Alvania densecostata

Alvania densecostata is an extinct species of minute sea snail, a marine gastropod mollusc or micromollusk in the family Rissoidae.[1]

Alvania densecostata
Shell of Alvania densecostata (holotype)
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Caenogastropoda
Order: Littorinimorpha
Family: Rissoidae
Genus: Alvania
Species:
A. densecostata
Binomial name
Alvania densecostata
Harmer, 1920
Synonyms

Rissoa densecostata A. Bell, 1893

Description

The length of the shell attains 3 mm, its diameter 1 mm.

(Original description) The solid, minute shell is elongate-turreted. The whorls are convex. They are ornamented by numerous fine, nearly straight ribs, crowded closely together, intersected by spiral striae which become stronger and more prominent below the periphery.[2]

Distribution

Fossils of this species were found in late Pliocene strata at St. Erth, Cornwall, Great Britain.

References


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