''Pernastela howensis'', also known as the Lord Howe pinhead snail, is a tiny
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
land snail
A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial gastropod mollusks that have shells (those without shells are known as ...
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 ...
to
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 ...
's
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 trochoidal shell of the mature snail is 1.8–2.1 mm in height, with a diameter of 3–3.3 mm, and a raised spire. It is cream to pale golden-brown in colour. The whorls are shouldered and
sutures impressed, with widely spaced radial ribs. It has an roundly lunate aperture, flattened on the upper side by the reflected lip, and a moderately wide
umbilicus. The animal is unknown.
Distribution and habitat
The snail is known only from three worn shells collected from the summit of
Mount Gower in 1912, and it may be
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
.
References
*
howensis
Gastropods of Lord Howe Island
Taxa named by Tom Iredale
Gastropods described in 1944
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