Article: Mode of life of a giant capulid gastropod from the Upper Cretaceous of Saghalien and Japan

The life habits of a huge Campanian patelliform gastropod, hitherto called 'Helcion giganteus', from Saghalien and Japan are discussed on the basis of several specimens adhering to enormous shells of Inoceramus (Sphenoceramus) schmidti. This gastropod is here transferred to the Capulidae of Mesogastropoda, and a new generic name, Gigantocapulus, is proposed for it. Its ecological relation with I. (S.) schmidti is regarded as parasitic by analogy to some living species of Capulus that attach to the valves of pectinids. This interpretation is supported by stratigraphic and geographic distribution patterns and by its functional morphology.