''Palaina levicostulata'', also known as the fine-ribbed staircase snail, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of staircase snail that is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland P ...

in the

Tasman Sea The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abe ...

Description

The conical pupiform shell of adult snails is 4.9–5.1 mm in height, with a diameter of 2.4–2.6 mm and a conical spire. It is very pale to dark golden-brown in colour, sometimes with a white peripheral band on the final whorl. It has fine, closely spaced, axal ribs. The umbilicus is closed. The circular aperture has a strongly reflected lip and an operculum is present. The animal has a white body with dark grey cephalic tentacles and black eyes.

Habitat

The snail is most common in the Settlement region, with a few records from elsewhere on the island.

References

levicostulata Gastropods of Lord Howe Island Taxa named by Tom Iredale Gastropods described in 1944 {{Diplommatinidae-stub