Original: Theropods first appeared during the Carnian age of the Late Triassic about 230 million years ago (Ma) and were the sole large terrestrial carnivores from the Early Jurassic until the close of the Cretaceous, about 65 Ma.
Simplified: Theropods first appear during the Carnian age of the Late Triassic about 220 million years ago. Then, they were the sole large terrestrial carnivores from the Early Jurassic until the close of the Cretaceous, about 65 million years ago.