The range of fossil species gives a comprehensive picture of a local Jurassic ecosystem. At times, the lagoons almost dried out, exposing sticky carbonate muds that trapped insects and even a few small dinosaurs. Over 600 species have been identified. Seven genera and up to 29 species of pterosaur have been found. This suggests that in this ecosystem pterosaurs were more common and diversified than birds. The pterosaur sizes ranged from that of a sparrow to 1.2 m (4 ft) in length.