Spinosaurus Jaws Discussion

Interesting. Can't say I agree entirely, but there are some good points. Does a 4 ton PSI bite force sound reasonable to you?

Agree entirely on what? This is all fact-based, not opinion-based. Anyway, 4 tons seems too high for spinosaurids in general. They did not require such powerful bites, given their primary diet of fish, and nor is such a powerful bite even confirmed given their cranial morphology (it has been studied before. Sakamoto said so here: http://www.askabiologist.org.uk/answers/viewtopic.php?id=9468 and I believe in a paper too). 2 tons seems more reasonable

On theses facts. I agree with most of it (opinions, just my opinion), but not all. I never thought that 4 tons would be a high estimate (Rex Vs Spino from the summer, anything negative against Spino was an insult and would be dealt with by rage, I always thought three tons before that). 

This is still quite interesting, I'll re-read to make sure I didn't miss anything. Did you see the discussion about an article that stated Spino was 55% the weight of Rex (about 4.4 tons)?

Here's the link:

Spinosaurus weight discussion

No, I did not read that yet. 4 tons as a bite force is unlikely for spinosaurus. It has been confirmed that, when basing it off of baryonyx, its bite force would not be very monstrous (strong, but not excessively strong), because we don't have much of spinosaurus towork with in this regard. Regardless of robusticity, its jaws and teeth were designed to grip and not crush.

Note that bite force does not depend on snout shape (hence why all crocodilians tend to possess similar biting forces), but the ability to crush does

I know. I was just saying my opinion (and people on team Spino got mad at me for giving it such a "low" bite force).

OH god...

Lets make a rule... A very good rule... The golden rule about spinosaurus and tyranasaurus rex... 

The info you provide can not be biased or opiniated, If you can please tip toe around the subject (When FBR first started it kicked up SO MUCH CONTREVERSY... which is werid becasue it was fact vs oppinion...) 

spino and rex is the most touchy subject ever... 

However this is fairly good Info, and i feel its reliable to an extent...

Also, heres a question for you to ponder, Would a fishing dinosaur have grown to such big of size just to hunt fish?

Definitely not. Spinosaurus, as stated, was characterized by a particularly dense rostrum, which means that overall strength would probably be much greater in this case than many believe. But yet, this argument is unusual, because it nonetheless was adapted to hunt rather large and powerful fish (trust me, many genera of Cretaceous fish were quite huge), and its morphology corresponds perfectly to their existence. Undoubtedly, being the largest terrestrial predator to have ever lived, opportunist feeding is definitely probable, but it was still a piscivorous creature fundamentally, and it was adapted to cope with that lifestyle

You say facts Godzillasaurus. We can't say facts. There are very few "facts" in paleontology. 99 percent of everything said is opinions and theories.

I've always estimated Spinosaurus' bite force at 4,000 psi. As far as it's teeth go, Spinosaurus' teeth were very straight. Great for grasping, but not tearing(I happen to own my own Spinosaurus tooth and I study it extensivley)...

Spinosaurus tooth

Tyrannosaurus teeth

Allosaurus teeth

There are basically three tooth designs. Gripping(Spinosaurus), slashing/tearing(Allosaurus), and crushing(Tyrannosaurus). Crushing teeth stand up to pressure the best, conical(gripping) second best, and slashing third.

Basically, the three biggest theropods(Tyrannosaurus, Spinosaurus, and Giganotosaurus) have varying bite forces depending on what they hunted and their overall musculature. Spinosaurus and Giganotosaurus had comparable bite forces of 3,000-6,000 psi. Strong, but not for their sizes. Tyrannosaurus came out with a force of 6,800-18,000 psi. 

In the end, Spinosaurus did not have weak jaws, but they really weren't anything special(except for their shape).

Those are interesting Rex Fan. You got Giga and Spino with a bite force of up to 6 000 PSI, and then Rex with more than that as a minimum. And people said we were biased in Rex's favour all the time

I'm never biased(I don't care what people say). I'm just stating opinions and theories(no facts).

I know. I try not to be. Some people are though (you know who I'm talking about. "I'm not going let go of Spino being bigger than Rex in EVERY way, especially weight). New scientific research points in the King's favour though.

I agree with that statement.

Notice how the only people who are online on a daily basis are on team Rex (and we have similar opinions)? Guess that's just the way the cookie crumbles (for now at least, just imagine the population explosion of JW once the first trailer hits the TV screens).

Interesting indeed. There are some statements I agree with, and other wich I don't. But very interesting overall. 

As said before, we can't rely on those "facts" in paleontology, as such things don't exist.

Here I mostly agree with RexFan and MrHappy, and you already know that. 

Also MrHappy, you're right. It'll be something like Godzilla forums those days. Before the trailer: 1-2 topics per day, a few people merely checking the forum. During and after the trailer: BOOOM!!!

I know. 

*Sudden realization* God help us when the noobs start posting on Rex vs Spino and start acting like they know more than us.

We're in the hands of admins :D

That's true. And it's kinda annoying when it happens. But here are some interesting thoughts.

Quote: You say facts Godzillasaurus. We can't say facts. There are very few "facts" in paleontology. 99 percent of everything said is opinions and theories. -Well then I am sorry. I typed too fast

Quote: As far as it's teeth go, Spinosaurus' teeth were very straight. Great for grasping, but not tearing(I happen to own my own Spinosaurus tooth and I study it extensively)…

-That is what I said…  Even though they were not necessarily designed for killing (they were not particularly enlarged, but yet their shape made penetration efficient.

Quote: There are basically three tooth designs. Gripping(Spinosaurus), slashing/tearing(Allosaurus), and crushing(Tyrannosaurus). Crushing teeth stand up to pressure the best, conical(gripping) second best, and slashing third.

-Resistance is not determined by the actual function of the teeth necessarily. But rather their actual robusticity and overall thickness. Spinosaurus general dentition shape was like that of an elongated and conical spike, most adept at piercing deeply into the hide of a prey animal and retaining a stable grip afterwards when struggling with a fish (hence why I also do not think that it was that weak...). BUT that does not mean that they were weak? Heck no! The conical shape is what allows them to grip; thinner-edged dentition would likely fracture too easily.

Quote: In the end, Spinosaurus did not have weak jaws, but they really weren't anything special(except for their shape).

-True. But they were designed for fishing, along with its overall dentition shape. It was special and unique in that regard, as is the spinosaurinae subfamily, and spinosauridae as a whole

Well, Godzillasaurus, they didn't intend that. No one of them hates Spino, on the contrary, is one of our favourite dinosaurs. So neither RexFan, MrHappy, or me hate Spino or think it "DROOLS!".

I can be sure on this, we're not trying anyway to start another Spino/Rex debate, on the contrary, again, we kinda try to avoid that. ;)

I often agree with them, that's what I meant.

And I do not agree on Spino's rostrum being more robust than that of Carcharodontosaurus, for starters. On the rest, I kind of agree with everything.

What would make you think I hate Spino? I saw 4 ton PSI as REASONABLE, you see it as 2 ton PSI. Rex Fan isn't biased, he does research, he knows what he's talking about, so he's not biased, just enforcing his opinion.

Very interesting. Also Spino is actually my favorite dinosaur above all, but T-Rex would be my second, And Rex Fan, you're lucky you have a Spino tooth, and 4 tons PSI is very reasonable.

Quote: And I do not agree on Spino's rostrum being more robust than that of Carcharodontosaurus, for starters.

-Carcharodontosaurus in general actually possessed a very lightly-built rostrum that was relatively narrow (it was exceptionally deep but lacked in any particular especial width) and was poorly adapted for gripping (the same thing goes for its teeth as well). It possessed a very surplus amount of large bodied fenestrae unlike spinosaurus which had a particularly denser and more heavily-constructed. Size or shape =/= robusticity, as spinosaurus' thin and specialized piscivorous snout and dentition was probably not that weak at all, contrary to popular belief. The depth that is present in carcharodontosaurus' rostrum along with its overall robust icing implies that it killed vertically and the laterally compressed profile of its teeth tell us that they were irresistant to lateral stress and only worked well in pulling and vertical actions.

Spinosaurus, however, was far better designed for gripping functions in its teeth and jaws; they faired far better in the resistance needed when catching large and powerful fish by comparison. Carcharodontosaurus was an adapted macropredator, but spinosaurus possessed a far more adept snout and tooth morphology that allowed for high resistance brought up my gripping.

And tyrannosaurus has a rough biting force at around 6 tons (roughly). For spinosaurus to have a bite strength only 2 tons less than this would imply that it was better adapted for crushing than it really was and possessed a very well-structured cranium for such (it likely did not possess the strongest jaw muscles). Spinosaurus did not need such a powerful bite, nor would the lack of exceptional width in its jaws house it. One would expect it to have a very wide snout along with much blunter-pointed dentition, which it did not, if it was a specialized crusher. Its snout was probably quite strong in terms of general balanced strength, but certainly not in terms of being well adapted for crushing

Thanks Gojira2K

Godzillasaurus, I clearly said I was NOT biased. I simply have a hard time believing these jaws...

Could exert pressure much higher than these jaws...

PS- I had made a top 10 highest bite forces list a while ago where I listed Spinosaurus at number 5, so try to call me biased now!

I have a hard time believing that too. Let's get out of the who's biased thing, alright? It's not getting us anywhere, and it's a waste of time.

Im trying to be nice, don't tick me off, I won't put up with it.

@Rexyfan, umm, I never said that spinosaurus had jaws that were as powerful as carcharodontosaurus… But even then, carcharodontosaurus still had relatively weakish-built jaws, as I just pointed out. You are getting overall robusticity and jaw strength mixed up; they are not the same thing. Both carcharodontosaurus and spinosaurus lacked in exceptional biting power most likely, because they did not need it (spinosaurus would have killed large animals probably with the combination of its at least decently vertically resistant rostrum and specialized puncturing dentition, and carcharodontosaurus likely killed using vertical and backward ripping techniques).

But spinosaurus still had generally stronger-constructed jaws and more robust dentition than carcharodontosaurus, as its skull lacked the visible large fenestrae present in that of carcharodontosaurus and its teeth were till very sturdy and were built like erect spikes as opposed to thin steak-knives

Rex fan has a point, Everything in paleontolgy is mostly theroies... BUT... If we began seperating paleontolgy, lets think about the entire world, Most of it is a string of theroies woven together into a nice fine quilt... However There are some frayed and unfinished parts of the quilt which are left unexplained... 

We can conclude all the theroies we like, HOWEVER, we will never know what their exact bite force was, you see we can rebuild muscle onto the skeleton, but thats not acurate, Becasue its a computer program Not actual nature... We can try and rebuild the said creature with DNA, sure why not, HOWEVER, it wont be a dinosaur, it will be a mutated bird or lizard enhanced with dinosaur DNA, to look like our idea of a dinosaur....

My point is, we honestly can't say anything by the book, becasue that book, is very thin with info on these prehistoric creatures... Everything is just an idea...

The line between fact and theroy is very thin, and blurred... 

However, yes, Most dinosaurs are being found to be more "interesting" then originally thought due to the new ideas being brought to the plate... no more then 50 years ago, we still believed they were slow moving lizards...  Thats about as old as doctor who...  Anyways, Theroies are starting to become facts without being proven, which is bad and good, bad becasue its not the exact truth, good becasue it gives us a set up to work on...

Woah Mr Happy, i said i would never let go of that till further evidence, which of right now the evidence is in my favor. Its just like how you guys wont let go of trex being the biggest. And PLEASE, with all of the power invested in you to stop referring to him as the "King". Im sorry, its just one of the things that really gets under my skin because its really seeming to me that you are really trying to make people agree what you think. PS, no anger towards any of you.

Well, let's not get into any Spino vs. Rex discussion, as the theories Godzillasaurus posted are only about Spinosaurus' skull.

This is getting closer and closer to an ugly debate, so please, let's just enjoy those interesting theories, and not start a no-end situation, shall we?

For EVERYBODY  (including me ;) )

@Backinaction, you need to stop dead in your tracks before you start something you cant end

Sorry S-Rex, didn't mean to sound like a jerk. About backinaction, I doubt he knows what he's talking about, and I say "The King," because Rex translates to King, and I like saying King.

About Spino's bite force, I would think it would be pretty strong. Why? Look at a crocodile or alligator of today. They have the strongest bite force of any known animal living today. Spinosaurus was a lot like these reptiles, so there you have it. I don't think it was super strong or anything, just an average bite force among carnivores.

    As far as diet goes, I really hate the theory of Spino sating ONLY fish. How could a dinosaur that big have a diet of 100% fish? I'd say like a crocodile. About 75% fish, and 25% other. Like, at certian times or places, they might eat different things. Take the orca for example. There's about three species of orcas, and each species eats different things, but mostly the same. My point is, Spinosaurus ate mostly fish, but not 100% fish.

For your plight about its diet, I pretty much agree. I must inform you, however, that the fish that likely made up most of spinosaurus' diet were quite large actually (like around 10-20 feet in length, and far heavier than both me and you combined) and their presence in spinosaurus' ecosystem correlated perfectly with its snout and tooth anatomy as well as its impressive forearms tipped with enlarged hook-like claws (they would have been useful as fish hooks)

no one said he ate goldfish mate. i'm pretty sure no one said they ate small fish...yes it ate large fish, Onchopristis wasn't a light weight!  the other fish in the area probably weren't small...and that's a possible reason it got adapted to eating them. CArcharodontosaurus, Sauroniops, Bahariasaurus, and this new abelisaur that i've heard so much about probably competed heavily for the sauropods and hadrosaurs on land. It would make sense for Spinosaurus to look to the water for prey, there's no competition! with the exception of Sarcosuchus of course..

That is basically what I said; spinosaurus was not entirely reliant on fish, but most of its diet is comprised of them. What the guy above me was implying was that spinosaurus was "too large to only prey on apparently small fish". It was simply very well designed for predation on the large freshwater fish that existed in its ecosystem, so naturally that seems to be depending on the whole competition factor.

Animals all have a certain niche by which they live and are adapted to cope with, thus it is no surprise as to why spinosaurus evolved distinctive gripping adaptations from all if not most non-spinosaur macrophagous theropods; as a physical adaptation for its primarily ichthyophagous lifestyle. Just as carcharodontosaurus and bahariasaurus (which was a macrophagous ceratosaur btw) for example were designed for killing larger animals mainly whereas spinosaurus was adapted for fishing. Of course spinosaurus was not preying on goldfish, but in response to the last guy's comment, every animal lives in a certain niche. Take baleen whales for example

yes, exactly. Onchopristis got what? over 15 feet long? with prey that big...of course Spino would evolve to better tackle them. That's something we can agree on Godzillasaurus ;)