Giants like T. rex probably ambushed their prey, charging at them with jaws wide open. They could run at a speed of 32 km/h, although probably for only a very short distance. The impact of seven tonnes of dinosaur hitting its prey with a jagged mouthful of teeth would probably kill most animals outright. Many similar but smaller theropods retained powerful front limbs and claws, and could cling to their prey while biting it.
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