Claim: Tusk shells, discovered in 1862, belong to the phylum Mollusca and are a class of shelled marine mollusk.
Evidence: The tusk shells or tooth shells, technically the Scaphopoda /skæˈfɒpədə/ (the scaphopods /ˈskæfəpɒdz/, from Ancient Greek σκᾰ́φης skáphē "boat" and πούς poús "foot"), are members of a class of shelled marine mollusc with worldwide distribution, and are the only class of exclusively infaunal marine molluscs. Phylum: Mollusca Scaphopoda
Bronn, 1862