A Look At "The Big Four": Lifestyle

Before I get started on this, this is not a "this dinosaur is better than this dinosaur because...." nor is it a "this dinosaur vs this dinosaur" type discussion. This is simply a rational look at the Lifestyles of "The Big Four," and speculation on what would happen if they were put in the environment of another.

Tyrannosaurus Rex, Giganotosaurus, Carcharodontosaurus, and Spinosaurus. These are the four dinosaurs that consist of "The Big Four." All four are over forty feet in length, all four weighed over seven tons. All four are viewed as the baddest of the bad, the meanest of the mean, and so on. All four were huge, and all four were unique.

Since Carcharodontosaurus and Giganotosaurus were almost the same animal, almost anything said here about Giganotosaurus can be applied to Carcharodontosaurus. If something applies to only one of the two, I will state that.

Tyrannosaurus Rex, Giganotosaurus, and Spinosaurus. Looking at all three, they are all visibly different from each other. Spinosaurus had large arms, a large sail, and a long, narrow skull. Giganotosaurus had mid sized arms, knifelike teeth, and eyes on the side of its head. Tyrannosaurus Rex had tiny arms that are the subject of many jokes, railroad spikes for teeth, and forward facing eyes. You may be wondering "What does this have to do with anything?" I'll get to that shortly.

What we have with T-Rex, Giganotosaurus, and Spinosaurus is three predators, all specially adapted for completely different lifestyles. Swap them around, and it's very likely none would last very long in the others environment.

Tyrannosaurus Rex had the potential to live in either Giganotosaurus or Spinosaurus's environment, but it's chances would be slim. Giganotosaurus had the potential to survive in Tyrannosaurus's environment, but would have difficulty taking on the King's game of choice. Spinosaurus would most likely thrive in Giganotosaurus's environment as there was plenty of fish and wetland for it to live, but the quantity of large predators would likely be it's downfall. In Tyrannosaurus Rex's environment, Spinosaurus was too specialized for an aquatic lifestyle to last very long in Tyrannosaurus Rex's home.

Now, let's focus on the two most important things that make these predators so specialized: Jaws and eye sight.

Jaws

Tyrannosaurus Rex

T-Rex has the highest bite force of any land animal to ever live. On top of that, it's jaws were filled with teeth like railroad spikes, capable of tearing five hundred pounds of flesh and bone off a carcass. Tyrannosaurus's favoured prey, Edmontosaurus, would most likely be easily dispatched by a well placed bite to the head, neck or spine.

Giganotosaurus

Giganotosaurus didn't have near the bite force of Tyrannosaurus Rex, but it didn't need the bite when it had teeth better designed for cutting through flesh. Giganotosaurus, unlike Tyrannosaurus, hunted sauropods. Sauropods aren't going to be taken out with a simple bite unless a predator could somehow reach the head. Instead, Giganotosaurus would attack its prey from the side, leaving large wounds that blood would flow from for hours on end. When the sauropod finally stopped, that's when Giganotosaurus would move in to finish the job.

Spinosaurus

Spinosaurus didn't have an exceptional bite force. It didn't need to have a strong bite though, because its teeth did the dirty work. Spinosaurus would catch fish in its jaws, and while the fish is held in place by the jaws, Spinosaurus would simply slash the fish until it died, or drop it on land and tear it to pieces with its foot claws.

Eye Sight

Tyrannosaurus Rex

T-Rex hunted prey its own size and smaller. Smaller targets require better aim, and how better to aim a bite then having depth perception? There isn't a better way. Tyrannosaurus eyes faced forward, giving it the ability to judge distance.

Giganotosaurus

Giganotosaurus was a sauropod slayer. It's targets would be in the twenty plus ton range most likely, so for targets that large, depth perception wouldn't be necessary.

Spinosaurus

Spinosaurus was piscivorous. It hunted fish, and while the sensors on the end of its snout would be sufficient, Spinosaurus also had depth perception. This makes Spinosaurus perfect for fishing.

Now, you see what makes these predators so specialized for their own environments. However, what would happen if they were put in the environment of one of the others?

Tyrannosaurus Rex

Put in Spinosaurus's environment, Tyrannosaurus would probably go for Hadrosaurs that lived in the area. Not a big deal, but there would be more sauropods than anything, and Tyrannosaurus wouldn't last long against them. Tyrannosaurus was also about as suited for fishing as a Spinosaurus was for hunting sauropods.

Put in Giganotosaurus's environment, Tyrannosaurus would go for the easiest meal. Unfortunately, there were no herbivores that weren't huge or extremely fast in Giganotosaurus's time. If it was forced to hunt sauropods, Tyrannosaurus wouldn't be able to do it. It wasn't agile enough, it didn't have the right teeth for the job, and while depth perception was great, a good field of view would be better for sauropod hunting.

Giganotosaurus

Put in Spinosaurus's environment, Giganotosaurus would probably thrive. Much like its cousin, Carcharodontosaurus, it would hunt sauropods.

Put in Tyrannosaurus's environment, Giganotosaurus would go for the easiest meal available, Edmontosaurus. It seems that Giganotosaurus wouldn't have any trouble at all, it's teeth being designed to cause blood loss, and it was a large predator. The problem wouldn't be finding its prey, and it wouldn't be attacking either. The problem would be hitting its target. Giganotosaurus was used to attacking sauropods, large targets that are easy to hit and precision wouldn't be needed. However, the neck of Edmontosaurus was a small target compared to what Giganotosaurus was used to, and that would ultimately be it's downfall.

Spinosaurus

Put in Giganotosaurus's environment, Spinosaurus would go to the rivers and be fine, other than the occasional Oxalaia that would likely challenge it.

Put in Tyrannosaurus's environment, Spinosaurus likely wouldn't last much more than a week or two. Yes, it had large claws, yes, it had depth perception. Spinosaurus would probably go for Edmontosaurus, but it's teeth and jaws would be a problem for dispatching its prey. Even if it did get a bite in and managed to start slashing, it wouldn't be quick, and the Edmontosaurus might be able to fight out and run away to die at its leisure.

Now, looking at this information, it's the Giganotosaurus that would fair best in the environment of the other two. Why? It was specialized, but not extremely specialized.

After Giganotosaurus, comes the Spinosaurus. While it wouldn't last a week in Tyrannosaur country, it would most likely thrive down in the south. While the quantity of theropods could cause some trouble, the sheer size of Spinosaurus, along with the sail on its back, would have most theropods take one look and then start running the other way.

Now, in last place for versatility, is Tyrannosaurus Rex. While it would manage in Spinosaurus's home, it wouldn't last too long, and it would last even less time in Giganotosaurus's home.