Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990) |
(Pl. 25m): GS11212, D45/H83, middle Slip Point Siltstone, Clifden, Clifdenian (GNS) |
Beu & Maxwell (1990): Chapter 11; p. 225; pl. 25 m.
Synonymy: Coluzea kiosk Finlay 1930e, p. 270
Classification: Turbinellidae: Columbariinae
Description: Moderately large for genus (height 47-115 mm), very long and slender, fusiform, spire pagodiform, 0.35 total height. Protoconch reportedly like that of C. dentata (Pl. 21 h) but more elongate. Teleoconch of 8 to about 10 whorls, sharply and prominently keeled slightly below middle on spire, keel becoming progressively more and more projecting and compressed during growth so that on adult whorls it forms a prominent, thin carina. Last whorl with a weak peribasal angulation, contracted quickly below to a very long, slender, almost straight neck. Axial sculpture of weak, short costae on early whorls, becoming confined to peripheral serrations or undulations on later whorls; 15-17 on adult whorls. Spiral sculpture on sutural ramp of a weak thread margining upper suture and 3 narrow, distant cords below; sides with a narrow cord margining lower suture and a stronger one about halfway between it and periphery. Supramargining cord emerging on last whorl to mark peribasal angulation, accompanied by 2 somewhat narrower ones on base, and about 12 thin, finely spinose or scaly cords on neck, becoming indistinct anteriorly. Other spiral sculpture of fine striae over most of surface except neck. Aperture triangular, constricted anteriorly; siphonal canal very long, almost straight, almost completely closed. Inner lip callus rather thin, restricted; outer lip thin, apparently smooth within.
Comparison: As Finlay (1930b, p. 270) stated, "this cannot be confounded with any other species, being the most bizarre of the group". In particular, it differs from all other species of Coluzea in its very slender shape, its thin, strongly projecting peripheral carina, and in having spinose spirals on the neck. A specimen from Postal Creek, Oparara district, southwest Nelson (Clifdenian) in the GNS collection may represent a distinct, related species; it differs in having the early teleoconch whorls descending more rapidly (i.e. having greater translation along the coiling axis), and in having five spiral cords (in addition to a submargining thread) on the sutural ramp.
Distribution: Altonian-Clifdenian; Calamity Point Sandstone, Calamity Point, Clifden, Southland, Altonian (type); Fouraye Siltstone, Long Beach Shellbed and Slip Point Siltstone, Clifden. Rare at all 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)