The Scenario

During the Jurassic the great inland seas of what is today Europe were home to a wide variety of vertebrates. In the foreground here the large marine crocodile Mystriosaurus chases a tasty-looking school of Dapedium. On the right, the large shark Hybodus is also after some fish, while overhead the pterosaur Campylognathoides skims along looking for its own prey. In the left background of the water are Plesiosaurus and the ichthyosaur Stenopterygius, large predators of the open sea.

The Environment

The inland seas of what is now Europe formed at various times during the Mesozoic. At times, they were ringed by coral reefs and pre-Alpine mountain-formation. During the Early Jurassic, a shallow sea formed in the area of central Europe; its sediments are the black shales of the Holzmaden Formation. This sea was very low in oxygen and nutrients, due to limited sea-water circulation, and this prevented animals from living on the sea bottom. Because there were no bottom-dwelling scavengers, animals that died while swimming or flying and fell to the sea's bottom, were preserved.