Sarcosuchus imperator vs Carcharodontosaurus saharicus

[theropod]

If you read any of my past posts, I never used its width solely, but rather the general morphology of that area in conjunction with its dental morphology rather indicates high correlation with bite force.

And what exactly of that general morphology correlates that well with strong bite force (Which I think you meant to say, because it probably does not correlate well with bite force at all, that´s simply not the case in crocodylomorphs.)? Its depth, barely greater than that of the premaxilla of Spinosaurus, in conjunction with being hollow? Its teeth that are similar in lenght and robusticity to those of a saltie a seventh its own size?

Actually its tooth morphology seems to correspond heavily with bite force. They were well adapted for resistance against crushing; not something that we would see in a more specialized animal.

Bite force is not determined by tooth size or shape...

hmm, strange.

Firstly, bite force is primarily correlated with total body mass in crocodilians. Even species like Gavialis gangeticus have fairly strong bites.
Thus, secondly, bite force is not the determining factor for the potency of its bite in macrophagy. I think nobody here is doubting Sarcosuchus had a powerful bite, but as already stated, that´s beside the point.
Crocodilians differ in the extend to which they excert strong shaking, rotation and pulling forces on large animals. And everything suggests Sarcosuchus was rather comparable to generalist, mostly piscivorous species, not macrophagous ones.

[Godzillasaurus]

It's correlated to the mass of the croc I know but if the teeth are about the same size as those of a 6m saltie then they are no stronger themselves than those of a 6m saltie, which means that every time Sarcosuchus bites with full force it's subjecting its teeth to proportionally much higher stress than if they were not small compared to its body size, this is not in any way an adaptation to resists proportionally huge forces.

They were actually perfectly designed for resistance, both laterally and dorsoventrally. Longer teeth do not indicate higher downward resistance necessarily, especially if they possess a slender morphology, which is not possessed by those belonging to sarcosuchus. The teeth possessed by sarcosuchus indicate perfect adaptations for resistance, most specifically those located in the premaxilla (which, according to you guys, was apparently horribly adapted for resistance and macrophagy).

all of them fairly broad

And sarcosuchus' dentition isn't?

All crocodilianss are technically bone crushers, even gharials (!) but crocodilians specifically adapted to bite hard stuff in a daily basis (be it bones, turtle shells or mollusk shells) show the exact same adaptations as the rest of bone crushers, short robust jaws with few big and broad teeth, Sarcosuchus doesn't have any of this features which means that is no more specialized for those things you claim than any random crocodilian, probably even less so than average for all the reasons that I and others have previously outlined.

Sarcosuchus was not necessarily designed for crushing hard prey items (such as those that you listed), but rather was designed solely for gripping, but doing so with exceptional biting force and snout resistance. But that being said, the morphology of its dentition does indicate that bone damage is very well possible, as they are well designed for piercing and resistance alike. I have no doubt in my mind that the sheer conjunction of sarcosuchus' bite force and robust dentition would be enough to cause any sort of internal leg damage to the theropod here.

and its teeth were twice as big in all dimensions as those of Sarcosuchus

What are you arguing? The dentition of deinosuchus and sarcosuchus are actually quite similar in that they were built and shaped like thick spikes and were designed for piercing, gripping, and resistance both laterally and dorsoventrally, even regarding size.

btw, the skull of Deinosuchus is actually proportioned like those of American alligators and fully grown saltwater and nile crocodiles.

What relevance does this have here? And what relevance does it have in any of my past posts in this thread?

And what exactly of that general morphology correlates that well with strong bite force (Which I think you meant to say, because it probably does not correlate well with bite force at all, that´s simply not the case in crocodylomorphs.)?

I have explained this previously.

Its depth, barely greater than that of the premaxilla of Spinosaurus, in conjunction with being hollow?

And I say again, that is the only argument that you guys have to "prove" that it was a gracile structure. And yet you guys are claiming that carcharodontosaurus had a more robust snout than both spinosaurus and sarcosuchus, which is simply incorrect (or unless I misunderstood you. I know some members do at least). By comparison to that of spinosaurus, this region was so much broader, correlated far better with bite force (it was likely very resistant both in gripping and crushing functions and was, yes, particularly a robust structure overall if you ignore the sinuses), and the teeth in this region were not structured the same way as spinosaurus but were rather so much better adapted for clamping down with very strong force and resisting it simultaneously, whereas spinosaurus' teeth were specially designed for gripping and piercing solely, not crushing and/or being driven with such massive force.

The premaxilla of sarcosuchus, in fact, indicates far more than specialized feeding behavior. And the sinuses are found in all modern crocodilians as well, you know that right?

Firstly, bite force is primarily correlated with total body mass in crocodilians. Even species like Gavialis gangeticus have fairly strong bites.

I know

Thus, secondly, bite force is not the determining factor for the potency of its bite in macrophagy. I think nobody here is doubting Sarcosuchus had a powerful bite, but as already stated, that´s beside the point.

The main idea of this is sarcosuchus' ability to effectively TRANSMIT that said powerful biting force and be able to RESIST it. Sarcosuchus' snout would not break on impact and even the bulla was far more robust than you guys are implying and instead appears to have been a perfect adaptation for macropredatoy nature. Sarcosuchus did not have a gracile snout; that is the bottom line.

Crocodilians differ in the extend to which they excert strong shaking, rotation and pulling forces on large animals. And everything suggests Sarcosuchus was rather comparable to generalist, mostly piscivorous species, not macrophagous ones.

Sarcosuchus was likely more than capable of resisting this kinds of forces, as its ability to effectively transmit such large bite forces in conjunction with its ability to effectively maintain a strong grip on large animals does not imply that it had a weak snout. The ability of its snout to resist forceful torsion (as you explained to me recently, this is much different from simply having a strong snout) was actually likely far higher than that of spinosaurus and modern slender-snouted crocodilians, even at the tip of its snout (which was much more gracile and specialized in those animals; far less well adapted for crushing and resistance against high forces acting against it).

[blaze]

I'm not talking about Sarcosuchus needing longer teeth, I'm talking about it needing bigger teeth in all dimensions, Sarcosuchus doesn't have short teeth, it has small teeth, big difference. Are you insinuating that bigger teeth (as in both longer and wider) won't be stronger at resisting forces applied to them than small teeth of the same shape? as if just the fact that they have the same shape gives them a fixed resistance value that can't be increased or decreased?

I'm going to mention info from Erickson et al. (2012) again, only the gharial, considered a highly piscivorous species and the freshwater and Orinoco crocodiles, considered semi-piscivorous show the condition of relatively elongated caniniform teeth, just them, no other species, all the others be it molluscivores, terrestrial foragers, broad-snouted generalists and slender-snouted generalists (Tomistoma schlegelii and Crocodylus acutus) have "caniniform teeth that abruptly broaden – moving from the crown apex to the tooth neck" which Sarcosuchus also shares which means that adults were not restricted to only eating small fish but that has never been what we've argued.

One of the most important points you've made regarding your hypothesis is the shape of the teeth which you've used to argue then that it must have been as capable at handling prey than niles and salties but when you have scientific research indicating that you can't distinguish a macrophagus species from one that only eats relatively small prey based on teeth shape because they all have pretty much the same teeth shape then teeth shape becomes irrelevant in advancing your hypothesis, all the things you've said about Sarcosuchus teeth apply to the teeth of all but the most piscivorous crocodilian species.

If teeth shape can't tell you what they eat or how strong were their jaws at resisting forces beyond being highly piscivorous or not then you have to look at other parts of its anatomy, in both the relative size of the teeth and their arrangement, in the shape of the jaws and so on, since we don't have the means to conduct a biomechanical analysis we can only look at animals with similar characteristics and extrapolate from them, what I and others have found is that:

1. The teeth are relatively small for its skull size, as seen in adult Tomistoma.
2. The teeth are relatively uniform in size throughout the length of the jaws, even the enlarged ones are not much more than ~3x as big as the smallest ones, as seen in Tomistoma.
3. There are 30 maxillary teeth, almost twice as many as in most extant crocodiles and more still than in Gavialis.
4. The jaws are 75% the length of the skull, as seen in Tomistoma and Gavialis and likely other longirostrine taxa.
5. The jaws have a rostral proportion of 0.24, similar to the freshwater and slender snouted crocodiles and the record Tomistoma.
6. The jaws are shallow, less than 10% their length at the midpoint.
7. The jaws have uniform depth throughout their length as seen in Tomistoma, Gavialis, and the longirostrine species of Crocodylus.

Can you put up a list like this that tells us in short sentences, concisely and clearly the characterisics that Sarcosuchus objectively shares with niles and salties? the more Sarcosuchus shares with them the more it is likely that it was as capable at handling prey as them and if you can't make one and return to argue about the shape of the teeth and making long sentences saying how it was obviously capable of doing this and that then your hypothesis rests mostly on subjective feelings.

[Godzillasaurus]

I'm going to mention info from Erickson et al. (2012) again, only the gharial, considered a highly piscivorous species and the freshwater and Orinoco crocodiles, considered semi-piscivorous show the condition of relatively elongated caniniform teeth, just them, no other species, all the others be it molluscivores, terrestrial foragers, broad-snouted generalists and slender-snouted generalists (Tomistoma schlegelii and Crocodylus acutus) have "caniniform teeth that abruptly broaden – moving from the crown apex to the tooth neck" which Sarcosuchus also shares which means that adults were not restricted to only eating small fish but that has never been what we've argued.

One of the most important points you've made regarding your hypothesis is the shape of the teeth which you've used to argue then that it must have been as capable at handling prey than niles and salties but when you have scientific research indicating that you can't distinguish a macrophagus species from one that only eats relatively small prey based on teeth shape because they all have pretty much the same teeth shape then teeth shape becomes irrelevant in advancing your hypothesis, all the things you've said about Sarcosuchus teeth apply to the teeth of all but the most piscivorous crocodilian species.

The tooth shape present in slender-snouted crocodilians in general, is, fundamentally, more reminiscent of thin needle-like structures over anything. Even large tomistoma specimens do not have comparable dentition to that of sarcosuchus:



Tooth shape does get considerably broader with age and size, but the tooth morphologies still indicate different specializations. In animals better designed for crushing, we rather see differently-shaped dentition; crushing dentition retain a blunter point but yet more broadened shape ideal for such crushing. Examples of these kinds of crocodilians include the Chinese alligator, American alligator, and deinosuchus, all of which possess teeth that are very well designed for crushing (although the latter two have teeth that are also pointed and ideal for piercing into the hides of PARTICULARLY LARGER ANIMALS). Sarcosuchus, while it does not possess nearly as robust of a rostrum as deinosuchus (less well designed for crushing bone), it was not weak, and its dentition were actually fairly similar to those present in the frontalmost region of the latter's snout, especially the premaxillary teeth (and that brings me back to one of my previous points; lack of any sort of specialized morphology in the bulla itself and the teeth that are anchored by it).

Sarcosuchus does not have to be ideal for crushing bone to be well designed for macrophagy, and its tooth morphology is actually very different from that of tomistoma in terms of actual anatomy itself (even in very old animals) and actually far more reminiscent of that of deinosuchus, despite the two animals differing in snout robusticity and aptitude for crushing bone and/or other hard structures (such as mollusk and turtle shells).

If teeth shape can't tell you what they eat or how strong were their jaws at resisting forces beyond being highly piscivorous or not then you have to look at other parts of its anatomy, in both the relative size of the teeth and their arrangement, in the shape of the jaws and so on, since we don't have the means to conduct a biomechanical analysis we can only look at animals with similar characteristics and extrapolate from them, what I and others have found is that:

The snout shape, again, is not nearly identical to that of tomistoma or mecistops (so far, those seem to be the best modern analogies for sarcosuchus), and is far wider and more robust. The morphology of its snout is in fact quite supportive of a high reliance on bite force in killing, as such a widened rostrum is in fact disadvantageous in piscivory, as it does not allow for such easy drag reduction and instead implies far greater aptitude for hunting and gripping much larger animals. We don't actually have a decent visual comparison as of now, so we will have to go with this:



The snout located on the left is that of a hypothetical(?) juvenile and/or immature sarcosuchus. It is roughly comparable to both tomistoma and mecistops. You can easily highlight differences regarding robusticity in this case; what is present in the mature animal is a much more enlarged and broadened premaxilla that does in fact appear to be rather indicative of macropredatory feeding; it is far more robust than that belonging to particularly MORE SPECIALIZED PISCIVOROUS ANIMALS and instead appears to have been very well designed for resistance in the gripping of a large terrestrial animal.

Can you put up a list like this that tells us in short sentences, concisely and clearly the characterisics that Sarcosuchus objectively shares with niles and salties? the more Sarcosuchus shares with them the more it is likely that it was as capable at handling prey as them and if you can't make one and return to argue about the shape of the teeth and making long sentences saying how it was obviously capable of doing this and that then your hypothesis rests mostly on subjective feelings.

The truth is, it really does not... I have highlighted several times why there is no reason to believe that sarcosuchus' rostrum was weak, and in turn I have discussed other morphologies that indicate high correlation with strong bite force and snout shape. Normally, more specialized and particularly more gracile animals possess far more slender dentition rooted within the premaxilla (and even in all, but I feel the premaxillary teeth are most relevant to talk about here); specifically well designed for piercing easily and deeply without much direct relationship with any sort of strong bite force. Let's look at spinosaurus again:



While we certainly do not see a weak snout (in terms of robusticity posterior to the premaxilla), the premaxilla of it was far more specialized and gracile than that of sarcosuchus. And even then, spinosaurus was still very well adapted for hunting very large and powerful fish (again, perfectly evident in its snout and tooth morphology), so there is no reason to believe that its snout was weak but actually the direct opposite. What makes its rostrum so robust in general is the centermost and rearmost region of it; its premaxilla was so much more gracile even in comparison to that of sarcosuchus, which obviously possessed a premaxilla that appeared to have corresponded far better with large forces acting against it.

In sarcosuchus, we not only see an entirely different premaxilla build but also an entirely different premaxillary dentition build that is not particularly well designed for similar tasks as that of spinosaurus which includes piercing deeply without much driving force involved. 

[Runic]

You guys have honestly been arguing over literally the same thing for 4+ pages...... and still no agreement. Wow.

[blaze]

So you can't make a list and did exactly what I asked you not to do. That isn't a large Tomistoma btw, 3m at most based on others I've seen with length mentioned, also, look at the big middle teeth, cut the fleshy part and at the same snout length, is the same size, both length and width as the big middle teeth in Sarcosuchus.

Sarcosuchus teeth are average crocodilian teeth, deal with it, unless you can prove otherwise with numbers then it's only your subjective opinion that they were special.

Spinosaurus isn't relevant to the discussion, oreinorostral vs platyrostral, not a swimming crocodilian, they cannot be fairly compared unless you have a way to make a biomechanical analysis on them.


Relevant



To add to this comparison, at the same snout length, an 3.4m saltie will be almost twice as wide at the middle* while a big saltie like lolong will be almost 3 times as wide.** Though I suppose that you are going to say I'm wrong because the tip is obviously much wider, yeah, is wider but that is not going to invalidate everything said about how its shape is not closer to macrophagus crocodilians like niles and salties.

Can you use data to support your hypothesis rather than just appeal to our emotions? you have not highlighted anything you've just told us that it was robust that it correlates to this and that, that it was powerful and clearly designed for this but you've never cited nor used data from any scientific study, though most of the things you said about its teeth were true but that also applies to any random crocodilian.


*Mean length of the individuals Erickson et al. 2012 used to get their mean rostral proportion value of 0.41.
**Based on measurements of lolong's skull in Britton et al. (2012)

Edit:
You know what I previously said I will not keep debating this, I failed at doing that but I won't do that again, we just can't convince you so I quit and will make my vote haha, there's no point in repeating the same things over and over again and I'm sure you'll agree on that.

[Carcharodon]

Godzillasaurus will often reject most of what you guys say, and he struggles to believe that sarcosuchus was not a robust-jawed, saltie-like generalist.

[theropod]

And I say again, that is the only argument that you guys have to "prove" that it was a gracile structure.

It´s not exactly robust otherwise either. That would surely be a pretty big piece of bone, but the amount of force it could excert would nevertheless be severely limited by the depth and width of the more posterior part of the rostrum.

And yet you guys are claiming that carcharodontosaurus had a more robust snout than both spinosaurus and sarcosuchus, which is simply incorrect (or unless I misunderstood you. I know some members do at least).

Because this is not incorrect. Its snout is similarly wide and FAR deeper. It wont be more pneumatic than the hollow premaxilla of Sarcosuchus either.

By comparison to that of spinosaurus, this region was so much broader, correlated far better with bite force (it was likely very resistant both in gripping and crushing functions and was, yes, particularly a robust structure overall if you ignore the sinuses)

BUT WE DO NOT IGNORE THE SINUSES! Thats like saying a sunflower stalk was tremendously strong! Its a reasonably thick piece. If you ignore it isn´t solid wood, you may well reach the conclusion you could use it for building scaffolding!

, and the teeth in this region were not structured the same way as spinosaurus but were rather so much better adapted for clamping down with very strong force and resisting it simultaneously, whereas spinosaurus' teeth were specially designed for gripping and piercing solely, not crushing and/or being driven with such massive force.

All the time you talk of "clamping down and resisting" as if those were two different things. Do you think Spinosaurus had a dentition built for a tremendously strong bite but that sadly wasn´t adapted to also withstand it?
Just for your information, Spinosaurus PRemaxillary teeth are not that gracile. Most importantly tough, they are generally larger than Sarcosuchus´, and thus likely more efficient puncturing tools.

The premaxilla of sarcosuchus, in fact, indicates far more than specialized feeding behavior. And the sinuses are found in all modern crocodilians as well, you know that right?

Yes, so why exactly are you not acknowledging its similarity to those very crocodilians? The only major difference between it and Mecistops or Tomistoma is that the hollow part in the front of its snout is hypertrophied, simply due to size-related issues.

Firstly, bite force is primarily correlated with total body mass in crocodilians. Even species like Gavialis gangeticus have fairly strong bites.

I know

The main idea of this is sarcosuchus' ability to effectively TRANSMIT that said powerful biting force and be able to RESIST it.

Extant crocodilians and in fact all predators are capable of resisting and transmitting their own bite forces. Most of them are capable of transmitting and resisting additional forces, such as shaking, pulling or torsion.

Sarcosuchus' snout would not break on impact and even the bulla was far more robust than you guys are implying and instead appears to have been a perfect adaptation for macropredatoy nature. Sarcosuchus did not have a gracile snout; that is the bottom line.

The bottom line is that in all its features it strongly resembles modern generalist crocodilians with relatively narrow snouts. Blaze has already given you a fairly detailed list.

Sarcosuchus was likely more than capable of resisting this kinds of forces, as its ability to effectively transmit such large bite forces in conjunction with its ability to effectively maintain a strong grip on large animals does not imply that it had a weak snout.

And here we go. Where from do you take the claim that it did? You cannot use the thing you are arguing for as an argument!

The ability of its snout to resist forceful torsion (as you explained to me recently, this is much different from simply having a strong snout) was actually likely far higher than that of spinosaurus and modern slender-snouted crocodilians

And why?

, even at the tip of its snout (which was much more gracile and specialized in those animals; far less well adapted for crushing and resistance against high forces acting against it).

That is the sunflower-stalk-view. Or the egg-stone view.

A practical example: Take a piece of clay. Make two balls of the same size. One you form into a bowl (representing a peumatic premaxilla), the other you leave as it is (representing a solid one). You then let the dry, and if you want burn them. Now you happen to throw both of them to the ground. Do you seriously think the bowl will be more resistant to the impact forces?

[Godzillasaurus]

Godzillasaurus will often reject most of what you guys say, and he struggles to believe that sarcosuchus was not a robust-jawed, saltie-like generalist.

Oh dear. You bash me because I have logical reasoning but yet you claim that carcharodontosaurus had a more robust snout than both spinosaurus and sarcosuchus. I'm sorry dude, but you need to try harder than just act like a douche without backing any of your points. Everyone here is debating with logical arguments, but yet you go around and claim me to be wrong just because "yoo thank sow!"

You guys have honestly been arguing over literally the same thing for 4+ pages...... and still no agreement. Wow.

Haha, I know

Sarcosuchus teeth are average crocodilian teeth, deal with it, unless you can prove otherwise with numbers then it's only your subjective opinion that they were special.

Aside from being conical, there is no such thing as an "average crocodilian tooth shape". I have explained this to you; tooth shape corresponds heavily with diet.

Spinosaurus isn't relevant to the discussion, oreinorostral vs platyrostral, not a swimming crocodilian, they cannot be fairly compared unless you have a way to make a biomechanical analysis on them.

The truth is, they can. Spinosaurus was very well adapted for hunting large fish, but that is just the reason to no believe that it was weak.

To add to this comparison, at the same snout length, an 3.4m saltie will be almost twice as wide at the middle* while a big saltie like lolong will be almost 3 times as wide.** Though I suppose that you are going to say I'm wrong because the tip is obviously much wider, yeah, is wider but that is not going to invalidate everything said about how its shape is not closer to macrophagus crocodilians like niles and salties.

I know that. My point is fundamentally that it wasn't a weak structure.

Can you use data to support your hypothesis rather than just appeal to our emotions? you have not highlighted anything you've just told us that it was robust that it correlates to this and that, that it was powerful and clearly designed for this but you've never cited nor used data from any scientific study, though most of the things you said about its teeth were true but that also applies to any random crocodilian.

Umm, no. I am not just using "my emotions". I have been making logical points this entire time (not to say you guys are not, however)

It´s not exactly robust otherwise either. That would surely be a pretty big piece of bone, but the amount of force it could excert would nevertheless be severely limited by the depth and width of the more posterior part of the rostrum.

Bite force has no reliance on snout shape in crocodilians...

Because this is not incorrect. Its snout is similarly wide and FAR deeper. It wont be more pneumatic than the hollow premaxilla of Sarcosuchus either.

It was bigger in multiple dimensions, but yet that does not prove that it was a more robust structure. SPINOSAURUS DID NOT HAVE A WEAK SNOUT! And there is no reason to believe that it did even with the most biased bit of inference.

Spinosaurus' snout was far more heavily-constructed (regardless of dimensions) and was well structured for gripping and multidirectional resistance, which is just what carcharodontosaurus was horribly adapted at. Carcharodontosaurus was well designed for quick and forceful downward and pulling attack motions, which means that its snout only needs to be reinforced vertically; its snout was very deep, but it was nonetheless very weakly-adapted for gripping/well-rounded resistance and was very lightly-constructed which was rather the polar opposite in spinosaurus. What we instead see in spinosaurus is a much more slender but yet more robust snout overall (adapted for reducing drag and for resistance purposes) that was far better designed for gripping particularly large fish and functional resistance coming with it:



There is no particular reason to believe that spinosaurus' snout was weak, because that is wrong. Its snout needed to be far more resistant in hunting, as it not only killed very large animals by gripping, but it did not kill in similar ways as carcharodontosaurus: quickly and vertically. The ability for its snout to withstand well-rounded stress is not only evident in its more robust morphology but also its well-rounded snout shape (the difference between its overall rostrum depth and width was far smaller, even though its rostrum was SLIGHTLY deeper than it was wide) and high aptitude for gripping.

I admit that I used to believe that carcharodontosaurus had a more robust rostrum than spinosaurus (about a year and a half ago) until YOU GUYS (yes, I'm talking about YOU and Spinodontosaurus) convinced me otherwise only hours later. Does that tell you anything?

All the time you talk of "clamping down and resisting" as if those were two different things. Do you think Spinosaurus had a dentition built for a tremendously strong bite but that sadly wasn´t adapted to also withstand it?

Similar to what I said about its snout; spinosaurus did not kill necessarily with vertical force-related tactics. It was, fundamentally, designed for gripping. The ability of its teeth to pierce deeply is attributed to their elongate shape and sheer aptitude for piscivory. They were not designed to have been used forcefully but rather solely to pierce and retain a strong grip without breaking. Spinosaurus simply did not need an excessively powerful bite.

Just for your information, Spinosaurus PRemaxillary teeth are not that gracile. Most importantly tough, they are generally larger than Sarcosuchus´, and thus likely more efficient puncturing tools.

I realize that; they were well designed for piercing into the hides of large fish and, despite their slender build, were very strong for lateral resistance. Just with carcharodontosaurus, they were designed for being used a certain way, but not for crushing.

I do not doubt that they were perfect puncturing tools, as that is what they were fundamentally designed for. But to claim that they were more resistant vertically and were used in conjunction with powerful bite forces to kill large animals more-so than sarcosuchus is incorrect (you probably do not believe this, but I misunderstand you guys a lot). The premaxillary teeth of sarcosuchus were far broader and less well adapted for piercing deeply without much driving force, and we would expect them to have been far different in morphology (such as begin in possession of a more elongate design) if they were designed the same way as those of spinosaurus (piercing into the hides of large fish without the need for much driving force due to lack of crushing aptitude overall).

Yes, so why exactly are you not acknowledging its similarity to those very crocodilians? The only major difference between it and Mecistops or Tomistoma is that the hollow part in the front of its snout is hypertrophied, simply due to size-related issues.

Sorry, meant to say "spinosaurus" on that one...

And here we go. Where from do you take the claim that it did? You cannot use the thing you are arguing for as an argument!

My memory says otherwise... Attribute the hint

And why?

Much wider snout at the tip (not very specialized. And unlike modern macrophagous crocodilians, appears to have been more-so used in predation rather than the center of the snout), much more indicative of macrophagous feeding (come on people, we talked about this!), and higher reliance on bite force rather than simple ability to maintain a strong grip on on fish while retaining the ability to effectively reduce drag in water.

A practical example: Take a piece of clay. Make two balls of the same size. One you form into a bowl (representing a peumatic premaxilla), the other you leave as it is (representing a solid one). You then let the dry, and if you want burn them. Now you happen to throw both of them to the ground. Do you seriously think the bowl will be more resistant to the impact forces?

And so I'm assuming that makes carcharodontosaurus' snout weak vertically because it is, generally, very lightly-built with the possession of such large fenestrae and lack of any adaptations for crushing or gripping...

What matters here instead is how well the structure wound fair in gripping large animals. We know that spinosaurus' preamaxilla was not particularly robust by nature but rather the opposite; it was very gracile and most likely had a very low breaking point despite the robusticity of the region posterior to that. The premaxilla of spinosaurus was most likely used to pluck only moderately-sized fish from the water and would likely not fare very well against an animal like mawsonia, which is rather the opposite case for the area just posterior to it.

[spinodontosaurus]

Jan 15, 2014 3:48:13 GMT 5 Godzillasaurus said:

I have explained this to you; tooth shape corresponds heavily with diet.

And Blaze has posted evidence from Erickson et al. that shows the exact opposite of what you claim.


All you are doing is continually repeating the same claims over and over again without ever actually substantiating them. That most of them (in relation to tooth morphology and snout morphology) were firmly rebutted several pages ago doesn't reflect well on you.


You are continually claiming Sarcosuchus had some sort of really robust rostrum, yet it has been demonstrated numerous times that 20 out of 22 extant crocodilian species had rostrums that are proportionally wider than that of Sarcosuchus. Please for heavens sake don't come back to me with three paragraphs repeating the mantra that Sarcosuchus has a robust rostrum, most of what you type doesn't even address the claims you respond to and in this case if were to try you would be flat out incorrect.

You are continually claiming Sarcosuchus has dentition that is really resistant and suited for stuff and blah blah blah, yet it has been demonstrated on countless occasions that it's teeth are fundamentally no different to those of several slender-snouted crocodilian species, and are dwarfed by those of species that tackle larger prey such as C. niloticus. So... what exactly is so exceptional about them?
You also seem incapable of accepting that the high number of small teeth (in relative terms) present in Sarcosuchus is closest to modern species such as Tomistoma and the Indian Gharial, and is the exact opposite of the condition seen in species that tackle larger prey (low number of large teeth). Why can you not accept this? Find a picture of the skull and count the number of teeth if you aren't convinced.

An explanation for the wider premaxilla has already been given. If the huge nares in Sarcosuchus are related to a heat exchange mechanism as has been proposed, then that right there is a perfect explanation. The main difference between the structure seen in Sarcosuchus and that seen in some modern species such as the Gharial is that, unlike in Sarcosuchus, modern species no not possess enlarged nares. If the premaxilla was trulli an effective predatory tool, one would surely expect it to show more adaptations for such a role than is seen in modern equivalents, yet what we actually see is an enlarged air hole there instead.

[theropod]

I know that. My point is fundamentally that it wasn't a weak structure.

well, the point regardless of that is that itÂ’s for all we know significantly weaker than a saltie skull.

It´s not exactly robust otherwise either. That would surely be a pretty big piece of bone, but the amount of force it could excert would nevertheless be severely limited by the depth and width of the more posterior part of the rostrum.

Bite force has no reliance on snout shape in crocodilians...

I know, I told you that. That is is not strongly correlated with skull robusticity or diet is the very reason IÂ’m of course not referring to bite force alone.

It was bigger in multiple dimensions, but yet that does not prove that it was a more robust structure.

Well, disprove it then, will you?

SPINOSAURUS DID NOT HAVE A WEAK SNOUT! And there is no reason to believe that it did even with the most biased bit of inference.

And yet you always repeat how Sarcosuchus has a far more robust and "generalized" snout than Spinosaurus, frankly because you denied the very thing you want to tell me here.

IÂ’m well aware of that fact. the problem is, that unlike With Sarcosuchus (were you can see from nostril size alone that that premaxilla is hollow, since the conjoined naris is almost as large as the whole premaxillaries), we know next to nothing about the extent of internal pneumatisation. Now I may consider this a valid reason to presume it isnÂ’t necessarily stronger in lateral direction, but with that skull depth itÂ’s simply unreasonable to propose it wasnÂ’t more resistant in the sagittal plane.

As it happens, that corresponds very well to the feeding style of these animals, one being reliant on causing massive trauma to large prey utilising mostly the upper jaw, and one being reliant on gripping or puncturing mid-sized stuff, thatÂ’s subdued quickly and without particular reliance on excerting strong force, with the aid of two 2m-long arms.

SpinosaurusÂ’ rostrum is less reinforced for resistance in one dimension, and its shear thinness keeps it from being tremendously strong enough overall to make up for that. Being "heavily constructed" to an extend you cannot even quantify is no reason why it should be resistant enough to compete here. And being adapted for gripping does not automatically make a structure overally strong, as you might see with gharial snouts.

Simply compare the rostra of these two.

I admit that I used to believe that carcharodontosaurus had a more robust rostrum than spinosaurus (about a year and a half ago) until YOU GUYS (yes, I'm talking about YOU and Spinodontosaurus) convinced me otherwise only hours later. Does that tell you anything?

Nope, it doesnÂ’t. Quote the part please, that may be a misunderstanding on your part.

I realize that; they were well designed for 

[/font]piercing into the hides of large fish and, despite their slender build, were very strong for lateral resistance. Just with carcharodontosaurus, they were designed for being used a certain way, but not for crushing.
[/quote]Ok, again, whether they were used for crushing is TOTALLY IRRELEVANT, no matter what definition you are using right now.
WhatÂ’s important is their ability to deal damage in accordance with what its skull and musculature were capable of.

I do not doubt that they were perfect puncturing tools, as that is what they were fundamentally designed for. But to claim that they were more resistant vertically and were used in conjunction with powerful bite forces to kill large animals more-so than sarcosuchus is incorrect

(you probably do not believe this, but I misunderstand you guys a lot)

OK, I would then advise you to read my posts more carefully.

IÂ’m very confident that Sarcosuchus has a 2-or more fold bite force advantage, and I have expressed this for several times now. ThatÂ’s simply totally beside the point of how well it could use its jaws in killing. It happens to lack an efficient puncturing dentition as usually found in Conical-toothed macrophagous species, and it also happens to lack a skull geometry that would suggest resistance to forceful postcranial forces, to eg. dismember or overpower a large prey animal, which it inevitably would have to do and be capable of if it killed prey as large relative to itself as saltwater crocodiles or analogous species.

Yes, so why exactly are you not acknowledging its similarity to those very crocodilians? The only major difference between it and Mecistops or Tomistoma is that the hollow part in the front of its snout is hypertrophied, simply due to size-related issues.

Sorry, meant to say "spinosaurus" on that one...

Well, then youÂ’ve made a step in the wrong direction.

My memory says otherwise... Attribute the hint

you know what my memory says? If I argue that a certain species had a strong skull indicating a certain feeding behaviour, you cannot invalidate an argument against that, like eg. "its snout is only half the width of the species to which you presume it is similar" or "yes its premaxilla is broad, but thatÂ’s simply to enlarge its naris for metabolic reasons" or "its teeth are the size of those of a saltie 7-8 times smaller in total body mass" by simply saying "thatÂ’s irrelevant, its snout and teeth are obviously built for macrophagy".

Much wider snout at the tip

(

not very specialized. And unlike modern macrophagous crocodilians, appears to have been more-so used in predation rather than the center of the snout), much more indicative of macrophagous feeding (come on people, we talked about this!), and higher reliance on bite force rather than simple ability to maintain a strong grip on on fish while retaining the ability to effectively reduce drag in water.

Firstly its snout, as I already pointed out, is perfectly adapted for reducing drag in water. crocodilians, at least in all the footage I know, snatch fish via sideways motions of their snouts, simply due top their body posture. This is as perfectly consistent with piscivory as SpinosaurusÂ’ snout shape is.

And so I'm assuming that makes carcharodontosaurus' snout weak vertically because it is, generally, very lightly-built with the possession of such large fenestrae and lack of any adaptations for crushing or gripping...

As I said, you cannot even quantify that "generally, very lightly built", and Allosaurus would suggest it is probably highly optimised for resisting vertical forces, regardless of that. This has nothing to do with crushing or gripping. It has to do with how much force the animal would excert on its prey, and frankly even in a slicerÂ’s bite thatÂ’s a considerable amount if the animal is 8-9t in weight and its prey is even larger. On the other hand, mere bite force used on a low-resistance target thatÂ’s disabled quickly does not by any means suggest greater resistance.

ItÂ’s simply to demonstrate you that a hollow structure isnÂ’t necessarily stronger than a solid one, just because its wider. Your only arguments as to why SarcosuchusÂ’ premaxilla was built for macrophagy are its teeth (resembling lolongÂ’s in overall size and robusticity...) and its width (due to it being hollow). The funny thing is, what use would it be to have a super-robust premaxilla if the part of the snout itÂ’s attached to is weaker anyway?

What matters here instead is how well the structure wound fair in gripping large animals.

yes, and SarcosuchusÂ’ wouldnÂ’t fare very well in this regard.

We know that spinosaurus' preamaxilla was not particularly robust by nature but rather the opposite; it was very gracile and most likely had a very low breaking point despite the robusticity of the region posterior to that.

Which is a highly logical configuration of material; anteriormost part being the weakest, because thatÂ’s also where the bite and postcranial forces are lowest, due to simply leverage.

The premaxilla of spinosaurus was most likely used to pluck only moderately-sized fish from the water and would likely not fare very well against an animal like mawsonia, which is rather the opposite case for the area just posterior to it.

Luckily it happens to have a fairly robust posterior region, which could be utilised effectively. ThatÂ’s far more useful than having a monstrously strong premaxilla anchored to a weak maxilla that will break long before the premaxilla does...
One more reason why it does by no means make sense for the premaxilla to be so specialized for macrophagy, but much more....for head exchange!

[gigadino96]

As every giant terrestrial macro predator vs a crocodrilian:

Carcharodontosaurus win on the land
Sarcosuchus win on the water

[theropod]

The latter I think is so obvious its not even noteworthy. Most terrestrial predators just arenÂ’t suitable, in terms of their body shape (even if they are fairly good swimmers), for fighting a semi-aquatic creature in the water (at least given that water is more than 2ft deep).

[Godzillasaurus]

IÂ’m well aware of that fact. the problem is, that unlike With Sarcosuchus (were you can see from nostril size alone that that premaxilla is hollow, since the conjoined naris is almost as large as the whole premaxillaries), we know next to nothing about the extent of internal pneumatisation. Now I may consider this a valid reason to presume it isnÂ’t necessarily stronger in lateral direction, but with that skull depth itÂ’s simply unreasonable to propose it wasnÂ’t more resistant in the sagittal plane

But the increased depth in spinosaurus' rostrum is rather an adaptation more-so for increased vertical resistance in gripping, as it hunted very large fish but yet did not kill with similar force-related tactics as sarcosuchus. Such exceptionally deep rostra are not necessarily factors that indicate crushing (even though tyrannosaurids possess relatively deep rostra, the depth present is nowhere near as specialized as that of carcharodontosaurus. But does that mean that carcharodontosaurus had a more robust rostrum?

Spinosaurus' increased depth rather indicates that vertical stress would not be a problem in gripping, because it did not bite so forcefully unlike sarcosuchus. Take deinosuchus and carcharodontosaurus for example, one had a much deeper snout while the other possessed a far more robust rostrum that was better designed for gripping resistance and crushing. It is really the same thing with sacosuchus and spinosaurus; one is far better adapted for crushing while the other was generally more gracile in build and was rather reinforced vertically.

As it happens, that corresponds very well to the feeding style of these animals, one being reliant on causing massive trauma to large prey utilising mostly the upper jaw, and one being reliant on gripping or puncturing mid-sized stuff, thatÂ’s subdued quickly and without particular reliance on excerting strong force, with the aid of two 2m-long arms.

Both animals were well adapted for gripping, so there are not many variables in that regard. The depth in spinosaurus' rostrum is again an indication for increased resistance in that direction; specifically attributed to it specializing in tackling large fish. The teeth of spinosaurus were well adapted for gripping most of all, so the killing style specifically revolving around such quick and precise puncturing still remains hypothetical. But interestingly, the increased depth does seen to correlate perfectly with its tooth morphology in that the increased vertical resistance parallels with the ability of its conical teeth to pierce deeply more-so than in sarcosuchus and similar animals. But again, this is more likely attributed to spinosaurus being well adapted for gripping large fish most of all as opposed to killing.

SpinosaurusÂ’ rostrum is less reinforced for resistance in one dimension, and its shear thinness keeps it from being tremendously strong enough overall to make up for that. Being "heavily constructed" to an extend you cannot even quantify is no reason why it should be resistant enough to compete here. And being adapted for gripping does not automatically make a structure overally strong, as you might see with gharial snouts.

Spinosaurus' rostrum was not exceptionally deeper in relation to wider, this was only slightly the case. It was not specialized to have been used in one certain direction to kill prey; it was well adapted for gripping. I admit that I was confused about this just recently; I thought that torsional resistance and gripping resistance were synonymous; they were not. I, too, used to think that its deep rostrum could be used to kill with violent shaking, but I now question why I ever even thought that. I think it was because of the present difference in depth and width, in which case its depth only slightly outweighs the values of its width.

The point is quite simply that the morphology present in spinosaurus does not imply that it was weak one bit and instead is an implication of a big chunk of its diet revolving around the gripping of impressively large fish. Naturally, increased resistance both laterally and vertically (multidirectional. This is rather not found in the other two genera) is a necessity with a killing style revolving around gripping and would be more-so present in spinosaurus than in allosaurus or carcharodontosaurus, as the former animal was well adapted for gripping. So what if carcharodontosaurus and allosaurus had a wider rostrum relative to length; they were still very poorly adapted for the same kind of gripping of large and powerful animals as found in spinosaurus; they were only adapted for killing quickly and vertically. Their snouts would not necessarily break in the event of gripping, but they were still simply poorly-adapted for such forceful handling of large prey and skull damage overall is a far greater possibility due to the lack of such gripping morphology but rather the opposite (far deeper rostrum that was much less heavily-constructed and was only well adapted for vertical resistance as opposed to multidirectional. As well, teeth that are also only adapted for working vertically and in pulling motions; they were not conical and designed for piercing deeply). The greater width of allosaur snouts are not necessarily exceptional or for a specific purpose, and predation/killing instead relies more on their impressive rostral depth and serrated teeth to cause tissue damage and/or intense blood loss:





There is no reason to believe that carcharodontosaurus was even in possession of a more robust rostrum, and even if it was, the stresses found in predation would be much smaller. There is also no reason to believe that the stress found in gripping large animals would be much less intense in the realm of skull damage for allosaurus than spinosaurus just because it had a proportionally wider snout; the much more voluminous but yet far less heavily-constructed structure of allosaur rostra would make such lateral pressures far more damaging not in the realm of the entire structure breaking but rather the sheer force being exerted causing different kinds of damage such as intense fracturing (this is not limited to completely going through the entire structure). Spinosaurus was far less vulnerable in this regard, as its snout was fundamentally more robust and was designed to grip large animals with a reduced risk of any sort of injury first and foremost; allosaurus was poorly adapted in this regard, and its snout would be particularly vulnerable due to its lessened ability to withstand lateral stress without fracturing. Width doesn't mean everything, but rather an animal's adaptations to do so in which case spinosaurus has the clear advantage in gripping.

Nope, it doesnÂ’t. Quote the part please, that may be a misunderstanding on your part.

It was on Carnivora, and not only am I banned from there, I dare go back...

Ok, again, whether they were used for crushing is TOTALLY IRRELEVANT, no matter what definition you are using right now. WhatÂ’s important is their ability to deal damage in accordance with what its skull and musculature were capable of.

THAT is true. But I say again, the morphology present in spinosaurus' snout and dentition were not designed for killing nonetheless

It happens to lack an efficient puncturing dentition as usually found in Conical-toothed macrophagous species

Lolwut? Didn't you state the direct opposite a multitude of times??? Besides, that would be incorrect anyway and would instead be the direct opposite.

Firstly its snout, as I already pointed out, is perfectly adapted for reducing drag in water. crocodilians, at least in all the footage I know, snatch fish via sideways motions of their snouts, simply due top their body posture. This is as perfectly consistent with piscivory as SpinosaurusÂ’ snout shape is.

That rather seems to be attributed to a lack of piscivorous morphology within their snout that is designed for reducing vertical drag...

As I said, you cannot even quantify that "generally, very lightly built", and Allosaurus would suggest it is probably highly optimised for resisting vertical forces, regardless of that. This has nothing to do with crushing or gripping. It has to do with how much force the animal would excert on its prey, and frankly even in a slicerÂ’s bite thatÂ’s a considerable amount if the animal is 8-9t in weight and its prey is even larger. On the other hand, mere bite force used on a low-resistance target thatÂ’s disabled quickly does not by any means suggest greater resistance.

A structure can be lightly-built and yet resistant simultaneously; that is the reason why allosaurus had no problems with that; because its snout was designed to be used vertically. Its snout possessed impressive depth, that is it and that is all that was necessary for it to be an effective predator. Spinosaurus, however, did not hunt the same things in quite the same way; it hunted fish and was specialized in gripping. Allosaurus possessed greater dimensions proportionally, but spinosaurus in general had a much stronger snout overall that was designed for gripping and multidirectional resistance as opposed to only being so well designed to have been used for killing vertically. There is no reason to believe that allosaurs were very well adapted for lateral resistance and gripping, even when their snouts are so much wider. The ability for them to be effective at resistance and forceful killing is attributed to their deep rostra, not necessarily implying that they had very heavily built rostra designed for withstanding the same pressures experienced by gripping.

The ability for spinosaurus to be efficient at gripping is the presence of a more well-suited snout overall for the job (not necessarily exceptionally reinforced one way, but still very strong in multiple directions to compensate for its diet of large fish) and presence of conical teeth. In allosaurus and carcharodontosaurus we rather see a more lightly-constructed rostrum in addition with slicing and ripping dentition; I am not saying that its snout would necessarily bend laterally, but it was not designed to be very strong in this direction as evidenced by its lack of specific gripping morphology found in spinosaurus.

ItÂ’s simply to demonstrate you that a hollow structure isnÂ’t necessarily stronger than a solid one, just because its wider. Your only arguments as to why SarcosuchusÂ’ premaxilla was built for macrophagy are its teeth (resembling lolongÂ’s in overall size and robusticity...) and its width (due to it being hollow). The funny thing is, what use would it be to have a super-robust premaxilla if the part of the snout itÂ’s attached to is weaker anyway?

And what use does such a generalized shape have in the first place, especially when the teeth in that region do not indicate similar functions as those of spinosaurus: penetrating deeply into the hides of large fish being rooted within a gracile premaxilla while possessing a morphology that indicates high correlation with bite force. Honestly, there is much more to sarcosuchus' bulla than just contemplating for the sinuses, just as allosaurus did not have a weak snout vertically necessarily. A huge hole does not necessarily make a structure weak... Overall, the bulla can be considered a rather robust structure given its morphology and dimensions.

yes, and SarcosuchusÂ’ wouldnÂ’t fare very well in this regard.

Why not? All of the evidence points to a generally predatory function surrounding it, even by comparison to the posterior parts of the rostrum. The only real support that you guys have is the presence of enlarged nares, which is still possessed by animals like deinosuchus (which also possesses a similarly-built premaxilla).

This region seems to have a perfect function in macrophagy: it is more generalized than the premaxillae of more specialized animals, it was probably very resistant (I have already explained this to you guys...), it was very well designed for effectively transmitting the creature's bite force to large animals (it would not be damaged on impact), and the dentition in this region do not imply similar piscivorous functions as those of animals like spinosaurus but are instead well designed like thick hooks. That is the bottom line.

Which is a highly logical configuration of material; anteriormost part being the weakest, because thatÂ’s also where the bite and postcranial forces are lowest, due to simply leverage.

But what we instead see in sarcosuchus is rather increased resistance, high aptitude for crushing, and greater macrophage ability in the premaxilla by comparison to the posterior regions of the snout. What other leverage do you guys have to prove that it was a weak structure besides the sinuses?

Luckily it happens to have a fairly robust posterior region, which could be utilised effectively. ThatÂ’s far more useful than having a monstrously strong premaxilla anchored to a weak maxilla that will break long before the premaxilla does...

Sarcosuchus did not have a weak maxilla... And even if you guys claim that it was because of its similarities to mecistops, I'll have you know that mecistops does not have a particularly weak maxilla either. The only crocodilian that truly possesses a really gracile rostrum is the Indian gharial, as it is the only living crocodilian that does not excercise generalist feeding, as its jaws would break very easily. This appears to be the opposite case in sarcosuchus, actually. The main factor contributing to its high snout resistance and ability to effectively grip large fish rather is firmly attributed to the robusticity of its maxilla, being very generalized both vertically and laterally while let alone being particularly dense. Its premaxilla was nothing special in this regard.

Simply compare the rostra of these two.

Carcharodontosaurus- Far lighter in build (less compact and dense, being in possession of very large fenestrae owing to larger pockets within the actual structure), characterized by impressive depth (was designed to withstand vertical stress and obviously killed vertically), wider (but not for increased resistance in that direction. The wider snouts of allosaurs rather seem to be accomodations for the killing of very large animals. The width was certainly not an adaptation for lateral resistance), lessened reliability on bite force, and laterally compressed/serrated teeth (best adapted for forceful backward motions to tear flesh)

Spinosaurus- Generally more heavily-constructed (far more compact and dense, possessing far smaller fenestrae and is more-so a solid piece), moderate depth (for increased vertical resistance in gripping events, not for killing. But this could also be correlated with its dentition as well), generally more specialized (but still very robust and resistant laterally in addition to vertically. Thinner shape in both dimensions is instead an adaptation for reducing drag in water and being more aerodynamic, but this clearly does not owe to a weak snout), more emphasis on a stronger bite (not monstrous, but the fact that it was well adapted for gripping large fish makes it more likely than in the former animal. It did not only utilize its maxillary teeth in predation), and finally conical teeth that are well designed for piercing and retaining a stable grip without breaking (not designed for killing necessarily, but their shape also correlates heavy with snout morphology in that the increased depth of its snout would make such deep puncturing less risky and the overall strength/resistance of its snout creates an ideal combination for gripping particularly large animals as opposed to killing)

Again, I do not know why I used to believe that spinosaurus would shake its head violently to kill prey. I didn't understand the difference between torsional resistance and gripping resistance, but yet I still knew that spinosaurus' snout was very strong because it was well adapted for gripping large and powerful fish with ease. I guess it was just because I knew that its morphology suggested a primary style of killing revolving around gripping and its snout was strong.

[Runic]

The facepalm emote exists.....