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.
The discovery that birds are a type of dinosaur showed that dinosaurs in general are not, in fact, extinct as is commonly stated. However, all non-avian dinosaurs as well as many groups of birds did suddenly become extinct approximately 66 million years ago.hile modern dinosaurs (birds) are generally small due to the constraints of flight, many prehistoric dinosaurs were large-bodiedâthe largest sauropod dinosaurs are estimated to have reached lengths of over 40 meters (130 feet) and heights of 18 meters (59 feet) and were the largest land animals of all time.