- Source: Zeradina aculeata
Zeradina aculeata is an extinct species of sea snail, a marine gastropod mollusk in the family Vanikoridae.
Description
The length of the shell attains 3.2 mm, its diameter 1.5 mm.
(Original description) The shell is small. The spire is high and narrow with a sharpened apex. The height of the spire is about ⅓ that of the body whorl. The whorls are convex. The suture is well cut-in, a little channelled. The two whorls of the protoconch are pointed with axial lamellae just below the suture for a short distance, spirals developing on the lower half of the last whorl. The body whorl is very long, convex in a broad sweep from suture to base. The aperture is ovate. The outer lip is effuse below. The inner lip is separated from the body anteriorly by a groove. The columella is long, thin and arcuate. It is set vertically. The axial sculpture, other than rude growth-plications, is lacking except on the first adult whorl where there are thin curved axial lamellae dependent on a short distance from the suture. Irregular weak spiral ridges and grooves are present over the surface of all whorls. None of these spirals are constantly more in evidence than others.
Distribution
Fossils of this marine species were found in Tertiary strata at Kaipara, New Zealand.
References
Maxwell, P. A. (2009). Cenozoic Mollusca. pp 232–254 in Gordon, D. P. (ed.) New Zealand inventory of biodiversity. Volume one. Kingdom Animalia: Radiata, Lophotrochozoa, Deuterostomia. Canterbury University Press, Christchurch.