Then, several hundred million years ago, huge and often terrifying new life forms, Pterosaurs, or flying dinosaurs, took the ascendancy. These massive creatures had wings of skin, stretched between one enormously elongated finger and their flanks. The bird was born. And so the flimsy biplane ceded aerial mastery to nature's many equivalents of the Boeing 767, Concorde, the B52 bomber, the stealth fighter. A huge variety of ancient bird types have come and gone and evolved to give us the 9000 different species we know today.
Many scientists are convinced that birds evolved from the dinosaurs.
Numerous finds in recent years have seemed to support the hypothesis that birds descended from two-legged, running dinosaurs called theropods. Archaeopteryx was possibly the most controversial prehistoric remain ever dug up. It is the oldest known bird fossil. Most biologists accept it as conclusive proof that dinosaurs sired birds. Archaeopteryx had three toes armed with claws and long, strong legs.