Despite the very close packing, a slope of 2 indicates a more plate-like structure (Glatter and Kratky, 1982) and would correspond to such an ordered distribution of thin chitin layers (fitted by plates with a thickness of 4.7 nm), inside a dense calcium carbonate (Fig. 5), under the presumption of a large enough density difference between the chitin and the mineral. Interestingly, the SAXS-pattern of the external layers shows a hump at around 0.9 nm1,