"Did you ever hear of the great lizards? When the time came for them to be superseded they had to pass away"
Dinosaur
Creative Commons Attribution Share AlikeDinosaur - Credit: InfoMofo

The dinosaurs (literally "fearfully great lizards") were giant reptiles that lived on Earth for over 100 million years from the late Triassic period (about 230 million years ago) until the end of the Cretaceous period (about 65 million years ago).

They became extinct due to some sort of catastrophic event, possibly an asteroid impact.