And a dinosaur that broke into a run 163 million years ago unwittingly ... out all kinds of biomechanical theories about how the big animals moved, and how theropods evolved.

When we think of big dinosaurs, it's often famous examples like ... But while two legs are good for running - and so all predatory dinosaurs were bipedal - four legs can support a much larger body.

Paleontologists have certainly found some big T. rex, about 40 feet long and ... And while paleontologists have found trackways made by running dinosaurs before, this year paleontologists ...