Sarcosuchus imperator vs Carcharodontosaurus saharicus

[Carcharodon]

Sarcosuchus imperator
Sarcosuchus (meaning 'flesh crocodile' and commonly called "SuperCroc") is an extinct genus of crocodyliform and distant relative of the crocodile that lived 112 Million years ago. It dates from the early Cretaceous Period of what is now Africa and is one of the largest giant crocodile-like reptiles that ever lived. It was almost twice as long as the modern saltwater crocodile and weighed approximately 8 to 10 tonnes. When fully mature, Sarcosuchus is believed to have been as long as a city bus (11.2–12.2 metres or 37–40 ft) and weighed up to 8 tonnes (8.75 tons). The largest living crocodilian, the saltwater crocodile, is less than two-thirds of that length (6.3 meters or 20.6 ft is the longest confirmed individual) and a small fraction of the weight (1,200 kg, or 1.3 tons). The very largest Sarcosuchus is believed to have been the oldest. Osteoderm growth rings taken from an 80% grown individual (based on comparison to largest individual found) suggest that Sarcosuchus kept growing throughout its entire 50–60 year average life span. Modern crocodiles grow at a rapid rate, reaching their adult size in about a decade, then growing more slowly afterward. Its skull alone was as big as a human adult (1.78 m, or 5 ft 10 inches). The upper jaw overlapped the lower jaw, creating an overbite. The jaws were relatively narrow (especially in juveniles). The snout comprises about 75% of the skull's length.


Carcharodontosaurus saharicus
Carcharodontosaurus is a genus of carnivorous carcharodontosaurid dinosaurs that existed between 100 and 93 million years ago, during the late Albian to early Cenomanian stages of the mid-Cretaceous Period. Carcharodontosaurus may have been as large or slightly bigger than the dinosaurs of the genera Tyrannosaurus and Giganotosaurus, but not as large as Spinosaurus. The genus Carcharodontosaurus is named after the shark genus Carcharodon (itself named from the Greek ? karcharo meaning "jagged" or "sharp" and odonto meaning "teeth"), and sauros, meaning "lizard" — "Carcharodon lizard". Carcharodontosaurus includes some of the longest and heaviest known carnivorous dinosaurs, with various scientists proposing length estimates for the species C. saharicus ranging between 12 and 13 m (39 and 43 ft) and weight estimates between 8 to 9 tons.

[Godzillasaurus]

Sarcosuchus wins. Both its jaws and teeth suggest that it was very well adapted for clamping down on large animals with immense force. Its jaws (specifically its rostrum) were actually quite robust and very generalized, and its teeth, as spike-like as they were, were very similarly designed to modern crocodiles, as they were both thick and conical alike, clearly designed for similar functions of resisting powerful downward forces exerted by the animal's jaws and retaining a stable grip. Because of its general snout and tooth robusticity, it was clearly well designed for taking down large animals and was not very specialized in piscivory. If it was a very specialized piscivore, one would expect its jaws to have been thinner and more gracile (such as having a much less heavily-structured premaxilla), and its teeth being much more slender and less adept at puncturing with large force and causing potential bone damage.

The way I see it, the sarcosuchus would bite its opponent's ankle or foreleg and cause a good deal of tibial or ankle-related damage through the use of sheer crushing, and possibly intense shaking or rolling (although it appeared to have been much less capable of this than something like deinosuchus, as its snout was more slender, but still not weak. Its overall resistance seems quite high actually, as its entire snout was, again, very heavily structured and its rostrum was quite wide). Carcharodontosaurus would have been very ill-adapted for killing such an animal anyway; it would most likely have too many problems penetrating the crocodylomorph's osteoderms alone.

[spinodontosaurus]

How is Sarcosuchus going to get to the ankles without having it's neck or torso lacerated by Carcharodontosaurus' rather large jaws?

Carcharodontosaurus is essentially Scott Hartman's Giganotosaurus with a modified skull; dorsal view of the skull is re-coloured from Theropod's reconstruction. Side view of Sarcosuchus is based on a chart Blaze posted, whilst the dorsal view is from Sereno et al.

Modern day crocodilians are not hugely adept at tackling opponents of similar size (both of these would be in the region of 8 tonnes) - even those that regularly kill large prey. Smaller prey specialists such as Tomistoma will fare even worse in this regard, and it is these smaller prey specialists that Sarcosuchus is morphologically closest to, at least superficially. Despite being the size of a man, Freshwater Crocodiles are even considered 'safe' to swim with.

Carcharodontosaurus should be able to relatively easily outflank the enormous crocodyliform, and then place a bite. Even if the bite isn't fatal, I would be a significant injury if not crippling considering all the ligaments, muscle and blood vessels that would be destroyed. Sarcosuchus will have a much harder time actually getting a decent bite, due to lower stature and it's un-mobile nature, and even when it does the bite will not be as effective at causing injuries.
Due to this, Carcharodontosaurus wins on land.

[Carcharodon]

Dec 26, 2013 2:41:59 GMT 5 Godzillasaurus said:

Sarcosuchus wins. Both its jaws and teeth suggest that it was very well adapted for both gripping and crushing alike. Its jaws (specifically its rostrum) were very robust in themselves and its teeth, as spike-like as they were, appeared to have been very similarly designed to modern crocodiles, as they were both thick and conical alike. What they appeared to have been very well designed at doing is clamping down with decent amounts of force and retaining a stable grip. Because of its general snout robusticity, it was clearly well designed for taking down large animals and was not very specialized in piscivory. If it was a very specialized piscivore, one would expect its jaws to have been thinner and more gracile, and its teeth being much more slender and less adept at puncturing with large force and causing bone damage.

Sorry but that is just wrong, i don't even know where your getting that from. Sarcosuchus did not have robust jaws, they were rather slender and had rather small teeth that would not create very large wounds. Yes it had a pretty wide rostrum but it is very shallow:

Even modern crocodiles don't take on larger prey, sarcosuchus has proportionally more gracile jaws and smaller teeth than most other crocs so it was clearly not designed for taking on such big prey. In fact its skull and tooth morphology is actually quite similar to that of the false gharial.

Carcharodontosaurus should take this on land imo. Given the crocodylomorph's poor stamina, carcharo could wear down sarcosuchus pretty easily, and then could pin it down with its foot and bite it on the side of the neck (which won't have as much osteoderms), severing the neck muscles sufficiently enough to incapacitate or kill it.

[Godzillasaurus]

Sorry but that is just wrong, i don't even know where your getting that from.

I am not getting that from anywhereÂ… I am using inference and observation to theorize that it was a generalist predatorÂ… Calling me wrong when I have explained to you why that is not the case on Animalia Enthusiasts just proves that you need to try harder.

Sarcosuchus did not have robust jaws, they were rather slender

And I do not see where you are getting that. Clearly, based on morphological features, sarcosuchus was a generalist predator: wide rostrum throughout, bulbous premaxilla (bulla), thick and robust dentition (clearly designed for gripping large animals as opposed to just fish. If it was a specialized piscivore, we would expect its teeth to have been more elongate and slender), teeth that did not interlock, and very generalized rostrum (if it was a specialized piscivore, we would expect its premaxilla area to at least be very specialized as opposed to broad).

and had rather small teeth that would not create very large wounds.

Umm, when did I say that it had to create large wounds? Clearly, its conical teeth were not designed for cutting and ripping but rather gripping and crushing. The sheer impact in the event that it manages to bite its opponent's would likely do good amounts of internal skeletal damage, as that is what generalist crocodilians are more than capable of; its teeth would be supplementary here. And shaking is a possibility as well, as its rostrum seems perfectly adapted to withstand such forces, considering its impressive constant width.

Yes it had a pretty wide rostrum

Yea dude, that is what makes it robust in the first place...

but it is very shallow:

So is that of the American alligator, and that thing has a VERY weak rostrum 

Even modern crocodiles don't take on larger prey

sarcosuchus has proportionally more gracile jaws

It had proportionally more elongate jaws that did not end in a point. That does not mean that they were more gracile. In fact, its overall robusticity seems quite similar to that of the saltwater crocodile, actually.

smaller teeth than most other crocs so it was clearly not designed for taking on such big prey

Its premaxillary teeth were actually quite large. So no, not ALL of its dentition was shorter. But even then, tooth size is not a very good indicator of what kind of prey and what killing style an animal utilized, at least in comparison to tooth shape. Sarcosuchus actually appeared to have been very well adapted for killing large animals, for the reasons that I stated above. If it was a specialized piscivore, we would expect its rostrum to be much thinner and be quite pointy, and we would expect its dentition to be much more slender and specialized. Sarcosuchus lacked all of these traits and instead had a very wide rostrum, a wide premaxilla, and very thick and spike-like dentition. Put two and two (or rather three and three in this case) together.

In fact its skull and tooth morphology is actually quite similar to that of the false gharial.

Its skull and tooth morphology is actually quite different from the false gharial, and instead implies more generalist feeding behavior. Its snout was much more robust (it was so much wider and more generalized), it did not end in a point (and was actually rather bulbous at the tip of both the rostrum and mandible alike), its teeth were so much more robust (they were built more like stout spikes as opposed to slender needles), it had a constant large-degree width throughout, and its teeth did not interlock. The false gharial is a decent analogy, but it seems far closer to the saltwater crocodile in terms of robusticity and build, actually. Sarcosuchus was clearly even so much more robust in terms of rostrum build than even this false gharial specimen:

Given the crocodylomorph's poor stamina, carcharo could wear down sarcosuchus pretty easily, and then could pin it down with its foot and bite it on the side of the neck (which won't have as much osteoderms), severing the neck muscles sufficiently enough to incapacitate or kill it.

How is Sarcosuchus going to get to the ankles without having it's neck or torso lacerated by Carcharodontosaurus' rather large jaws

The killing style that you are proposing implies that such a mechanical disadvantage would be able to easily sever the crocodilymorph's and be able to effectively sever its spinal cord. Carcharodontosaurus was designed for killing particularly taller animals (specifically sauropods), and a quick killing style that it would have utilized to cause spinal damage was the hatchet-bite technique to attack an animal's back with a large amount of downward force. This would not work here and there would likely not be enough driving force behind such a bite.


Quote: Sarcosuchus will have a much harder time actually getting a decent bite, due to lower stature and it's un-mobile nature, and even when it does the bite will not be as effective at causing injuries.

Carcharodontosaurus was much better designed for creating broad tissue and musculature damage. With sarcosuchus it is more the direct opposite. Its snout was clearly very well constructed to withstand stress and exert it, its premaxilla was nowhere near specialized and would have instead served as a decent "hook", and its teeth were far more robust in overall build designed to pierce with intense amounts of force. Even though its posterior dentition was not actually that large in size, their build is still quite reminiscent of that of stout spikes and they were still very strong and robust, capable of dealing intense amounts of leg damage with precise and powerful biting.

[Godzillasaurus]

Check out this paper by Sereno, Larsson, and Sidor: ecosystems.wcp.muohio.edu/studentresearch/costarica02/crocodiles/articles/dinoeatingcroc01.pdf

I quote it (this is one of the sources in which my plights originate from, although a lot of it is also simple observation):

"Several of these jaw features characterize S. imperator (3) and contrast sharply with the proportionately narrower snouts and more elon- gate, interlocking teeth of extant crocodylians that are primarily ichthyophagous (4 ). Terres- trial mammals comprise a substantial propor- tion of the diet of large extant crocodylids such as Crocodylus niloticus (4). Adult S. imperator may well have had a similar generalized diet that included large terrestrial prey such as the abundant dinosaurs that cohabited the region."

[blaze]

Sarcosuchus skull at the same DCL as a generalized drawing of a Saltwater crocodile head modified to fit Lolongs proportions.

Correct me if I'm wrong but aren't underbites a characteristic of animals that eat mostly fish? due to its size Sarcoscuhus would have hunted big fish though. There isn't any biomechanical study of the effects of Sarcosuchus bulla to its bite but I guess it will be detrimental when biting, for example, the leg of a dinosaur, most of the bulla will not be covered by the lower jaw and I imagine the clash of the bulla with anything with force will put great stress on the maxilla-premaxilla articulation. The only mention I've seen of why is there was in the conference abstract Moreno-Bernal (2007).

This is what he says about this (from an extended version he uploaded on Scribd):

Gigantism in crocodilians and other reptiles implies higher and more stable body temperatures, with a risk of overheating, and reduced basking habits 8'9'10(Colbert, 1946; Grigg, et al, 1998; Seebacher, et al, 1999). A head- body temperature gradient has been observed in some extant reptiles, which strongly suggests that physiological mechanisms are involved on avoiding brain overheating11. Huge nares seen in giant fossil Crocodiliformes such as Sarcosuchus, Mourasuchus amazonensis and Purussaurus could have been related with a heat exchange mechanism.

So, mature Sarcosuchus got wider snouts but they were still considerably shallow, while the increase in size of the bulla could be the development of that heat exchange mechanism which became necessary at the larger body sizes attained by adult Sarcosuchus, the increase in width of the snout could even be in response to supporting the bulla rather than an adaptation for proportionally bigger prey. This is all speculation of course.

[theropod]

Very interesting.

Godzillasaurus: I don't think anybody denies that Sarcosuchus was an opportunist and not just completely piscivorous. But contrary to what you stress, it's skull is not hugely robust. It's not even close ton being comparable to salties, but rather, as I already pointed out some time ago, to Mecistops cataphractus, which it actually shares many morphological traits with. I also don't doubt it had a massive bite force, but that alone does not make for a particularly effective bite.
I think it fed on large fish and mid-sized dinosaurs, a diet broadly overlapping Spinosaurs'. It does not appear to be a specialized macrophage (relatively of course) the way Broad-snouted extant crocodilians can be.

[blaze]

I just read Erickson et al (2012) again, I had missed this even though it's the beginning of the discussion section lol

The results of our investigation into the biomechanics and evolutionary ecology of crocodilian feeding revealed a number of unexpected findings. We found negligible support for the commonly held view that bite forces correlate strongly with rostral form – a proxy for strength. Rather, bite forces vary independently of rostral morphology, so much so that in some cases same-sized taxa from the extreme bounds of crocodilian rostal morphology and dietary ecology (e.g. the slender-snouted, Crocodylus johnsoni and robust-snouted, Caiman latirostris; Figure 1) show “pound for pound” comparable molariform bite forces (Figure 3A). During cladogenic events, when rostral form was modified into different types (presumably to allow access to different prey), bite forces were just as likely to increase as decrease.

Our findings suggest that for crocodilians of similar body mass, the same absolute bite forces will be generated at equal distances from the quadrate-articular joint. A consequence of this is that more slender-snouted forms will at the same time experience higher stresses to their jaws since they have lower area moments of inertia with which to resist bending. Furthermore, since they have relatively longer snouts, equal loads applied at the tip of the jaws will lead to higher absolute bending moments than in shorter-snouted forms. This begs the question: How do slender-snouted species sustain bite forces typical of more robust-snouted crocodilians? We suspect the answer lies primarily in their prey selection. They target small prey relative to their size (e.g. fish and crustaceans, and/or birds and small mammals by the larger species) whose low inertia contributes little to resistance forces. It is also plausible that their jaws experience stresses closer to rupture strength (i.e. lower safety factor [24]) during feeding than the other ecomorphs. This is certainly the case during other behaviors such as fighting and defense, where they show a much greater propensity to sustain broken jaws [25].

Bold mine.

So while Sarcosuchus could bite as hard (at the same distance from the articulation) as other giant crocodilians of its size (be it 8 or 5 tonnes) that doesn't mean that its snout was able to resists the same forces as those of shorter snouted forms so while snout shape is not indicative of biteforce it does suggests us what they were hunting, giving how Sarcosuchus has a rostral proportion similar to those of the slender snouted crocodile and the freshwater crocodile, analyzing their diets could give us insight into how big, proportionally, was the prey of Sarcosuchus. I agree with theropod, it probably fed on large fish and medium to small dinosaurs.

Biting Carcharodontosaurus will cause damage to the theropod but it will probably come at the risk of breaking its own jaws.

[Godzillasaurus]

I don't think anybody denies that Sarcosuchus was an opportunist and not just completely piscivorous

Chief Carnosaur does...

But contrary to what you stress, it's skull is not hugely robust. It's not even close ton being comparable to salties,

The picture that Blaze posted talks about Lolong, not salties in general. Of course it is not THAT close to salties in that realm, but it was certainly a good deal more generalized than what some might expect. Sarcosuchus still had a conparably robust rostrum in comparison with mainly piscivorous species. When comparing it to something like the false gharial, sarcosuchus possesses so many more generalist adaptations: wider and more robust snout overall, more robust premaxilla (bulla area), more robust dentition, and its rostrum doesn't end in a point but is rather more bulbous at the tip. Certainly, its rostrum was more elongate and slender in comparison to generalist crocodilian species (such as the saltwater crocodile), but it was still very robust in its own regard, and it implies a generalist lifestyle.

So, mature Sarcosuchus got wider snouts but they were still considerably shallow, while the increase in size of the bulla could be the development of that heat exchange mechanism which became necessary at the larger body sizes attained by adult Sarcosuchus, the increase in width of the snout could even be in response to supporting the bulla rather than an adaptation for proportionally bigger prey.

The bulla seems actually to be quite a decent region to use in killing; it is quite robust itself (in mature animals) and holds the largest and most heavily-built dentition present in the maxilla hands-down. Based on its robusticity, it appears to have been very useful as a "hook" in the act of predation on dinosaurs. Its resistance here is being underestimated. Of course, that area would have the least force driving it (as it was obviously at the tip of the rostrum, where the bite force is most subtle), but that area was certainly not specialized in piscivory and was in fact very heavily built.

but that alone does not make for a particularly effective bite. 

In sarcosuchus' case, its ability to crush is supplementary to the actual damage done to large terrestrial animals. It likely killed by drowning, as its teeth were conical and clearly designed to grip (although they, being as thick as they were, would be complementary to any crushing damage done) or by lateral shaking in the event that it catches a small enough prey item to lift up that cannot fit down its throat. Sarcosuchus did not need an effective bite overall, just a powerful one (and strong jaws) to grip large animals.

I think it fed on large fish and mid-sized dinosaurs, a diet broadly overlapping Spinosaurs'. It does not appear to be a specialized macrophage (relatively of course) the way Broad-snouted extant crocodilians can be.

While I do agree with you, it was wayyy more generalized in terms of snout robusticity than spinosaurus and its closest kin (all spinosaurids in general). Its rostrum was clearly much more robust (although, as I have said in the past, spinosaurus had a very robust rostrum of its own. But it still paled in comparison), as it was more wide, and was clearly better designed for crushing. Sarcosuchus was likely more of a generalist predator than spinosaurus.


Quote: that doesn't mean that its snout was able to resists the same forces as those of shorter snouted forms

Of course not, but the overall morphology of its rostrum implies that resistance as a whole was likely not that much of an issue, at least as much as you guys are implying. One thing for sure is that its resistance would definitely be much higher than that of more specialized animals such as mecistops, tomistoma, and spinosaurus as it was much more broadened dorsally than the rostra of all those genera. Its impressive rostrum width as well implies a strong proficiency at exerting crushing forces (not as proficient as an animal like deinosuchus for example, however), so resistance as a whole seems to be quite high for sarcosuchus.

Sarcosuchus in no way possessed a very specialized snout; it was relatively elongate, but it was still very broad and generalized.

[Carcharodon]

Dec 27, 2013 2:41:34 GMT 5 Godzillasaurus said:

I don't think anybody denies that Sarcosuchus was an opportunist and not just completely piscivorous

Chief Carnosaur does..

Since when did i?

[theropod]

blaze: Depends on where it bit. I could still see a bite to the foot or lower leg being quite effective for example, it could crush the structure, or at the very least puncture (weaken) it and rip apart important connective tissues, and in the case of movements it's jaws don't have to remain still but can release it again or move. Such a bite would certainly be crippling and could decide such a confrontation.
The problems ensue when gripping a region with a high mass, that can excert a great amount of force on it.
For example I would see it having some serious trouble (hypothetically, since it won't be able to bite that anyway) biting a big theropod in the axial region or proximal hindlimb and hauling it into the water to drown it, or using torsional forces to dismember it.
Another problem is that less risky-to-bite regions of the theropod are out of reach, fast moving or both, and a 7-8t crocodilian won't be making particularly athletic maneuvers on land (not just because it's large and in a terrestrial environment, but simply because it has short semi-erect legs of comparatively low efficiency in terrestrial locomotion, and a huge weight distributed over a very long body and beefy tail lasting on them).

The combination of it's jaw geometry and it'slocomotive system with it's great mass imo don't make it what one would call a very effective fighter on land, unlike Carcharodontosaurus, which certainly was both an agile and a deadly animal for something so huge.

Godzillasaurus: It's also very shallow compared to Spinosaurus...
Yes, it's wider, and I'm indeed suggesting it had a (way) stronger bite force, one of the strongest among terrestrial animals (because, as blaze has shown, in crocodilians bite force does not appear to be strongly linked to snout morphology, while I suppose that's not the case in other animals, even if superficially similar).
But bite force alone is not always that indicative of killing abilities (as I explained I think Spinosaurus didn't just kill the same was as crocodiles do, and thus also developed its different adaptions) or ecology.

and it seems the bulla is formed by the premaxilla. A strong force excerted with it (not saying it wouldn't be a very effective hook tough, since that's really a perfect purpose for it and unidirectional pulling may be easier to withstand) would cause extreme stresses of the premaxillonasalomaxillary (?my new favourite word!) articulation.

[blaze]

theropod
True

Godzillasaurus

That the biggest teeth are found in the distalmost part of the snout is similar to a feature present in the gharial and the freshwater crocodile, whose most prominent teeth are found in a more rostral position than in other crocodilians (Erickson et al. 2012), the biggest teeth in generalist crocs are actually in the middle of the snout. The arrangement of Sarcosuchus is almost exactly the same as in Terminonaris, which also has a hook-like premaxilla and conical teeth, which suggest is not an adaptation for bigger prey, though it is true that Terminonaris lacks the increased with of the premaxilla.



But large individuals of Gharial also have enlarged premaxilla as you can see above (and looking at photos on the internet), the skull of the juvenile Sarcosuchus actually looks a lot, proportions-wise, like that of the large Gharial also figured, it is important to point out that Sarcosuchus is not alone in getting a broader, more robust skull with size, this is true for all crocodilians including longirostrine forms as the gharial and the false gharial.

Another point that distinguishes Sarcosuchus from generalist crocs is the number and size of the teeth, nile and saltwater crocodile have about 14 maxillary teeth, slender snouted and freshwater crocodiles too, gharials have about 23 but Sarcosuchus has 30 and they all are proportionally small. I've looked at the teeth in large individuals of several of the "piscivorous" crocodilians and only the gharial retains needle-like teeth at large body sizes, the others have teeth that look superficially like Sarcosuchs. This, along with it's rostral proportion indicates that Sereno et al. (2001) conclusion could be summarized as follows:

We conclude that Sarcosuchus was a giant, generalist, dinosaur-eating crocodiliform because its snout morphology is not exactly as in the gharial or false gharial, we however, will not realize comparisons with semi-piscivorous taxa like the slender snouted crocodile or the freshwater crocodile.

Also the bulla is not a solid, robust piece of bone, it's mostly hollow, housing Sarcosuchus's enourmous nose.

There's nothing wrong with using lolong, it's a perfect example of a fully grown saltwater crocodile, in that case should we use the gharial-like skull of the juvenile Sarcosuchus as a representative of Sarcosuchus? if you see a photo of an skull from a saltie or a nile crocodile and it looks narrow and shallow it is pretty much a given that is either a juvenile or small, still actively growing adult, which will be hunting mostly fish anyway.

[Godzillasaurus]

It's also very shallow compared to SpinosaurusÂ…

I realize that, but spinosaurus had a much more gracile and specialized rostrum by comparison. It was much thinner dorsally and was not designed for crushing, but rather gripping fish solely. By comparison, sarcosuchus clearly had the much more robust and generalist-based rostrum. In sarcosuchus' case, it remains similarly wide throughout and is characterized by a particularly blunt tip. Whereas spinosaurus, with its much more gracile and pointed rostrum, was more specialized in quickly snapping its jaws in an aquatic environment to catch fish. By comparison, spinosaurus did not have nearly as robust of a rostrum as sarcosuchus did.

and it seems the bulla is formed by the premaxilla. A strong force excerted with it (not saying it wouldn't be a very effective hook tough, since that's really a perfect purpose for it and unidirectional pulling may be easier to withstand) would cause extreme stresses of the premaxillonasalomaxillary (?my new favourite word!) articulation.

With such a constantly wide and generalized rostrum, sarcosuchus would likely have small issues with resistance. Its rostrum, being very constantly wide and broadened, would have had little issues dealing with lateral stress and implies that this animal was very adept at crushing. In that case, high-degree dorsal resistance would also be a necessity, and it would thus be possessed by the animal. I am really bad with physics and "breaking points", so don't judge me on this. 

That the biggest teeth are found in the distalmost part of the snout is similar to a feature present in the gharial and the freshwater crocodile, whose most prominent teeth are found in a more rostral position than in other crocodilians (Erickson et al. 2012), the biggest teeth in generalist crocs are actually in the middle of the snout. The arrangement of Sarcosuchus is almost exactly the same as in Terminonaris, which also has a hook-like premaxilla and conical teeth, which suggest is not an adaptation for bigger prey, though it is true that Terminonaris lacks the increased with of the premaxilla.

One thing that you must remember though is that, aside from tooth arrangement, sarcosuchus' tooth and snout morphology suggests that it was a generalist predator to say the very least. Specifically, the premaxillary teeth found in sarcosuchus (along with all dentition posterior to it) are very robust and are built more like stout spikes, clearly an adaptation for both gripping and crushing alike.

it is important to point out that Sarcosuchus is not alone in getting a broader, more robust skull with size, this is true for all crocodilians including longirostrine forms as the gharial and the false gharial. 

The main factor in this regard that sets sarcosuchus apart from those two animals is the extant of which its snout is broadened. Regardless of snout robusticity in juvenile animals (which, as you said, is very specialized for piscivory. You can see it in Part A of the picture taken from the paper that you posted), that of mature animals is actually very high by comparison to both the Indian gharial and false gharial, and even quite high in general. Sarcosuchus' rostrum (after the animal has reached adulthood) is so much broader and more robust than those two species, to an actually quite high extent.

I've looked at the teeth in large individuals of several of the "piscivorous" crocodilians and only the gharial retains needle-like teeth at large body sizes, the others have teeth that look superficially like Sarcosuchs

I wouldn't say that. As I have pointed out above, sarcosuchus possessed much more broad and robust dentition that would have fared better in not only the taking down of large animals but also the action of crushing. In sarcosuchus, its teeth clearly were not very well designed for piscivory, as they were not very slender. Slender-snouted crocodile species possess far more specialized dentition overall.

Also the bulla is not a solid, robust piece of bone, it's mostly hollow, housing Sarcosuchus's enourmous nose.

Of course not, but that does not completely denote the fact that this area in sarcosuchus was still very broadened and robust in its own regard. Just the sheer fact that it anchored such large premaxillary teeth alone indicates that this area was not weak at all, as biting an animal with that area would be risky in regards to breaking (if sarcosuchus had such a weak premaxilla area, this dentition, which was clearly designed for generalist feeding behavior, would be practically useless). Of course, we know that its entire rostrum as a whole was most likely very resistant (given its impressive width and generalized structure), let alone the much more broadened bulla region.

Since when did i?

I quote you:

"Even modern crocodiles don't take on larger prey, sarcosuchus has proportionally more gracile jaws and smaller teeth than most other crocs so it was clearly not designed for taking on such big prey."

[blaze]

The teeth of Sarcosuchus are conical, that's it, Sereno et al. (2001) describes them as stout but that doesn't tells us much and since they kept to themselves any comparisons between the teeth and those of generalist crocodiles I decided to use some photographs to get some measurements, I used the cast of the skull made by Sereno's team (and scaled it to the size of the largest skull) and a photo of the largest saltie skull.

The biggest teeth Pmx4 and Mx10 have crowns about 7cm long, the base of Pmx4 is about 4cm wide while the base of Mx10 is 3cm, most other teeth are between 3 to 4cm long and around 2cm wide. The saltie, biggest teeth is Mx4, about 6cm long and 3cm wide, most other teeth are 3 to 4cm long and about 2cm wide. If the teeth of Sarcosuchus were adapted for taking on (proportionally) big prey why aren't they shaming those of the saltie?

Yes, the teeth are not needle-like but that doesn't imply big game generalist, this are the characteristics that distinguishes Sarcosuchus from generalist like the Saltie and the nile crocodile: a high number of relatively small and similarly sized teeth, an underbite, a proportionally shallow and slender snout. The last point is exemplified by its rostral proportion which is comparable to that of the freshwater crocodile and the slender-snouted crocodile, for comparisons with the nile and saltwater crocodile, at the same length their snouts will be almost twice as wide as that of the largest Sarcosuchus.

The bulla is the odd one out but we do not really know its function or its effects. I don't know why are you interpreting the width of the bulla as indicating a robust and broad snout overall. At the middle, the snout is only 10cm in depth and is only 31cm wide, this measurements are about the same or lower than those of Lolong and C. thorbjarnarsoni respecitevely, skulls which are about half as long and from individuals a fraction of the mass. In fact, the total articulated height of the head (skull and lower jaws) of the largest Sarcosuchus and largest C. thorbjarnarsoni are pretty much identical (39cm vs 38cm) and the widest tooth in the largest C. thorbjarnarsoni is also 4cm like in the largest Sarcosuchus.