FIGURE 5. Life posture in Sinepecten segonzaci n. gen., n. sp. with byssal fixation compared in juveniles (sp. 2–4) and in the largest adult specimen (sp. 6), i.e. the holotype. a: parasagittal sections of bivalve specimens: tight byssal fixation fitting the lower (right) valve to the substrate; b: external view of antero­dorsal region of shell underside. Inner surface of upper (left) valve (grey) appears behind byssal notch of lower valve; c: parasagittal section along x­y showing byssus emerging from byssal notch. aa: anterior auricle; bf: byssal fasciole; bn: byssal notch; bs: byssal sinus. Arrows in (b) and (c) indicating relative growth direction of dorsal and ventral edges of byssal notch. On all figures, thick outline corresponding to lower (right) valve, coarse stipple to shell interior, and fine stipple to inner face of left valve.