Spinophorosaurus nigeriensis vs Acrocanthosaurus atokensis

[Carcharodon]

Spinophorosaurus nigeriensis
Spinophorosaurus (meaning 'spine-bearing lizard') is a genus of early sauropod dinosaur from Niger. It was recovered in a rock formation belonging to the lower part of the Irhazer Group, the age of which is unknown but may be Middle Jurassic or older. It is unusual for having spiked osteoderms, probably from the tail, similar to the famed thagomizer of stegosaurs. The type species, S. nigerensis, was described by Remes et al. in 2009. A study of its braincase showed that its neuroanatomy was in some ways intermediate between that of basal sauropodomorphs and that of neosauropods. It was about 14 metres long and may have weighed somewhere in the region of 7-10 tonnes.


Acrocanthosaurus atokensis
Acrocanthosaurus (meaning "high-spined lizard") is a genus of carcharodontosaurid theropod dinosaur that existed in what is now North America during the Aptian and early Albian stages of the Early Cretaceous. Like most dinosaur genera, Acrocanthosaurus contains only a single species, A. atokensis. Its fossil remains are found mainly in the U.S. states of Oklahoma, Texas, and Wyoming, although teeth attributed to Acrocanthosaurus have been found as far east as Maryland. Acrocanthosaurus was a bipedal predator. As the name suggests, it is best known for the high neural spines on many of its vertebrae, which most likely supported a ridge of muscle over the animal's neck, back and hips. Acrocanthosaurus was a huge theropod, approaching 11-12 metres in length and a mass of 5-6 tonnes. Its skull alone was nearly 1.3 metres in length. Recent discoveries have elucidated many details of its anatomy, allowing for specialized studies focusing on its brain structure and forelimb function. Acrocanthosaurus was the largest theropod in its ecosystem and likely an apex predator which possibly preyed on large sauropods and ornithopods.

[Vodmeister]

Acrocanthosaurus would most certainly win. The size disparity between the two isn't particularly big (5.5 tonnes vs 8 tonnes) and the theropod is much better armed than the sauropod. Those jaws of the archo look as if they could dish out some fatal damage to the spino.

[Deleted]

Acrocanthosaurus would win(around ~55-70% imo) unless the sauropod gets a good hit on the carnosaur(impaling it's legs or it's belly with it's thagomizers), which would allow it to finish it off while it's down. This is a predator adapted to take on this type of prey.

[Carcharodon]

A good bite to the neck or flanks should give acrocanthosaurus the win here.

[Godzillasaurus]

Given the fact that this wasn't a necessarily impressively large sauropod (unlike some of the other sauropods that would have been predated on by carcharodontosaurids), I see no reason why the theropod could not easily sever the creature's spinal cord in its neck, or to the very least cause massive ripping and blood-loss trauma! A flank bite seems more unlikely, given the fact that the two were rather close in size (whereas allosaurs would have most likely killed sauropods much larger than themselves by attacking the flanks). I think I am going to have to go with acrocanthosaurus here.

Also note that the tails of such sauropods would really only be VERY effective against animals much smaller than themselves (in that case, a few good whips could likely break some of the bones of the predators. Against larger predators, I could see some typical whipping damage occurring, but I do not think that would be fatal necessarily). Even putting the thagomizers into consideration, they do not seem to have been as well adapted for defense as those of stegosaurs.

[Infinity Blade]

I wouldn't be surprised if the spikes on the sauropod's tail were a lot (as in 2x as much) bigger than the bone cores, and if that were the case, this is a roughly even match IMO. Otherwise, Acrocanthosaurus wins.

[theropod]

Apr 3, 2014 3:22:22 GMT 5 Godzillasaurus said:

Given the fact that this wasn't a necessarily impressively large sauropod (unlike some of the other sauropods that would have been predated on by carcharodontosaurids), I see no reason why the theropod could not easily sever the creature's spinal cord in its neck. A flank bite seems more unlikely, given the fact that the two were rather close in size (whereas allosaurs would have most likely killed sauropods much larger than themselves by attacking the flanks). I think I am going to have to go with acrocanthosaurus here.

Also note that the tails of such sauropods would really only be VERY effective against animals much smaller than themselves (in that case, a few good whips could likely break some of the bones of the predators. Against larger predators, I could see some typical whipping damage occurring, but I do not think that would be fatal necessarily). Even putting the thagomizers into consideration, they do not seem to have been as well adapted for defense as those of stegosaurs.

What do you base that on? Sauropod tail-osteoderms remain poorly studied, but there’s no reason why they should be ineffective, considering the use of the tail as a defensive organ was likely common among sauropods anyway.

Is there anything that would preclude an allosauroid from attacking the flank of a similar-sized animal? If it could do that with a larger one, it could do so even more easily with a same-sized prey item.
I see no reason why it should even go after the spinal chord in a sauropod, it is much easier to cut the (really long) throat and watch it fall into shock and bleed to death.

[Godzillasaurus]

What do you base that on? Sauropod tail-osteoderms remain poorly studied, but there’s no reason why they should be ineffective, considering the use of the tail as a defensive organ was likely common among sauropods anyway.

The rather whip-like tail in sauropod groups like the diplodocoids and titanosaurs (for example) is the deadly factor (and possibly even their necks could be used as blunt bludgeoning weapons, but that is beside the point); a powerful whip could without a doubt cripple a much smaller carnivore. But in this case, the two animals were very close in size, so a tail whip would be less effective. Just a theory; long and whip-like sauropod tails would have been very deadly in groups that possessed them, whereas the stegosaurs were clearly in possession of thagomizers as their primary weapons.

Is there anything that would preclude an allosauroid from attacking the flank of a similar-sized animal? If it could do that with a larger one, it could do so even more easily with a same-sized prey item.

Depending on the positioning of the jaws and the height of the prey animal. If the two animals were of similar height at least (the theropod's head would be roughly in line with the sauropod's back), it would make sense to utilize the impalation and then backward ripping strategy to either sever the spinal cord that way or fundamentally rip apart the prey animal's dorsum, causing much physical trauma and blood loss alike. It would make more sense this way if the two were of similar size, as flank-biting seems to be the best way to attack a very large sauropod in relation to the theropod's size. Flank biting would simply be unnecessary if the theropod's head was in good enough position to attack in the way that I proposed.

I see no reason why it should even go after the spinal chord in a sauropod, it is much easier to cut the (really long) throat and watch it fall into shock and bleed to death.

Both are possible, but the throat is located below the spine. So in that case, the theropod would need to use both its jaws to clamp down on the sauropod's neck and pull backward that way. It is possible, but it is likely that there would be far more power if it utilized only its maxilla to impale the back of the neck and then rip backward that way. But again, both are possible, but it is just my theory.

[Infinity Blade]

I don't recall titanosaurs having tail whips. I thought they (tail whips) only existed in diplodocids and possibly some closely related-enough groups.

True that it probably might not have been exactly the best weapon against animals of the same size (though it will still cause nasty-looking wounds). But just so you know, even with a tail whip, diplodocids probably likely used the much thicker, fleshy midsesction to actually beat and bludgeon with.

[Godzillasaurus]

Titanosaurs did not have as whip-like of tails as diplodocids, but their tails were still long enough to have been used as whips, and were certainly rather whip-like in their own regard. But sauropod necks regardless would have been VERY deadly weapons assuming that the vertebrae would not be damaged; their necks were generally very thick and could easily cripple predators if used as a bludgeon:



And it seems highly unlikely that diplodocids would deliberately "position" their tails so that the thicker mid-base region would be used to clobber predators. Even though they were designed much like whips, they could still easily cripple smaller predators (and heavily damage larger and more powerful ones) regardless of where the tail makes contact. Enough force exerted could indeed lead to immense bone-breaking among smaller carnivores.

Or as I said, sauropod necks could have been used against larger predators, simply because their necks were generally more robust and thicker than their tails. It is like comparing a whip and a long club

[Infinity Blade]

Titanosaurs did not have as whip-like of tails as diplodocids, but their tails were still long enough to have been used as whips, and were certainly rather whip-like in their own regard.

But clearly not to a significant extent where it will matter.

And it seems highly unlikely that diplodocids would deliberately "position" their tails so that the thicker mid-base region would be used to clobber predators.

Why? Even Scott Hartman believes this could have been the case.

"The tails are ludicrously powerful, but I'm not convinced that the whip part is what you'd want to hit them with. Whips are really intended to not hurt too bad (i.e. be loud and sting) to coerce a desired behavior out of something. If you really want to do some damage you'd reach for a baseball bat or a lead pipe, and I suspect likewise that a diplodocid using its tail in defense would be trying to whack a theropod with the middle part of the tail, which is heavy enough to transfer some serious kinetic energy into your attacker.

As for people, I think a full-on hit from a large sauropod tail would have liquified parts on contact."

scotthartman.deviantart.com/art/quot-Thunder-Lizard-quot-82746236

[Godzillasaurus]

But clearly not to a significant extent where it will matter.

But they were still potential weapons regardless of if they are shorter proportionally than diplodocid tails

"The tails are ludicrously powerful, but I'm not convinced that the whip part is what you'd want to hit them with. Whips are really intended to not hurt too bad (i.e. be loud and sting) to coerce a desired behavior out of something. If you really want to do some damage you'd reach for a baseball bat or a lead pipe, and I suspect likewise that a diplodocid using its tail in defense would be trying to whack a theropod with the middle part of the tail, which is heavy enough to transfer some serious kinetic energy into your attacker.

But who is to say that a whip-like structure would not be damaging against considerably smaller predators? If allosaurus were to attack a fully grown apatosaurus, I do not see the theropod's skeleton faring too well if it gets struck. As it said, their tails were quite powerful, but it seems unusual to believe that the whip function could not be used to cripple considerably smaller predators.

I thought you were talking about the base region of the tail at first (where it would be too difficult to effectively strike an attacker). In which case, I can definitely see the thicker middle region of the tail being used as opposed to the more specialized and whip-like tip to attack a predator. I was misunderstood there for a moment. But still, the difference in robusticity does not seem to be THAT immense from the tip of the tail to the middle region, so any immense damage done with the whip-like tip is not completely out of the region; as that can still be used to transfer immense kinetic force (only in this case the damage would be less broadened). Any well-placed and powerful-enough strike of a diplodocid tail could easily cause massive physical trauma to any smaller predator's skeleton

[theropod]

On sauropod defense behaviour:

We can only speculate, I presume the whip could very well have been used in defense (along with display), but if a sauropod wanted to do really serious damage it would have used a heavier part of the tail in order to generate sufficient force.
Sure, the whip would hurt and cause lacerations, but if you want do break decent-sized bones or knock over large animals you’re gonna want to use something that has a greater mass.

The necks-as-bludgeons-theory never made much sense to me. Of course it is again a matter of weight, surely a 70t Argentinosaurus could have used its neck against a <1t Skorpiovenator. But in actions that would require large forces, and ones involving (relatively) large and formidable predators, the neck would be too fragile and vulnerable an organ.

Sauropod necks are relatively thick, but that’s because they are litterally air-balloons. The vertebrae have to be so inflated and pneumatic to have sufficient stiffness to operate at that scale, which essentially means two things:
• The amount of cushioning soft tissue around those vertebrae is relatively small (see figure 4 in Taylor & Wedel 2013→)
• The vertebrae themselves are relatively delicate things, susceptible to local fractures etc.

So I really cannot see a sauropod using its neck to deal out forceful blows of any kind.

Godzillasaurus:

Depending on the positioning of the jaws and the height of the prey animal. If the two animals were of similar height at least (the theropod's head would be roughly in line with the sauropod's back), it would make sense to utilize the impalation and then backward ripping strategy to either sever the spinal cord that way or fundamentally rip apart the prey animal's dorsum, causing much physical trauma and blood loss alike. It would make more sense this way if the two were of similar size, as flank-biting seems to be the best way to attack a very large sauropod in relation to the theropod's size. Flank biting would simply be unnecessary if the theropod's head was in good enough position to attack in the way that I proposed.

It can be in a perfect position for both… I’d presume a carnosaur approaching a prey item would simply bite the first (vital or fleshy) area it got access to, that way the time the prey has to retaliate is minimised and it can claw into it or go on to bite another part.

If it approaches from the front, it will bite the neck and cut the throat, if it approaches from the side, it will attack the flanks or belly, if it comes from posterolaterally, it will attack the tail base or tigh. A carnosaur bite is a quick and explosive matter, like a shark’s or komodo dragon’s, not a long gripping-and-wrestling-situation. It doesn’t need to be picky and precise with what it bites.

Both are possible, but the throat is located below the spine. So in that case, the theropod would need to use both its jaws to clamp down on the sauropod's neck and pull backward that way. It is possible, but it is likely that there would be far more power if it utilized only its maxilla to impale the back of the neck and then rip backward that way. But again, both are possible, but it is just my theory.

Well, attacking the dorsum isn’t really the most efficient way itself, there’s spinous processes that obstruct the way to the spinal chord. Carnosaurs aren’t really built for doing that sort of thing–that of course doesn’t mean they couldn’t under any circumstances, but there are better ways for them to kill.
The throat bulges out laterally, it can be attacked, depending on the angle the head is held in, by both the upper and the lower jaw. In any case it isn’t a very tough target, so a pull bite should in both cases do the trick.

But in this case, the two animals were very close in size, so a tail whip would be less effective. Just a theory; long and whip-like sauropod tails would have been very deadly in groups that possessed them, whereas the stegosaurs were clearly in possession of thagomizers as their primary weapons.

But we are talking about a sauropod that has thagomizers, not one that relies on a whip and blunt trauma.

[Fragillimus335]

I see Acrocanthosaurus winning at least 70% of the time, it's a specialized, 6 ton sauropod hunter taking on a 7-8 ton sauropod… I favor one of my favorite theropods over one of my favorite sauropods in this matchup.

[Godzillasaurus]

We can only speculate, I presume the whip could very well have been used in defense (along with display), but if a sauropod wanted to do really serious damage it would have used a heavier part of the tail in order to generate sufficient force. Sure, the whip would hurt and cause lacerations, but if you want do break decent-sized bones or knock over large animals you’re gonna want to use something that has a greater mass.

The difference in thickness of the center and tip of the tail isn't extreme. Any impact would be very damaging to a much smaller predator; as long as the size difference is major, the whip-like morphology of diplodocid and titanosaur tails would be crippling. But of course the damage would be more sufficient against a much larger predator comparably, but I would not take away the possibility that a powerful enough tail strike to the skull of such a creature (especially in acrocanthosaurus' case, which obviously did not possess a very robust skull) could easily incapacitate it.

Sauropod necks are relatively thick, but that’s because they are litterally air-balloons. The vertebrae have to be so inflated and pneumatic to have sufficient stiffness to operate at that scale, which essentially means two things:
• The amount of cushioning soft tissue around those vertebrae is relatively small (see figure 4 in Taylor & Wedel 2013→)
• The vertebrae themselves are relatively delicate things, susceptible to local fractures etc.

The vertebrae are designed to support the neck, but they do not make it up entirely. Sauropod necks are made up of immense amounts of muscle as well.

If it approaches from the front, it will bite the neck and cut the throat, if it approaches from the side, it will attack the flanks or belly, if it comes from posterolaterally, it will attack the tail base or tigh. A carnosaur bite is a quick and explosive matter, like a shark’s or komodo dragon’s, not a long gripping-and-wrestling-situation. It doesn’t need to be picky and precise with what it bites.

Well that is true. But depending on how tall it is compared to its prey (in this case, they were not that far apart in size), it seems highly unlikely that it would go in for the flanks if it were taller. But still, a bite anywhere would be very damaging; it is just the fact that the two were so similar in size that makes flank biting seem more unlikely.

Well, attacking the dorsum isn’t really the most efficient way itself, there’s spinous processes that obstruct the way to the spinal chord. Carnosaurs aren’t really built for doing that sort of thing–that of course doesn’t mean they couldn’t under any circumstances, but there are better ways for them to kill.

True, but I was referring to the probability that the most damage done in such a scenario would be done with violent downward strikes of the creature's skull (axe-biting). With enough precision, such a bite would easily be able to sever it. But the effects of such a forceful downward bite would still be very disastrous regardless of if it impacted the spinal cord; we are talking about serrated knife-like teeth being driven very forcefully into the dorsum of a prey animal, where it would likely be followed by immense blood loss. It is simply a very quick way to kill if you ask me. I am not denying that simply biting the musculature of the neck would be very deadly (it in fact would, as the theropod's teeth and jaws were perfectly designed for this)