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This shell has seven and a half whorls A fossil shell of the marine gastropod Turritella communis. This shell has nine whorls. A whorl is a single, complete 360° revolution or turn in the spiral or whorled growth of a mollusc shell. A spiral configuration of the shell is found in numerous gastropods, but it is also found in shelled cephalopods ...
The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less but may have a remnant within the mantle, or in some cases the shell is reduced such that the body cannot be retracted within it .
Species attributed to the genus Thapsia sensu lato have shell diameters ranging from about 15 to 30 mm, with 5½-6½ whorls. These rather featureless dextral shells are characterized by a low spire and their yellow to brown color. The spiral sculpture of the postembryonic shell is slender. In some larger * The sculpture of the radial ribs is ...
The molluscan shell has been internalized in a number of lineages, including the coleoid cephalopods and many gastropod lineages. Detorsion of gastropods results in an internal shell, and can be triggered by relatively minor developmental modifications such as those induced by exposure to high platinum concentrations. [41]
The first gastropods were exclusively marine, with the earliest known representatives appearing in the Late Cambrian (e.g., Chippewaella, Strepsodiscus). [37] However, their only definitive gastropod feature is a coiled shell, which raises the possibility that they may belong to the stem lineage of gastropods, or might not be gastropods at all ...
In gastropods the opposite to the aperture. [1] Ectocone – The outer cusp on the teeth of the radula. [1] Edentulous – Without teeth or folds, as the aperture in some gastropods. [1] Efferent – Carrying out. [1] Elliptical – With an oval form. [1] Elongated – Drawn out, as the spire of a shell. [1] Emarginate – Bluntly notched. [1]
Crepidula, commonly known as the slipper snails, slipper limpets, or slipper shells, is a genus of sea snails, marine gastropod mollusks in the family Calyptraeidae.This family includes the slipper snails (Crepidula), hat snails (), spiny slipper snails (Bostrycapulus), and cup-and-saucer snails as well as Crepipatella, Siphopatella, Grandicrepidula, and Maoricrypta.
shell of Rhodacmea filosa 31 May 2011 - the Wicker ancylid Rhodacmea filosa, (shell pictured) listed as extinct by the IUCN Red List, has been rediscovered. New gastropod taxa described in 2011; 18 April 2011 - Research on the mating of Chelidonura sandrana contradicts the traditional theory about mating in simultaneous hermaphrodites.