[RoughDobermann]

Yes, I think it was Walking with Dinosaurs on Discovery.

[goldstategop]

I have that one. The special effects are so realistic. The same team made the sequel, Walking With Prehistoric Beasts. Its out now. Anyway, even T-Rex didn't move that fast, it likely moved fast enough to take a prey animal by surprise. T-Rex in the Cretaceous food chain was more analogous to a cat than a dog. The smaller theropods probably ran in packs and hunted their prey down like modern canids do. Then again paleontology is guesswork, for one has ever seen a living T-Rex in action and the scientists would concede they don't know exactly how fast T-Rex did move over the prehistoric world's landscape.