GNS Science

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

New Zealand Cenozoic Mollusca

Polinices (Polinella) esdailei (Marwick, 1924)


(Pl. 8a): GS9508, J40/f8803, McCulloch's Bridge, Kaiatan (GNS)

Beu & Maxwell (1990): Chapter 8; p. 119; pl. 8 a.

Synonymy: Uber esdailei Marwick 1924d, p. 567

Classification: Naticidae: Poliniceinae

Description: Size moderate for family (height 15-25 mm), globose or ovate (probably sexually dimorphic), spire up to 0.3 total height. Protoconch depressed dome-shaped, of about 3 smooth whorls. Teleoconch of up to 2.5 whorls, spire whorls convex, last whorl weakly concave below suture, otherwise strongly convex. No sculpture apart from growth lines. Aperture semilunular; inner lip almost straight, parietal callus moderately heavy, spreading anteriorly to fill or nearly fill umbilicus. Umbilical callus not projecting on outer margin, but flush or distinctly concave, bearing a distinct horizontal groove near middle, some shells with a low, rounded but rather irregular ridge above. Outer lip almost straight, inclined at about 20° to vertical.

Comparison: Polinices (Polinella) esdailei is rather similar to P. (Polinella) modestus (Altonian, North Otago) but differs in having callus barely filling the umbilicus (rather than projecting as in the latter species), and in having a shorter but wider transverse groove on the umbilical callus. Maxwell (1992, p. 101) raised Polinella to a genus, following the sensible conclusion that a close phylogenetic relationship is impossible to establish between fossil subgenera and, although we have much sympathy with his point of view, Polinella is so very similar to Polinices (particularly to some tropical Pacific species assigned there) as to leave considerable doubt about the value of recognising it, and we retain it as a subgenus.

Distribution: Kaiatan-Runangan; Waiareka Volcanic Formation, Lorne, Kaiatan(?) (probable type locality); McCulloch's Bridge; Kapua Tuff, Waihao River; Trig M, Totara. Moderately common at McCulloch's Bridge, less so at other localities.

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)


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