Supplementary Figure 1

Three-dimensional contour diagrams depicting the postural stability (1/Λ) and the available space for soft-body (E) values on the Γ-Δ apertural inclination morphospace for various combinations of the translation rate T and umbilical width D (for the whorl translation rate W = 100.2). The positions of actual specimens with parameters close to the values depicted on the diagrams are plotted by symbols representing their respective habitats (land, freshwater, and marine). The criterion for including a specimen on the diagram is that the measured parameters (W, T, and D) fall within a certain range of the plotted values ( , Ts, and Ds), such that W = , T = Ts ± 0.5, and D = Ds ± 0.1.