molluscan foot A major structure in molluscan morphology. In gastropods the foot is the muscular sole that the animal crawls with. In cephalopods the funnel, and possibly the arms and tentacles are derived from the molluscan foot. The evolutionary origin of the latter is still uncertain. They may represent outgrowths of the head (favored by anatomical evidence: nerve connections) or modifications of the molluscan foot that have migrated around the mouth (favored by embryological evidence: migration of arm primordia). foot organism subdivision