Fig. 4 in Exceptional cameral deposits in a sublethally injured Carboniferous orthoconic nautiloid from the Buckhorn Asphalt Lagerstätte in Oklahoma, USA

Fig. 4. Details of shell wall of the orthoconic nautiloid specimen BSPG 2011 0002 from the Carboniferous Buckhorn Asphalt Quarry, Oklahoma, USA. A. Venter showing the damage on the shell filled with sediment and proving that the damage extends through layer 1, thus opening the chamber for seawater, this establishes that alteration of the original cameral fluid was possible. B. Large spherical dark brownish deposits (layer 6; that the deposit directly above the bite mark appears whitish is an effect of the imaging technique; compare with thin section in Fig. 7A1). C. Siphuncular and cameral deposits in the adapical chamber; siphuncular deposits are best preserved at the adoral end of the chamber inside the connecting ring and adjacent to the ventral side of the septal neck. D. Fragmented siphuncle in the apical chamber with late post−mortem cement filling. Within the connecting ring there are blocky cements, hydrocarbons and some sediment, on the outside outer surface of the connecting ring cameral deposits are present. E. Preserved (circle on the right) and diagenetically altered (circle on the left) aragonite of the middle septum. Hydrocarbons partly cover the nacreous structure. F. Sector of the thin section in Fig. 7A1 illustrating the area of the ventral hole. In the upper right, the boundary between the dark brown cameral deposits is visible (arrow b). On the left and right of the hole the cauliflower−like layer 3 is present, identical structures are missing directly above the bite. On the left and right of and above the hole are the black deposit is present, but this layer is missing within the hole (arrows a). Vertical cracks (arrows c) through the whitish layer (layers 3 and 4) indicate that external pressure was exerted from the outside of the shell. On the right above the bite the whitish deposits shows a structure suggesting that the part left of the crack was moved upward (arrow d).