GNS Science

Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)

New Zealand Cenozoic Mollusca

Aethocola (Neocola) alpha (Finlay, 1926)



scale

(Pl. 25b): GS11182, D45/f8819, Fouraye Siltstone, Clifden, Altonian (GNS)

Beu & Maxwell (1990): Chapter 11; p. 226; pl. 25 b.

Synonymy: Austrofusus (Neocola) alpha Finlay, 1926b, p. 233; Beu & Maxwell 1990, p. 226, pl. 25b.

Classification: Buccinulidae

Description: Small for genus (height 24-34 mm), elongate-ovate, spire 0.45-0.5 total height. Protoconch conical, of about 3.5 whorls, last half-whorl or so with narrow opisthocyrt costellae, remainder smooth. Teleoconch of 5.5-6 whorls, first whorl convex, later whorls prominently shouldered at, or somewhat below, middle on spire; sutural ramp steep, concave, riding up high onto previous whorl. Last whorl with weak basal subangulation, contracted below to short, twisted neck. Axial sculpture commencing as low, rounded costae reaching from suture to suture but soon becoming obsolete on sutural ramp, and on last whorl of many shells restricted to nodules on shoulder angulation and much weaker, irregular nodules or folds on basal subangulation, typically without obvious connecting costae; 10-13 nodules or costae on last whorl. Spiral sculpture of numerous narrow, rounded cords with interstitial threads, those on shoulder angle and on basal subangulation typically slightly but noticeably stronger than others and slightly thickened where they cross axial nodules or costae. All spirals crossed by numerous, fine growth lines. Aperture ovate, constricted posteriorly, columella almost straight above, strongly twisted to left below; siphonal canal short, deeply notched; fasciole very prominent, bounded above by a sharp, continuous ridge. Inner lip rather thickly callused; outer lip thin, with a shallow notch near anterior end, margin finely crenulate, lirate within, 2-4 lirae at posterior end typically stronger than others.

Comparison: See under Aethocola (Neocola) beta.

Distribution: Early Altonian; Fouraye Siltstone, Clifden (type); Otahu Formation, Clifden; Mount Brown Formation, Tommy's Creek, Upper Waipara River; Karamea district; upper Takaka valley.


Cite this publication as: "A.G. Beu and J.I. Raine (2009). Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990). GNS Science miscellaneous series no. 27."
© GNS Science, 2009
ISBN 978-0-478-19705-1
ISSN 1177-2441
(Included with a PDF facsimile file copy of New Zealand Geological Survey Paleontological Bulletin 58 in CD version from: Publications Officer, GNS Science, P.O. Box 30368 Lower Hutt, New Zealand)

References

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