Turbinidae have a strong, thick calcareousoperculum readily distinguishing them from the somewhat similar Trochidae or top snails, which have a corneous operculum. This strong operculum serves as a passive defensive structure against predators that try to enter by way of the aperture or that would break the shell at the outer lip. These operculum are rounded ovals that are flat with a swirl design on one side and domed on the other. They are known as Pacific cat's eye or Shiva eye shells or mermaid money, and are used for decorative purposes.
Etymology
The common nameturban snail presumably refers to the shell's similarity in appearance to a turban. However, the scientific name Turbinidae is based on the genus name Turbo, which is Latin for spinning top, a child's toy. The word turbine has a similar derivation.
Taxonomy
Previously[when?] they were classified in the subclass Prosobranchia, in the order Archaeogastropoda in the superfamily Trochacea. Trochaecea is now a synonym for the superfamily Trochoidea. However, this is a quite ancient group of gastropods, probably originating in the Permian period 298 to 250 million years ago.[2] They have typical primitivecharacters like the nacreous interior of the shell.
Turbinidae was redefined and moved to the redefined superfamily Trochoidea according to Williams et al. (2008):[4]Angariidae was elevated to family level, Colloniinae was elevated to family Colloniidae within Phasianelloidea,[4] Margaritinae was moved to Turbinidae from Trochidae.[4]
This family consists of five following subfamilies according to Williams et al. (2008):[4]
Turbinids occur in shallow and deep waters. The family has a large distribution, from the tropics to the polar regions, but most of the species live in tropical and subtropical shallow waters.
^Alf A., Kreipl K. & Poppe G. T. (2003) The Family Turbinidae, Subfamily Turbininae, Genus Turbo. In: Poppe G. T. & Groh K. (eds.): A Conchological Iconography: 68 pp., 95 colour plates, ConchBooks, Hackenheim, ISBN3-925919-27-9.
^ abGofas, S. (2009). Prisogasterinae. In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2009) World Marine Mollusca database. Accessed through the World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=382193 on 2010-04-19
^Alf A. & Kreipl K. (2011) The family Turbinidae. Subfamilies Turbininae Rafinesque, 1815 and Prisogasterinae Hickman & McLean, 1990. In: G.T. Poppe & K. Groh (eds), A Conchological Iconography. Hackenheim: Conchbooks. pp. 1-82, pls 104-245.
Marshall, B.A. 1988. Skeneidae, Vitrinellidae and Orbitestellidae (Mollusca: Gastropoda) associated with biogenic substrata from bathyal depths off New Zealand and New South Wales. Journal of Natural History 22(4): 949–1004.
Vaught, K.C. (1989). A classification of the living Mollusca. American Malacologists: Melbourne, FL (USA). ISBN0-915826-22-4. XII, 195 pp.
Williams S.T., Karube S. & Ozawa T. (2008) Molecular systematics of Vetigastropoda: Trochidae, Turbinidae and Trochoidea redefined. Zoologica Scripta 37: 483–506.
External links
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