Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 30c): GS3209, N34/f6272, Double Corner Shellbeds, Lower Waipara Gorge, North Canterbury, Waiauan (GNS, ex P.A. Maxwell collection)
(Pl. 30d): GS3209, N34/f6272, Double Corner Shellbeds, Lower Waipara Gorge, North Canterbury, Waiauan (GNS, ex P.A. Maxwell collection)
Beu & Maxwell (1990): Chapter 13; p. 266; pl. 30 c,d.
Synonymy: Zelandiella fatua Finlay 1926b, p. 237; Beu & Maxwell 1990, p. 266, pl. 30c, d.
Description: Small for genus (30-33 mm high), evenly oval and weakly sculptured, with low spire (a third height of aperture and canal), tall, steep, flat sutural ramp becoming weakly concave over last whorl, evenly convex periphery, and very short, widely open, strongly twisted, deeply notched anterior canal with prominent, long fasciole margined by high, thin ridge and bearing prominent, foliose costellae. Sculpture of simple, smooth, prominent, widely spaced spiral cords only, on most specimens; a few juvenile shells and very few adults have small, rounded nodules around top of peripheral swelling. Aperture large, relatively narrow, drawn out above into shallow posterior caned; interior of outer lip lightly thickened, bearing many low spiral ridges in some specimens; inner lip wide and moderately thick, swollen over neck into typical but relatively low Zelandiella callus, largely limited to narrow tongue curling back around neck. Protoconch abraded in all material seen but clearly multispiral, presumably as in Z. subnodosa, above.
Comparison: Zelandiella fatua is distinguished from the partly sympatric Z. subnodosa (Pl. 21i) (or a similar, unnamed species) by its lack of nodules, its more prominent spiral cords, its slightly narrower shape and smaller size, and its more subdued inner-lip callus. Specimens of Z. fatua from East Grey River, North Canterbury, show the remnants of an original colour pattern preserved as paler cords on a pale brown ground. Adoption of Aethocola is discussed under A. acuticostata (Pl. 6m).
Distribution: Waiauan (-Tongaporutuan?); Double Corner Shellbeds, Lower Waipara Gorge, North Canterbury, Waiauan (type); common at a few North Canterbury Waiauan localities of very shallow-water, near-shore, sandy facies, and uncommon at a few Waiauan (and possibly Tongaporutuan) localities in southern Hawke's Bay, southern Wairarapa, and Westland. Not known in the common southern Wairarapa early Tongaporutuan "Hurupi faunas".
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)