Archaeopteryx. Computer artwork of an Archaeopteryx defending its territory near the shore of a prehistoric sea. Archaeopteryx lived in the late Jurassic period (around 130 million years ago) and is the earliest known example of a fully feathered dinosaur. It was about the size of a modern European Magpie and is seen as the link between reptiles and birds. The highly evolved feathers may have permitted Archaeopteryx to glide short distances, however it's unlikely it could fly like a bird.