Tyrannosaurus rex, often shortened to T. rex, is one of the most famous dinosaurs in the world. Its name means “tyrant lizard,” and it roamed North America during the late Cretaceous period, roughly 66 million years ago.
Giganotosaurus, meaning “giant southern lizard,” lived earlier in the mid-Cretaceous period — about 98 million years ago — in what is now South America. Fossils of both species have given paleontologists a treasure trove of data to study.
