In the cretaceous era, the T-Rex is thought to be the most feared and powerful carnivore, but how? It is very slow, with a maximum speed of 15 mph. It is not agile whatsoever, taking a full two seconds to make a 40 degree turn. It has almost no arms at all. Even though it stands and a tall 40 feet (12 meters) it is basically a big mouth on legs. All it has is a very strong mouth. It has tiny, two fingered, human sized arms that it can't even reach its own mouth with. I watched the Discovery Channel last night and it even said that the triceratops was a huge challenge for it and many other dinosaurs used their arms to kill prey. What do you think?
It does seem to be a powerful dinosaur, What it lacks in agility and arms, It makes up for extremely powerful jaws that can slice through solid bones, and a big powerful tail that it possibly used to sweep aside enemies, And it's large body mass that it supposedly used to ram into enemies, outbalancing them, and giving it the chance to bite into the opposing dinosaur's flesh.
I think they are slightly over rated because they lacked the use of their arms and they where nather slow.