From Wikipedia, the free encyclopedia. A teenager, or teen, is a young person whose age falls within the range from 13â19. They are called teenagers because their age number ends with teen. Usage by ordinary people varies, and also varies in different societies.
Astronomers and other scientists often speak of the extinction of dinosaurs on this earth. They believe that dinosaurs disappeared from the earth some 65 million years ago, long before man came along.They make these statements as if it were a known, proven scientific fact that dinosaurs were long gone by the time men appeared on the earth.hey believe that dinosaurs disappeared from the earth some 65 million years ago, long before man came along. They make these statements as if it were a known, proven scientific fact that dinosaurs were long gone by the time men appeared on the earth.
Dinosaurs became extinct about 65 million years ago at the end of the cretaceous period (see what cretaceous dinosaurs were around at this time). About 70% of all animal life on earth died out. Scientists call it a mass extinction â it wasnât the first mass extinction in earthâs history and it probably wonât be the last! Having existed for 165 million years, why did dinosaurs die out? There are many different theories about why this happened.