Amalda australis

Amalda australis
A shell of Amalda australis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Neogastropoda
Family:	Ancillariidae
Genus:	Amalda
Species:	A. australis
Binomial name
Amalda australis (Sowerby, 1830)
Synonyms
Amalda (Baryspira) australis(G. B. Sowerby I, 1830)· accepted, alternate representation † Amalda waikopiroensis(Suter, 1917) Ancillaria australisG.B. Sowerby I, 1830 (original combination) Ancillaria pyramidalisReeve, 1864 Baryspira australis(G.B. Sowerby I, 1830) † Baryspira australis epacraOlson, 1956

Amalda australis, common name the southern olive, is a medium-sized sea snail, a gastropod mollusc of the family Ancillariidae. ^[1]

Description

The length of the shell attains 52 mm, its diameter 23 mm.

The shell is elongate and fusiform, with a smooth, glossy surface. The spire is relatively short compared to the large body whorl, and the overall shape is sleek and streamlined, allowing the snail to easily burrow into sand. The coloration of the shell varies from creamy white to light brown, often with subtle darker bands or streaks. The aperture is long and narrow, with a thin outer lip. The inner lip and columella are typically coated with a thin callus. ^[2]

Habitat

These predatory snails live in the intertidal sand, ^[3] an environment that lends itself to high probability of fossilization. ^[4] Amalda australis fossils date back to the Pliocene and reveal morphological stasis. ^{[5] [6]}

Distribution

A live Amalda australis collected from seagrass bed at Kohimarama Beach, Auckland

This marine species is endemic to New Zealand. ^[3] and occurs off North Island and northern part of South Island down to Banks Peninsula. ^[7]

References

1. Sartori, A.; Rosenberg, G. (2014). Amalda australis (G.B. Sowerby I, 1830). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=409967 on 2014-01-30
2. Sowerby G.B. I (1830). Species Conchylirum or concise original descriptions and accompanied by figures of all the species of Recent shells, with their varieties. G.B. Sowerby, London. page(s): Species 27, pl. 211, fig. 1,2 This article incorporates text from this source, which is in the public domain .
3. Michaux, B. (1987). "An analysis of allozymic characters of four species of New Zealand Amalda (Gastropoda: Olividae: Ancillinae)" . New Zealand Journal of Zoology. 14 (3): 359–366. doi:10.1080/03014223.1987.10423006. ISSN   0301-4223.
4. Gemmell, Michael R.; Trewick, Steven A.; Hills, Simon F. K.; Morgan‐Richards, Mary (2019). "Phylogenetic topology and timing of New Zealand olive shells are consistent with punctuated equilibrium". Journal of Zoological Systematics and Evolutionary Research. 58 (1): 209–220. doi: 10.1111/jzs.12342 . ISSN   0947-5745.
5. Michaux, B. (1989). "Morphological variation of species through time" . Biological Journal of the Linnean Society. 38 (3): 239–255. doi:10.1111/j.1095-8312.1989.tb01577.x. ISSN   0024-4066.
6. Reeve L.A. (1864). Monograph of the genus Ancillaria. In: Conchologia Iconica, vol. 15, pl. 1-12 and unpaginated text. L. Reeve & Co., London. This article incorporates text from this source, which is in the public domain .
7. New Zealand Mollusca: Amalda australis

• Olson, O.P. (1956). "The genus Baryspira (Mollusca) in New Zealand". New Zealand Geological Survey Paleontological Bulletin. 24: 12.
• Powell A W B, New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN   0-00-216906-1
• Glen Pownall, New Zealand Shells and Shellfish, Seven Seas Publishing Pty Ltd, Wellington, New Zealand 1979 ISBN   0-85467-054-8
• Michaux, B. (1991). "The Evolution of the Ancillinae with Special Reference to New Zealand Tertiary and Recent Species of Amalda H. & A. Adams, 1853 (Gastropoda:Olividae:Ancillinae)". Venus. 50 (2): 130–149.
• Spencer, H.G., Marshall, B.A. & Willan, R.C. (2009). Checklist of New Zealand living Mollusca. Pp 196–219. in: Gordon, D.P. (ed.) New Zealand inventory of biodiversity. Volume one. Kingdom Animalia: Radiata, Lophotrochozoa, Deuterostomia. Canterbury University Press, Christchurch.

External links

• Suter, H. (1917). "Descriptions of new Tertiary Mollusca occurring in New Zealand, accompanied by a few notes on necessary changes in nomenclature". New Zealand Geological Survey Paleontological Bulletin. 5 (i–iv): 42.