''Roblinella'' is a

monotypic genus 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 "unispe ...

of small

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 molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

s in the family

Charopidae Charopidae is a Taxonomy (biology), taxonomic family (biology), family of small air-breathing land snails (and semi-slugs such as ''Otoconcha dimidiata''), terrestrial molluscs, terrestrial pulmonate gastropod mollusks in the superfamily Punctoi ...

. The sole species is ''Roblinella roblini'', also known as Roblin's pinwheel snail. It is

endemic Endemism is the state of a species being found only 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 foun ...

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

. Other species formerly included in ''Roblinella'' have been transferred to other genera. However, Bonham (2007) pointed to existence of other, undescribed species that could be ''Roblinella roblinis closest relatives.

Distribution and habitat

''Roblinella roblini'' is known only from near

Launceston, Tasmania Launceston () is a city in the north of Tasmania, Australia, at the confluence of the North Esk River, North Esk and South Esk River, South Esk rivers where they become the Tamar River, Tasmania, Tamar River (kanamaluka). As of 2021, the Launc ...

. It is known from two localities about 30 km apart and is scarce at both. Surveys in the area did not reveal other populations. Specimens have been collected under/on

dolerite Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grain ...

rocks and in leaf litter in mid-slope scrub along a creek and in a gully under a fern.

Description

''Roblinella roblini'' is a small, white snail. Adults of 4.15–4.5 whorls measure in diameter, with historic records up to . The spire is flat or slightly raised. The ratio of shell height to diameter ranges from about one-third to one-half. The

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called " ...

has many small discrete interstical riblets that are not quite perpendicular to the primary spirals – this feature most clearly separates it from '' Gadoropa gadensis'' and most other small charopids in the region.

References

{{Taxonbar, from=Q3073723 , from2=Q106235950 Charopidae Taxonomy articles created by Polbot Monotypic gastropod genera Gastropods of Australia Invertebrates of Tasmania Endemic fauna of Tasmania Taxa named by Tom Iredale