Turbinidae have a strong, thick calcareousoperculum readily distinguishing them from the somewhat similar Trochidae or top snails, which have a corneousoperculum. 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.
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 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. They have typical primitive characters like the nacreous interior of the shell.
2005 taxonomy
Turbinidae belongs to superfamily Turbinoidea according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).
This family consists of eight following subfamilies (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005):
Prisogasterinae Hickman & McLean, 1990 - synonym: "Prisogastrinae" in Bouchet & Rocroi (2005) is a spelling error.
Skeneinae W. Clark, 1851 - synonym: Delphinoideinae Thiele, 1924
Tegulinae Kuroda, Habe & Oyama, 1971
2008 taxonomy
Turbinidae was redefined and moved to the redefined superfamily Trochoidea according to Williams et al. (2008): Angariidae was elevated to family level, Colloniinae was elevated to family Colloniidae within Phasianelloidea, Margaritinae was moved to Turbinidae from Trochidae.
This family consists of five following subfamilies according to Williams et al. (2008):
Tegulinae Kuroda, Habe & Oyama, 1971: upgraded to the rank of family Tegulidae Kuroda, Habe & Oyama, 1971
Prisogasterinae Hickman & McLean, 1990
The following subfamilies (sensu Bouchet & Rocroi (2005) classification of subfamilies in Turbinidae) were kept in Turbinidae :
Moellerinae Hickman & McLean, 1990 - Moelleria was not included in the molecular studies performed in 2010.
† Moreanellinae J. C. Fischer & Weber, 1997
Distribution
The family Turbinidae, as defined by Williams et al. (2008):, consist of clades, occurring in shallow and deep water. 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.
