Locality and stratigraphy of Bonenburg clay pit #3 of Lücking Brick Company. A. Location of the clay pit in the eastern part of the State of North Rhine-Westphalia, Germany; B. Simplified stratigraphy of the Norian to Hettangian section exposed at the Bonenburg clay pit, with a special emphasis on the location of the four bone beds and the plesiosaur skeleton in the section. The main part of the section is made up by the Exter Formation which is subdivided into the Postera Beds, Contorta Beds and Triletes Beds, in ascending order. The thick dashed line on top of the Contorta Beds indicates truncation by a low-angle fault. Note that the reddish mudstones above the dashed white line also belong to the Triletes Beds. Colours of the rock types in the main stratigraphic column approximate colours in fresh outcrop. General abbreviations: Bb, bone bed; Cly, claystone; Fss, fine-grained sandstone; Het., Hettangian; L. J., Lower Jurassic; Md, mudstone; Nor., Norian; PF, Psilonotenton Formation; Slt, siltstone. Abbreviations of palynozones: CE, Classopollis-Enzonalasporites palynozone; RL, Rhaetipollis-Limbosporites palynozone; RP, Riccisporites-Polypodiisporites palynozone; PiK, Pinuspollenites-Kraeuselisporites palynozone. Subzones are labelled alphabetically. Modified from Wintrich et al. (2017), palynostratigraphy is from Gravendyck et al. (2020).