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. 25q): GS10365, D45/f8598, Long Beach Shellbed, Clifden, Altonian (GNS) |
Beu & Maxwell (1990): Chapter 11; p. 230; pl. 25 q.
Synonymy: Falsicolus inurbana Laws 1932, p. 195; Falsicolus (sensu lato) inurbana, Beu & Maxwell 1990, p. 230, pl. 25q; Lepidocolus inurbana, Maxwell 2009, p. 246
Classification: Turbinellidae, Columbariinae (Maxwell 2009, p. 246)
Description: Medium-sized for genus (height 40-55 mm), fusiform, spire pagodiform, about half total height. Protoconch narrowly conical, of about 4 convex whorls, last whorl with axial costellae. Teleoconch of 7-8 whorls, sharply keeled near middle on spire; last whorl strongly excavated, with a long, slightly curved neck. Axial sculpture of prominent rounded costae reaching virtually from suture to suture on spire, but not extending onto neck on last whorl; 7-10 per whorl. Spiral sculpture prominent, consisting of a strong cord on peripheral keel, a slightly weaker one about halfway between it and lower suture, and 5-6 additional cords, some with interstitial threads, on base. Neck with numerous cords and threads, 3 considerably stronger than others. Peripheral cord forming vertically compressed tubercles where it crosses axial costae; other cords slightly thickened at intersections. All spirals rendered scaly by numerous lamellar growth ridges. Aperture ovate, with long siphonal canal; inner lip with prominent callus, its outer edge standing clear of the last whorl; outer lip thin, lirate within.
Comparison: Lepidocolus inurbana is only doubtfully distinct from L. corrugata (Altonian ?, Pakaurangi Point) as the alleged differences cited by Laws (1932, p. 195) do not seem to be constant. However, the only available topotypes of L. corrugata are subadult and, therefore, difficult to compare satisfactorily with Clifden specimens. L. corrugata and L. inurbana differ markedly from typical Falsicolus species in having a prominent, raised columellar callus plate (or collar) and in having scaly spiral sculpture. They are similar in teleoconch characters to "Fusinus" dictyotis (Tate, 1888) (Balcombian, Middle Miocene, Victoria) but differ in having a conical rather a mamillate protoconch. These species were segregated as the genus Lepidocolus by Maxwell (1992, p. 125), who suggested that they belong in Turbinellidae Columbariinae, and this position was adopted by Maxwell (2009).
Distribution: Altonian-Clifdenian; Long Beach Shellbed, Clifden, Altonian (type); Slip Point Siltstone, Clifden, uncommon.
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
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copy of New Zealand Geological Survey Paleontological Bulletin 58 in CD version
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