Penion haweraensis

Penion haweraensis Temporal range: late Pliocene 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:	Austrosiphonidae
Genus:	Penion
Species:	P. haweraensis
Binomial name
Penion haweraensis (A. W. B. Powell, 1931)
Synonyms [1] [2]
Aeneator contractusLaws, 1940 Austrosipho (Verconella) haweraensisA. W. B. Powell, 1931

Penion haweraensis is an extinct species of sea snail, a marine gastropod mollusc in the family Austrosiphonidae. ^[1] Fossils of the species date to late Pliocene strata of the Tangahoe Formation in New Zealand.

Description

Reverse view of holotype

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

The fossil species is most distinctive in its early whorls, which are crossed by distant broad axial folds, nine to thirteen per whorl. These persist over all the post-nuclear whorls, although subobsolete in development. Typical mandarina never has axials on the later whorls, although there are from eighteen to twenty-one closely spaced axial folds on the early spire whorls. Whorls estimated at about nine. The protoconch is missing in the holotype, but a paratype shows a well preserved nucleus of three whorls...the spiral cords, which number nine on the penultimate and about twenty-four on the body-whorl, show a tendency to widen rather than to become prominently elevated, as in mandarina. The true outline of the Hawera species is a little narrower than shown in the holotype, which has been subjected to dorso-ventral pressure in the matrix. ^[3]

The holotype of the species has an estimated height of 123 mm (4.8 in), and a diameter of 58 mm (2.3 in). ^[3] It can be distinguished from P. mandarinus due to having nine primary cords and one thread per interspace on the penultimate whorl, compared to 10-12 primary spiral cords and between 2-6 spiral threads per interspace in P. mandarinus. ^[3]

Taxonomy

The species was first described by A. W. B. Powell in 1931, who named the species Austrosipho (Verconella) haweraensis. ^[3] As Austrosipho was synonymised with Penion in 1930, ^[4] the current accepted name for the species is Penion haweraensis. ^{[1] [5]} Powell believed that the species was ancestral to P. mandarinus , due to similarities in form and size, but differentiated the species based on sculpture detail differences. ^[3] In 1973, A. G. Beu synonymised Aeneator contractus with the species, finding that A. contractus was a juvenile form of the species. ^[2]

The holotype was collected in January 1931 from near the mouth of Waihi Stream near Hāwera, Taranaki, and is held in the collections of Auckland War Memorial Museum. ^{[6] [7]}

Distribution

This extinct marine species occurs in late Pliocene (Waipipian) strata of the Tangahoe Formation, primarily associated with the Taranaki and Manawatū–Whanganui regions of New Zealand. ^[6] Fossils of the species have been found near Hāwera, South Taranaki, ^[3] Martinborough in the South Wairarapa District, ^[8] and near Masterton in the Masterton District. ^{[9] [10]}

References

1. Penion haweraensis (A. W. B. Powell, 1931) † . Retrieved through: World Register of Marine Species  on 27 January 2026.
2. Beu, A. G. (September 1973). "Descriptions of new species and notes on taxonomy of New Zealand Mollusca, No.2". Journal of the Royal Society of New Zealand. 3 (3): 307–332. doi:10.1080/03036758.1973.10421860. ISSN   0303-6758. Wikidata   Q104025763.
3. Powell, A. W. B. (1931). "Waitotaran Faunules of the Wanganui System and Descriptions of New Species of Mollusca from the New Zealand Pliocene". Records of the Auckland Institute and Museum . 1: 85–112. ISSN   0067-0464. JSTOR   42905938. Wikidata   Q58676540. This article incorporates text from this source, which is under a CC BY 4.0 license.
4. Clench, William J. (April 1920). "On the status of Penion Fischer". Journal of Conchology. 19 (1): 21. doi:10.5962/p.406635 – via Biodiversity Heritage Library.
5. Maxwell, P.A. (2009). "Cenozoic Mollusca". In Gordon, D.P. (ed.). New Zealand Inventory of Biodiversity. Volume one. Kingdom Animalia: Radiata, Lophotrochozoa, Deuterostomia. Christchurch: Canterbury University Press. p. 245. ISBN   978-1-877257-72-8.
6. 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.
7. "Penion haweraensis". Collections Online. Auckland War Memorial Museum . Retrieved 27 January 2026.
8. "Penion haweraensis". Collections Online. Auckland War Memorial Museum . Retrieved 27 January 2026.
9. "Penion haweraensis (Powell, 1931)". Collections Online. Te Papa . Retrieved 27 January 2026.
10. Wells, Patricia E. (1989). "Late Neogene stratigraphy of the Carrington area, western Wairarapa, North Island, New Zealand". Journal of the Royal Society of New Zealand. 19 (3): 283–303. doi:10.1080/03036758.1989.10427183.