Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
| | Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990) |
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  (Pl. 49b): Lower Kai-Iwi Siltstone, Kai- Iwi Beach, west of Castlecliff, Wanganui, Castlecliffian (GNS, early collection) |
Beu & Maxwell (1990): Chapter 16; p. 362; pl. 49 b.
Synonymy: Buccinulum caudatum Powell 1929, p. 75.
Classification: Buccinulidae
Description: Large for genus (35-55 mm high), moderately tall and narrow, with well rounded whorls, moderately tall spire and moderately long, only weakly bent canal without fasciole; sutural ramp weakly to quite strongly concave. Sculpture of many low, wide, closely spaced spiral cords with several orders of interstitial threads, crossed by many low, closely spaced axial ridges; low peripheral gemmae or small nodules at sculptural intersections on some specimens. Aperture large, oval; inside of outer lip with a row of prominent short transverse ridges; inner lip with large parietal tubercle and 3-4 low ridges on base of columella. Protoconch small, dome-shaped, of 2 smooth whorls.
Comparison: Buccinulum caudatum is a distinctive species distinguished from the contemporaneous and living B. linea by its much larger size, its more strongly concave sutural ramp, its consistently wide, relatively prominent spiral cords, and its longer, more prominent ridges inside the outer lip. The protoconch also is correpondingly larger than that of B. linea.
Distribution: Early Castlecliffian only; "between Kai-Iwi and Okehu, Wanganui", i.e., probably from Lower Kai-Iwi Siltstone, beach west of Kai-Iwi, west of Wanganui, early Castlecliffian (type); common in Lower Kai-Iwi Siltstone, Omapu Shellbed, and Lower Westmere Siltstone, only, at Castlecliff, Wanganui, in offshore siltstone facies where Buccinulum is uncommon at present.
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)