''Dignamoconcha'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of pinhead or dot snails 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 els ...

to Australia'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 ...

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 ...

Species

* ''

Dignamoconcha dulcissima ''Dignamoconcha'' is a monotypic genus of pinhead or dot snails that is endemic to Australia's Lord Howe Island in the Tasman Sea. Species * '' Dignamoconcha dulcissima'' Iredale, 1944 – the pagoda pinhead snail Description The trocho ...

'' Iredale, 1944 – the pagoda pinhead snail

Description

The trochoidal shell of the mature snail is 3.3 mm in height, with a diameter of 5.7 mm, with a stepped, pagoda-like spire. It is pale golden-brown in colour, with white radial streaks. The whorl profile is flattened above and below a strongly keeled periphery. It has a diamond-shaped aperture and widely open

umbilicus Umbilicus may refer to: *The navel or belly button *Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy * ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants *Umbilicus urbis Romae The ...

. It is the largest known punctid in Australia.

Distribution and habitat

Although the snail is sometimes reported from other sites on the island, its main area of occurrence is on the slopes of the southern mountains, at altitudes of 200–600 m in

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfo ...

, where it is arboreal and found on the undersides of green leaves, especially those of palms.

References

* Punctidae Monotypic gastropod genera Taxa named by Tom Iredale Gastropods described in 1944 Gastropods of Lord Howe Island {{Punctidae-stub