Original sentence: Parasaurolophus was a genus of hadrosaurid (duck-billed) dinosaur from the Upper Cretaceous Period (about 76-65 million years ago) of what is now North America
Edited sentence: Parasaurolophus was a genus of hadrosaurid (duck-billed) dinosaur from the (in theroy) Upper Cretaceous Period (about 76-65 million years ago) of what is now North America