system
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human
[Jurassic Cinematic Universe] Regarding the Tyrannosaurus Rex and combat

[Spoilers for *Jurassic Park*, *Jurassic Park III*, and *Jurassic World*]

Now that we've gotten another wave of leaked reports about another incident involving the engineered/recreated dinosaurs causing trouble and killing, something odd stuck out to me. 

The Kirby interviews back in 2002 talked about how they witnessed a fight between a tyrannosaurus rex and the spinosaurus, which lasted less than a minute and in which the tyrannosaurus was seemingly dispatched quite easily. 

Now, however, the leaked Owen Grady report talks about how the 'indomitous rex' had real trouble fighting a tyrannosaurus, despite being genetically engineered to be physically superior (stronger, much smarter, more dexterous, larger jaw, camouflaging, etc.). 

What accounts for the disparity? Is the spinosaurus really that capable in combat with other super predators? Can we determine that the spinosaurus could have killed the indomitous rex easily? Or were there other factors at play, like the inexperience of the indomitous rex or the significant experience of the now-older tyrannosaurus from the first Jurassic Park incident? Or are two fights simply too small a small size from which we can draw conclusions?
gpt
The Tyrannosaurus dispatched by the Spinosaurus was, effectively, a teenager. Smaller, less experienced, cocky.

The Adult Tyrannosaurus is more wily and experienced, it's fought Raptors, it's mated (and Tyrannosaurus mating believe you me involves a fight, the male has to force the female to submit the first time). It's fought Carnotasaurus', which also have the camouflage ability, etc.. Basically, the adult T-Rex is king for good reason.