GNS Science

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

New Zealand Cenozoic Mollusca

Tropicolpus (Amplicolpus) healyi Marwick, 1971


(Pl. 14k): GS9805, F44/f9501, Coal Brook Station, Wendon Valley, Southland, Duntroonian (GNS)

Beu & Maxwell (1990): Chapter 10; p. 156; pl. 14 k.

Synonymy: Tropicolpus (Amplicolpus) healyi Marwick 1971a, p. 40

Classification: Turritellidae

Description: Large for family (height 110-155 mm), stout, narrowly conical. Protoconch mamillate, of 3 smooth whorls. Teleoconch of about 16 whorls, early whorls convex or flat-sided, later whorls concave, "telescoped"; peribasal angulation well-defined, base almost flat or gently convex. Primary spirals (A, B, C) commencing at about the same stage, B initially strongest, A weakest, but C becoming stronger than B by 5th or 6th whorl, A gradually becoming subdued and overshadowed by secondary spirals; adult whorls with C forming a prominent, narrow ridge not far above suture, B scarcely distinguishable from secondaries. Base with several cords similar in strength to, or weaker than C, and fine interstitial threads. Outer lip sinus moderately deep, apex near middle of whorl, abapical limb steeper than adapical; basal sinus shallow. Figured specimen with prominent lamellae on last half-whorl, representing former positions of outer lip.

Comparison: Tropicolpus healyi is one of a number of large mid-Cenozoic New Zealand turritellids variously assigned to Tropicolpus (sensu stricto), T. (Amplicolpus) or Maoricolpus (see Marwick 1971a). T. (Amplicolpus) cavershamensis (Otaian-Altonian, widespread) is closest to T. healyi, but is rather more slender and does not have spiral C so strongly projecting on adult whorls.

Distribution: Duntroonian; Chatton Formation, Wendon Valley (type); Knapdale, near Gore, Southland; Shell Gully, Chatton; Wharekuri Greensand, Wharekuri.

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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