Alvania cossmanni is an extinct species of minute sea snail, a marine gastropod mollusc or micromollusk in the family Rissoidae.[1]
| Alvania cossmanni | |
|---|---|
| |
| Shell of Alvania cossmanni (holotype) | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Order: | Littorinimorpha |
| Superfamily: | Rissooidea |
| Family: | Rissoidae |
| Genus: | Alvania |
| Species: | †A. cossmanni
|
| Binomial name | |
| †Alvania cossmanni Harmer, 1920
| |
Description
editThe length of the shell attains 1 mm, its diameter 1 mm.
(Original description) The minute, ovate shell is solid. The whorls are convex. The body whorl is ventricose and much the largest. The whorls are ornamented by very fine but distinct reticulate sculpture on the upper part of the body whorl. On the base and on the lower part they show rather strong spiral ridges. The spire is short. The aperture is subcircular and expanded. The suture is clearly marked. [2]
Distribution
editFossils of this species were found in late Pliocene strata at St. Erth, Cornwall, Great Britain.
References
edit- ^ MolluscaBase eds. (2024). MolluscaBase. Alvania cossmanni Harmer, 1920 †. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1027564 on 2024-02-06
- ^ Harmer F. W. (1920-1925). The Pliocene Mollusca of Great Britain, being supplementary to S.V. Wood's monograph of the Crag Mollusca. Vol. 2. Monographs of the Palaeontographical Society. 72(344): 485-652, pl. 45-52 (part 1, December 1920); 73(346): 653-704, pl. 53-56 (part 2, July 1921); 75(352): 705-856, pl. 57-64 (part 3, December 1923); 76(354): i-xiv, 857-900, pl. 65 (part 4, January 1925)
This article incorporates text from this source, which is in the public domain.
