Spinosaurus aegyptiacus vs Carcharodontosaurus saharicus

[creature386]

I calculated roughly 2,1 m, by scaling it to 16 m. 16/11*1,43=2,08

[theropod]

I don't quite understand what you did. 1.43 is the amount the 80cm humerus is bigger than Suchomimus' (80/56), why did you multiply it by the amount Spinosaurus' estimate is bigger than Sucho's?

[creature386]

Sorry, I thought 1,43 is the forelimb length.

[theropod]

We'll have to look at the limb proportions more closely, it should be clear that what I used was a mere approximation.

[Godzillasaurus]

Spinosaurus' snout would have actually been far more resistant to lateral forces experienced by gripping large animals than that of carcharodontosaurus. Despite being a lot shallower and narrower than the snout of carcharodontosaurus (it lacked the same dimensions), the latter animal killed by vertical slicing/ripping, and its rostrum was quite voluminous but yet quite weakly-built and sparse (it was not very heavily-built and was not designed for crushing or gripping alike).

Spinosaurus, however, was in possession of a far more heavily-constructed snout that were far better designed for gripping and withstanding pressures experienced in fishing. Basically, they were very much stronger and far better adapted for gripping large animals than those of carcharodontosaurus; the sheer stress from gripping would very likely damage the latter's snout heavily due to its lack of gripping morphology, low lateral resistance (but yet very high vertical resistance), and lightly-built rostrum (by comparison to the denser rostrum of spinosaurus that was designed for multidirectional resistance as opposed to only laterally or vertically. Just something to think about; bigger jaws do not necessarily merit a more powerful bite and/or better resistance to force, as this is entirely relevant here.

[theropod]

Carnosaur skulls are deep, as you just pointed out, which equals being thick in one dimension, and the only carnosaur studied in this regard turned out to be highly resistant to vertical stress. I highly doubt spinosaurs can compete in this regard, but their jaws may be more resistant to torsional loads due to them being less pneumatic, and also due to the more conical tooth design.

Since they obviously have jaws built for gripping at least moderately large animals it's out of the question they were not weak.

[Godzillasaurus]

Carnosaur skulls are deep, as you just pointed out, which equals being thick in one dimension, and the only carnosaur studied in this regard turned out to be highly resistant to vertical stress.

Of course, but I was referring to the claim that allosaur jaws were more resistant to stress overall (as in multidirectional) and that spinosaurus' jaws were weak and could not resist very much stress. This is obviously not true, as I have pointed out.

Since they obviously have jaws built for gripping at least moderately large animals it's out of the question they were not weak.

That is my point. By comparison to carcharodontosaurus' rostrum, spinosaurus was a very good deal more resistant in terms of gripping resistance (it was well designed for such, the former simply was not and would likely have its very lightly-built structure damaged in the process via fracturing.

[theropod]

You mean the opposite of "impressive vertical stress". Having a lot of stress is a bad thing. No it does not automatically, but it's probably this way in most animals, and very probably in carnosaurs.

Overall resistance is a complicated measure, but I doubt overally Spinosaurus' cranium was as resistant as Carcharodontosaurus', it would have to be extremely strong laterally and torsionally for its dimensions to make up for its lack of depth and width.

The last sentence was actually meant to apply to Spinosaurus.

Carcharodontosaurus' jaws did not grip, and while I think they would have excerted impressive (3t bite force + cervical pulling and depression) forces perpendicular to the jaw surface (hence they were certainly strong), they did not need or get the oppurtunity to hold onto something, because the teeth were built for slashing and slicing large wounds, not puncture and hold.

Obviously that's a jaw design that can cause much more damage, but those of Spinosaurus would come in handy to catch and immobilise an opponent (as I already explained together with the forelimbs), or simply be in the way of a bite aimed at the throat.

[Godzillasaurus]

The last sentence was actually meant to apply to Spinosaurus.

Sorry about that. I read it too fast. I thought you were talking about carcharodontosaurus.

Overall resistance is a complicated measure, but I doubt overally Spinosaurus' cranium was as resistant as Carcharodontosaurus', it would have to be extremely strong laterally and torsionally for its dimensions to make up for its lack of depth and width.

Actually, spinosaurus' snout seemed far more resistant than the latter animal; so what if it was smaller in multiple dimensions, it was well structured for gripping while carcharodontosaurus simply was not. The ability for it to effectively grapple a decently-sized prey item with little risk of injury heavily rivals that ability of carcharodontosaurus, as a much denser rostrum that was indicative of such feeding behavior (it being very slender and specialized in spinosaurus for reduced drag in water) would naturally be far better suited for gripping, as their overall multidirectional resistance would be far better designed for it as opposed to a considerably more voluminous but yet generally "spacey" and lightly-built rostrum that was highly reinforced dorsally but yet lacked in any exceptional width and lateral resistance (let alone a killing style that simply does not require enhanced lateral resistance. Use this for reference:

Carcharodontosaurus' jaws did not grip, and while I think they would have excerted impressive (3t bite force + cervical pulling and depression) forces perpendicular to the jaw surface (hence they were certainly strong), they did not need or get the oppurtunity to hold onto something, because the teeth were built for slashing and slicing large wounds, not puncture and hold.

That is true, however the only thing missing there is an "it was not adapted and designed for gripping". I have explained this you to previously; its rostrum was very well designed for both exerting and resisting vertical forces, but it would be in danger of being heavily damaged through the stresses found in gripping (this rather applies to all allosaurus as well) because of a simple lack of any adaptations for it and the presence of a very lightly-built rostrum.

[theropod]

Greater cross-sectional area is what you are talking about.
The question is whether it being more solid (in terms of the extend of internal sinuses) is really enough to make up for significantly smaller lateral and dorsoventral widths of the structure as a whole, whether in combination it could really match the stress resistance.

Since we lack data on the extent of this difference (in fact we don't have cross-sections of either), that's entirely speculative on your part thus far. Sure, Spinosaurus had a capacity of gripping large animals with its jaws, but that doesn't automatically mean its skull is as strong or stronger. It would be proficient at gripping, and it is certainly more so than Carcharodontosaurus, but that rather ows to the tooth design (give Carcharodontosaurus conical teeth and it may be good at that as well, but its jaws wouldn't be very helpful for their actual purpose any more).

What I think we can expect (and in fact, see) is that it is less reinforced in one direction but rather generalised to resist multidirectional loads.

compare both dorsal and lateral views here:

(you can ignore the postrostral part in Spinosaurus since its not known)

[Godzillasaurus]

The question is whether it being more solid (in terms of the extend of internal sinuses) is really enough to make up for significantly smaller lateral and dorsoventral widths of the structure as a whole, whether in combination it could really match the stress resistance.

As I have said before, what matters here is common prey type and killing style. One animal was far better designed for gripping and likely enhanced strength in that regard, as evidenced by its comparably more robust snout, while the other animal was poorly adapted for such and instead possessed a far more fragile snout (as with pretty much all allosaurs) and a much deeper profile. The notable density of spinosaurus' rostrum is fundamentally what makes it generally a robust structure in the first place, at least in combination with its considerable width and depth in the centralmost portions of the structure. It was most likely much less prone to fracturing based on what morphological evidence that we have, and based on its ecology.

Since we lack data on the extent of this difference (in fact we don't have cross-sections of either), that's entirely speculative on your part thus far. Sure, Spinosaurus had a capacity of gripping large animals with its jaws, but that doesn't automatically mean its skull is as strong or stronger. It would be proficient at gripping, and it is certainly more so than Carcharodontosaurus, but that rather ows to the tooth design (give Carcharodontosaurus conical teeth and it may be good at that as well, but its jaws wouldn't be very helpful for their actual purpose any more).

The thin shape of spinosaurid jaws are, first and foremost, an adaptation for piscivory. Similar to modern slender-snouted crocodilians, they were thin so that they would have as little drag in the water as possible when catching fast-moving fish (but in this case, they were very large and powerful simultaneously). I say again, the capacity for which spinosaurus can maintain a strong grip is attributed to snout and tooth morphology alike. Not only was its snout very robustly-built and in possession of reasonable dimensions as an adaptation for increased resistance, but its teeth were conical and were designed for piercing deeply. Carcharodontosaurus on the other hand, killed entirely different animals in an entirely different way; meaning that lateral resistance was far less necessary; and it clearly was likely not as prominent as in the former creature. The main reason why it was so impervious to vertical stress was the fact that its skull was very deep and DESIGNED FOR SUCH, not because it was heavily built.

If carcharodontosaurus was adapted for gripping in the same fashion as spinosaurus, we would expect its snout morphology to have been much more reminiscent of those of spinosaurus and related genera (I am not talking about the family spinosauridae as a whole, as the gripping adaptations are less prominent in baryonychines) including being characterized by a particularly less lightly-constructed and sparse build (generally denser), reasonable dimensions for decent strength multidirectionally, and a much more reminiscent tooth design. You simply cannot "give" carcharodontosaurus the same tooth morphology for it to be efficient at gripping; you would more-so also expect its snout to be more well-suited for the "job" simultaneously.

What I think we can expect (and in fact, see) is that it is less reinforced in one direction but rather generalised to resist multidirectional loads.

Are you talking about spinosaurus or carcharodontosaurus?

[theropod]

I don't deny that Spinosaurus probably has a denser skull than a carnosaur (or tyrannosaur) would, in fact I recall having read about this. But the extent is an unknown.

The last thing referred to Spinosaurus of course.

[dinokid202]

carcharodontosaurus wins easily. spinosaurus was a fish eater and was smaller (carchy is the second biggest carnivorous dinosaur after only giganotosaurus). spinosaurus ate trout-sized fish while carchy took down sauropods!

[Carcharodon]

Spinosaurus is actually the largest of theropod dinosaurs. The second is either carcharodontosaurus, giganotosaurus, t.rex or mapusaurus.

But anyways spinosaurus should be the favorite over any other theropod due to its sheer size and strength.

[Deleted]

Jan 22, 2014 4:16:35 GMT 5 dinokid202 said:

spinosaurus ate trout-sized fish

Are you f***king kidding me.



How the heck is a multi-tonne dinosaur gonna live on fish that small!? I know that dinosaurs are more energy-efficient than mammals, but Spinosaurus as a predator of trout-sized fish? I can't believe that someone would say that in WoA of all places! This is not Youtube, this is a place for quality scientific discussion.

I thought I would never have to do this here, guess I was wrong...