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 first appeared in the Triassic period about 230 million  years ago. Non-avian dinosaurs roamed the earth until about 65  million years ago and then were wiped out,â¦ most like by the impact  of an asteroid or comet. Birds, which are now classified with the  dinosaurs, continue to live to this day. Dinosaurs lived on earth for over 160 million years. They were the dominant terrestrial vertebrates from the late Triassic period (around 230 million years ago) to the end of the Cretaceous period (around 65 million years ago).