Fig. 16 in The dorsal shell wall structure of Mesozoic ammonoids

Fig. 16. Construction of the complete dorsal shell wall (transversal section, centrifugal). Lobolytoceras costellatum (Pavia, 2002), BSPG MAn-3059, late Oxfordian, Sakaraha, Morondava Basin, SW Madagascar. A. The dorsal shell wall consists of a dorsal outer prismatic layer, a dorsal nacreous layer and a dorsal inner prismatic layer. B. Close-up of A; the thick dorsal inner prismatic layer consists of two sub-layers. C. Close-up of A; the dorsal outer prismatic layer. Abbreviations: dipl, dorsal inner prismatic layer; dncl, dorsal nacreous layer; dopl, dorsal outer prismatic layer.