Allosaurus vs Stegosaurus

[Godzillasaurus]

Dec 3, 2013 4:16:34 GMT 5 Infinity Blade said:

Ankylosaurs and stegosaurs were MUCH more closely related to one another than elephants and whales are today, so that is irrelevant.

That wasn't the point at all. The point was that being made of the same thing=/=being similar. Try Moeritherium and a modern elephant.

Stegosaur plates and ankylosaur armor was still probably, as theropod stated, homologous.

[theropod]

Yes; it is still thin in shape, I'll give you that, but that does not mean it cannot be muscular and "thick" at the same time. A better answer for this would be that allosaurus would not just cut right through it like butter, as you are implying. A bite would certainly do a good amount of damage to it, but not to the point of the herbivore's head simply coming right off. Having a neck THAT weak would be a horrible adaptation for evolving alongside allosaurids (or any large theropods really).

Well, as we agreed about a bite to this region would be deadly either way.

Having a thin neck does not mean that it is entirely weak;

it doesn't have to be "entirely weak" in order for a potent slicing bite to sever the soft tissues quite easily.

just look at sauropods and long-necked plesiosaurs. I guess the bottom line is that, despite being thin IN SHAPE, stegosaurus still had a relatively thick and quite muscular neck, hinting at a much greater resistance to allosaurid bites than you are implying.

And why?
The bottom line is that it's small and thin enough to easily fit in an Allosaurus' mouth, and with sufficient damage to the musculature resulting from the bite, the craniocervical connection could be severed too.
What is suggestive that stegosaurs (with their very small gracile skulls and no need for bearing any considerable weights or any other cervical activity that required them to be strong) had particularly resistant necks?

That is definitely the most vulnerable region of the animal, but that certainly does not mean that it is weak in general.

It is simply small, gracile and not built to resist trauma.

Plus, the theropod would need to cut through the neck vertebrae as well in order to completely rip off its head, which its jaw and tooth structure simply is not designed for, so that is another factor to remember here.

No it wouldn't have to cut any bone (save for some thin osteoderms in the throat perhaps, but they are hardly noteworthy and not the main issue). Cut the muscles, tendons, ligaments etc. holding the thing together. The pulling action will likely tear apart what remains, ie. it will separate the craniovertebral or intravertebral joints.
we both agree a bite would certainly inflict fatal soft tissue exanguination on the neck. Due to the comparatively small size of the whole structure, it would likely be bitten off.

But even then, the herbivore's plates, despite not being used for defense purposes, would still serve as a major hinderance for a well-placed bite to its neck, as they would force the allosaurus to go for the sides of it as opposed to the top. This would certainly lead to a good amount of blood loss and/or (as you said) musculature being torn out, but it still would not be enough to simply rip the herbivore's head off.

A bite to the back to the skull base or anteriormost aspect of the neck, as I suggested, wouldn't encounter any plates in its way. It would have to cut a sheet of musculature and the bones would be pretty much exposed.

I was thinking more in terms of blood loss and the "hatchet-bite" technique.

That's the direct consequence of a "hatchet bite", or any of the alternate suggestions for its bite mechanism. A slashing, striking or pulling action wouldn't merely do superficial scratches to a prey item.

Of course it would cause lots of blood loss, as its primary means of killing, but besides that it would also go deep enough to do significant damage to deep structures, ie. damage internal organs or large muscles (think of chunks taken out of shark's prey, just with different shape). There's a considerable amount of ventroflexive musculature powering the bite.

Ankylosaurs and stegosaurs were MUCH more closely related to one another than elephants and whales are today, so that is irrelevant.

How do you measure that? as i said, they share a homologous structure which doesn't automatically mean that structure was functionally or morphologically similar.

Both groups of animals evolved unique dorsal characteristics. It is highly unlikely that stegosaur plates and ankylosaur armor evolved independently due to their close phylogenic relationship.

That's what I said, homologues. But that alone doesn't mean much in terms of functional properties.

You read my posts, you know I do not doubt the plates' (especially large ones') capability of obstructing acess to part of the animal. That however doesn't make them some sort of strong armour, like that of Ankylosaurs.

[Fragillimus335]

Dec 3, 2013 2:17:30 GMT 5 Infinity Blade said:

I think at 7 meters, Stegosaurus is 2-ish tonnes (if I remember correctly. I think from scaling from a 9m, 5t Stegosaurus once, forgot how to scale down though).

But I also cam across this.

fragillimus335.deviantart.com/art/Ten-Ton-Porcupine-398362307

Of course, it's not what one would call a reliable source, but Fragillimus is a knowledgable person.

Estimations of course, but I would place solid bets that Dacentrurus is the largest stegosaur we currently have remains of. Look at top view restorations of steggy, the hips aren't even close to 1.5 meters wide. There is one on page 3 of this discussion.

[theropod]

I agree, a 1.5m wide pelvis is definitely much more than any Stegosaurus I ever heard of. It's plainly gigantic. However we cannot rule out their body widths weren't the same relative to their size. Still I'd consider Dacentrurus the bigger animal because that's what our material shows at the moment.

Hopefully there'll be some better documentation on this stuff, perhaps a systematic revision of the genus Dacentrurus.

[Godzillasaurus]

And why?
The bottom line is that it's small and thin enough to easily fit in an Allosaurus' mouth, and with sufficient damage to the musculature resulting from the bite, the craniocervical connection could be severed too.

It would definitely be able to fit directly in the theropod's neck, but that is assuming that it completely lacked plates in that area overall, which it did not. The plates, despite not being used for defense/armor purposes, would certainly serve as a major hinderance for the allosaurus to simply wrap its maw around the stegosaurus' entire neck girth.

What is suggestive that stegosaurs (with their very small gracile skulls and no need for bearing any considerable weights or any other cervical activity that required them to be strong) had particularly resistant necks?

Their necks do not have to be resistant as a whole, they just needed to still be at least partially resistant towards bites from predators and not get ripped off as easily as you are implying. They weren't the longest, deepest, or widest necks in the entirety of dinosauria, but they were still quite muscular and much more resistant to a bite than you are implying.

No it wouldn't have to cut any bone (save for some thin osteoderms in the throat perhaps, but they are hardly noteworthy and not the main issue). Cut the muscles, tendons, ligaments etc. holding the thing together. The pulling action will likely tear apart what remains, ie. it will separate the craniovertebral or intravertebral joints.

Oh yea, I completely forgot about tendons and ligaments. My bad; you are correct.

A bite to the back to the skull base or anteriormost aspect of the neck, as I suggested, wouldn't encounter any plates in its way. It would have to cut a sheet of musculature and the bones would be pretty much exposed.

An allosaur bite to any portion of a prey animal's skull would probably be very superficial in the realm of damage done and potency, as their jaws were designed for slicing and ripping softer tissue and flesh as opposed to crushing bone. A bite may cause a few slight puncture marks on the surface, but it would most definitely not penetrate it.

That's the direct consequence of a "hatchet bite", or any of the alternate suggestions for its bite mechanism. A slashing, striking or pulling action wouldn't merely do superficial scratches to a prey item.

In the event of a hatchet-bite, the direct impact itself would be driven by immense vertical force (hence the animal's deep skull) which means that its teeth would work more as "impalers" as opposed to "cutters" or "rippers". They would have been driven very deeply into the dorsum (back) of a prey animal, causing a good deal of spinal and muscle damage.

But yes, the pulling backward of the theropod's jaws (after the actual impact itself) would definitely rip out a good deal of musculature and flesh (as the allosaurus' teeth were recurved and were perfectly designed to do so). But remember, this doesn't pertain to the initial penetration of the prey's hide.

How do you measure that? as i said, they share a homologous structure which doesn't automatically mean that structure was functionally or morphologically similar. 

The actual functions of the two different structures, as we already know, were very different from one another, as stegosaurid plates were obviously not used as armor. But they still were very similar in physicality. Structures can be similar in morphology but not function.

You read my posts, you know I do not doubt the plates' (especially large ones') capability of obstructing acess to part of the animal. That however doesn't make them some sort of strong armour, like that of Ankylosaurs.

That was already agreed by us a few pages back.

[Fragillimus335]

And don't forget Stegosaurus evolved it's neck armor for a reason. If every bite to that region was an insta-kill it would have no reason to evolve!

[creature386]

Dec 4, 2013 3:42:39 GMT 5 Godzillasaurus said:

And why?
The bottom line is that it's small and thin enough to easily fit in an Allosaurus' mouth, and with sufficient damage to the musculature resulting from the bite, the craniocervical connection could be severed too.

It would definitely be able to fit directly in the theropod's neck, but that is assuming that it completely lacked plates in that area overall, which it did not. The plates, despite not being used for defense/armor purposes, would certainly serve as a major hinderance for the allosaurus to simply wrap its maw around the stegosaurus' entire neck girth.

We have a fossil of a cervical Stegosaurus plate which was bitten trough by an Allosaurus (Source), this shouldn't be much of a hindrance.

Dec 4, 2013 3:42:39 GMT 5 Godzillasaurus said:

What is suggestive that stegosaurs (with their very small gracile skulls and no need for bearing any considerable weights or any other cervical activity that required them to be strong) had particularly resistant necks?

Their necks do not have to be resistant as a whole, they just needed to still be at least partially resistant towards bites from predators and not get ripped off as easily as you are implying. They weren't the longest, deepest, or widest necks in the entirety of dinosauria, but they were still quite muscular and much more resistant to a bite than you are implying.

Of course the head won't get ripped off easily, but a bite to the neck would still cause a wound which is easily lethal enough to kill a Stegosaurus.

Dec 4, 2013 3:42:39 GMT 5 Godzillasaurus said:

A bite to the back to the skull base or anteriormost aspect of the neck, as I suggested, wouldn't encounter any plates in its way. It would have to cut a sheet of musculature and the bones would be pretty much exposed.

An allosaur bite to any portion of a prey animal's skull would probably be very superficial in the realm of damage done and potency, as their jaws were designed for slicing and ripping softer tissue and flesh as opposed to crushing bone. A bite may cause a few slight puncture marks on the surface, but it would most definitely not penetrate it.

The neck has rather small bones (when compared to the rest of the body), so what makes you doubt it couldn't penetrate at least some bones?

[creature386]

Dec 4, 2013 19:09:13 GMT 5 Fragillimus335 said:

And don't forget Stegosaurus evolved it's neck armor for a reason. If every bite to that region was an insta-kill it would have no reason to evolve!

Even though they may be useful for protection, most of the posters here (even Godzillasaurus) agreed that they didn't EVOLVE for being some kind of an armor. I have posted a paper on page three which shows that the armor hypothesis is quite weak.

[Godzillasaurus]

We have a fossil of a cervical Stegosaurus plate which was bitten trough by an Allosaurus (Source), this shouldn't be much of a hindrance.

The source did not clarify whether or not it actually bit THROUGH the plate itself, it only told of puncture wounds. It does not seem very probable that allosaurus would be able to just bite through a bony plate, which, despite being thin and weak compared to ankylosaur armor, was still quite tough and sturdy in its own regard.

Of course the head won't get ripped off easily, but a bite to the neck would still cause a wound which is easily lethal enough to kill a Stegosaurus.

I believe that was agreed on a previous page.

The neck has rather small bones (when compared to the rest of the body), so what makes you doubt it couldn't penetrate at least some bones?

Right, but allosaurus could not just cut right through even the smallest of vertebrae as if they were butter. As theropod stated (which I completely forgot about until he reminded me yesterday), the best way in which the theropod could sever the spinal cord is if it managed to sever the ligaments connecting the vertebrae. The vertebrae themselves would have little to no problems dealing with a bite from the theropod, as it would merely cause a few minor puncture wounds and would not pierce through the entirety of the bone. Remember, allosaurs were not characterized by particularly powerful bites or thick dentition as seen in tyrannosaurids, and instead utilized other killing strategies like the "hatchet-bite" (although this maneuver in itself would have still been very effective and deadly, causing very deep penetration wounds and most likely causing some major spinal damage).

[creature386]

Dec 4, 2013 19:46:57 GMT 5 Godzillasaurus said:

We have a fossil of a cervical Stegosaurus plate which was bitten trough by an Allosaurus (Source), this shouldn't be much of a hindrance.

The source did not clarify whether or not it actually bit THROUGH the plate itself, it only told of puncture wounds. It does not seem very probable that allosaurus would be able to just bite through a bony plate, which, despite being thin and weak compared to ankylosaur armor, was still quite tough and sturdy in its own regard.

Maybe that's because we only have the preview. The paper was cited here and it said "bitten trough":

www.bio.utk.edu/biologyinbox/unit1/readings/Hone%20&%20Rauhut%202009%20-%20Feeding%20behaviour%20and%20bone%20utilization%20by%20theropod%20dinosaurs.pdf

[theropod]

It would definitely be able to fit directly in the theropod's neck

Not in its neck, in its jaws. An Allosaurus can pretty easily encompass the whole anterior neck of a Stegosaurus in its mouth, which gives you a pretty good idea of the amount of damage a bite would do.

, but that is assuming that it completely lacked plates in that area overall, which it did not.

I'm talking about the anterior region of the neck, directly adjacent to the skull base, before the point were the plates start. That way it wouldn't have to bite through any plates to reach what is below. It's obvious this only applies to an anterior bite, I never claimed it could easily decapitaste it no matter were it bit (of course there'd be no real difference since the Stegosaurus would still have a severed carotid or two, or a cut jugularis vene).

I merely propesed that a well-placed bite to the back of the head/anteriormost part of the neck would quite possibly rip the skull off as well. I argued this is a possible consequence of a bite to the neck, under these circumstances, not that it is automatically the consequence of a bite to the neck in general.

I merely found it noteworthy because it bases on, and demonstrates the relationships between their killing capcities. In the right situations, both have weaponery that can deal horrific injuries, and it all depends on positional advantage; because either is quite vulnerable to the other's weapons given it's in the wrong position (Allosaurus can get speared when hit by the tail, Stegosaurus may have its throat cut or even the skull severed off the neck if it's frontal side is attackes).

The plates, despite not being used for defense/armor purposes, would certainly serve as a major hinderance for the allosaurus to simply wrap its maw around the stegosaurus' entire neck girth.

Only where there are plates, especially where there are ones of a reasonable size.

Their necks do not have to be resistant as a whole, they just needed to still be at least partially resistant towards bites from predators and not get ripped off as easily as you are implying.

And how many animals have bite-resistant necks? Not many!

They weren't the longest, deepest, or widest necks in the entirety of dinosauria, but they were still quite muscular and much more resistant to a bite than you are implying.

they are among the most gracile, and most important didn't need to be "quite muscular". they are totally ordinary necks that would show no particular resistance to a bite cutting through its flesh.

Oh yea, I completely forgot about tendons and ligaments. My bad; you are correct.

Are you referring to all the above, or just that there are ligaments and tendond in the neck that serve for holding it together?

An allosaur bite to any portion of a prey animal's skull would probably be very superficial in the realm of damage done and potency, as their jaws were designed for slicing and ripping softer tissue and flesh as opposed to crushing bone. A bite may cause a few slight puncture marks on the surface, but it would most definitely not penetrate it.

Most likely, it would ghash the skull and slite into the muscles attaching to it, cutting them clean through.
But stegosaur skulls don't exactly offer much in terms of resistance.
If a bite doesn't puncture the brain cavity (which I admit is a pretty unlikely type of injury, because, for starters, stegosaur skulls are small, and the brain's still small compared to them, and really hard to even hit with anything that does damage to the skull), it would still probably damage more superifical but still vital structures, such as the carotis interna or externa, the vena jugularis, the facial nerves and arteries, the basicranial and jaw musculature where they are entering, exiting, attaching to or running close to the skull.

In fact, many bony elements in that area are likely not beyond even an Allosaurus' capacity to bite through (eg. neural arches).

Hone & Rauhut 2009 said:

Some medium-sized bones (e.g. ver-
tebrae and ribs) could be bitten through or at least
have parts removed relatively easily (e.g. neural
arches) by large theropods. Even those genera that do
not appear to be well adapted to biting on bone could
probably have broken a neural spine that was only a
few millimetres thick.

And as creature showed there's a cervical plate of Stegosaurus that's been bitten through by an allosaurid, indicating a pretty powerful attack on that region occurred. Not that that would be necessary, it would just take a bit of pulling if enough damage to the soft tissue has been done, and I read even tigers often don't break vertebrae but just separate them by sliding their teeth in between.

Bone crushing is no requirement for this kind of damage, it becomes more important when dealing with a more massive structure (like the skull and neck of a Ceratopsian or Ankylosaur).
Of course no attack is 100% lethal, but it has a very good chance of succeeding.

In the event of a hatchet-bite, the direct impact itself would be driven by immense vertical force (hence the animal's deep skull) which means that its teeth would work more as "impalers" as opposed to "cutters" or "rippers". They would have been driven very deeply into the dorsum (back) of a prey animal, causing a good deal of spinal and muscle damage.

And they would consequently be ripped back out, causing severe exangunation and perhaps removal of chunks of the flesh its'driven into. That's why it has ziphodont dentition very much alike monitor-lizards or some sharks. First drive them in, then tear them out again.

But yes, the pulling backward of the theropod's jaws (after the actual impact itself) would definitely rip out a good deal of musculature and flesh (as the allosaurus' teeth were recurved and were perfectly designed to do so). But remember, this doesn't pertain to the initial penetration of the prey's hide.

The two would likely follow immediately after one another, just like the placing of the jaws and subsequent mandibular adduction do in a gnathostome.
It strikes or pushes its jaws into its prey, then tears through the bitten part. Like a shaking shark, or a pulling ora. Perhaps more comparable to the shark for the initial stage, and more to the monitor for the secondary one.

The actual functions of the two different structures, as we already know, were very different from one another, as stegosaurid plates were obviously not used as armor. But they still were very similar in physicality. Structures can be similar in morphology but not function.

No, since function determines morphology and vice versa

Two structures can evidently have a similar ancestry, which might still be visible in some part of their morphology. But their overall morphology is dependant on what they are used for.

[Godzillasaurus]

Dec 4, 2013 22:09:46 GMT 5 creature386 said:

Dec 4, 2013 19:46:57 GMT 5 Godzillasaurus said:

The source did not clarify whether or not it actually bit THROUGH the plate itself, it only told of puncture wounds. It does not seem very probable that allosaurus would be able to just bite through a bony plate, which, despite being thin and weak compared to ankylosaur armor, was still quite tough and sturdy in its own regard.

Maybe that's because we only have the preview. The paper was cited here and it said "bitten trough":

www.bio.utk.edu/biologyinbox/unit1/readings/Hone%20&%20Rauhut%202009%20-%20Feeding%20behaviour%20and%20bone%20utilization%20by%20theropod%20dinosaurs.pdf

Does it tell of a certain age that the stegosaurus was? It is entirely likely that it was a juvenile and/or a sub-adult, as adult animals had considerably thicker plates.

Not in its neck, in its jaws. An Allosaurus can pretty easily encompass the whole anterior neck of a Stegosaurus in its mouth, which gives you a pretty good idea of the amount of damage a bite would do.

I meant to say jaws, I'm sorry about that. 

I'm talking about the anterior region of the neck, directly adjacent to the skull base, before the point were the plates start. That way it wouldn't have to bite through any plates to reach what is below. It's obvious this only applies to an anterior bite, I never claimed it could easily decapitaste it no matter were it bit (of course there'd be no real difference since the Stegosaurus would still have a severed carotid or two, or a cut jugularis vene).

I see

And how many animals have bite-resistant necks? Not many!

By "resistant", I was not talking completely 100% immune to bites overall, as this is obviously not the case in any herbivorous dinosaur, just simply being ripped off.

Are you referring to all the above, or just that there are ligaments and tendond in the neck that serve for holding it together?

While you are certainly not wrong about other factors here, I was only talking about the tendons and ligaments holding the vertebrae together.

they are among the most gracile, and most important didn't need to be "quite muscular". they are totally ordinary necks that would show no particular resistance to a bite cutting through its flesh.

As I just stated, stegosaurus obviously wasn't immune to bites overall, just being ripped off as easily as if its neck were made of rubber.

Most likely, it would ghash the skull and slite into the muscles attaching to it, cutting them clean through.

I was talking about the skull itself, not the musculature and tendons surrounding it.

In fact, many bony elements in that area are likely not beyond even an Allosaurus' capacity to bite through (eg. neural arches).

The description that you posted stated that vertebrae only a few mm thick could easily be damaged by genera such as Allosaurus. It did not tell of any other (and thicker) bones, specifically skulls that could be damaged quite easily by allosaurus and related genera. Instead, it was much more vague in the beginning, only referring to LARGE THEROPODS. We do not know if they were talking about only tyrannosaurids or other groups of theropods as well. Carnosaurs in general were ill-adapted for penetrating large and thick skeletal structures. In their case, spinal or skeletal damage would rely mostly on the severing of tendons and ligaments, as you stated earlier in this thread.

Besides, it does seem unlikely that a hatchet-bite would cause any sort of major damage to the vertebrae or the skull themselves, as it was a technique that was used for causing deadly (and deep) puncture wounds in an animal's hide and possibly causing damage to the spinal CORD itself, not the vertebrae. Allosaurus and its closest relatives did not have particularly powerful jaws, nor did they have the dentition or the skull structure designed for crushing, so major damage to vertebrae (I'm talking more than just minor tooth marks) is even unlikely if they could get their jaws around the stegosaurus' neck entirely. An allosaurus bite would more-so cause immense muscular, nerve, and tissue damage.

And as creature showed there's a cervical plate of Stegosaurus that's been bitten through by an allosaurid, indicating a pretty powerful attack on that region occurred. Not that that would be necessary, it would just take a bit of pulling if enough damage to the soft tissue has been done, and I read even tigers often don't break vertebrae but just separate them by sliding their teeth in between.

There is no indication as to whether or not the stegosaurus was an adult. Plus, stegosaur plates were not very thick or dense inherently, as least compared to many other skeletal structures.

Bone crushing is no requirement for this kind of damage, it becomes more important when dealing with a more massive structure (like the skull and neck of a Ceratopsian or Ankylosaur).

Large ceratopsians and ankylosaurs evolved when tyrannosaurids were the dominant terrestrial predators, not allosauroids. This means that they needed thicker skulls. Tyrannosaurids were much better adapted for bone damage and force-related killing strategies than allosauroids, so all allosauroids in general were much better adapted for severing tendons and muscles. 

No, since function determines morphology and vice versa

Different functions can mean SIMILAR morphology, as seen in both stegosaurs and ankylosaurs, but not necessarily IDENTICAL

[Fragillimus335]

Dec 4, 2013 19:24:16 GMT 5 creature386 said:

Dec 4, 2013 19:09:13 GMT 5 Fragillimus335 said:

And don't forget Stegosaurus evolved it's neck armor for a reason. If every bite to that region was an insta-kill it would have no reason to evolve!

Even though they may be useful for protection, most of the posters here (even Godzillasaurus) agreed that they didn't EVOLVE for being some kind of an armor. I have posted a paper on page three which shows that the armor hypothesis is quite weak.

I'm talking about the gular-pouch armour not plates.

[Godzillasaurus]

Dec 5, 2013 10:33:14 GMT 5 Fragillimus335 said:

Dec 4, 2013 19:24:16 GMT 5 creature386 said:

Even though they may be useful for protection, most of the posters here (even Godzillasaurus) agreed that they didn't EVOLVE for being some kind of an armor. I have posted a paper on page three which shows that the armor hypothesis is quite weak.

I'm talking about the gular-pouch armour not plates.

I see. But the way you worded it made it sound like you were talking about the animal's plates, not its thick chin scutes.

[theropod]

Does it tell of a certain age that the stegosaurus was? It is entirely likely that it was a juvenile and/or a sub-adult, as adult animals had considerably thicker plates.

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")

By "resistant", I was not talking completely 100% immune to bites overall, as this is obviously not the case in any herbivorous dinosaur, just simply being ripped off.

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).

While you are certainly not wrong about other factors here, I was only talking about the tendons and ligaments holding the vertebrae together.

those, and the muscles, can be cut.

As I just stated, stegosaurus obviously wasn't immune to bites overall, just being ripped off as easily as if its neck were made of rubber.

I daresay a neck made out of rubber wouldn´t be easy to rip off at all.

I was talking about the skull itself, not the musculature and tendons surrounding it.

I know, I was referring to the amount of damage the bite would do, regardless of what exactly it damaged.

The description that you posted stated that vertebrae only a few mm thick could easily be damaged by genera such as Allosaurus.

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.

It did not tell of any other (and thicker) bones, specifically skulls that could be damaged quite easily by allosaurus and related genera.

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).

Instead, it was much more vague in the beginning, only referring to LARGE THEROPODS. We do not know if they were talking about only tyrannosaurids or other groups of theropods as well.

They were referring to non-tyrannosauroids, namely those not so well adapted for bone crushing.

Carnosaurs in general were ill-adapted for penetrating large and thick skeletal structures.

Which is because that´s absolutely unnecessary for them.

In their case, spinal or skeletal damage would rely mostly on the severing of tendons and ligaments, as you stated earlier in this thread.

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.

Besides, it does seem unlikely that a hatchet-bite would cause any sort of major damage to the vertebrae or the skull themselves, as it was a technique that was used for causing deadly (and deep) puncture wounds in an animal's hide and possibly causing damage to the spinal CORD itself, not the vertebrae.

Regardless of what it did, Stegosaurus neck would be very vulnerable, and certainly did not offer much in terms of resistance to a bite of an Allosaurid.

Allosaurus and its closest relatives did not have particularly powerful jaws, nor did they have the dentition or the skull structure designed for crushing, so major damage to vertebrae (I'm talking more than just minor tooth marks) is even unlikely if they could get their jaws around the stegosaurus' neck entirely. An allosaurus bite would more-so cause immense muscular, nerve, and tissue damage.

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.

There is no indication as to whether or not the stegosaurus was an adult. Plus, stegosaur plates were not very thick or dense inherently, as least compared to many other skeletal structures.

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.

Large ceratopsians and ankylosaurs evolved when tyrannosaurids were the dominant terrestrial predators, not allosauroids. This means that they needed thicker skulls. Tyrannosaurids were much better adapted for bone damage and force-related killing strategies than allosauroids, so all allosauroids in general were much better adapted for severing tendons and muscles. 

Yes, that is exactly what I was implying. You need increasing adaption to crush bones the more massive the bones you have to bite get.
Whatever bone An Allosaurus would sever by a strike/slash/saw/pull approach would be pretty small and gracile (eg. a rib or neural arch of an Ornithopod, Stegosaur or other Theropod). The bones a specialized boine crusher would bite through, employing massive adductor forces, massive mandibles and thick, blunt, deeply rooted teeth in the process, are a different matter; massive skulls, limb bones, osteoderms or whole vertebrae of very bulky animals.

Different functions can mean SIMILAR morphology, as seen in both stegosaurs and ankylosaurs, but not necessarily IDENTICAL

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?

gular pouch armour: Komodo dragons have specialized slicing bites and extensive covering of at least comparable osteoderms, and they still kill each other. I think whatever animal the gular pouch protected from, it was smaller and less powerful.