• This monotonous series of dark, poorly laminated claystones was deposited in a oxic epicontinental marine basin [22]. Sedimentation rates and subsidence were relatively high, and the fauna includes soft-bottom dwellers (bivalve Bositra buchi, gastropods Teretrina opalina and ‘‘pelikan foot’’ Toarctocera subpunc- tata), ammonites (Leioceras opalinum, Pachylytoceras torulosum), brachio- pods (Discina sp.), and plankton (coccoliths, radiolarians, and dinoflagellates) [20,22]. Driftwood is common. Vertebrate remains such as ganoid fishes (Dapedium sp.) and ichthyosaur vertebrae are rare, but in southern Germany the general lack of Aalenian reptiles is caused by the rare exposure of Middle Jurassic rocks rather than preservational bias. However, the fast sedimentation rates of the Opalinuston Formation (120–150 m for only the Lower Aalenian) suggest that vertebrate finds should be fewer per cubic meter than, for instance, in the Toarcian Posidonia Shale. At Zell and Heiningen, the articulated ichthyosaurs were found in hard, sideritic limestone concretions