It's kinda nuts how powerful that animal was. T. rex is a so-called durophage, an animal adapted to cracking extremely hard prey items. Some durophagous birds specialize in cracking nuts, a triggerfish may take a nice bite out of a piece of coral rock, an alligator may snack on a turtle - but a T. rex could crush the shell of an Ankylosaurus. Its jaws were powerful enough to not just crush bones, but to pulverize them.