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Syrnola Thelma
''Syrnola thelma'' is an extinct species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.W.H. Dall (1913), ''On a Brackish Water Pliocene Fauna of the Southern Coastal Plain''; Proceedings U. S. National Museum, Vol. 46—No. 2023 Description The small shell has an elongate-conic shape. It has a smooth appearance, except for incremental lines. The suture is distinct but not deep. The apical portion is decollate. The aperture is narrowly ovate. The outer lip is simple and blunt. The base of the shell rounds into a strongly twisted short pillar. The body of the shell has no visible callus. The length of decollate fragment (two whorls) measures 2 mm, the diameter 1 mm. Distribution A fragment of the shell of this brackish water species has been found near Alexandria Alexandria ( or ; ar, ٱلْإِسْكَنْدَرِيَّةُ ; grc-gre, Αλεξάνδρεια, Alexándria) is the second largest city in Egypt, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod Shell
The gastropod shell is part of the body of a Gastropoda, gastropod or snail, 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. Some gastropods appear shell-less (slugs) 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 (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the Aperture (mollusc), aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. Shell layers The gastropod shell has three major layers secreted by the Mantle (mollusc), mantle. The calcareous central layer, tracum, is typically made of calcium carbonate precipitated into an organic matrix known as c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
