Amalda mucronata

Amalda mucronata
Shell of Amalda mucronata (specimen at the Natural History Museum, Rotterdam)
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Neogastropoda
Family:	Ancillariidae
Genus:	Amalda
Species:	A. mucronata
Binomial name
Amalda mucronata (G.B. Sowerby I, 1830)
Synonyms
Amalda (Baryspira) mucronata(G. B. Sowerby I, 1830) alternative representation Ancillaria mucronataG.B. Sowerby I, 1830 (original combination) † Baryspira ericaOlson, 1956 (junior subjective synonym) † Baryspira gladiolariaOlson, 1956 (junior subjective synonym) Baryspira mucronata(G.B. Sowerby I, 1830)

Amalda mucronata is a species of medium-sized sea snail, a marine gastropod mollusc in the family Ancillariidae. ^[1]

These snails live in the sandy subtidal near-shore environment where they eat bivalves. Fossil material of this species provides evidence of morphological stasis over 5 million years. ^{[2] [3]}

Shell description

The shell height is up to 61 mm, and the width is up to 27 mm.

(Original description) The solid, stubby shell is oblong, shiny and is pink to pale brown. The acuminated, callous spire is thickly coated in enamel. The pointed apex is paler. The body whorl features a white-bordered band near its upper section, while a faintly impressed line ends in a small, blunt tooth at the lower edge of the outer lip.

Two bands are visible near the lower part of the body whorl, with a very indistinct groove marking the beginning of the columellar varix, which is narrow, whitish, and subtly striated. The wide aperture is somewhat acute at the top and notched at the bottom. The outer lip is slightly thickened at the edge, with a single small tooth near the base. The upper portion of the inner lip extends over the spire. The columella shows a central ridge and is twisted anteriorly. ^[4]

Distribution

This marine species is endemic to and occurs off New Zealand. ^[5]

References

1. 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.
2. 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.
3. Gould, Stephen Jay (1991). "Opus 200". Natural History. 100 (8): 12–18.
4. 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. This article incorporates text from this source, which is in the public domain .
5. 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.

• 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)". ENUS (The Japanese Journals of Malacology). 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. Christchurch: Canterbury University Press.

External links

• Massey University NZ Fauna Scanned 3D model of Amalda mucronata fossil