Lithophaga, the date mussels, are a genus of medium-sized marine bivalve molluscs in the family Mytilidae. Some of the earliest fossil Lithophaga shells have been found in Mesozoic rocks from the Alps and from Vancouver Island.Ludvigsen, Rolf & Beard, Graham. 1997. West Coast Fossils: A Guide to the Ancient Life of Vancouver Island. pg. 102Kleemann, K.H., 1994. Mytilid bivalve Lithophaga in Upper Triassic coral Pamiroseris from Zlambach Beds compared with Cretaceous Lithophaga alpina. Facies 30, 151–154.
The shells of species in this genus are long and narrow with parallel sides. The animals bore into stone or coral rock with the help of pallial gland secretions,"integument (mollusks)."Encyclopædia Britannica. 2009. Encyclopædia Britannica 2006 Ultimate Reference Suite DVD hence the systematic name Lithophaga, which means "stone-eater". Their club-shaped borings are given the trace fossil name Gastrochaenolites.
Species Species within the genus Lithophaga include: Lithophaga antillarum (d'Orbigny, 1842) - giant date mussel Lithophaga aristata (Dillwyn, 1817) - scissor date mussel Lithophaga attenuata (Deshayes, 1836) - attenuated date mussel Lithophaga balanas Dall Lithophaga balanus Dall Lithophaga bisulcata (d'Orbigny, 1842) - mahogany date mussel Lithophaga cardigera Lithophaga cavernosa Lithophaga cinnamomeus Lithophaga dactylus Lithophaga fasciola Dall, Bartsch, & Rehder Lithophaga gracilis Philippi Lithophaga hawaia Dall, Bartsch, & Rehder Lithophaga ilabis (Deshayes) Lithophaga lithophaga (Linne) Lithophaga nigra (d'Orbigny, 1842) - black date mussel Lithophaga plumula (Hanley, 1844) - feather date mussel Lithophaga punctata (Kleemann & Hoeksema, 2002) Lithophaga rogersi S. S. Berry, 1957 - Roger's date mussel Lithophaga truncata (Gray, 1843) Lithophaga simplex
References
Stephen D. A. Smith, Densities of the endolithic bivalve Lithophaga lessepsiana (Vaillant, 1865) in Pocillopora damicornis, Solitary Islands Marine Park, northern NSW, Australia; Molluscan Research 31(1): 42–46; ISSN 1323-5818