Tyrannosaurus rex vs. Giganotosaurus carolinii

[Deleted]

Sept 21, 2013 3:47:03 GMT 5 wiffle said:

How? A higher bite force is never a disadvantage.

I never said it was a disadvantage, I said that raw bite force is not an advantage alone

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It is when the bite force is about 6 times higher.

So are you saying that Tyrannosaurus had a ~120 kilonewton bite force?

I asked Scott Hartman about Giganotosaurus' bite force, and he said that 20 kilonewtons is at the right ballpark for the bite force of Giganotosaurus, I posted such info in the giant theropods overview thread.

A bite force of ~120 kilonewtons would shatter Tyrannosaurus' jaw. That's megalodon-level bite force.

Tyrannosaurus had a bite force estmated at around ~35-57 kilonewtons. That's only ~1.75-2.85 times that of Giganotosaurus.

"Models predict that adult T. rex generated sustained bite forces of 35000–57000 N at a single posterior tooth"

Source: Estimating maximum bite performance in Tyrannosaurus rex using multi-body dynamics

Question: Where did you get the "6 times higher" thing from?

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There's nothing to suggest Tyrannosaurus' teeth couldn't slice, albeit less effectively.

But they aren't really as specialized. And "less effectively" is the keyword(s)

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Great white sharks actually have a fairly significant bite force, well in excess of 1 ton at the posterior jaws.

That's why I said relatively, not absolute. And I refer to sharks in general.

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Furthermore, it is silly to suggest that even Giganotosaurus' teeth have the slicing potential of a shark's.

I just showed the example to show that specialized slicing dentition + wide gape is a devastating combination that shouldn't be downplayed. And if anything, the related taxon Carcharodontosaurus, had teeth that were compared to that of sharks, which gave it it's name.

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So do you suggest Giganotosaurus will have any advantage in that area?

I never said that Giganotosaurus had a mechanical advantage

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Creature386 already cleared the first study up. You only have to look to see that Tyrannosaurus' hips allow for much more muscle attachment. The leg proportions are also more cursorial, and according to Persons and Currie, "...the mass of the M. caudofemoralis was further increased by dorsoventrally lengthening the hemal arches." With that being said, given both the weight and caudofemoralis studies I would not be surprised if Tyrannosaurus' speed were more in line within the 21-22 mph range.

I was only basing off published sources.

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How is it "not really an advantage"? Greater depth perception helps gauge distances and therefore informs Tyrannosaurus more precisely on the matter of exactly how fair it has to charge/lunge to attack, and how much it needs to move to counter or dodge. I would imagine that people would be much more comfortable with Tyrannosaurus' vision than Giganotosaurus' if they were involved in a fight.

And you need agility to actually dodge it. At these sizes, it's really hard to be agile enough. They aren't gonna run circles around each other. Even at the smaller scales where agility is far more pronounced, a crocodile, an animal that isn't known for it's agility, caught a lioness, an animal that is very agile.

[theropod]

I guess I have to post this again, but in case someone is wondering, there is a thread dealing with such subjects:

Comparison of the
cutting ability of fossilised teeth to that of varied replica blades
demonstrated that stout tyrannosaurid teeth (Figure Id) functioned as
pegs with poor cutting ability. Instead, the teeth were used to ‘grip-
rex
and-rip’ prey – the ‘puncture–pull’ feeding hypothesis

Barret & Rayfield, 2006

and

Abler (1992, 2001) modeled the mechanical properties of tyrannosaurid tooth serrations and found that unlike those of the large lamnid shark Carcharodon, they do not function as hacksaw blades. Instead, Tyrannosaurid teeth cut meat more like a dull, smooth blade.

Holtz, 2004

This is not comparable to the cutting ability and consequent evisceration potential of the teeth of lamniforms, komodo dragons or Carnosaurs. It is a payoff. An animal cannot simply have a stronger bite force and do everything else just as well. A stronger bite force for biting through bones requires the teeth, including their carinae, to become sturdier, which also means duller.

btw you are letting youself get fooled by a comparison using the mouth gape to make T. rex' skull look especially big and comparing the biggest T. rex to the smallest (on top of that, inaccurate) Giganotosaurus. I have already replicated that comparison earlier to demonstrate that point.

[theropod]

Weight, no. For brawlers that are incapable or have difficulties attaining quick kills, bodily strength is relevant, but it matters almost nothing here.

If it doesn't, and the first bite is all that counts, why does stronger bite force count for you?

That size comparison I posted. For Giganotosaurus to use its claws while both are in a normal posture, its head, neck, and shoulders would have to warp right through Tyrannosaurus. Even if it reared up, the arms could not reach very far, and any contact would do minimal tissue damage.

It was found that the humerus can swing posteriorly into a horizontal position but can neither swing laterally to glenoid height nor anteriorly much beyond the glenoid. The forearm can approach but not achieve full extension and right-angle flexion. Pronation and supination are precluded by immobility of the radius relative to the ulna. Motion also seems to be restricted at the wrist. The palm faces medially, and digital movement is subtransverse. All three digits are capable of extreme hyper-extension.

onlinelibrary.wiley.com/doi/10.1017/S0952836905006989/abstract

Sufficient movement range to be used, as is consensual for Carnosaurs, for predation.

Because the
majority of carnivorous dinosaurs are bipedal, the forelimbs are free from locomotor
obligations and may be used for prey acquisition. This advantage may have even
selected for a bipedal gate in early Dinosauria (Sereno, 1993). Long, powerfully built
forelimbs of many carnosaurs, ceratosaurs, and herrerisaurids were probably used in prey
handling (Ostrom, 1969a; Sereno, 1993; Holtz, 2002).

D'amore, 2009

That's because they do.

Of course they do!

Tyrannosaurus, I think, had a range of motion of only 40 degrees, and probably could not extend its arms outwards at all (although the effectiveness of such an action if it were somehow possible would be laughable).

Tyrannosaurs have more limited ranges of movement than Carnosaurs, an atrophied brachial plexus and comparatively short and slender forelimbs. Any reason why they are comparable?

Bite force and speed don't matter now?

You don't usually see antelopes winning against lions, do you? Or crocodiles against hippos.

Also, I tought everything behind the cranium was more or less irrelevant (weight, size, arms...), or is this only the case if it's not in favour of T. rex?

Bite force=Quicker kill and much less time to retaliate, whereas speed reduces the window of time to react and counter a charge, and could also prove handy for running away if Tyrannosaurus ever needed it.

bite force=/=quicker kill=/=better weapon

Take a bite to the neck; it would sever the jugular, carotids and vagus nerve. Blood would not reach the brain any more, it would flow away from the brain tough, and the blood loss and shock would come very quickly considering major blood vessels plus important nerves are severed. And even ignoring that, an animal subjected to such a bite would have torn muscles and probably be caught by a pair of powerful arms afterwards...

D'amore, 2009 said:

Bite force only analyzes force unidirectionally, but as shown in this dissertation
there is a large amount of lateral and distal repositioning of the rostrum. The medial-
caudal arc shows dramatic movement of the head, neck and forelimbs when defleshing.
185
This most definitely applies force to its food in a direction other than that of adduction.
Finite element analysis has also indicated that the skull is well built to handle stresses in
the lateral and caudal directions (Moreno et al., 2008). Measuring the strength of the
medial-caudal arc by using a pull gauge should give a more complete picture of
ziphodont function.

When did I saw that?

I meant to say you considered far more important things miniscule. I can still hit a person with one of my eyes closed, the difference is miniscule. Most predators throughout history didn't evolve or need good stereoscopic vision.

On the other hand, what most people are forgetting about is that the direct consequence of lacking/badly developed binocular vision is a wider field of vision, certainly not a mere disadvantage. I'm not saying T. rex doesn't have a bit of an advantage in terms of vision, but nowhere near as notable as many seem to assume it is.

The fossil record indicates that intraspecific fighting was common within Tyrannosaurus.

This was the case with other theropods too, eg. Sinraptor and possibly Allosaurus (there are injuries that could be related to either intraspecific fights or hunting, such as the "Labrosaurus" mandible)

Doing battle with a Triceratops should require faster reflexes than fighting a sauropod. It's like fighting an elephant versus fighting a whale-the elephant is better suited for combat and is faster and more agile, whereas the whale is extremely powerful and can take out just about anything with a single swipe but has numerous exposed areas and a limited degree of accuracy.

and has an extreme bulk meaning there is a much longer struggle rather than a single precise ambush attack ending the fight.

Any evidence for that?

How about a probably much lighter skull (yes, a massive bite force definitely has it's cost)?

How? A higher bite force is never a disadvantage.

If you want to attack a sauropod, it certainly is. like this their bites are both very deadly. Bite force is important to kill something that's very bony, bulky and perhaps armoured-or when an animal is biphyodont and cannot afford loosing part of a more gracile dentition.

It is when the bite force is about 6 times higher.

This is ridiculous, no offence (not that it would matter tough).

Based on results from the same study, T. rex bit perhaps 2-3 times as hard.

There's nothing to suggest Tyrannosaurus' teeth couldn't slice, albeit less effectively.

Which is the point, see the last post. What it would slice less effectively balances what it would crush.

Great white sharks actually have a fairly significant bite force, well in excess of 1 ton at the posterior jaws.

Which is pretty low for an animal their size, a good deal lower than that of a 3 times smaller crocodile (and still, certainly not inferior, are they?). Sharks kill by their sawing motion and very sharp teeth, which are deadly.

Furthermore, it is silly to suggest that even Giganotosaurus' teeth have the slicing potential of a shark's.

Why so?

Studies into the komodo dragon's bite force didn't take neck muscles into account.

they did: www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0026226
Giganotosaurus would not just deliver a static bite, in fact, most animals use pulling or torsional feeding to deal damage, especially those for which simply elevating the mandible won't do the job.

So do you suggest Giganotosaurus will have any advantage in that area?

For Carcharodontosaurus, it is suggested to be significantly higher at least posteriorly, so when the jaw joint achieves a decent degree of flexion it could bite down pretty hard. If it doesn't, sawing slashes at an opponent will still be devastating.

You only have to look to see that Tyrannosaurus' hips allow for much more muscle attachment. The leg proportions are also more cursorial, and according to Persons and Currie, "...the mass of the M. caudofemoralis was further increased by dorsoventrally lengthening the hemal arches." With that being said, given both the weight and caudofemoralis studies I would not be surprised if Tyrannosaurus' speed were more in line within the 21-22 mph range.

While I basically agree, I wouldn't forget that T. rex also supposedly has a more massive body than what it is being compared to (the holotype of Giganotosaurus), and perhaps quite extensive abdominal airsacks invading the tighs (as in birds).

I already explained that speed/cursoriality is only relevant in races. Acelleration and maneuverability are important in combat.
Persons and Currie make points aplicable to all theropods, and nobody really studied the tail musculature of allosaurs so far.

Giganotosaurus and it's relatives also have long chevrons and long tails over which a muscle can contract, i.e. a muscle contraction of a longer muscle will also cause a greater movement.

[creature386]

Sept 21, 2013 16:33:43 GMT 5 theropod said:

That size comparison I posted. For Giganotosaurus to use its claws while both are in a normal posture, its head, neck, and shoulders would have to warp right through Tyrannosaurus. Even if it reared up, the arms could not reach very far, and any contact would do minimal tissue damage.

It was found that the humerus can swing posteriorly into a horizontal position but can neither swing laterally to glenoid height nor anteriorly much beyond the glenoid. The forearm can approach but not achieve full extension and right-angle flexion. Pronation and supination are precluded by immobility of the radius relative to the ulna. Motion also seems to be restricted at the wrist. The palm faces medially, and digital movement is subtransverse. All three digits are capable of extreme hyper-extension.

onlinelibrary.wiley.com/doi/10.1017/S0952836905006989/abstract

Sufficient movement range to be used, as is consensual for Carnosaurs, for predation.

Why did you highlight a sentence what says that the humerus cannot swing much beyond the glenoid? Also, I explained why I think Giganotosaurines may did not have as flexible forelimbs as Acrocanthosaurus.

Sept 21, 2013 16:33:43 GMT 5 theropod said:

Bite force and speed don't matter now?

You don't usually see antelopes winning against lions, do you?

You should read what Ursus arcos wrote in the "Intelligence in Animal Fights" thread about such arguments.

[theropod]

Because that sentence means it could swing anteriorly at least as far as the glenoid, which most people apparently don't think about much.

I know, it was a simplistic argument. Still, mere running speed is not relevant unless you want to flee from your opponent.

[wiffle]

Tyrannosaurus had a bite force estmated at around ~35-57 kilonewtons. That's only ~1.75-2.85 times that of Giganotosaurus.

6x may be a bit of an overstatement now that I look at it, but the upper limit is still over 4x that of Gigaonotosaurus'.

A bite force of ~120 kilonewtons would shatter Tyrannosaurus' jaw.

Wrong.

www.livescience.com/1557-rex-secret-weapon-discovered.html

That's why I said relatively, not absolute.

"Relative" bite force isn't really important. An ant's bite is extremely strong for its size, but it will do much less damage than a human's.

In fact, based on the chart, Giganotosaurus' bite force really isn't even much higher than a GWS's.

And if anything, the related taxon Carcharodontosaurus, had teeth that were compared to that of sharks, which gave it it's name.

Those would be basal comparisons. Allosaurus fragilis isn't exactly a china doll.

Here is a Carcharodontosaurus tooth:
upload.wikimedia.org/wikipedia/commons/5/5f/Carcharodontosaurus_saharicus_DentIII.jpg

And a shark's:

And you need agility to actually dodge it. At these sizes, it's really hard to be agile enough.

They don't need to hop out of the way like a bunny rabbit. Simply moving the targeted area can cause an attack to miss.

As I've already pointed out, Tyrannosaurus may also have been more agile.

This is not comparable to the cutting ability and consequent evisceration potential of the teeth of lamniforms, komodo dragons or Carnosaurs.

The point is that they can still slice to some degree. The neck muscles would have facilitated this:
www.bioone.org/doi/abs/10.1666/06059.1?journalCode=pbio

One only has to look to see that the neck vertebrae of Tyrannosaurus are thicker than those of Gigaonotsaurus.

btw you are letting youself get fooled by a comparison using the mouth gape to make T. rex' skull look especially big and comparing the biggest T. rex to the smallest (on top of that, inaccurate) Giganotosaurus. I have already replicated that comparison earlier to demonstrate that point.

The photo was to show that Tyrannosaurus Rex's skull is much more robust, not that it was bigger. 

If it doesn't, and the first bite is all that counts, why does stronger bite force count for you?

Because a higher bite force actually increases the effectiveness of a giant theropod's primary offensive attack.

It's hard for Giganotosaurus to land an immediately fatal bite-even a chomp to the neck would still give Tyrannosaurus a couple of seconds to live. (People actually have survived getting their carotid and jugular vein slit.) On the other hand, Tyrannosaurus weaponry ensures a quick death against a similarly sized opponent unless an extremity is bitten.

Sufficient movement range to be used, as is consensual for Carnosaurs, for predation.

Not for use as an effective killing weapon against a theropod of similar height. As I've already noted, it's simply impossible for Giganotosaurus to utilize its claws in this fight unless it rears up or has some magic capability that allows its head to warp through flesh.

You don't usually see antelopes winning against lions, do you?

How often does an antelope attack a lion, rather than simply act in self defense? If an antelope charges, a lion has a small window of time to move out of the way or counterattack.

Also, where did you get it that antelopes had a stronger bite force than lions? Do you see antelopes biting at all?

This was the case with other theropods too

Tyrannosaurus seems to have been particularly unkind towards its kin. Many fossil specimens show scars and damage most likely inflicted by another T. rex, and face biting has been seen in skulls.

If you want to attack a sauropod, it certainly is.

So how would a higher bite force be disadvantageous, in any way, to Giganotosaurus?

bite force=/=quicker kill

A snapped neck is instantly incapacitating, so yes, it does.

Based on results from the same study, T. rex bit perhaps 2-3 times as hard.

More like 2.7-4.38 times. 

Mason B. Meers and Tyrrell Museum both estimated the bite force of Tyrannosaurus to be around 200,000 newtons. A blog states the scaling for the study was erroneous, and the actual bite force would have ranged from 5.6-9 tons. The study did use a 5 ton Tyrannosaurus when the weight range was though to be from 5-7 tons, with 6 tons being average, so the numbers are rather conservative going by that likely mistaken method. Realistically this would be equal to the bite force of a Tyrannosaurus of about 6.4 tons when taking account og the recent studies. Sue's should be somewhat higher.

www.ingentaconnect.com/content/tandf/ghbi/2003/00000016/00000001/art00001

And the blog:

mambobob-raptorsnest.blogspot.com/2007/04/maximum-bite-force-in-tyrannosaurus-rex.html

and has an extreme bulk meaning there is a much longer struggle rather than a single precise ambush attack ending the fight.

If Giganotosaurus needed to, it could simply run away, rest, and come back to finish the fight.

they did: www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0026226

This was sometime after the study saying Komodo dragons had a weaker bite force than house cats, which was presented in 2008.

In spite of this, Komodo dragons still don't instantly decapitate prey.

How about a probably much lighter skull (yes, a massive bite force definitely has it's cost)?

Granted, but the strong neck muscles would have compensated for this.

www.bioone.org/doi/abs/10.1666/06059.1?journalCode=pbio

"However, even with high latitude for estimation errors, the results indicate that adult T. rex could strike rapidly at prey and engage in complexly modulated inertial feeding, as seen in extant archosaurs."

so when the jaw joint achieves a decent degree of flexion it could bite down pretty hard.

I highly doubt it would approach Tyrannosaurus'. Neither Carcharodontosaurus nor Giganotosaurus seem to have adaptations for resisting such forces or for applying it in a more efficient manner.

I already explained that speed/cursoriality is only relevant in races. Acelleration and maneuverability are important in combat.
Persons and Currie make points aplicable to all theropods, and nobody really studied the tail musculature of allosaurs so far.

That quote applied specifically to Tyrannosaurus.

Digital muscle reconstructions based on measurements of fossil specimens and dissections of modern reptiles showed that the M. caudofemoralis of many non-avian theropods was exceptionally large. These high caudofemoral mass estimates are consistent with the elevation of the transverse processes of the caudal vertebra above the centrum, which creates an enlarged hypaxial region. Dorsally elevated transverse processes are characteristic of even primitive theropods and suggest that a large M. caudofemoralis is a basal characteristic of the group. In the genus Tyrannosaurus, the mass of the M. caudofemoralis was further increased by dorsoventrally lengthening the hemal arches. The expanded M. caudofemoralis of Tyrannosaurus may have evolved as compensation for the animal's immense size. Because the M. caudofemoralis is the primary hind limb retractor, large M. caudofemoralis masses and the resulting contractile force and torque estimates presented here indicate a sizable investment in locomotive muscle among theropods with a range of body sizes and give new evidence in favor of greater athleticism, in terms of overall cursoriality, balance, and turning agility.

[Deleted]

Sept 21, 2013 23:47:19 GMT 5 wiffle said:

A bite force of ~120 kilonewtons would shatter Tyrannosaurus' jaw.

Wrong.

www.livescience.com/1557-rex-secret-weapon-discovered.html

Why do you think Tyrannosaurus' jaws and skull could withstand that force? There are things called limits, you know?

Not all the info you can find on the net is reliable. Even megalodon, yes, the massive 60+ tonne megalodon!, was estimated to have LESS than 200 kilonewtons of bite force. And I wouldn't even get started on how much larger megalodon and it's jaws are compared to Tyrannosaurus.

[creature386]

The maximum resistance does not equal maximum bite force (and this source only talked about resistance). But yeah, Tyrannosaurus' skull being able to survive 20 t sounds highly unlikely.

P.S. 18 t was for a 100 t Megalodon, a 60 t one would have a far lower one.

[Deleted]

Sept 22, 2013 0:55:59 GMT 5 creature386 said:

The maximum resistance does not equal maximum bite force (and this source only talked about resistance). But yeah, Tyrannosaurus' skull being able to survive 20 t sounds highly unlikely.

P.S. 18 t was for a 100 t Megalodon, a 60 t one would have a far lower one.

And a megalodon, whether it be a ~100-tonne or a ~60-tonne specimen, would crush Tyrannosaurus' entire skull with one bite.

[creature386]

By the way, there is a paper what claims Tyrannosaurus' bite force to be 18,3-23,5 t (this is no joke). For comparison, the highest estimate for Megalodon is 18,2 t.
I would like to know where they get such figures from.

[Runic]

What are these people doing with their lives XD

[Grey]

From Wroe et al.

The assumption that all potentially
biting teeth were similarly loaded yields a ?gure of 156 120 N
(Ray?eld, 2004), a ?gure of a magnitude comparable to the
estimate of 183 000–235 000 N for T. rex obtained by Meers
(2003) based on the scaling relationship of bite force to body
mass in extant reptilian and mammalian carnivores. However, although the skull of T. rex was clearly adapted to
offer considerable resistance (Snively, Henderson & Phillips,
2006), it is unlikely that all teeth would have contacted a
prey item simultaneously and if force is scaled for tooth size,
then bite force for T. rex in this instance was 31 000 N
(Ray?eld, 2004). Furthermore, it is impossible to determine
whether this force was generated solely by jaw adducting
musculature or ampli?ed by cervical or other postcranial muscles.

[theropod]

Sept 21, 2013 23:47:19 GMT 5 wiffle said:

Tyrannosaurus had a bite force estmated at around ~35-57 kilonewtons. That's only ~1.75-2.85 times that of Giganotosaurus.

6x may be a bit of an overstatement now that I look at it, but the upper limit is still over 4x that of Gigaonotosaurus'.

And far less at the lower limit, so you'd better take the best estimate. Even better is to scale from their own estimate for Allosaurus, not a figure they just quoted, so the figures will at least be roughly compatible.

Again, that would yield about 3t of bite force, not that it mattered much...

"Relative" bite force isn't really important. An ant's bite is extremely strong for its size, but it will do much less damage than a human's.

No, an ant's bite is relatively weak for it's size. In fact, an ant is generally far weaker than a human of equal size. Scaled up to our size it would collapse under it's own weight (not to mention it would suffocate anyway ).

As I've already pointed out, Tyrannosaurus may also have been more agile.

There is no evidence for this. All the data basically speaks of cursoriality.

The point is that they can still slice to some degree.

To some degree, not even close to being as effective. This is the payoff I'm talking about.

The neck muscles would have facilitated this:
www.bioone.org/doi/abs/10.1666/06059.1?journalCode=pbio

Carcharodontosaurs also have neck muscles.

One only has to look to see that the neck vertebrae of Tyrannosaurus are thicker than those of Gigaonotsaurus.

Thickness of the neck vertebra is not the same as neck-muscle strenght.

The photo was to show that Tyrannosaurus Rex's skull is much more robust, not that it was bigger. 

How robust it is also has to do with how big it is. A gunea pig is much more compact than a Girtaffe, but of course it is dwarfed by it in any regard.

besides, nobody here doubt's T. rex has the stronger bite force, this just simply is not a relevant factor, and it's skull does by no means dwarf that of Giganotosaurus in the way that image makes you think. One of the quotes I probably most often recite is "Adductor-driven bite force is not a good predictor of killing performance among ziphodont taxa".

Because a higher bite force actually increases the effectiveness of a giant theropod's primary offensive attack.

Nope, it does not.

It's hard for Giganotosaurus to land an immediately fatal bite-even a chomp to the neck would still give Tyrannosaurus a couple of seconds to live. (People actually have survived getting their carotid and jugular vein slit.) On the other hand, Tyrannosaurus weaponry ensures a quick death against a similarly sized opponent unless an extremity is bitten.

People have also survived getting their necks broken, does that mean they would fight afterwards? Besides, I'd like the accounts were people survived (outside an ER or OR) a carotid and jugular dissection.

A bite to the neck by a carcharodontosaur is a near-instant kill to any similar-sized animal, a few seconds in shock, bleeding and with cut muscles are no time in which any animal could strike back.

Tyrannosaurus bite ensures a quick kill in the case of a neck bite, or one to the skull. Nowhere else, for it couldn't even bite the torso due to it's girth.

Not for use as an effective killing weapon against a theropod of similar height.

You're still getting me wrong. I'm by no means talking about a killing weapon. as I explained earlier, I'm talking about grappling hooks.

As I've already noted, it's simply impossible for Giganotosaurus to utilize its claws in this fight unless it rears up or has some magic capability that allows its head to warp through flesh.

Since you apparently think Something could survive having it's throat cut and still fight back, how about seizing it after delivering the bite?

How often does an antelope attack a lion, rather than simply act in self defense? If an antelope charges, a lion has a small window of time to move out of the way or counterattack.

I admit that was a rather bad analogy, but it's irrelevant. Both may be able to dodge to some degree, neither for long. But speed has nothing to do with this

Also, where did you get it that antelopes had a stronger bite force than lions? Do you see antelopes biting at all?

Did I claim so?

OK, do you see wolves killing cougars all day?

Tyrannosaurus seems to have been particularly unkind towards its kin. Many fossil specimens show scars and damage most likely inflicted by another T. rex, and face biting has been seen in skulls.

Thanks, but I'm fully aware of tyrannosaurid pathologies. That still doesn't mean any given other theropod wasn't just as agressive, and most likely coexisted with a greater number of other large predators.

So how would a higher bite force be disadvantageous, in any way, to Giganotosaurus?

It would limit it's gape and force it to develope sturdier and in consequence blunter teeth as well as a heavier skull limiting the speed with which it can place a bite.

This would cause it to be unable to bite most parts of it's prey, and make it's attack on those parts it could bite less effective and slower.

eg. if a Tyrannosaurus tried to bite the leg of a sauropod, it would take time to bite down and gnaw, pull and twist at the bone, eventually breaking it (unless it is just too big to do so, which may also be the case with some sauropods). A Giganotosaurus on the other hand would just have to nip at the leg to sever tendons and blood vessels, something that takes only one quick slash, and it would have no problems actually biting the belly due to it's gape.

A snapped neck is instantly incapacitating, so yes, it does.

A cut throat also is. I think you should check out the "slicing bite vs crushing bite" thread

More like 2.7-4.38 times. 

Based on results from the same study, T. rex bit perhaps 2-3 times as hard.

I explained this earlier. Btw Really sorry if I'm sounding a bit too rude, that's not meant to be this way.

Mason B. Meers and Tyrrell Museum both estimated the bite force of Tyrannosaurus to be around 200,000 newtons. A blog states the scaling for the study was erroneous, and the actual bite force would have ranged from 5.6-9 tons. The study did use a 5 ton Tyrannosaurus when the weight range was though to be from 5-7 tons, with 6 tons being average, so the numbers are rather conservative going by that likely mistaken method. Realistically this would be equal to the bite force of a Tyrannosaurus of about 6.4 tons when taking account og the recent studies. Sue's should be somewhat higher.

we cannot be sure of that, it may also be that the estimate was for a large and/or large skulled specimen, and was simply very conservative. That wouldn't impact the bite force.

www.ingentaconnect.com/content/tandf/ghbi/2003/00000016/00000001/art00001

And the blog:

mambobob-raptorsnest.blogspot.com/2007/04/maximum-bite-force-in-tyrannosaurus-rex.html

Thanks, I'll look at that tomorrow.

If Giganotosaurus needed to, it could simply run away, rest, and come back to finish the fight.

So could T. rex should it miss it's target.

they did: www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0026226

This was sometime after the study saying Komodo dragons had a weaker bite force than house cats, which was presented in 2008.

In spite of this, Komodo dragons still don't instantly decapitate prey.

I guess you meant to write "discapacitate"

Anyway, that's because
A: they often hunt animals much larger than themselves
B: they bite the legs, not the neck
C: they and their prey are both smaller, meaning more resistant due to the square cube law.

And of course we should not forget they still incapacitate much of their prey pretty quickly, since shock also comes quickly. You should ask coherentsheaf about this, he's our dragon specialist along with VD.

Granted, but the strong neck muscles would have compensated for this.
"However, even with high latitude for estimation errors, the results indicate that adult T. rex could strike rapidly at prey and engage in complexly modulated inertial feeding, as seen in extant archosaurs."

I'm not sure of that. Those strong neck muscles in turn will take longer to move the skull and make the structure less flexible, just like a bigger, more massive animal (eg. T. rex) isn't as fast as a smaller one (eg. Albertosaurus), despite it's greater muscle mass.

Then again, the hard data (look at the other Snively et al., 2007) is not suggestive of as massively stronger neck muscles as often portrayed. Tyrannosaurs merely have bigger lateroflexors (Jaw mechanics thread), and much of the internal structure is the thicker bone needed to bear the skull and the

I highly doubt it would approach Tyrannosaurus'. Neither Carcharodontosaurus nor Giganotosaurus seem to have adaptations for resisting such forces or for applying it in a more efficient manner.

Well, for once, Allosaurids have tremendously strong crania, but I'm unsure whether and how much this applies to Carcharodontosaurs. Secondly, the high mechanical advantage is what applies that force effectively.
Thirdly, I'm of course speaking of a bite force twice lower than that of T. rex, not one equally powerful, which still fully suffices for their jaws.

That quote applied specifically to Tyrannosaurus.

Digital muscle reconstructions based on measurements of fossil specimens and dissections of modern reptiles showed that the M. caudofemoralis of many non-avian theropods was exceptionally large. These high caudofemoral mass estimates are consistent with the elevation of the transverse processes of the caudal vertebra above the centrum, which creates an enlarged hypaxial region. Dorsally elevated transverse processes are characteristic of even primitive theropods and suggest that a large M. caudofemoralis is a basal characteristic of the group. In the genus Tyrannosaurus, the mass of the M. caudofemoralis was further increased by dorsoventrally lengthening the hemal arches. The expanded M. caudofemoralis of Tyrannosaurus may have evolved as compensation for the animal's immense size. Because the M. caudofemoralis is the primary hind limb retractor, large M. caudofemoralis masses and the resulting contractile force and torque estimates presented here indicate a sizable investment in locomotive muscle among theropods with a range of body sizes and give new evidence in favor of greater athleticism, in terms of overall cursoriality, balance, and turning agility.

Sure, but it compares it to smaller animals, noting that has to do with it's large size. The rest applies to all theropods however, the basic function is the same.

[wiffle]

Why do you think Tyrannosaurus' jaws and skull could withstand that force?

You realize they tested it for skull strength, right?

Tyrannosaurus had numerous adaptations for resisting as well as transferring bite force:

The skull bones were massive and the nasals and some other bones were fused, preventing movement between them; but many were pneumatized (contained a "honeycomb" of tiny air spaces) which may have made the bones more flexible as well as lighter. These and other skull-strengthening features are part of the tyrannosaurid trend towards an increasingly powerful bite, which easily surpassed that of all non-tyrannosaurids.[20][21][22]

Not all the info you can find on the net is reliable.

We're not talking about a mindless piece of troll spam on Wikipedia that gets undone within 1 minute, buddy. Those are published scientific studies. You can find some of the researchers' papers here:
www.ohio.edu/people/es180210/eric%20snively%20CV.html

By the way, there is a paper what claims Tyrannosaurus' bite force to be 18,3-23,5 t (this is no joke). For comparison, the highest estimate for Megalodon is 18,2 t.
I would like to know where they get such figures from.

It was obtained from scaling up extant carnivores. The ratio was likely off; the bite force for a 5 ton Tyrannosaurus would have been in the range of 5.6-9 tons. If you take into account the new mass estimates, this would be the bite force of a 6.4 ton Tyrannosaurus.

And a megalodon, whether it be a ~100-tonne or a ~60-tonne specimen, would crush Tyrannosaurus' entire skull with one bite.

By that logic, if a Tyrannosaurus bit another one's skull, the other Tyrannosaurus should come out undamaged.

And far less at the lower limit, so you'd better take the best estimate.

So we are required to skew data in favor of Giganotosaurus now?

Even better is to scale from their own estimate for Allosaurus, not a figure they just quoted, so the figures will at least be roughly compatible.

Why would scaling an Allosaurus up produce accurate figures for Giganotosaurus' bite?

How robust it is also has to do with how big it is. A gunea pig is much more compact than a Girtaffe, but of course it is dwarfed by it in any regard.

Completely inapplicable, considering the size differential is much greater and a guinea pig is not robust.

I meant to say you considered far more important thigs miniscule. I can still hit a person with one of my eyes closed, the difference is miniscule.

That's because your brain fills in the rest to create a 3D image. The fact that some predators don't have excellent binocular vision is a far cry from saying it does not help.

No, an ant's bite is relatively weak for it's size.

Regardless, relative bite force is only going to get you so far. Absolute bite force is what does the damage.

Thickness of the neck vertebra is not the same as neck-muscle strenght.

Larger neck bones offer more muscle attachment and can support both them and the skull more easily.

Nope, it does not.

Of course it does. A dinosaur with a bite force of 20,000 pounds is going to do far more damage than one with a bite force of 2,000 pounds.

People have also survived getting their necks broken, does that mean they would fight afterwards? Besides, I'd like the accounts were people survived (outside an ER or OR) a carotid and jugular dissection.

There are none, but they would still be in fighting condition for a small amount of time-as publicized by the Zimmerman trial, even a destroyed heart would still give someone about 15 seconds to react. Furthermore, a crushed and torn jugular, carotid, windpipe, and spinal cord will kill faster than a sliced jugular, carotid, and windpipe. If Tyrannosaurus is bitten of the neck, it still has a chance to take down Giganotosaurus with it.

Tyrannosaurus bite ensures a quick kill in the case of a neck bite, or one to the skull. Nowhere else, for it couldn't even bite the torso due to it's girth.

A Tyrannosaurus tooth was lodged in Sue's rib, so yes, it is possible. The back is also a possible target if Tyrannosaurus rears up.

You're still getting me wrong. I'm by no means talking about a killing weapon. as I explained earlier, I'm talking about grappling hooks.

Which doesn't explain how Giganotosaurus can get within range to use them in the first place.

But speed has nothing to do with this

Of course it does. Is it easier to move out of the way of a jet plane or car?

Did I claim so?

I said that bite force and speed are relevant and you said that antelopes don't win against lions. Thus I would infer that you are claiming the antelope has an advantage in both respects.

OK, do you see wolves killing cougars all day?

Mammalian tactics are often irrelevant in a giant theropod fight, and the wolf's bite hasn't crossed into the immediately disabling territory.

That still doesn't mean any given other theropod wasn't just as agressive

It does mean they don't fight each other as often. Experience counts.

It would limit it's gape and force it to develope sturdier and in consequence blunter teeth as well as a heavier skull limiting the speed with which it can place a bite.

I was not saying that Tyrannosaurus would be just as effective as hunting a sauropod. What I was saying was that if Giganotosaurus's bite force was higher, that would not harm its ability to hunt.

eg. if a Tyrannosaurus tried to bite the leg of a sauropod, it would take time to bite down and gnaw, pull and twist at the bone, eventually breaking it (unless it is just too big to do so, which may also be the case with some sauropods). A Giganotosaurus on the other hand would just have to nip at the leg to sever tendons and blood vessels, something that takes only one quick slash

If a Tyrannosaurus bit the same portion of leg, it would also pierce, tear, and crush connective tissue and muscle. It need not crush bone to do harm. 

A cut throat also is.

As has been previously pointed out, no.

I explained this earlier.

And you were wrong. The range would be 35,000/13,000 to 57,000/13,000. 

we cannot be sure of that, it may also be that the estimate was for a large and/or large skulled specimen, and was simply very conservative. That wouldn't impact the bite force.

The bite force in the Meers study was for a 5 ton Tyrannosaurus.

So could T. rex should it miss it's target.

If Tyrannosaurus missed, Triceratops would likely mount a quick counterattack. T. rex can't just run away.

I guess you meant to write "discapacitate"

No, I meant to say decapitate, as in To slice someone's head off." A bit of purposeful hyperbole, I suppose, but the point is that Komodo dragons do not shear off limbs without some time and effort.

I'm not sure of that. Those strong neck muscles in turn will take longer to move the skull and make the structure less flexible, just like a bigger, more massive animal (eg. T. rex) isn't as fast as a smaller one (eg. Albertosaurus), despite it's greater muscle mass.

Apparently that did not matter.

We examine accelerative and work-generating capacity (WGC) of neck muscles in adult Tyrannosaurus rex, using a 3-D vector-based method that incorporates aspects of muscle force generation, reconstruction of muscle morphology and moment arms, and rotational inertias of the head and neck. Under conservative assumptions, radial accelerations of the head by large superficial muscles (M. transversospinalis capitis, M. complexus, and M. longissimus capitis superficialis) enabled rapid gaze shifts and imparted high tangential velocities to food sufficient for inertial feeding.

Then again, the hard data (look at the other Snively et al., 2007) is not suggestive of as massively stronger neck muscles as often portrayed.

That is Snively's 2007 study.

Secondly, the high mechanical advantage is what applies that force effectively.

And its efficiency? How much energy is lost from the strike? Tyrannosaurus had fused nasals that allowed it to impart the force to the prey without losing much of it in the process-Giganotosaurus did not possess this feature.

Sure, but it compares it to smaller animals, noting that has to do with it's large size. The rest applies to all theropods however, the basic function is the same.

The study notes that the increased caudofemoralis mass would have enhanced agility. This muscle was particularly large in Tyrannosaurus.

Because the M. caudofemoralis is the primary hind limb retractor, large M. caudofemoralis masses and the resulting contractile force and torque estimates presented here indicate a sizable investment in locomotive muscle among theropods with a range of body sizes and give new evidence in favor of greater athleticism, in terms of overall cursoriality, balance, and turning agility.

In the genus Tyrannosaurus, the mass of the M. caudofemoralis was further increased by dorsoventrally lengthening the hemal arches.

[Deleted]

Sept 22, 2013 7:04:46 GMT 5 wiffle said:

Why do you think Tyrannosaurus' jaws and skull could withstand that force?

You realize they tested it for skull strength, right?

And Tyrannosaurus damaged Tyrannosaurus skulls with bite forces that are much less than 200 kilonewtons.

Tyrannosaurus had numerous adaptations for resisting as well as transferring bite force:

The skull bones were massive and the nasals and some other bones were fused, preventing movement between them; but many were pneumatized (contained a "honeycomb" of tiny air spaces) which may have made the bones more flexible as well as lighter. These and other skull-strengthening features are part of the tyrannosaurid trend towards an increasingly powerful bite, which easily surpassed that of all non-tyrannosaurids.[20][21][22]

Not all the info you can find on the net is reliable.

We're not talking about a mindless piece of troll spam on Wikipedia that gets undone within 1 minute, buddy. Those are published scientific studies. You can find some of the researchers' papers here:
www.ohio.edu/people/es180210/eric%20snively%20CV.html

There is actual fossil evidence of Tyrannosaurus damaging other Tyrannosaurus skulls with their bites. 200-kN resistance is therefore very unlikely, unless you think Tyrannosaurs have bite forces approaching 200 kN.

And a megalodon, whether it be a ~100-tonne or a ~60-tonne specimen, would crush Tyrannosaurus' entire skull with one bite.

By that logic, if a Tyrannosaurus bit another one's skull, the other Tyrannosaurus should come out undamaged.

If their skulls really can withstand 200 kilonewtons, then a ~35-57 kilonewton bite force would be lucky to even dent it's face. And yet, Tyrannosaurus bites can do quite a number on Tyrannosaurus skulls.

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