Monkey Directory: Science: Earth Sciences: Paleontology: Dinosaurs (2)   Dinosaurs are animals that dominated the Earth until the end of the Cretaceous period, 65 million years ago.   Sites: Wikipedia.org: Cretaceous-Tertiary extinction event Information about the period of massive extinction of species that occurred about 65.5 million years ago, best-known for the extinction of the dinosaurs. http://en.wikipedia.org/wiki/Cretaceous-Tertiary_extinction_event - Added: 25-Nov-05 MR: 7 Wikipedia.org: Dinosaur Overview, classification, evolution, extinction theories and links. http://en.wikipedia.org/wiki/Dinosaur - Added: 25-Nov-05 MR: 7