Vertebrate Fossils

The first fossil was not found in the Solnhofen Limestone, it was discovered in the Posidonienschiefer near Holzmaden, Germany in bituminous shaly marls. This is a similar anoxic lagoonal depositional environment as Solnhofen. These shales were deposited in the Lower Toarcican a little earlier in the Jurassic Period than the Solnhofen Limestones. The Posidonienschiefer is world renowned for the complete vertebrate fossils and the preservation of skin imprints fossilized in the rocks. There are some fossils preserved with stomach contents, and a large number of pregnant females in these shales. This may indicate a "birthing" ground which the ichthyosaurs may have migrated to for birthing (Briggs, 1990).

What makes the first two images so special is that this ichthyosaur, Stnepterygius quadriscissus , is that there is three embyros inside the body and another in the birthing process (modified from Briggs, 1990).
This is a close up of the above photo showing the birth of a young ichthyosaur (modified from Briggs, 1990).
This young ichthyosaur, Macropterugius pasthumus , Wagner, was found in the Solnhofen Limestone and its eye socket is 83 mm in diametre (modified from Barthel et. al., 1990).