurus (which has a deep and laterally only lightly convex body), eg a theropod, whose flanks are generally in a more favourable position and shape for such a bite. Whether it could bite through the ribs of a Stegosaurus is, again, size dependant, but I think generally Allosaurus would prefer the abdominal region or or tigh which is easier to bite.

Ahh, I see. Although the actual damage done to the ribs themselves would still probably be superficial (again, due to the allosaurus not being well designed for crushing skeletal structures) unless the allosaurus had an immense size advantage. But I do see where you are going with this.

Btw I think the body shape of Stegosaurus offers some notable advantages in this regard;
-sides flat, tricky to bite and require wide gape
-acess to more convex dorsum obstructed by the largest plates

I do agree that, against an animal with such a deep yet not very wide body (as in post neck), a dorsal bite would probably be the most severe.