Parietal callus

Semicassis granulata has a parietal callus, visible here on the left side of the mouth of the housing, below the wall of the penultimate turn (parietal wall).

The parietal callus is part of the shell of various species of snail . It is a thickening of the parietal wall, that is the wall of the penultimate turn next to the spindle (columella) through further calcium deposits. The parietal callus is usually smooth and shiny, but can also be sculptured.

The function of the parietal callus has not yet been clarified, although it takes up a large part of the snail shell near the mouth, especially in many marine snails, and seems to have arisen several times independently of one another in various, unrelated snail families ( convergence ).

A parietalkallus is present in some families of marine shell snails such as the Ranellidae , Cassidae , Nassariidae , Ringiculidae , Olividae , Drilliidae, and Strombidae . But it also occurs in some families of terrestrial snails , e.g. B. with the Mulmnadeln (Aciculidae) and the Polygyridae .

Individual evidence

1. ↑ Lauren M. Maistros: Microstructure analysis of unusually extreme parietal callus in fossil Neogastropods. Paper No. 172-19, 2009 Portland GSA Annual Meeting, October 18-21, 2009 ( Paper )
2. ↑ José Kelbel: Daedalochila peninsulae - Morphology . University of Wisconsin website , 2007

literature

• T. Pain: A short glossary of molluscan terms. Conchological Society of Great Britain and Ireland, Papers for Students, no.4, London 1960

Web links

• Steve Wilson: Diagrams of parts of gastropod shell and glossary of terms: Callus . The Conchological Society of Great Britain and Ireland, revised on November 5, 2012 (accessed July 30, 2013)