Fig. 4From: Morphological disparity in extant and extinct sepiid phragmocones: morphological adaptions for phragmocone strength compared to those related to cameral liquid emptying hypothesesDeep water cuttlebones. Shorter than shallow water, with internal curvature of chambers and dorsal shield strengthening. High septal density, curvature of both internal septa and dorsal shield, which show series of ribs, or central rib for overall strengtheningBack to article page