Cochlespira semiplana
| Cochlespira semiplana Temporal range:
| |
|---|---|
| Holotype from Auckland War Memorial Museum | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Order: | Neogastropoda |
| Family: | Cochlespiridae |
| Genus: | Cochlespira |
| Species: | †C. semiplana
|
| Binomial name | |
| †Cochlespira semiplana A. W. B. Powell, 1944
| |
| Synonyms[1] | |
| |
Cochlespira semiplana is an extinct species of sea snail, a marine gastropod mollusc, in the family Cochlespiridae.[1] Fossils of the species date to late Eocene strata of the St Vincent Basin of South Australia, and the Otway Basin between South Australia and Victoria.
Description
In the original description, Powell described the species as follows:
Shell of similar proportions to venusta, but with a more flange-like keel, bearing weaker tubercles, not upcurved, about 20 per whorl. There are no spirals on the spire-whorls, and the basal spirals are plain, not gemmulate. The body-whorl has a strong, sharply raised keel emerging from the suture and encircling the base. There are no spirals above this keel, but 21 plain cords from below it to the end of the anterior canal. Sinus and protoconch as in venusta.[2]
The holotype of the species measures 9.6 mm (0.38 in) in height and has a diameter of 3.9 mm (0.15 in).[2] It can be distinguished from other members of the genus Cochlespira due to having a broadly conical spire.[3] The species has a globose to sub-globose protoconch, a deviated tip which measures between 1.5-2 smooth whorls which merged with the teleoconch.[4]
Taxonomy
The species was first described by A. W. B. Powell in 1944, using the name Coronasyrinx semiplana.[2] In 1969, Powell recombined the species, leading to the currently accepted scientific name Cochlespira semiplana.[3] The holotype was collected prior to 1944 from Aldinga, South Australia, and is held by the Auckland War Memorial Museum.[5][6] The holotype has much of the ventral surface broken off, and represents an individual who was not fully adult.[3]
Distribution
This extinct marine species occurs in late Eocene strata of the St Vincent Basin of South Australia, including the Blanche Point Formation, and the Otway Basin between South Australia and Victoria, at the Browns Creek Formation.[5][7]
References
- ^ a b Cochlespira semiplana (A. W. B. Powell, 1944) †. Retrieved through: World Register of Marine Species on 23 February 2026.
- ^ a b c Powell, A. W. B. (1944). "The Australian Tertiary Mollusca of the Family Turridae". Records of the Auckland Institute and Museum. 3: 3–68. ISSN 0067-0464. JSTOR 42905993. Wikidata Q58676624. This article incorporates text from this source, which is under a CC BY 4.0 license.
- ^ a b c Powell, A. W. B. (9 September 1969). "The family Turridae in the Indo-Pacific. Part 2. The subfamily Turriculinae". Indo-Pacific mollusca. 2 (10): 215–416. ISSN 0073-7240. Wikidata Q136806872.
- ^ Long, D. C. (1981). "Late Eocene and Early Oligocene Turridae (Gastropoda: Prosobranchiata) of the Brown's Creek and Glen Aire Clays, Victoria, Australia" (PDF). Memoirs of the National Museum of Victoria. 42 (1): 15–55. doi:10.24199/J.MMV.1981.42.03. ISSN 0083-5986. Wikidata Q56195002.
- ^ a b 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.
- ^ "Cochlespira semiplana". Collections Online. Auckland War Memorial Museum. Retrieved 23 February 2026.
- ^ Darragh, Thomas A. (August 2024). "A checklist of Australian marine Cenozoic Mollusca". Memoirs of Museum Victoria. 83: 37–206. doi:10.24199/J.MMV.2024.83.02. ISSN 1447-2546. Wikidata Q136396722.