No one knows for sure, but there is a good chance that thedinosaur extinction came about as a result of a very large meteorstrike on Earth. Such a strike would have filled the air aroundEarth with dust, blocking a lot of sunlight. Without enoughsunlight, plants would die back, causing many dinosaurs to starve.(They needed tons and tons of plant material a day to eat.)With a scarcity of plant-eating dinosaurs, the meat-eatingdinosaurs in turn starved to death. Little animals that did not eatmuch mostly have survived.