Fasciolariidae, or spindle or tulip shells, is a family of small to large marine gastropod molluscs.   The shells are spindle-shaped and biconic and moderate to large size.  The size ranges between 10mm and 600mm. The largest species within the Fasciolariidae family is Triplofusus giganteus, commonly known as the Florida horse conch or giant horse conch that can reach a shell length of up to 600 mm. This makes it not only the largest fasciolariid, but also one of the largest shelled gastropods globally.  There are approximately 200 living species.