GNS Science

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

New Zealand Cenozoic Mollusca

Drepanocheilus (Tulochilus) bensoni Finlay & Marwick, 1937


(Pl. 2e): holotype, Boulder Hill, Wangaloan (Auckland Museum)

Beu & Maxwell (1990): Chapter 5; p. 81; pl. 2 e.

Synonymy: Drepanocheilus (Tulochilus) bensoni Finlay & Marwick 1937, p. 63

Type species of Tulochilus Finlay & Marwick, 1937

Classification: Aporrhaidae

Description: Small for family (height c. 11 mm). Protoconch unknown; teleoconch whorls angled below middle on spire, last whorl with prominent peribasal keel emerging from suture and stopping abruptly at base of wing. Axial sculpture on early whorls of narrow, low costae reaching from lower suture almost to upper suture and slightly thickened on angulation, but restricted to peripheral tubercles on later whorls; about 16 per whorl. Spiral sculpture on spire of fine threads; last whorl with cord marking peribasal keel, and about 4 cords with interstitial threads on base. Columella slightly concave, inner lip callused; outer lip with a broad, thin wing spreading adapically as far as upper suture. A narrow groove running from upper angulation to extremity of wing.

Comparison: Drepanochilus bensoni is one of the very few Cenozoic aporrhaids recorded from New Zealand. Most members of the family are of Mesozoic age, but extant species occur in the Northern Hemisphere. All are characterised by having lateral extensions to the outer lip, and are among the most bizarre gastropods known. Tulochilus differs from Drepanocheilus (sensu stricto) in having angled rather than convex spire whorls, in having the outer lip extending further up the spire and in having a less strongly produced columella.

Distribution: Wangaloan, Boulder Hill (type)(rare).

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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