Tyrannosaurus rex vs. Giganotosaurus carolinii

[creature386]

Jan 28, 2021 0:44:38 GMT 5 sirjacob said:

The surface area of the skull may be a factor, anyone have any numbers on that.

Well, two skulls with the same surface area can still have very different structures (not to mention that it doesn't determine the bite musculature either), so, I don't think the precise number is that important.

[sirjacob]

Jan 28, 2021 13:27:16 GMT 5 creature386 said:

Jan 28, 2021 0:44:38 GMT 5 sirjacob said:

The surface area of the skull may be a factor, anyone have any numbers on that.

Well, two skulls with the same surface area can still have very different structures (not to mention that it doesn't determine the bite musculature either), so, I don't think the precise number is that important.

Crap I said it wrong. Not the surface area, the volume. Sorry for such a horrible mistake.

[Infinity Blade]

Wow, I can't believe it. Actual paleontologists agree with the take I've had on this locker room question since I joined Carnivora forum in 2012.

(Although, I think some limited use of the feet as weapons is possible, unlike what the article claims.)

www.popsci.com/science/giganotosaurus-vs-t-rex/

[theropod]

Infinity Blade
theworldofanimals.proboards.com/post/64494/thread

Giganotosaurus brains were half the size. “You don’t have to have a lot of focus if you’re going after walking walls of meat,” Holtz says. They came from a long line of giant predatory dinosaurs. Their “basic body plan” prepared them to hunt “long, slow-moving” herbivores, such as stegosaurs and sauropods.

This is quite clearly factually incorrect though.

The Giganotosaurus holotype has an endocast volume of 275 cm² (Carabajal and Canale 2010), the endocast volume of T. rex FMNH PR 2081 is 414 cm² (Hurlburt et al. 2013), so even at this extreme, it is about 50% more voluminous, not twice as voluminous.

Other T. rex specimens have smaller endocast volumes, that of AMNH 5117 is 314 cm² (Hurlburt et al. 2013), and that of AMNH 5029 is 343 cm² (Larsson et al. 2000) to 382 cm² (Hurlburt et al. 2013; I am not sure what exactly the reason for this difference is, as they seem to have used similar methods in both cases, whereas I am disregarding the GDI estimates for brain volumes as they seem to consistently produce overestimates for the same specimens based on Hurlburt et al.’s table), so that is a difference of 15% to 39 %, not 100%.

These two are unfortunately a bit lacking when it comes to size estimates (a general problem with these brain size studies); the only one available is a mass estimate of 4312 kg for AMNH 5117 when compared to Sue’s 5634 kg (based on the outdated stylopodial equations). This is cited as "Erickson pers. comm." by Hurlburt et al., and it is not clear how exactly it was estimated (as the specimen doesn’t have a femur), but is specifically stated to base on the same methodology (so presumably some sort of scaling from a specimen that had its mass estimated from this regression). Based on that, it is about 77% the mass of Sue (i.e., 6.4 t based on Hartman’s 8.4 t sue GDI), which would make this a fairly good representation of your average T. rex, and thus likely the average T. rex’ brain size.

So while this might shatter some people’s illusions, T. rex likely did not have a brain twice the size of Giganotosaurus’, but rather a brain about 15% larger for typical specimens, possibly up to 50% when comparing a particularly large T. rex and a small Giganotosaurus.

So between normal specimens, that’s an almost negligible difference, of the sort you can easily get between individuals of a single species (in fact the gap between AMNH 5117 and FMNH PR 2081 is far wider than that between the former and Giganotosaurus). Larsson et al. 2000 would suggest there might be a significant difference when it comes to cerebrum size. However, Hurlburt et al. suggest that the claims in this regard aren’t actually reproducible, with relative cerebrum size in Carcharodontosaurus being only slightly smaller than in T. rex, and relative cerebrum size in Allosaurus even being noticeably larger. Also, cerebrum size in Giganotosaurus hasn’t been quantified, with all previous comparisons basing on only Carcharodontosaurus (which has a smaller endocast overall, so naturally is expected to have a smaller cerebrum too). Perhaps this could be tried following Larsson et al.’s ellipsoid method based on the figures in Carabajal and Canale though, but I have my doubts about the solidity of that method, tbh. What’s really needed is a stronger statistical basis, incorporating specimens with more constrained mass estimates (the Giganotosaurus holotype is a lot more useful in this regard than Carcharodontosaurus), because many of the specimens analyzed are sorely lacking in this regard. 

Certainly I would agree with the statement that there is a probable trend of T. rex having a slightly bigger brain than giant carcharodontosaurs of similar size, but it is not even close to the claims commonly getting tossed around, and, at this stage, not very statistically solid either. What people on the internet make of this, namely that T. rex was some sort of genius when compared to other large theropods, is simply sensationalist BS.

I do wonder why after all this time, people still feel this innate need to exaggerate when it comes to T. rex? We keep stressing how T. rex is such a unique theropod, but if we always support that claim with exaggerations, it really takes away from the actual point, by making it from a unique theropod, primarily into a uniquely overhyped theropod.
Being so unique, shouldn't it be able to stand on its own merits, without exaggerations or biased assumptions?

Carabajal, A.P. and Canale, J.I. 2010. Cranial endocast of the carcharodontosaurid theropod Giganotosaurus carolinii Coria & Salgado, 1995. Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen 258 (2): 249–256.
Hurlburt, G.R., Ridgely, R.C. and Witmer, L.M. 2013. Relative size of brain and cerebrum in tyrannosaurid dinosaurs: an analysis using brain-endocast quantitative relationships in extant alligators. In: Tyrannosaurid Paleobiology, 1–21.
Larsson, H.C., Sereno, P.C. and Wilson, J.A. 2000. Forebrain enlargement among nonavian theropod dinosaurs. Journal of vertebrate Paleontology 20 (3): 615–618.

[Infinity Blade]

Jul 29, 2023 17:27:11 GMT 5 theropod said:

Infinity Blade

Giganotosaurus brains were half the size. “You don’t have to have a lot of focus if you’re going after walking walls of meat,” Holtz says. They came from a long line of giant predatory dinosaurs. Their “basic body plan” prepared them to hunt “long, slow-moving” herbivores, such as stegosaurs and sauropods.

This is quite clearly factually incorrect though.
The Giganotosaurus holotype has an endocast volume of 275 cm² (Carabajal and Canale 2010), the endocast volume of T. rex FMNH PR 2081 is 414 cm² (Hurlburt et al. 2013), so it is about 50% more voluminous, not twice as voluminous.

Other T. rex specimens have smaller endocast volumes, that of AMNH 5117 is 314 cm² (Hurlburt et al. 2013), and that of AMNH 5029 is 343 cm² (Larsson et al. 2000) to 382 cm² (Hurlburt et al. 2013; I am not sure what exactly the reason for this difference is, as they seem to have used similar methods in both cases, whereas I am disregarding the GDI estimates for brain volumes as they seem to consistently produce overestimates for the same specimen based on Hurlburt et al.’s table), so that is a difference between 15% and 39 %.

These two are unfortunately a bit lacking when it comes to size estimates; the only one available is a mass estimate of 4312 kg for AMNH 5117 when compared to Sue’s 5634 kg (based on the outdated stylopodial equations). This is cited as "Erickson pers. comm." by Hurlburt et al., and it is not clear how exactly it was estimated (as the specimen doesn’t have a femur), but is specifically stated to base on the same methodology (so presumably some sort of scaling from a specimen that had its mass estimated from this regression).

Based on that, it is about 77% the mass of Sue (i.e., 6.4 t based on Hartman’s 8.4 t sue GDI), which would make this a fairly good representation of the average T. rex, and thus likely the average brain size of T. rex.

So while this might shatter some people’s illusions, T. rex likely did not have a brain twice the size of Giganotosaurus’, but rather a brain about 15% larger for typical specimens, possibly up to 50% when comparing a particularly large T. rex and a small Giganotosaurus. So between normal-sized specimens, that’s a variation you can also easily get between members of one species, e.g. different individual humans. There might be a significant difference when it comes to cerebrum size, but this seemingly hasn’t been quantified for Giganotosaurus, only Carcharodontosaurus (which has a smaller endocast overall). Perhaps this could be tried following Larsson et al.’s ellipsoid method based on the figures in Carabajal and Canale though.

I do wonder why after all this time, people still feel this innate need to exaggerate when it comes to T. rex? We keep stressing how T. rex is such a unique theropod, but if we always support that claim with exaggerations, it really takes away from the actual point, by making it from a unique theropod, primarily into a uniquely overhyped theropod.

Carabajal, A.P. and Canale, J.I. 2010. Cranial endocast of the carcharodontosaurid theropod Giganotosaurus carolinii Coria & Salgado, 1995. Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen 258 (2): 249–256.
Hurlburt, G.R., Ridgely, R.C. and Witmer, L.M. 2013. Relative size of brain and cerebrum in tyrannosaurid dinosaurs: an analysis using brain-endocast quantitative relationships in extant alligators. In: Tyrannosaurid Paleobiology, 1–21.
Larsson, H.C., Sereno, P.C. and Wilson, J.A. 2000. Forebrain enlargement among nonavian theropod dinosaurs. Journal of vertebrate Paleontology 20 (3): 615–618.

I should stress that what I agree with is the overall “winner” of this hypothetical fight; I think it could go either way, as Holtz himself puts it (“If either of them managed to get a good bite onto the other one first, they’re probably going to win”). I think pretty much everyone who’s still posting on this forum agrees with this take.

There are still things in the article I disagree with, and the more I look at it, the more I take issue with it. In addition to the use of feet as weapons (or lack thereof) as I mentioned, I don’t think brain size is at all relevant here. Heck, I don’t even think it’s that relevant of a metric of animal intelligence in general. So yeah, don’t take this to mean I 100% endorse this article.

[Life]

Hmm, in view of recent posts, my vote is 50/50.

[tyrannasorus]

I just had a thought that in such a battle, wouldn't reach be most important? assuming both animals are of similar mass and seeing that they have a similar enough body plan they'd both roughly be about as strong as each other in using their weight(you could argue for T.rex being slightly more so due to its proportionally larger leg musculature)

I've seen in some comparisons that Giganotosaurus is taller than an equally sized T.rex and has a longer skull, ehich could give it an edge

in the end it's still a 50/50 from me 

[Infinity Blade]

Theropods in general would have had a ton of reach thanks to their body plans. Not only from their skull and necks, but also their torsos sticking straight out right from where they stood. They wouldn't have needed to properly outflank their foes, they could literally just turn their heads/necks/bodies to the side to sideswipe an opponent and grab them with their mouth. In fact, the distribution of facial bite marks in tyrannosaurids suggested they would attack with lateral swings of the head.

Given the high density of lesions on the lateral surfaces of the centers of the maxilla and dentary relative to the few lesions seen on the premaxilla and nasal (Fig. 5), and the fact that serial lesions are largely aligned with the long axis of the skull (e.g., TMP 1967.009.0164, 2003.045.0084; Supplementary Dataset S1) the most likely relative positions of the two animals is with their heads positioned side by side (lateral to each other), with the bites being delivered with lateral swings of the head (Fig. 12).

www.cambridge.org/core/journals/paleobiology/article/intraspecific-facial-bite-marks-in-tyrannosaurids-provide-insight-into-sexual-maturity-and-evolution-of-birdlike-intersexual-display/4AC2A6108BC1CE8E849280D9BC4BD9BB

So I'm not thinking reach is going to be a humongous deal, as both animals here have it in spades, can easily bring their primary weapons to bear, and will do so in pretty much the same way.

[brobear]

IMO; T-rex is a more sophisticated animal. I believe that the Coelurosauria were more "warm-blooded" than the Carnosaurs, thus greater stamina. I believe that pound-for-pound, T-rex is the stronger of the two, although Giganotosaurus might have has a slight edge in speed. It is also a contest of a mouth full of steak knives vs bone-crushing jaws filled with strong banana-sized teeth.

[theropod]

Aug 25, 2024 23:59:16 GMT 5 brobear said:

IMO; T-rex is a more sophisticated animal. I believe that the Coelurosauria were more "warm-blooded" than the Carnosaurs, thus greater stamina. I believe that pound-for-pound, T-rex is the stronger of the two, although Giganotosaurus might have has a slight edge in speed.

Are these beliefs in the religious sense, or is there a scientific basis behind them (if so, which one?)?
Asking because I am getting the impression debates on topics like this one keep going in circles, and the same handful of claims keep getting made (not specifically in this thread, but across iterations of it) without evidence.

[brobear]

Aug 26, 2024 16:54:03 GMT 5 theropod said:

Aug 25, 2024 23:59:16 GMT 5 brobear said:

IMO; T-rex is a more sophisticated animal. I believe that the Coelurosauria were more "warm-blooded" than the Carnosaurs, thus greater stamina. I believe that pound-for-pound, T-rex is the stronger of the two, although Giganotosaurus might have has a slight edge in speed.

Are these beliefs in the religious sense, or is there a scientific basis behind them (if so, which one?)?
Asking because I am getting the impression debates on topics like this one keep going in circles, and the same handful of claims keep getting made (not specifically in this thread, but across iterations of it) without evidence.

Coelurosauria appear to be more "aimed" at warm bloodedness considering so many proven to have had feathers. T-rex had Stereoscopic vision. A bigger brain. Stronger jaws. 
Where do you see religion. Have you discovered the "Book of Tyrannosaurus"?

[creature386]

Aug 30, 2024 14:21:10 GMT 5 brobear said:

Aug 26, 2024 16:54:03 GMT 5 theropod said:

Are these beliefs in the religious sense, or is there a scientific basis behind them (if so, which one?)?
Asking because I am getting the impression debates on topics like this one keep going in circles, and the same handful of claims keep getting made (not specifically in this thread, but across iterations of it) without evidence.

Coelurosauria appear to be more "aimed" at warm bloodedness considering so many proven to have had feathers. T-rex had Stereoscopic vision. A bigger brain. Stronger jaws. 
Where do you see religion. Have you discovered the "Book of Tyrannosaurus"?

Well, in science, it is good practice to cite your sources and use precise language.

"Warm-bloodedness" is a vague term, for example. "Homeothermy", "tachymetabolism", and "endothermy" are more specific.

Also, when making statements like "T. rex had stronger jaws", it's best to provide numbers with references, as different studies can, depending on their methods, get different results.

This is not to say that your statements are wrong. theropod's point is just that discussions are more constructive when we are clear and concise.

[brobear]

Quote; "Warm-bloodedness" is a vague term, for example. "Homeothermy", "tachymetabolism", and "endothermy" are more specific.
________________________________________________________________________________________________________

Bull crap "Fake Professor". If you lack the common horse sense to know the difference between "lizard cold-blooded" and "bird warm-blooded", then you're lost in this meaningless debate.
________________________________________________________________________________________________________

Also, when making statements like "T. rex had stronger jaws", it's best to provide numbers with references, as different studies can, depending on their methods, get different results.
________________________________________________________________________________________________________

So "Fake Professor", you have never researched this topic but you want me to research it for you?

[theropod]

Aug 30, 2024 14:21:10 GMT 5 brobear said:

Aug 26, 2024 16:54:03 GMT 5 theropod said:

Are these beliefs in the religious sense, or is there a scientific basis behind them (if so, which one?)?
Asking because I am getting the impression debates on topics like this one keep going in circles, and the same handful of claims keep getting made (not specifically in this thread, but across iterations of it) without evidence.

Coelurosauria appear to be more "aimed" at warm bloodedness considering so many proven to have had feathers. T-rex had Stereoscopic vision. A bigger brain. Stronger jaws. 
Where do you see religion. Have you discovered the "Book of Tyrannosaurus"?

I do not see religion, but when I see claims about beliefs presented without evidence, I think it is fair to question what the nature of said beliefs is.

I’m not sure what bite force and stereoscopic vision have to do with endothermy.

As for brain size, I think I’ve made a post on that on this very thread showing the difference is nowhere near what the online paleosphere has come to believe. Herculano-Houzel (2023) tried to use relative brain size as a predictor of metabolism (and vice versa, talk about a circular argument), but that work has received severe criticism on multiple accounts (e.g. Caspar et al. 2024), some of which I’ve summarized here→. Even then, she considered theropods in general to be endothermic (which is in agreement with the current consensus on the matter), not just tyrannosaurids. Either way, the error margins of any brain size estimate that arise simply due to us not knowing the precise fraction of the endocast occupied by brain tissue are much larger than the brain size differences between taxa that you are referring to, so this is not a meaningful line of evidence

Thermoregulatory feathers do imply something about metabolism, but I can make a good case for those to be a synapomorphy of all ornithodirans (shared with pterosaurs and ornithischians), or, even if not, at least fairly widespread among theropods (there is hard evidence of feathers in at least megalosauroids and allosauroids, which therefore covers Tetanurae at the least). See Cuesta et al. 2018, Rauhut et al. 2012 (and Cau 2024 regarding the phylogenetic relationships of Sciurumimus). We have a greater abundance of coelurosaur fossils preserving evidence of feathers not because there’s any reason non-coelurosaurs didn’t have them (such as supposedly being "less warm-blooded"), but because we have an abundance of small, well-preserved coelurosaur fossils, something we mostly lack for non-coelurosaurs.


---
Caspar, K.R., Gutiérrez-Ibáñez, C., Bertrand, O.C., Carr, T., Colbourne, J.A.D., Erb, A., George, H., Holtz Jr, T.R., Naish, D., Wylie, D.R. and Hurlburt, G.R. . How smart was T. rex? Testing claims of exceptional cognition in dinosaurs and the application of neuron count estimates in palaeontological research. The Anatomical Record n/a (n/a).
Cau, A. 2024. A Unified Framework for Predatory Dinosaur Macroevolution. Bollettino della Società Paleontologica Italiana 63 (1): 1–19.
Cuesta, E., Ortega, F. and Sanz, J.L. 2018. Appendicular osteology of Concavenator corcovatus (Theropoda: Carcharodontosauridae) from the Lower Cretaceous of Spain. Journal of Vertebrate Paleontology 38 (4): 1–24.
Herculano-Houzel, S. 2023. Theropod dinosaurs had primate-like numbers of telencephalic neurons. The Journal of Comparative Neurology.
Rauhut, O.W., Foth, C., Tischlinger, H. and Norell, M.A. 2012. Exceptionally preserved juvenile megalosauroid theropod dinosaur with filamentous integument from the Late Jurassic of Germany. Proceedings of the National Academy of Sciences 109 (29): 11746–11751.

[theropod]

Sept 2, 2024 16:35:29 GMT 5 brobear said:

Quote; "Warm-bloodedness" is a vague term, for example. "Homeothermy", "tachymetabolism", and "endothermy" are more specific.
________________________________________________________________________________________________________

Bull crap "Fake Professor". If you lack the common horse sense to know the difference between "lizard cold-blooded" and "bird warm-blooded", then you're lost in this meaningless debate.
________________________________________________________________________________________________________

Also, when making statements like "T. rex had stronger jaws", it's best to provide numbers with references, as different studies can, depending on their methods, get different results.
________________________________________________________________________________________________________

So "Fake Professor", you have never researched this topic but you want me to research it for you?

He is no Professor, fake or otherwise. But I do suggest you use a more respectful tone in the future, especially considering I’m pretty sure he has at least two paleontology degrees more than you.

If you lack the common horse sense to know the difference between "lizard cold-blooded" and "bird warm-blooded", then you're lost in this meaningless debate.

What lizard exactly are you talking about?
Because lizards are not all the same. Monitor lizards for example have low basal metabolic rates, but elevated maximum metabolic rates (giving them levels of stamina closer to those of mammals or birds than other reptiles). The same likely applies to most basal (non-Cynodont) Synapsids according to a study done by a friend of mine→. So are they "lizard cold-blooded" or "bird warm-blooded" by your definition? What exactly are you talking about?
What do you "believe" the basal and maximum metabolic rates of non-coelurosaurian theropods (which ones exactly?) to be as opposed to those of coelurosaurs?