Article: Floating orientations of cephalopod shell models
Accurately constructed models of ammonoid shells were used in experiments on floating orientations. These experiments show that inflated shells of the cadicone type float stably, with or without liquid in the final chambers. Highly compressed involute shells are unstable unless the last two chambers contain liquid. The highly evolute shell type, represented by Dactylioceras, floats on its side when empty and vertically when the last four chambers contain liquid.