Allodiscus turbotti
{{Short description|Species of land snail}}
{{Use New Zealand English|date=August 2024}}
{{Speciesbox
| image =Allodiscus turbotti MA70898 001.jpg
| image_caption = Holotype of Allodiscus turbotti from the collections of Auckland War Memorial Museum
| taxon = Allodiscus turbotti
| authority = Powell, 1948
| status = NU
| status_system = NZTCS
| status_ref = {{cite web|url=https://nztcs.org.nz/nztcs-species/11923 |title=Allodiscus turbotti Powell, 1948 |website=New Zealand Threat Classification System |access-date=22 August 2024}}
| synonyms =
}}
Allodiscus turbotti is a species of land snail in the family, Charopidae.{{GBIF |title=Allodiscus turbotti Powell, 1948 |id=4598369 |access-date=22 August 2024}} The species was first described by Baden Powell in 1948, and is endemic to Manawatāwhi / Three Kings Islands in New Zealand.
Taxonomy
The species was identified by Powell in 1948, based on a shell found by Evan Graham Turbott on Manawatāwhi / Great Island in 1946, among sparse pōhutukawa and kanuka forest.{{Cite Q|Q58676663}}{{cite web|url=https://www.aucklandmuseum.com/discover/collections/record/223766 |title=Allodiscus turbotti |website=Auckland War Memorial Museum |access-date=16 August 2024}} Powell named the species after Turbott.{{Cite q|Q58628992}} Gene sequencing noted that A. turbotti was significantly different to other members of Allodiscus, meaning the species may potentially belong to a distinct genus.{{cite journal |last1=Marshall |first1=Bruce |last2=Barker |first2=Gary |title=A revision of the New Zealand landsnails referred to Allodiscus Pilsbry, 1892 and Pseudallodiscus Climo, 1971, with the introduction of three new genera (Mollusca: Gastropoda: Charopidae) |journal=Tuhinga |date=1 June 2008 |volume=19 |pages=57–167 |doi=10.3897/tuhinga.19.e34170|doi-access=free}}
Description
Powell's original text (the type description) described below:
{{cquote|
Shell globose, multicostate, umbilicate, pale-brown with a complicated pattern of radial bars, spots and chevrons. Whorls tightly coiled, 5½, including a low, convex protoconch of 14 whorls, all but the nucleus sculptured with closely-spaced thin radials. Spire about two-thirds height of aperture. Post-nuclear sculpture of dense narrow radials, 42 on the first whorl, 85 on the penultimate and about 150 on the bodywhorl. Interstices with from 4 to 10 exceedingly fine crisp radial threads. Radials flexuous, slightly protractive from suture and noticeably retractive before entering the umbilicus. Umbilicus open, one-tenth major diameter, deep, cylindrical, and slightly bridged by the reflexed inner lip. The base flattens somewhat towards the umbilicus and then resolves into a narrowly rounded encircling rim. Aperture lunate; peristome thin and flexuous, slightly protractive above, broadly rounded medially and deeply insinuated at the junction between the basal and inner sections of the lip. Suture deeply impressed, almost channelled. Colour pale brown with a chestnut colour pattern composed of irregular radially disposed rectangular patches at the suture which resolve into spots, and streaks of chevron form over the rest of the shell, base included. Major diameter, {{cvt|5.7|mm}}.; minimum diameter, {{cvt|5.1|mm}}.: height, {{cvt|4.15|mm}}.
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Powell noted that the species resembled A. cassandra, but could be told apart by A. turbotti being much smaller in adult size, open umbilicate, and by the presence of more numerous radial ribs. A. turbotti differs from other members of the genus due to prominent axial riblets on its protoconch, and finer spiral threads.
Distribution and habitat
The species is endemic to New Zealand, found on three islands of the Manawatāwhi / Three Kings Islands group: Manawatāwhi / Great Island, Oromaki / North East Island and Moekawa / South West Island. The species is common on Manawatāwhi / Great Island, and less common on the other two islands. The snail lives in leaf litter of broadleaf and kanuka forests.{{Cite journal| doi = 10.1080/03014223.2002.9517684| issn = 0303-6758| volume = 32| issue = 1| pages = 61–88| last = Brook| first = FJ| title = Changes in the landsnail fauna of Great Island, Three Kings Islands, northern New Zealand| journal = Journal of the Royal Society of New Zealand| date = 2002| bibcode = 2002JRSNZ..32...61B}} Due to its preference for forest leaf litter, the species is significantly less common than A. cassandra.{{cite Q|Q104026163}}
References
{{Reflist}}
{{Taxonbar|from=Q21362862}}
{{Authority control}}
Category:Gastropods described in 1948
Category:Gastropods of New Zealand
Category:Endemic fauna of New Zealand
Category:Endemic molluscs of New Zealand