Allodiscus tessellatus
| Allodiscus tessellatus | |
|---|---|
| Holotype from the Auckland War Memorial Museum | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Order: | Stylommatophora |
| Family: | Charopidae |
| Subfamily: | Charopinae |
| Genus: | Allodiscus |
| Species: | A. tessellatus
|
| Binomial name | |
| Allodiscus tessellatus A. W. B. Powell, 1941
| |
| Synonyms[1] | |
| |
Allodiscus tessellatus is a species of land snail belonging to the family Charopidae.[2] Endemic to New Zealand, the species is found across the North Island and northern South Island in a range of forested and scrub habitats, often in association with rotting logs.
Description
In the original description, Powell described the species as follows:
Shell small, depressed, openly umbilicated, thin, closely radially ribbed, 12 per millimeter, interstices minutely reticulated with close, microscopic radial lines and still finer and closer spiral striae. Spire 1⁄4 height of aperture. Whorls 41⁄4, including a typical lightly convex spirally striated protoconch of 13⁄4 whorls. Outline of whorls strongly and evenly convex. Aperture lunate. Base rounded, impressed towards an open circular umbilicus one twentieth the major diameter of the shell. Inner lip very little reflexed, scarcely encroaching upon the umbilicus. Colour pattern in the form of an even tessellated pattern of rectangular patches of reddish-brown upon a pale buff ground. A circular zone around the umbilicus is clear of colour markings. On the spire whorls there are three spiral series of tessellations.[3]
The holotype of the species measures 2.3 mm (0.091 in) in height and 3.8 mm (0.15 in) in diameter,[3] with some individuals reaching a diameter of up to 4.5 mm (0.18 in).[4] The protoconch has 1.25-1.5 convex whorls, and is translucent buff in colour. The teleoconch has up to 2.75 convex whorls, and is translucent/white with a pattern on red-brown to yellow-brown axial marks of irregular width on spire.[4]
Taxonomy
The species was first described by A. W. B. Powell in 1941, using the name Allodiscus tessellata.[3] The holotype was collected by A.E. Brookes at an unknown date prior to 1941, from near Rūātoki in the Bay of Plenty, at an elevation of 244 m (801 ft) above sea-level. The holotype is held by the Auckland War Memorial Museum.[5][6]
Distribution and habitat
The species is endemic to New Zealand, found across the North Island and on the northern South Island, in the Tasman and Marlborough districts, as well as Nelson.[7][4] The species is found in a range of habitats, including podocarp, broafleaf and mixed broadleaf/podocarp forests, ranging from sea level to subalpine scrub up to an elevation of 1,560 m (5,120 ft) above sea-level. It is commonly found in association with leaf litter and wood debris, especially in areas with limestone soil, including the transitional zones of caves.[4] The species is often found near rotten logs.[8][9]
Fossils of the species dating to the Late Pleistocene and Holocene are known to occur in lake beds.[4]
Gallery
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Side view of A. tessellatus holotype
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Underside view of A. tessellatus holotype
References
- ^ Powell, A.W.B. (1979). New Zealand Mollusca: Marine, Land and Freshwater Shells. Auckland: Collins. p. 321. ISBN 0002169061.
- ^ Allodiscus spiritus A. W. B. Powell, 1952. Retrieved through: World Register of Marine Species on 8 December 2025.
- ^ a b c Powell, A. W. B. (1941). "Seven New Species of New Zealand Land Mollusca". Records of the Auckland Institute and Museum. 2: 260–264. ISSN 0067-0464. JSTOR 42905986. Wikidata Q58676617.
- ^ a b c d e Marshall, Bruce A.; Barker, Gary M. (2008). "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)". Tuhinga: Records of the Museum of New Zealand Te Papa Tongarewa. 19. Te Papa: 57–167. doi:10.3897/TUHINGA.19.E34170. ISSN 1173-4337. Wikidata Q106839774.
- ^ Blom, Wilma M. (2025). "Annotated Catalogue of Fossil and Extant Molluscan Types in the Auckland War Memorial Museum". Bulletin of the Auckland Museum. 22. doi:10.32912/BULLETIN/22. ISSN 1176-3213. OCLC 1550165130. Wikidata Q135397912.
- ^ "Allodiscus tessellatus". Collections Online. Auckland War Memorial Museum. Retrieved 8 December 2025.
- ^ "Allodiscus tessellatus Powell, 1941". NZ Mollusca. Retrieved 8 December 2025.
- ^ Solem, Alan; Climo, Frank M.; Roscoe, David J. (October 1981). "Sympatric species diversity of New Zealand land snails". New Zealand Journal of Zoology. 8 (4): 453–485. doi:10.1080/03014223.1981.10427971. ISSN 0301-4223. Wikidata Q107391994.
- ^ Barker, Gary M. (2005). "The character of the New Zealand land snail fauna and communities: some evolutionary and ecological perspectives". Records of the Western Australian Museum, supplement. 68 (1): 53. doi:10.18195/ISSN.0313-122X.68.2005.053-102. ISSN 0313-122X. Wikidata Q106728496.