T-Rex/Spinosaurus comparison

I agree with ya MrHappy. I am pretty sure that Tyrannosaurus did have extra ribs for one thing. Spino was almost certainly slimmer overall. That's one reason why I think it was relativity light weight. Did not have the overall muscle mass of other large theropods.

Thing is though, Spino didn't need to be as muscled as other large theropods. Spino may have hunted sometimes, but it would go for anything small or weak (like any other theropod given the choice), but had the extra ability to catch fish if land animals were scarce.

Why do you say that ? To me, Spinosaurus probably had to be more muscled than other theropods, my reason being, it swam a lot, which had to give it a lot of exercise, it had to drag huge fish out of the water, had to be able to stand up against other predators, like the ones i mentioned in my last discussion ( Sarchosuchus, Charcarodontosaurus, and Rugops ) And in my opinion, it must have hunted larger dinosaurs too. So, to me, it must have had just as much or more muscle than other Theropods.

We may never know how heavily muscled any dinosaur is. For all we know, Spino might not have even eaten fish. Scientists believe Spino was a fish eater because of fish scales found in a Baryonyx fossil. Swimming would be great exercise, but it likely would not have gone past knee deep most of the time. Dragging huge fish out is where Spino would have to work at it. If Spino did hunt large prey, it would likely do what any other predator would do and go for the stragglers. I think Spino would have intimidated it's opponents more often than not. If it did get into a fight, it would slash it's opponent (this is where dragging large fish out of the water would help). Spino was probably heavy muscled, but maybe not as muscled compared to other theropods pound for pound. I hope you agree with this answer. Great question, I really had to think about my answer.

Also, as far as how strong Tyrannosaurus was, it was not just strong when it comes to it's bite force and neck muscles. It's leg design suggests that it could walk long distances in search of prey, territory, etc. Great exercise right there. It would have very strong leg muscles along with it's jaws and neck.

As far as competition for T-rex goes, sure it did not have much. The only thing a Tyrannosaurus would fear, would be a larger Tyrannosaurus. Now, the reason why T-rex had no competition may be because nothing could compete with it. No other predator of similar size, could survive. It seems when the tyrannosaurs moved into a new location, they drove everything else out. They migrated to N. America from Asia at about the same time predators like Acrocanthosaurus died out. Coincidence? I don't think so. Once the big tyrannosaurs, Daspletosaurus, Albertosaurus, etc, showed up and then later Tyrannosaurus, nothing could compete with them.

Spinosaurus and T. Rex are two very different animals. Spinosaurus Aegypticus had a very frightening and intimidating appearance by dinosaur standards, but Tyrannosaurs had more complex brains, because they are later than Spinosaurus Aegypticus. In many circumstances the two would avoid each other. I find it unlikely that they would fight each other.

I have that same thought. In the end, it often comes down to intimidation. Or they would not be sure if the other was prey or a rival. Because their diets were probably different, they would probably ignore one another.

They all would get exercise somehow. All dinosaurs walked around, they didn't go to a prehistoric fast-food restaurant and sit on couches all day. Spino would swim, Rex would walk for hours on end. They would likely ignore each other due do differences in diet, but in desparate times, they would likely fight for anything and everything. For the most part though, they would likely leave each other alone.

T-Rex would have trouble getting up if it fell because of it's small arms but I don't think it would die from it unless another T-Rex or carnivore was involved. Other than that, it's a reasonable comparison between the two.

I think any carnivore that weighs over 8 tons would sustain injury if it fell no matter what. When you have that much weight falling, I don't care how big your arms are, it's gonna hurt.

im sure Spino probably walked a lot too, probably more than swimming

That's true. Any dinosaur is going to walk a lot. T-Rex and other large predators would probably follow a herd of dinosaurs around and therefore walk more than Spino, which likely would have just stayed near the same lake or river until it needed to find a newer, better fishing ground. It would walk more to find carrion and hunting small dinosaurs (not saying it can't take a larger dinosaur).

I have a comment to sort of turn this discussion in a different direction, based on a sub-discussion from another thread: I've always had this theory that Spino was not truely that attuned for swimming as depicting in Jurassic Park III. I thought that that fight scene was more fictional than scientific. But if you look at the skeleton and build, the clawed limbs would not be built for paddling through deep water. There's also the formation of the limbs in which the legs are longer than the arms, making it difficult for swimming (except in very deep water) unless the back legs were sprawled out behind. Also, while Spino's eyesight was good, I can't imagine it being able to see well underwater. To imagine Spino gliding through the water hunting fish is to me like imagining an ostrich taking flight. I do think Spino would have hunted fish, but either standing in or beside the river, and at most wading into it, but not actually swimming underwater. (Keep in mind I'm on team Spino, not by any stretch trying to undermine my favorite dinosaur or anything). Thoughts?

That is interesting. I think i mentioned something about it not swimming much on a different discussion.

I agree. It could probably swim if it had to, but not on a daily basis. That sail could catch a breeze and blow it off course if it was above the water, then again, it could act like a sail on a sailboat, I don't know. There is one thing I would like to point out about Spinosaurs. It's not downgrading him or anything. It's the way it won the fight I JP3. Of course Spino could beat a Rex once and a while, especially a sub-adult like in JP3. However, the way he did it was all wrong. It should have used it's claws more. They had him grab the Rex by the back of the neck in it's jaws and hold it's shoulders and head with it's hands to keep it from getting away. That was one thing. Then, he used his hands to twist the Rex's neck which broke it. Based on my research, which I did a lot before I brought this point up, Spino did not have the wrist action required to do this motion. It's not a matter of it's jaw strenth, but how it's wrists and hands could move. I just thought that was interesting.

Spino had a pretty good grasp on Rex's neck, and he used his arms to his advantage, aiding his neck muscles in snapping Rex's neck.

Yes, like I said, Spino did not have the wrist action needed to do that motion. I found it interesting that the Spino "magically" slipped free from the Tyrannosaurs' jaws. I think Spino should have used it's claws far more than anything else. The Rex should have used it jaws more than just head-butting the Spino.

I found an image with a skull comparison. [img]http://images3.wikia.nocookie.net/__cb20101003190116/archosauria/images/e/e2/Skulls2.png[/img] Pretty sure the one on the left is Carchar.

It is. It can also represent Giga in a way. All of them are huge. Spino and Carchar/Giga may have longer skulls than Rex, but Rex's is more powerful. It's like a bull-dog or Rottweiler compared to a husky or Labrador. Not as long, but stronger.