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. Clearly it walked and perched like a bird. Its head had the reptilian feature of jaw bones. Its spine was extended into a bony tail - just like a reptile's. On both sides of the tail bones, clearly visible, were the clinching characteristics of birds - feathers.