Localities of the Jurassic: The Solnhofen Limestone of Germany Towards the end of the Jurassic, about 155 milion years ago, a warm shallow sea studded with islands covered much of what is now Germany. Sponges and corals grew on rises in this sea, forming reefs that divided up parts of this sea into isolated lagoons. These lagoons were cut off from the ocean and also from terrestrial runoff.