Figure 1
The different shell layers of the modern terebratulide brachiopod Magellania venosa. (a) Schematic deduced from our FE-SEM and TEM results depicting the position of the periostracum, the two mineralized shell layers and the location of the mantle epithelium. The schematic shows the spatial relationship between the outer (OME) and inner (IME) mantle epithelium as well as the connective tissue in the growing shell. (b) AFM vertical deflection image visualizing the structure of the outward primary and inward fibrous shell layer. The corresponding lateral deflection image is shown in Fig. A2a; for additional information see Fig. A1a. The fibres are sectioned transversely. Clearly visible is the transitional area between the primary and fibrous shell layers.
