Sixty-six million years after the last Tyrannosaurus rex walked the earth, its teeth still leave an impression — literally. In the badlands of Wyoming, researchers sifting through more than three thousand Cretaceous fossils found four bones bearing marks that match, with striking precision, the dental signature of the great predator. The discovery is less about the drama of ancient violence than about the quieter discipline of learning to read what stone has preserved: the difference between a kill and a meal, between predation and patience, between signal and noise.