The discovery of Tyrannosaurus mcraeensis, a sister species of the famous Tyrannosaurus rex , suggests that tyrannosaurid dinosaurs originated on Laramidia, an island continent that existed between 100 and 66 million years ago and stretched from modern-day Alaska to Mexico. Life reconstruction of Tyrannosaurus mcraeensis. Image credit: Sergey Krasovskiy. āTyrannosaurid dinosaurs were the dominant predators
