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The gastropod shell is part of the body of many gastropods, including snails, a kind of mollusc. The shell is an exoskeleton , which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage.
The anal sulcus, also called the anal sinus or anal canal, in Gastropods is a notch, a shelly tube at the top of the aperture. [1] It is the first notch close to the suture. It houses the anal siphon through which the snail expels water and waste products. Shell of Drillia poecila Sysoev & Bouchet, 2001, showing the anal sulcus on top of the ...
Found in 1921 in the Wealden area of Sussex in England during construction of an arterial road, Dinocochlea was originally presumed to be a fossilised gastropod shell.As such, it was given a Latin name that translates to "giant terrible snail" using the "dino-" prefix in a nod to Dinosaur ("terrible lizard") and refers to the nearby, paleontologically significant, quarry that featured many ...
Siphonal indentations have evolved multiple times in gastropods and are widespread among many clades. Euomphanilae gastropods in the genus Scalites developed siphons in the early Ordovician period (448-443 MYA); however, they are not observed in any other members of the clade. 22 of an estimated >23 instances of siphonal indentations evolved in Murchosinoniinae gastropods - the two major ...
The shell of Semicassis pyrum has a large parietal callus, at the top in this image The shell of Cymatium pileare has a narrow parietal callus around the surface of the aperture nearest the columella, on the left of the shell opening as it is shown here. A parietal callus is a feature of the shell anatomy of some groups of snails, i.e. gastropods.
Gastropods whose shells have varices are primarily families and species within the taxonomic groups Littorinimorpha and Neogastropoda. The varix is a thickened axial ridge, a subcylindrical protrusion, in the shell which exists in some families of marine gastropods. It is an important shell character in generic classification.
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 ...
A spire is a part of the coiled shell of molluscs. The spire consists of all of the whorls except for the body whorl. Each spire whorl represents a rotation of 360°. A spire is part of the shell of a snail, a gastropod mollusc, a gastropod shell, and also the whorls of the shell in ammonites, which are fossil shelled cephalopods.