Tyrannosaurus rex

Tyrannosaurus rex (meaning “king of the tyrant lizards”) was one of the largest meat-eating dinosaurs, reigning at the top of the food chain during the late Cretaceous period of the Mesozoic Era. It went extinct approximately 66 million years ago during the K-Pg extinction event.

Key Facts

• Classification: Theropoda, Tyrannosauridae
• Size: Up to 12-13 meters long; 8-9 tons weight
• Habitat: Western Laramidia (modern-day North America)
• Diet: Apex predator; scavenging behavior debated

Extinction and Context

The extinction of T. rex and other non-avian dinosaurs was caused by the chicxulub-impact event. Recent analysis of the immediate aftermath and Earth’s subsequent recovery highlights the severity of the climatic collapse that eliminated apex predators while allowing some smaller species to survive.

For detailed analysis of the impact mechanics, ecological collapse, and the transition to the Cenozoic Era, see Dinosaur Extinction Event: Chicxulub Impact, Aftermath, and Earth’s Recovery.