GNS Science

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

New Zealand Cenozoic Mollusca

Genus Syrnola A. Adams, 1860


(Pl. 57g): Syrnola finlayi (Laws, 1937) (type species of Finlayola); GS12324, J41/fl98, Old Rifle Butts, Cape Wanbrow, Oamaru (Altonian)

Beu & Maxwell (1990): Chapter 17; p. 388; pl. 57 g.

Synonymy: Finlayola Laws, 1937

Classification: Pyramidellidae: Odostomiinae

Description: Height 2.3-6.7 mm, turriculate, attenuate, spire elevated, outline almost straight. Protoconch strongly tilted, planorboid or helicoid. Teleoconch whorls numerous, flat-sided or weakly convex or slightly overhanging anteriorly; no sculpture other than very fine growth lines and, in some species, spiral striae. Aperture relatively small, columella straight or slightly concave, with a single strong plait at posterior end; outer lip smooth within.

Comparison: Syrnola differs from Odostomia in its more slender shape, higher spire, and its more numerous teleoconch whorls, but some species may be difficult to assign confidently to one or other of these genera. Finlayola was proposed for species resembling Syrnola in general teleoconch characters, but having a planorboid rather than a helicoid protoconch. As is discussed under Turbonilla, such a difference is not in itself an adequate reason for supraspecific distinction, and Finlayola was synonymised with Syrnola by Beu & Maxwell (1990, p. 390).

Puposyrnola Cossmann, 1921 differs from Syrnola in its pupiform shape (i.e. the spire outline is distinctly convex) and in having a distinct parietal callus pad. Tibersyrnola Laws, 1937 is similar to Syrnola but has an internally lirate outer lip.

Distribution: Mangaorapan?, Bortonian-Recent, New Zealand; widespread, probably cosmopolitan, ranging from Paleocene to Recent.

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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