Heterocithara miocenica

Heterocithara miocenica 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:	Mangeliidae
Genus:	Heterocithara
Species:	†H. miocenica
Binomial name
†Heterocithara miocenica A. W. B. Powell, 1944

Heterocithara miocenica is an extinct species of sea snail, a marine gastropod mollusc in the family Mangeliidae. ^[1] Fossils of the species date to the middle Miocene, and occurs 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:

Short fusiform-biconic; spire turreted; angle just below middle. Sculptured with narrowly-crested axial folds, extending from upper suture to over base, but not on the anterior end, 12 per whorl; crossed by narrow, widely-spaced spiral cords and a dense surface pattern of fine lirations, which are rendered granular by still finer and closer axial threads. There are three primary spirals on the spire-horls, upper-most at the periphery, lowest half immersed at the lower suture, and eight primary spirals on the body-whorl. Protoconch polygyrate, conic, of 34 whorls, with small, smooth tip, everted and inrolled; remaining whorls with obliquely curved, sharp axials. Adult apertural features unknown, as both available specimens are immature. ^[2]

The holotype of the species measures 7.9 mm (0.31 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 Balcombe Bay, Mornington, ^[3] Victoria at an unknown date prior to 1944, and is held by the Auckland War Memorial Museum. ^{[4] [5]}

Distribution

This extinct marine species dates to the middle Miocene, and occurs in the strata of the Port Phillip Basin of Victoria, Australia, from the Gellibrand Formation. ^{[4] [6]}

References

1. Heterocithara miocenica A. W. B. Powell, 1944 † . 18 November 2025. Retrieved through: World Register of Marine Species .
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.
3. Darragh, Thomas A. (1970). "Catalogue of Australian Tertiary Mollusca (except chitons)" (PDF). Memoirs of the National Museum of Victoria. 31: 181. doi:10.24199/J.MMV.1970.31.14. ISSN   0083-5986. Wikidata   Q56194898.
4. 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. Wikidata   Q135397912.
5. "Heterocithara miocenica". Collections Online. Auckland War Memorial Museum . Retrieved 17 November 2025.
6. 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.