Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 20a): GS9520, J41/f8029, Awamoa Creek, Oamaru, Altonian (GNS)
Beu & Maxwell (1990): Chapter 11; p. 188; pl. 20 a.
Synonymy: Zeacolpus (Zeacolpus) pukeuriensis Marwick 1934, p. 12
Description: Size moderate to large for family (height 45-115 mm), spire tall, slender. Protoconch turbiniform (1.5 nearly 2 whorls) or mamillate (2.5 nearly 3 whorls). Teleoconch of up to 18 whorls, early whorls strongly convex or medially angled, becoming slightly campanulate on about 9th whorl, adults typically with a rounded ridge abapically, giving whorls a frustate profile. B and C commencing at beginning of teleoconch, B remaining the stronger and medially angulating whorls until about 8th whorl when C rivals and eventually surpasses it, becoming flanked by 1 or more subsidiary cords on abapical ridge. A commencing very weakly on about 3rd whorl, not equalling B until 12th whorl or later. Subsidiary spirals becoming as strong as primaries on later whorls, which typically have 12 to 14 subequal, fine spirals. Outer lip sinus moderately deep, apex above middle of whorl.
Comparison: Zeacolpus fyfei (Lillburnian-Waiauan, Gisborne district) is very similar to Z. pukeuriensis but has early and adolescent whorls more cylindrical and less frustate, and most specimens have a median zone of weaker sculpture. Along with Z. lawsi (Otaian-Altonian, Northland), these species form the "fyfei stock" of Marwick (1971a, p. 28), characterised by having frustate adult whorls with numerous subuniform spirals. Z. awamoaensis (Altonian, widespread) occurs, apparently sympatrically, with Z. pukeuriensis at several localities; it is readily distinguished by having primary spirals A and B remaining much stronger than the subsidiaries, and in having campanulate adult whorls.
Distribution: Altonian-Lillburnian; Mount Harris Formation, Pukeuri, Oamaru, Altonian (type) (common) and other Altonian localities in North Otago and Canterbury, and several localities in Southland and North Island. Most common in off-shore siltstone and fine sandstone.
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
(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)