Maoritomella balcombensis

Maoritomella balcombensis Temporal range: middle Miocene PreꞒ Ꞓ O S D C P T J K Pg N ↓
Holotype from Auckland War Memorial Museum
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Neogastropoda
Family:	Borsoniidae
Genus:	Maoritomella
Species:	†M. balcombensis
Binomial name
†Maoritomella balcombensis A. W. B. Powell, 1944

Maoritomella balcombensis is an extinct species of sea snail, a marine gastropod mollusc, in the family Borsoniidae. ^[1] Fossils of the species date to the middle Miocene, and are found in the strata of the Port Phillip Basin of Victoria, Australia.

Description

Reverse view of holotype

In the original description, Powell described the species as follows:

Shell slender, sculptured with rounded spiral cords and dense, flexuous interstitial axial growth striae. Whorls lightly convex, very slightly angled by a peripheral carina, situated about or just below the middle. Above the carina there are two closely-spaced narrow cords submargining the suture, and two distant threads on the shoulder. Below the carina there are two cords equal in strength to the peripheral carina. About 16 primary spirals over body-whorl from the carina to the anterior end. Body-whorl rapidly contracted over base, leaving a long, slender, slightly twisted neck and anterior canal. ^[2]

The species has shells that measure 11.9 mm (0.47 in) in height and 4 mm (0.16 in) in diameter, with the holotype measuring 9.75 mm (0.384 in) in height and 3.5 mm (0.14 in) in diameter. ^[2]

Taxonomy

The species was first described by A. W. B. Powell in 1944. ^[2] The holotype was collected from Fossil Beach, Balcombe Bay, Victoria, Australia, at an unknown date prior to 1945. It 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]}

References

1. Maoritomella balcombensis A. W. B. Powell, 1944 † . Retrieved through: World Register of Marine Species  on 15 December 2025.
2. 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.
3. 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.
4. "Maoritomella balcombensis". Collections Online. Auckland War Memorial Museum . Retrieved 15 December 2025.
5. 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.