Tyrannosaurus rex versus Spinosaurus aegyptiacus

[Vodmeister]

Spinosaurus of course. Size matters.

It's like Tiger vs Brown Bear, at size parity I'd favor the more fierce Tiger, at maximum sizes I'd favor the considerably larger Bear. Same goes with T-Rex vs Spino.

[wiffle]

Sorry for the necropost, but here is an actual comparison:

Not as tall as you thought, eh?

Judge from the head height, not Spinosaurus' sail/hump-it can't attack from there. In fact, just ignore it altogether.

In case it wasn't already obvious, those skeletal reconstructions are Scott Hartman's, although Spinodontosaurus compiled them all together. CM 3980's and Spinosaurus' weight are also his works.

[Deleted]

Sept 19, 2013 11:32:25 GMT 5 wiffle said:

Sorry for the necropost, but here is an actual comparison:

Not as tall as you thought, eh?

Judge from the head height, not Spinosaurus' sail/hump-it can't attack from there. In fact, just ignore it altogether.

In case it wasn't already obvious, that's Scott Hartman's.

I will not debate about the outcome of the fight itself, but I will comment on comparisons, points, and diagrams from both sides.

Spinosaurus is theorized to have short legs, which is the reason it's not so overly tall.

As you can see, a ~15.6-meter Spinosaurus aegyptiacus has a minimum ground-to-underside clearance of only roughly ~1.8 meters.

It actually helps to support weight better, as well as the benefits of making it more stable and less prone to falling over, as long legs aren't really the best for weight support and being stable, short legs do these better, as the center of gravity is lower.

[Grey]

Wiffle, The estimate of Spino at 12.5 tonnes and of CM 9380 at 7.5 tonnes are from Hartman ? He already posted his weight estimate for Spino ?

[Deleted]

Sept 19, 2013 17:56:49 GMT 5 Grey said:

Wiffle, The estimate of Spino at 12.5 tonnes and of CM 9380 at 7.5 tonnes are from Hartman ? He already posted his weight estimate for Spino ?

It's Spinodontosaurus' comparison, not Scott Hartman's

He scaled down FMNH PR2081 to get the CM 9380 mass estimate, which isn't really a wise option

And the Spinosaurus mass estimate wasn't shartman's, if it was then you would be able to find it at skeletaldrawing.com, and well, it's not there...

[Grey]

I know that's why I asked.

[creature386]

Sept 19, 2013 18:19:02 GMT 5 @brolyeuphyfusion said:

He scaled down FMNH PR2081 to get the CM 9380 mass estimate, which isn't really a wise option

Hasn't he said CM is also a robust morph?

[Deleted]

Sept 19, 2013 21:08:01 GMT 5 creature386 said:

Sept 19, 2013 18:19:02 GMT 5 @brolyeuphyfusion said:

He scaled down FMNH PR2081 to get the CM 9380 mass estimate, which isn't really a wise option

Hasn't he said CM is also a robust morph?

That's irrelevant, there is virtually no real gap between robust and gracile morphs, here's what blaze explained about morph differences on carnivoraforum on the "differences between male and female theropods" thread:

But the measure of robusticity and mass used by Larson was made from quadrupedal animals and while it results in reasonable mass estimates for quadrupedal dinosaurs it appears to fail hard with theropods, as an example, according to it, Stan and MOR 555 are around 60-70% heavier than the Acrocanthosaurus named Fran but mass estimates based on 3D models derived from laser scans of their mounted skeletons estimate their masses at about the same for the three specimens, this is obvious looking at their full skeletons, Fran is every bit as big and its comparatively "gracile" femur does not have such a profound effect on its mass.

I have no idea why this happens but it happens, and the results are the opposite of what's seen in quadrupedal dinosaurs where that equation generally results in higher estimates than those based on volumetric models from say, Greg Paul, but in theropods, the results are the lightest out there, examples being 2.4 tonnes for the almost 12m long Fran, 4 tonnes for Giganotosaurus and just over 5.5 tonnes for Sue, the largest T. rex, that's why in this case I go for femur length, femoral length is certainly a poor proxy for body size across different, distantly related clades or with different proportions and adaptations but among closely related taxa or within the same species? I doubt is bad enough as too fail at estimating the body size of individuals and the fact is, that in Tyrannosaurids, femora in the 1.1-1.2m range are indicators of total body lengths around 9-10m, are they robust? yes they are, are they heavier than gracile morphs with femora approaching 1.3m in length? I wouldn't be so sure, as I've explained above.

I also question the assignment of robust/gracile, there's 1% of difference between the upper end of gracile and the lower end of robust morph, does Larson ever account for ontogeny (honest question, I don't know)? why the 28 year old Sue is assigned to the robust morph when is only 1% more robust the the more robust of the gracile morph which is an 18 year old? does he mention stratigraphy? what if there's more than one species like in Triceratops?

I can't look at the plots anymore, they also got blocked in google books in my country but from what I remember (and the fact that there's only 1% of difference in the legnth/circumference ratio separating one morph from another) there weren't defined clusters, making the separation into two morphs rather arbitrary, specially since he doesn't seem to account for any other variable other than length vs circumference.

Scott Hartman also stated that CM 9380 would have been similar in mass to the Giganotosaurus carolinii holotype, and he even states that the carnosaur would probably edge CM 9380 out by a bit.

[theropod]

I'm quite sure to most people this was already totally clear anyway, but the myth of the hypertrophied spinous processes being some sort of Spinosaurus-achilles tendon is hopelessly flawed.
According to Molnar, 2001, two specimens of Acrocanthosaurus have healed fractures of their anterior caudal neural spines. This is obviously not a fatal type of injury.

[Grey]

Even in 2005 I was fighting that ridiculous idea against Spino-haters. That is so obvious it does even deserve a mention.

[Godzillasaurus]

Let me just keep this simple and say spinosaurus due to its large margin of a size advantage. Nuff said

[Grey]

Found again the quote from Greg Paul I think where he considers Carcharodontosaurus to be more powerful than Spinosaurus :

s6.postimg.org/ho2y1jqg1/Spinosaurus_Greg_Paul.png

This was mainly what brings my doubts about the claimed superiority of Spinosaurus in sheer strength compared to any other theropod.

[theropod]

Really, a quote from the Princeton Field Guide?

That's a good book, especially in terms of illustrations, but not all the claims are consistent or scientifically rigorous. Eg. he estimates Spinosaurus as 25% heavier than Giganotosaurus and even 2/3 more than Carcharodontosaurus, and yet claims them to be the same size.
An indication perhaps, but the main reason?

Even I personally could think of better reasons why that might be true, altough I don't believe it is.

[Godzillasaurus]

Dec 7, 2013 0:59:08 GMT 5 Grey said:

Found again the quote from Greg Paul I think where he considers Carcharodontosaurus to be more powerful than Spinosaurus :

s6.postimg.org/ho2y1jqg1/Spinosaurus_Greg_Paul.png

This was mainly what brings my doubts about the claimed superiority of Spinosaurus in sheer strength compared to any other theropod.

As in what? Bite force? Skull strength? What?

Unfortunately, he never stated the specifics of his argument. It seems to be mainly attributed to spinosaurus being an ichthyophage as opposed to an obligate macrophage, which is quite the opposite case in carcharodontosaurus. The strength of spinosaurus over many other theropods mainly comes from its size, in which case spinosaurus obviously has the advantage. But what he said is an opinion if I may say so myself; spinosaurus' lifestyle overall seems to be far more reliant on power.

For carcharodontosaurus, it most likely did not kill powerfully but instead would have only used its maxillary dentition in predation, which makes it no surprise as to why its skull morphology indicates high aptitude for backward pulling to rip apart the hide of a prey item. In spinosaurus, it was less-so well adapted for taking down exceptionally large animals in relation to its own absolute size and was instead probably more of an opportunist predator similar to most modern crocodilians (in which the false gharial and freshwater crocodile most closely resemble spinosaurus in terms of snout shape), basically meaning that the ability for it to kill dinosaurs does not come from its specialization in doing so but instead is attributed more to its overall size.

Spinosaurus comparably possessed a far more "corresponding" morphology to powerful predation, as it suggested that the creature was very well adapted for gripping fish, particularly those that were huge. This heavily overlaps tomistoma and similar animals, as they are primarily piscivorous by nature but yet exercise opportunism simply because they were powerful enough to kill animals much smaller than itself. If spinosaurus was comparable to the Indian gharial (which it was obviously not), it would likely have been restricted much more-so to very small animals overall and would have been ineffective at killing large and powerful animals (due to its considerably lower snout breaking point in this case, whereas in reality its snout was actually quite strong). This is why I find that claim by Greg Paul to be quite biased; there is no reason to believe that spinosaurus was nowhere near as powerful as carcharodontosaurus simply because it killed in a very different fashion (gripping vs cutting)

-But as for the actual fight, I feel inclined to say spinosaurus here. And while it certainly was the more gracile predator of the two, a large size advantage would make a victory a decent possibility.

[Runic]

It'd be nice to know if spinosaurus enacted a bite and shake method like dogs do to strong lateral resistance compared to say the bite and pull method of some carnosaurian theropods like Charcharadontosaurus. It'd of course be to a lesser extent than a tyrannosaur though.