New research using computer models to reconstruct the jaw muscle of Tyrannosaurus rex, has suggested that the dinosaur had the most powerful bite of any living or extinct terrestrial animal.Previous studies have estimated that T. rex's bite had a force of 8000 to 13,400 Newtons, but given the size of the animal, thought to weigh more than 6000kg, researchers suspected that its bite may have been more powerful than this. Even with error margins factored in, the computer model still showed that the T. rex had a more powerful bite than previously suggested. The smallest values predicted were around 20,000 Newtons, while the largest values were as high as 57,000 Newtons.
Researchers also found that the results for the juvenile T. rex had a relatively the weaker bite than the adult T. rex, even when size differences and uncertainties about muscle size were taken into account. The large difference between the two measurements, despite the error margins factored in, may suggest that T. rex underwent a change in feeding behaviour as it grew. link