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]
Glen Pownall, New Zealand Shells and Shellfish, Seven Seas Publishing Pty Ltd, Wellington, New Zealand 1979 ISBN0-85467-054-8
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.