Etremopsis opposita
| Etremopsis opposita Temporal range:
| |
|---|---|
| Holotype from Auckland War Memorial Museum | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Order: | Neogastropoda |
| Family: | Clathurellidae |
| Genus: | Etremopsis |
| Species: | †E. opposita
|
| Binomial name | |
| †Etremopsis opposita A. W. B. Powell, 1944
| |
Etremopsis opposita is an extinct species of sea snail, a marine gastropod mollusc, in the family Clathurellidae.[1] Fossils of the species date to middle Miocene strata of the Port Phillip Basin of Victoria, Australia.
Description
In the original description, Powell described the species as follows:
Small, fusiform, with tall turreted spire. Whorls convex, but with a straight sloping shoulder at two-thirds whorl height, which forms a slight angle above the greatest peripheral convexity. Sculptured with strong, rounded, vertical axials, 11 per whorl, extending from upper suture over base to neck; crossed by primary cords and secondary lirations. On the penultimate there are 5 lirations on the shoulder, 4 primary cords from shoulder angle to the lower suture, second from above at the periphery, and a single intermediate thread in each interspace. There are 16 primary cords on the body-whorl, last 7 closely spaced on the anterior end. Outer-lip strengthened by a heavy varix. Sinus deep, rounded, occupying the shoulder. Parietal tubercle scarcely developed; no other apertural processes. [2]
The holotype of the species measures 6 mm (0.24 in) in height and has a diameter of 2.7 mm (0.11 in).[2]
Taxonomy
The species was first described by A. W. B. Powell in 1944.[2] The holotype was collected at an unknown date prior to 1944 from the Altona Bay brown coal shafts in Victoria, Australia, and is held by the Auckland War Memorial Museum.[3][4]
Distribution
This extinct marine species occurs in middle Miocene strata of the Port Phillip Basin of Victoria, Australia, including the Gellibrand Formation.[3][5]
Gallery
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Reverse view of holotype
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Side view of holotype
References
- ^ Etremopsis opposita A. W. B. Powell, 1944 †. Retrieved through: World Register of Marine Species on 19 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 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.
- ^ "Etremopsis opposita". Collections Online. Auckland War Memorial Museum. Retrieved 19 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.