Prehistoric fossils. Fossilised remains of a Aspidorhynchus sp. ray-finned fish (centre) and a Rhamphorhynchus sp. pterosaur (upper left). Rhamphorhynchus were flying reptiles that lived during the Late Jurassic period (150-148 million years ago). They had jaws with teeth, a long tail and a wingspan of just under two metres. Aspidorhynchus were slender fast-swimming fish that lived during the Jurassic and Cretaceous periods (200-65 million years ago). They grew up to 60 centimetres long and had tooth-lined elongated jaws.