Dinosaurs – Transcript
Dinosaurs are a varied group of extinct reptiles. They were the dominant land animals of the Mesozoic era (approximately 250 to 65 million years ago). Over 500 different kinds of dinosaurs are known. Fossils of dinosaurs have been found on every continent, and there are still frequent new discoveries.
Dinosaurs appeared about 250 million years ago. By the early Jurassic period, they dominated most environments on land. They continued to thrive until a sudden extinction event that occurred 65 million years ago. Many scientists believe that a meteor hit the Earth around this time, and wiped out all the dinosaurs.
From the fossil record, we know that birds are living feathered dinosaurs. They evolved from the earliest theropods during the Jurassic period. They were the only line of dinosaurs to survive to the present day.