This is the underside of a Knobed Welk (Busycon carica) with is foot retracted and its Operculum clossing it off. | Mermaiden Studio of Photography & Design
Buyscon spiniger or Busycon Carica, Whelk - Member Collections - The Fossil Forum
Busycon carica (Melongenidae) image 12362 at PlantSystematics.org
Knobbed whelk - Wikipedia
42 immagini, foto stock, oggetti 3D e immagini vettoriali Busycon carica | Shutterstock