Alvania argillensis

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

Description
The length of the shell attains 1.6 mm, its diameter 1.1 mm.

Distribution
Fossils of this marine species were found in Oligocene strate in Aquitaine, France (age range: 28.4 to 23.03 Ma)