Powellisetia comes is an extinct species of marine gastropod mollusc in the family Rissoidae.[1] First described by Harold John Finlay in 1926, it is known to have lived in New Zealand during the early Miocene.
| Powellisetia comes | |
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| Holotype of Powellisetia comes from Auckland War Memorial Museum | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Order: | Littorinimorpha |
| Family: | Rissoidae |
| Genus: | Powellisetia |
| Species: | P. comes
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| Binomial name | |
| Powellisetia comes (Finlay, 1926)
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| Synonyms[1] | |
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Description edit
Finlay described the species as follows:
Shell [subulate, highly polished, milk-white], but smaller, more inflated, and less slender [than Onoba lactea]. Whorls more convex, with deeper sutures. Peripheral subangle marked by a thread, indications of other spiral threads present. Faint axial plicae on upper whorls. Spire about 1½ times aperture in height, outlines a trifle convex. Outer lip and varix not nearly so crass as in last species, aperture suboval, less emarginate below. Umbilicus about same size, but less prominent, due to absence of encircling blunt angulation and rounder base. Height, 2 mm.; diameter, 1.2 mm. Locality,—[Pukeuri sandy clays (Awamoan, i.e. "Miocene") near Oamaru]. Nearly related to [Haurakia semireticulata], but shorter, with weaker peripheral thread and umbilicus.[2]
Distribution edit
Fossils of the species have only been identified in New Zealand.[1] The holotype was collected from the Mount Harris Formation near Pukeuri, Otago, which dates to the early Miocene era.[3][4]
References edit
- ^ a b c Bieler R, Bouchet P, Gofas S, Marshall B, Rosenberg G, La Perna R, Neubauer TA, Sartori AF, Schneider S, Vos C, ter Poorten JJ, Taylor J, Dijkstra H, Finn J, Bank R, Neubert E, Moretzsohn F, Faber M, Houart R, Picton B, Garcia-Alvarez O, eds. (2022). "Powellisetia comes Finlay, 1933". MolluscaBase. World Register of Marine Species. Retrieved 22 November 2022.
- ^ H. J. Finlay (23 December 1926). "A Further Commentary on New Zealand Molluscan Systematics". Transactions and Proceedings of the New Zealand Institute. 57: 320–485. ISSN 1176-6158. Wikidata Q96032915.
- ^ Blom, Wilma M. (2020). "Fossil and Recent molluscan types in the Auckland War Memorial Museum. Part 4: Gastropoda (Caenogastropoda - Neocyclotidae to Epitoniidae). [Cyclophoroidea, Cerithioidea, Littorinimorpha]". Records of the Auckland Museum. 55: 101–150. doi:10.32912/RAM.2020.55.7. ISSN 1174-9202. JSTOR 27008995. S2CID 229670783. Wikidata Q106828489.
- ^ "Powellia comes". Auckland War Memorial Museum. Retrieved 23 November 2022.
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