Simplify the following text for a Grade 10 native English-speaking person.
Original: Tarbosaurus ( ; meaning `` alarming lizard '' ) is a genus of tyrannosaurid theropod dinosaur that flourished in Asia between 70 and 65 million years ago , at the end of the Late Cretaceous Period .
Simplified: It was a tyrannosaurid theropod dinosaur that flourished between 70 and 65 million years ago , at the end of the Cretaceous period .