Sorry to read that, such accidents can be really annoying
?
Giganotosaurus almost certainly has a bigger temporal cavity (due to a probably wider skull and greater anteroposterior lenght of the quadrate and quadratojugal bar), which is where the bulk of the adductor musculature is. Larger openings have little to do with gape, much more with bite force actually.
They might have known, but we don't. Which are the studies you refer to?
No, actually it's pretty close, even tough
T. rex has a more pronounced step between post- and antorbital parts of the cranium, mostly due to it's rostrum being narrower (Indication for the usefulness of an narrow rostrum in centering the produced force? You tend to see similar things with crocodiles and alligators...). Check out Snively et al., 2006 (the theropod nasals)
It can do that either way, the force an animal applies in it's bite always reflects maximum resistance of the cranium minus the margin of safety you always find. Whether this force is applied by the adductor musculature alone, or by postcranial forces, it not important.
It does not rely on adductor force alone but of course also pulling forces (since I already posted the study I suppose you are familiar with the differences between adductor and pulling forces in
V. komodoensis, which are quite considerable).
What you posted was not the definition of conservative.
The neck muscle estimates for other theropods aren't more liberal than those used in the study, we have no reason to assume they are and for sure other reconstructions
seem to be comparable for all we can say about them.
A conventional bite aided by ventroflexion and pulling and a strike-pull bite, the latter being agreed to be everything but ordinary action, if present.
I must note
Giganotosaurus basicranial anatomy isn't the same as that of
Allosaurus, making a powerful ventrally directed strike seem rather unlikely, but it has the sheer toothrow lenght to produce horrific exanguination of what it bit.
You realise skeletal diagrams are usually far more accurate than mounts?
www.plosone.org/annotation/listThread.action?root=16333I realise it
can, tough not near as easily, quickly or frequently as penetrating and lacerating trauma.
The main amount of damage would be to the bone.
Compared to what
Giganotosaurus would do, it would not be effective at damaging the soft tissue, in the same way
Giganotosaurus by comparison would be ineffective at damaging the vertebrae. This is for the same reason a crocodile bite to the neck of a zebra doesn't cause it to bleed to death quickly.
Ergo, just because it has a stronger bite force it isn't automatically more dangerous, but that's what you seem to be arguing.
The ribs are supposed to withstand a bite from
Giganotosaurus?
I doubt it, given that they are relatively thin bones relative to the forces and size of the skull and teeth thrown at them. The bite would probably break those ribs by the sheer power of the jaws clamping down on them, or otherwise saw it's way through. It could go very deep.
It's not as if once there's some gracile bone in the way that would absolutely disable the jaws from cutting through just because it's not a crushing specialist. You can also see sharks slashing through such comparatively small bones (eg. a human femur or a dolphin in great white shark attacks).
The shear strenght of osseous tissue is ~5160N/cm² (acccording to
this?, 5400-5700 according to
this?). The thickest of Sue's ribs is ~4.5cm broad at the upper part of the shaft, getting significantly further ventrally, and probably only about half as thick in lateral view.
Note that based on figure 73 in Brochu [2003], the ribs appear to be hollow. We can approximate the cross-section with an ellipse (pi*2.25*1.125=~7.9cm², and probably less than half of that is actual bone).
In other words,
Giganotosaurus can probably bite/saw through a
T. rex rib without problems.
Adding the main (pulling-)force (that will probably constitute a very large part of the total force excerted in the bite) and taking into account the encountered ribs will likely be thinner (because the largest part of the rib shaft is, because most ribs are, and because most
T. rex specimens are smaller than sue), two or three, as would be expected should it bite the torso, probably aren't a major hindrance. If all that is added into the equation, a bite to the torso would cause extreme amounts of damage through both the teeth and probable bone fragments.
More widely spaced? To a neglegible amount at best, and I don't see how that influences it's cutting potential to a notable extend.
The last time I noted Carcharodontosaur teeth were thicker than carcharodon's teeth and increased robusticity may simply be related to the square-cube law (which I still think), I got called a fanboy afterwards because what I wrote included the notion of them being "relatively robust".
I don't see why a triangular contact area should be disadvantageous for causing deep-going damage with a pull-bite.
btw this is from D'amore, 2009:
and
It should be pretty clear a
Tyrannosaurus' bite would be less effective at cutting as a payoff of its greater crushing power, because of A) carinae designed rather to hold than cut and B) thicker teeth with round or D-shaped cross-section.
A better phrasing would be that
Tyrannosaurus' is increased. I don't get the point of this,
T. rex teeth also have reduced cutting ability compared to Carnosaur's.
Do you realise much of this also applies to
T. rex' abilities?
It is mere hypothesis how effective it would be compared to extant animals or other theropods, your mere guess that it's bite would be more effective than that of
G. carolinii. It could just as well be the other way around.
But if we use them as an analogy you don't see it having a more effective bite at all. Now several of your arguments in this regard seem to be constructed around the hypothesis that
Giganotosaurus was in some way inferior to those extant analogies, while
T. rex was superior. I don't see that being backed up by anything, no offence.
Giganotosaurus likely had a bite force in the 2-3t range, that's also far from "weak" (not that it really mattered), however you try to define that term scientifically.
btw for what it's worth Scott Hartman agreed with my inferences on the bite-force issue:
scotthartman.deviantart.com/art/Big-honkin-theropod-of-the-southern-hemisphere-302541476A posterior bite force of roughly 3t as based on Bates' & Falkingham's
Allosaurus is realistic.
And sharks wouldn't cut out huge chunks without lateral slashes of their jaws either. Some additional action is required for major mechanical damage in most types of bites, especially those that do not produce a huge amount of force perpendicular to the apical/terminal line of the teeth (ie. puncture/crush feeders).
Modern examples demonstrate bite force is a bad predictor of killing potency.
Various sources have demonstrated that, so there's no need for me to repeat the reasons again.
Bakker 1998 may be interesting to you in this regard since it summarises some of the points in favour of a reduction of bite force in favour of greater gape and neck-muscle powered slashes.
It is much easier to open the thorax of a dead or immobilised animal than that of a living animal fighting back. I'm sure surgeons are gonna confirm you that thoracotomies are preferrably performed on sedated patients.
An animal can be quite capable of something in a feeding situation, that doesn't mean it has even decent chances of performing it on a living animal.
That's even more so in
Giganotosaurus.
There is nothing to suggest it wasn't save for the other specimen likely being smaller, which is also why I don't assume MUCPv-95 is the norm, but that the norm is the average of the known individuals, int eh absence of anything better than that.
There is nothing to suggest sue was the norm for
T. rex, in fact everything suggests it wasn't.
As it turns out there's only a single one of those fragmentary specimen that actually holds up to closer examination (forget about MOR 008, C-rex, and the UCMP maxilla, they are all either on-the-field guesses never again mentioned in rigorous works but only by fanboys, or turn out to be smaller than sue), and that specimen happens to be a single phalanx referred to
T.rex merely based on size, age and locality...
Elephants are in roughly the same size range as mid-sized sauropods, ie.
Diplodocus (or, more importantly,
Limaysaurus or
Andesaurus), and sauropods have more well-developed locomotory musculature (Nima).
You can see they are capable of doing that, that's the way people get up an elephant when they want to ride it. It's impractical to use against a lion that's sitting on it's back, and apart from lions they hardly have any natural enemies to use it against.
Which you don't know at all, you just presume because the prey is slower it also means the predator doesn't have to be as fast, but there is not a simple linear relationship between predator/prey reflexes, many more factors play a role here.
firstly, I did not claim that, I claimed the importance this has is overrated, which are two very different things. I'm totally right in claiming T. rex is overrated for example, which of course does not equal me claiming it was a whimpy scavenger.
Who said that Crocodiles and varanids had better stereoscopic vision than
Giganotosaurus, and especially, to a notable degree?
As far as I know
Allosaurus,
Carcharodontosaurus and Crocodilians (and, surprisingly, volant pidgeons!) all have a comparable
stereoscopic field (~20-25°), and it has been proposed this may be due to a
balance between the need for depth perception and panoramic vision.
Just the teeth wouldn't plug up the wounds (that's what would most likely happen during a
T. rex bite tough), they don't do that in sharks and monitor lizards either, because the jaw doesn't make prolongued contact with the prey, it just slashes through it.
That depends on what kind of mortal injury you are talking about.
In what place do they tell people to fight back after having their hearts or carotids ripped to shreds? That's not just entirely useless, even if it was applicable, it's also apparently insuccessful, because otherwise the internet would be full of videos of people getting a knife or bullet somewhere in their central circulatory system just to then disarm and kick the guy with the knife/gun.
People who are having a heart failure very rarely tent to walk around, let alone fight. The reasons should be obvious.
Excellent example. So Humans are extremely durable animals and a
Giganotosaurus wouldn't be able to kill one easily, because apparently even getting a knife to the brain can't....
Or maybe they were just lucky enough for the knife to miss vital parts and not cause major damage to the surrounding tissue. You see, on occasion that just happens with brain injuries.
Well, they apparently didn't do enough harm to kill it, did they?
So it wasn't a mortal injury. And we have absolutely no clue as to that being a display of more extreme durability than what we see in other theropods, which is probably why scientists don't walk around claiming "T. rex was the most durable of theropods because stan has a hole in it's skull and survived".
Adaptability is the same as survivability, Darwin, 1859.
Quick death usually kills immediately, which wasn't the case in either animal. It is impossible to survive quick dead, and if it was, it would not be a sign of durability, but some overnatural power being on your side.
There is no way to defend against something that's immediately fatal, as you yourself seem to argue about crushed spines and
Giganotosaurus-otherwise, for sure it would just need to be durable to survive that.
How easily a wound gets infected depends on the surface area covered by it, and on the place it is in. A puncture to the brain is not really meeting either criterium in a way that makes it particularly prone to getting infected.
But we are not talking about infection, which is a truly slow killer indeed.
Do you have a description of Stan's injuries that you can post btw?
I only found this bit of info from wiki:
en.wikipedia.org/wiki/Theropod_paleopathologyCiting an apparently very comprehensive paper I couldn't find anywhere online. If anyone has a copy of Molnar, 2001 I'd be very grateful!
But the note that it had holes in the right side of it's skull and the statement that it had a punctured brain with resulting brain injuries are two different pairs of shoes.
I encourage you to have a look at other
theropod palaeopathologies. They are alltogether durable animals and are known to survive horrendous injuries. That doesn't only apply to
T. rex.
You either survive a brain injury, or you don't. There'll hardly be a difference between taxa here, or any influence of durability which rather influences whether you actually sustain deadly injuries, surviving it will always be luck.
Firstly, if the models used to conclude the stuff
about the bodies (it doesn't say RI has anything to do with the arctometatarsus, unless you are referring to the RI of the metatarsus itself at unit lenght) were those or similar to those from Snively & Henderson, 2003, I wouldn't trust them, since they obviously produced flawed weight estimates and are based on restorations of questionable accuracy (namely the quite strange, highly anteroposteriorly compressed Paul-skeletal of sue).
I don't see how the structure of the foot has any notable influence on the whole animal's rotational inertia. If anything, it could be relevant to the transmittal of torque, but I also doubt this will be relevant since we do not see any such consequences in the morphology of extant animals (ie. the abilities to accellerate). IN fact the opposite seems to be the case, long, elongate-legged animals, while often faster at maximum, seem to be inferior in terms of accelleration.
The conclusions I have seen pronounce the supposed use is an untested hypothesis, and this is not without reason.
They make no extant comparisons, and extant examples don't show elongate, akinetic metatarsals to enhance agility, merely efficiency (leading to increased top speed or the ability to sustain it), because of somewhat lower weight and lower energy loss to deformation at uniform stride lenght.
The anterior thorax is not, the posterior one is.
And the former part is expanded and long in
Tyrannosaurus, while it tapers in
Giganotosaurus. And in front of that, there's a thick neck and even thicker skull, that, while pneumatic, definitely makes it more front-heavy.
That does more than just balance out the caudofemoralis. There is hardly any doubt the torsos are heavier than the tails either way in theropods, making them even heavier is not an advantage for stability or Rotational Inertia.
It's "larger locomotor muscles" at lenght or femur lenght parity I may add, which may have been extensively pneumatised like in aves.
At weight parity, I highly doubt
T. rex has notably larger locomotor musulature. Of course that is not all too surprising if we compare a 7-8t specimen to a 6-7t one.
A smaller animal doesn't need as much locomotor-muscle-mass to control its weight.
You just did
Do deer or ratites have increased stability?
And how come artiodactyls are being caught by komodo dragons which are FAR slower, shorter-legged and concentrate less muscle in their legs? The former and the latter simply have nothing or little to do with accelleration and maneuverability, which are more relevant to agility as a whole than mere top-speed is.
See above. What do you mean by "location of the muscles"? Concentration of primary hind-limb retrators in the tail and knee flexors between ilium and tibia/fibula are common traits of reptiles and even tetrapods.
The ankle and the pes is not described for
Giganotosaurus, and would likely not be significantly longer in a large
T. rex than even in MUCPv-Ch1, let alone at weight parity. Besides, leg lenght is not necessarily synonymous with agility.
There seems to be a bit of a difference in the proportions. As it happens, the anterior hemal arches of
Giganotosaurus aren't known, they are a mere reconstruction.
Either way I don't see why exactly the lenght of the arch is of any significance, not that of the
process.
I never denied it did, it's also almost certainly an overally bigger animal at lenght parity, so that's no surprise, and it has a far more voluminous skull and must accordingly have a more rigidised, more sturdy neck. But the neural spines are hypertrophied in this area and along the back compared to
T. rex, which would usually imply a big deal of neck musculature, especially m. longissimus cervicis.
Not if the structure is generally lighter, because a lighter structure=less inertia=less muscle action required for movement. If it only weighs half or so, it will still be bigger (cou can calculate it yourself).
Quite the opposite. The weight in Carnosaurs seems to be very well balanced, especially since the pneumatic parts are particularly in the terminal region of the skull (nasal and antorbital sinuses)(see Snively et al., 2013, which also brings forth lots of evidence for quick striking in
Allosaurus [and
Giganotosaurus is definitely closer to
Allosaurus than to
T. rex in these terms]).
this is a nice visualization:
.
If at all,
T. rex is the one with the less balanced skull, since it's posterior skull-bones appear to be more extensively pneumatised by comparison to the anterior ones.
That's the case in
T. rex, not
Giganotosaurus.
