Achatinella thaanumi

Achatinella thaanumi is an extinct species of snail from the endemic on the island of Oahu breathing land snail genus Achatinella.

Description

Achatinella thaanumi reached a body length of 19.1 mm and a case diameter of 11.6 mm. The diameter of the mouth was 10.3 mm. There were six turns. The white casing was perforated, linksgewunden, ovate - conical, thin but moderately enhanced. Above and below the edge region surrounding two chocolate belts the housing. The embryonic windings were white and were towards the tip blue gray. The shiny surface was marked with fine growth lines and with almost faded spiral strips. The spindle was conical with nearly straight outlines and a tiny tip. The seam had a narrow border. The mouth was drawn with faint white bands. The white aperture rim was pointed and inward slightly thickened. The white columellar fold was reinforced.

Dissemination

The occurrence was limited to a gorge of Mount Kaala in the region of Waianae on Oahu.

Status

The species is known only from two specimens from the collection of malacologists Ditlev Thaanum that were described in 1914 by Henry Augustus Pilsbry and Charles Montague Cooke. She died from the beginning of the 20th century. The reasons for the disappearance are unknown.