Fig. 6 in Conellae, enigmatic structures on cephalopod shells -shapes, distribution, and formation

Fig. 6. Various inclusions in sediment-filled conellae. A, C. Sand grains in the conellae on the body chamber of Middle Callovian macroconch Rondiceras sp. from Nikitino locality, Ryazan region, Russia. A. GIN MPC 4/16, large sand grain on the top of conella. C. GIN MPC 4/17, small sand grain in the sediment which infilled the conella. B. Sand grain in the conella on phosphorite phragmocone of Late Volgian Virgatites virgatus (Buch, 1830) (GIN MPC 4/18) from Borsheva locality, Moscow region, Russia. D. Various algal microfossils in the internal mould of a body chamber and a conella, Amoeboceras serratum (Sowerby, 1813) [M] (GIN MPC 4/19) from Late Oxfordian, Rybaki locality in Moscow region, Russia.