Life in the Jurassic Sea 180 million years ago
180 million years ago, Europe was almost completely covered by the Jurassic Sea. Present-day southern Germany was then a shallow sea basin at the edge of the Tethys Sea, which gave rise to one of the world’s most celebrated fossil sites: Holzmaden.
The exceptional preservation of the fossils is due to the following factors:
- the low oxygen content at the bottom of the sea. This prevented the formation of decay gases in the animal corpses on the sea bed, which would have caused them to rise to the surface. Furthermore, no scavengers could inhabit the sea bed.
- a marine mud that was very fine and could penetrate all cavities and the finest pores of a dead animal.
- the lack of water movement and currents. The marine mud was deposited undisturbed in extremely fine layers. The bones of the dead marine creatures did not drift. They became embedded in the fine marine mud in situ as an intact skeleton.
Even the fates of individual sea creatures can be reconstructed.