Archaeopteryx bird-like dinosaurs, illustration. These small dinosaurs lived 147 million years ago during the late Jurassic period. They measured 0.5 metres in length and are widely thought to be one of the first flying dinosaurs. Archaeopteryx fossils were a crucial piece of evidence showing that birds evolved from small, predatory dinosaurs. Twelve specimens of Archaeopteryx have been found, all from the Solenhofen limestones in what is now Bavaria, Germany.