Additional file 1: Movie 1. of Development of a lecithotrophic pilidium larva illustrates convergent evolution of trochophore-like morphology

Invagination of cephalic and trunk discs in larvae of Micrura sp. “dark.” A running z-projection movie of the confocal z-series used to make Fig. 4. Specimen stained with phalloidin (white) and propidium iodide (orange). Transverse sections (apical to vegetal), anterior lobe is up. Scale bar 50 µm. (MOV 11208 kb)