[ko_kyi]

Another thing - since predators are usually pretty fast, that thing would have had to eat ridiculous amounts of food. Are there any non-sea predators anywhere close to that size?

Scavenger makes a lot more sense. It is big enough to shoo away actual predators from their kills.

[mewzilla]

Well, fast is relative. Cheetahs are fast, but they're built for sprinting not long endurance runs. TR had really great thighs, so maybe he could sprint and bring down something that couldn't put up much of a fight. And as far as size goes, I think the carnosaurs were all over the place, weren't they? From the little nano-tyrano deals up to the really big guys? Probably affected how much they caught rather than how they caught it. I guess. I haven't kept up.

[presidio9]

Another thing - since predators are usually pretty fast, that thing would have had to eat ridiculous amounts of food. Are there any non-sea predators anywhere close to that size?

As someone pointed out, fast is relative. Also, predator-prey relationship are relative. There are no prey animals today the size of dinosaurs, but the largest land carnivore today, the polar bear, is plenty large relative to the seals it hunts.