The Archaeopteryx is an impressive genus of early bird found among the Late Jurassic (about 150 million years ago) shale in Baviera (southern Germany, when Europe was just an archipelago of islands in a shallow warm tropical sea closer to the Equator than it is now). It shows the clear characteristics of reptiles and birds: articulated tail, formed with a lot of vertebra and feathers, maxila provided with tooth, anterior members transformed into wings, but conserving fingers and a reptile structure. The feathers supersede in the shown marvellous lithographic chalk. The Archaeopteryx is transitional between feathered dinosaurs and modern birds and could grow until 0.5 meters.
Quite interestingly, this specimen of Archaeopteryx was discovered two years after Charles Darwin published “On the Origin of Species” and it seemed luckily to confirm his theory of evolution, although apparently not clearly explaining how feathers have appeared suddenly.