Columbian Mammoth vs. Giganotosaurus carolinii

[kekistani]

Jan 3, 2020 7:24:13 GMT 5 denis said:

Jan 3, 2020 7:23:09 GMT 5 denis said:

I have to disagree with your claim. Triceratops was bigger than T.rex and it still hunted them. Edmontosaurus is another good example. The largest prey Giganotosaurus hunted only weighed 7-10 tons, according to George Paul. Giganotosaurus didn’t even hunt prey much larger than itself. Tyrannosaurus rex probably hunt Alamosaurus. It doesn’t matter if T.rex had a bone crushing bite. Did T.rex had teeth designed for hunting prey as large or larger than it, yes it did.

Don’t know why I put it in quotes but I’ll continue anyway. Giganotosaurus wasn’t even designed to hunt prey that had armed weapons like horns or tusk. T.rex had the experience not to mention, T.Rex was far smarter and more agile than Giganotosaurus.

But it was designed to hunt large, slow quadrupeds. Giganotosaurus is better designed for mammoth-hunting than T.rex. T.rex is slower than Giganotosaurus and less agile (It's extremely bulky) and you're neglecting to mention Giganotosaurus has experience hunting sauropods in its own habitat.

[Infinity Blade]

T.rex is slower than Giganotosaurus and less agile (It's extremely bulky)

T. rex, if anything, was faster than Giganotosaurus, and potentially more agile. Tyrannosaurids show modifications in their leg anatomy for greater speed such as more cursorial limb proportions, shock absorbing structures in their feet (to withstand the stresses of running better), greater room for leg musculature, and (at least in the case of the very largest tyrannosaurs and carcharodontosaurs) stouter femora.

While Tyrannosaurus is very bulky and probably had to move a more massive head when turning, in exchange it has the aforementioned shock absorbing structures in its feet, leg musculature, and I think(?) a more abbreviated torso that created less inertia when turning. So when it comes to adaptations for agility, it wasn't all one sided in favor of Giganotosaurus and its kin.

[kekistani]

Jan 18, 2020 22:10:40 GMT 5 Infinity Blade said:

T.rex is slower than Giganotosaurus and less agile (It's extremely bulky)

T. rex, if anything, was faster than Giganotosaurus, and potentially more agile. Tyrannosaurids show modifications in their leg anatomy for greater speed such as more cursorial limb proportions, shock absorbing structures in their feet (to withstand the stresses of running better), greater room for leg musculature, and (at least in the case of the very largest tyrannosaurs and carcharodontosaurs) stouter femora.

While Tyrannosaurus is very bulky and probably had to move a more massive head when turning, in exchange it has the aforementioned shock absorbing structures in its feet, leg musculature, and I think(?) a more abbreviated torso that created less inertia when turning. So when it comes to adaptations for agility, it wasn't all one sided in favor of Giganotosaurus and its kin.

Well, I never said it was one sided.

I still stand by the belief that Tyrannosaurus is slower than a theropod that is more gracile (by a good ton or two I think?) than it. The dinosaur need not be a faster runner to have better adaptations for running.

[Infinity Blade]

Well, I don't think you can broadly say that T. rex would have been slower than a theropod more gracile than it when, in fact, adult T. rex still overlap in size with the theropod in question. There would have been adult T. rex about as massive as even a Giganotosaurus that weighed closer to ~6.8 tonnes.

If you think a Tyrannosaurus' greater size would override any adaptations for speed it has, though, fine. I myself am not sure or would probably still lean towards the tyrannosaur being the faster of the two, but who really knows, I suppose.

[kekistani]

Jan 18, 2020 22:33:38 GMT 5 Infinity Blade said:

Well, I don't think you can broadly say that T. rex would have been slower than a theropod more gracile than it when, in fact, adult T. rex still overlap in size with the theropod in question. There would have been adult T. rex about as massive as even a Giganotosaurus that weighed closer to ~6.8 tonnes.

If you think a Tyrannosaurus' greater size would override any adaptations for speed it has, though, fine. I myself am not sure or would probably still lean towards the tyrannosaur being the faster of the two, but who really knows, I suppose.

I never said the great size would override adaptations for speed, just that it would be slower than a lighter and more gracile theropod. At the same weight, I think a 7 ton giganotosaurus would be longer but not as bulky than the equivalent T.rex. besides, t.rex actually achieved greater weight.

[Infinity Blade]

I never said the great size would override adaptations for speed, just that it would be slower than a lighter and more gracile theropod. At the same weight, I think a 7 ton giganotosaurus would be longer but not as bulky than the equivalent T.rex. besides, t.rex actually achieved greater weight.

Wait, I'm confused. You're saying that you don't think great size would override adaptations for speed, but then you say that a theropod that's more gracile and additionally lighter should be able to run faster than one that's more adapted to speed?

I know T. rex achieved greater weights (at least, potentially), my point was that some Tyrannosaurus could still be as light as Giganotosaurus, and in such a case, only the point regarding bulk/gracility would remain. And even then I don't really think being bulkier would be enough to make Tyrannosaurus slower.

[kekistani]

Jan 19, 2020 2:02:55 GMT 5 Infinity Blade said:

I never said the great size would override adaptations for speed, just that it would be slower than a lighter and more gracile theropod. At the same weight, I think a 7 ton giganotosaurus would be longer but not as bulky than the equivalent T.rex. besides, t.rex actually achieved greater weight.

Wait, I'm confused. You're saying that you don't think great size would override adaptations for speed, but then you say that a theropod that's more gracile and additionally lighter should be able to run faster than one that's more adapted to speed?

I know T. rex achieved greater weights (at least, potentially), my point was that some Tyrannosaurus could still be as light as Giganotosaurus, and in such a case, only the point regarding bulk/gracility would remain. And even then I don't really think being bulkier would be enough to make Tyrannosaurus slower.

T.rex can still move quickly. That doesn't necessarily mean it is going to be faster. Stride length is also a factor. Who would have the longer stride?

Well, I think so.

[Infinity Blade]

Stride length is also a factor. Who would have the longer stride?

The T. rex.

In other words, for a given femur length, tyrannosaurids have a longer distal limb length than those of most other theropods. Similarly, tyrannosaurids and ornithomimids of the same femur length have comparable tibia and metatarsal lengths. Thus, for a given angle of motion of the femur, a tyrannosaur could cover more distance than an allosauroid, ceratosaur, or other large-bodied theropod of the same femur length. Because distance covered per unit of time is the definition of speed, all other things being equal, tyrannosaurids should have been faster than any other comparably sized theropod.

www.academia.edu/293223/A_critical_re-appraisal_of_the_obligate_scavenging_hypothesis_for_Tyrannosaurus_rex_and_other_tyrant_dinosaurs

[kekistani]

Jan 19, 2020 2:59:35 GMT 5 Infinity Blade said:

Stride length is also a factor. Who would have the longer stride?

The T. rex.

In other words, for a given femur length, tyrannosaurids have a longer distal limb length than those of most other theropods. Similarly, tyrannosaurids and ornithomimids of the same femur length have comparable tibia and metatarsal lengths. Thus, for a given angle of motion of the femur, a tyrannosaur could cover more distance than an allosauroid, ceratosaur, or other large-bodied theropod of the same femur length. Because distance covered per unit of time is the definition of speed, all other things being equal, tyrannosaurids should have been faster than any other comparably sized theropod.

www.academia.edu/293223/A_critical_re-appraisal_of_the_obligate_scavenging_hypothesis_for_Tyrannosaurus_rex_and_other_tyrant_dinosaurs

Well then, that changes things.

Come to think of it, Giganotosaurus doesn't need to be particularly fast to hunt its prey.

I still stand by the opinion that Giganotosaurus is better equipped for hunting large bodies obligate quadruped, though.

[Verdugo]

Jan 18, 2020 21:59:42 GMT 5 kekistani said:

T.rex is slower than Giganotosaurus and less agile (It's extremely bulky)

Studies suggest the opposite trend though.
Snively et al 2019

Large tyrannosaurids (between 2 and 10 tones) have at least twice the Agilityforce or Agilitymoment values of the non-tyrannosaurids. For theropods in the 300–700 kg range, this gap increases to two to three times greater agility in juvenile tyrannosaurids than in allosauroid adults of similar mass. Comparing specimens of different body masses, tyrannosaurids have similar agility values to those of other theropods about half their size.

This study, through quantification of multi-body, multifaceted performance metrics, finds strong relationships between morphology, agility, and a distinctive performance capacity by tyrannosaurids. With respect to other theropods, tyrannosaurids are increasingly agile without compromising their large body mass, such that in a pairwise comparison, tyrannosaurids are achieving the same agility performance of much smaller theropods (Figs. 3–5). For example, a 500 kg Gorgosaurus has slightly greater agility scores than the 200 kg Eustreptospondylus, and an adult Tarbosaurus nearly twice the agility scores of the lighter Sinraptor This agility performance stratification suggests that these two groups may have had different ecologies, inclusive of both feeding and locomotory strategies.

Anyway, if you want more direct T-rex vs Giganotosaurus comparison, you can look at Table 3

Giganotosaurus (holotype):
Mass: 6907 kg
Inertia body: 35821
Agility scores (under four assumptions): 0.1; 0.511; 0.13; 0.507

T-rex (Sue):
Mass: 9130 kg
Inertia: 28847
Agility scores (under four assumptions): 0.231; 0.97; 0.227; 0.95

As you can see, the massive Sue specimen still has lower rotational inertia and higher agility scores (achieved by a combination of lower rotational inertia and relatively larger locomotion muscles) than the Giganotosaurus holotype.

Sue's agility would be about 1.75 times (one leg pivoting + no torque assumption) to 2.31 times (two leg pivoting + no torque assumption) greater than that of Giganotosaurus holotype despite being estimated to be about 2 tonne heavier

This study is consistent with earlier study such as Henderson & Snively (2003) which also suggests relatively lower rotational inertia in Tyrannosaurids (Figure 2). However, earlier study did not take into account of locomotion muscles like the later one did.

[elosha11]

I am still undecided on the mammoth v gigantosaurus for this conflict, but the insightful comments from @infinity Blade and Verdugo above do push me to be a bit more pro-T Rex in the classic T Rex v. Gigantosaurus match up.

[kekistani]

Jan 19, 2020 7:21:13 GMT 5 elosha11 said:

I am still undecided on the mammoth v gigantosaurus for this conflict, but the insightful comments from @infinity Blade and Verdugo above do push me to be a bit more pro-T Rex in the classic T Rex v. Gigantosaurus match up.

I put 50/50, because even with greater agility for T.rex Giganotosaurus is still a formidable carnivore of similar length. At parity it's one of 3 carnivores that actually stands a good chance of defeating rex.

[elosha11]

^Sure, pros and cons (I suppose) for both theropods. I might look up our current thread on T Rex v Gigantosaurus and see what has been posted there...