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. 22d): GS951A, J41/f8475, Target Gully Shellbed, Oamaru, Altonian (GNS) |
Beu & Maxwell (1990): Chapter 11; p. 214; pl. 22 d.
Synonymy: Aphera scopalveus Finlay 1926b, p. 246
Classification: Cancellariidae: Cancellariinae
Description: Rather small for family (height 18-21 mm), ovate, spire 0.4 total height. Protoconch mamillate, of 1.5 smooth whorls. Teleoconch of 4 convex whorls, last whorl unexcavated. Spiral sculpture of numerous, fine, dense grooves cutting surface up into low, flattened cords, which are finely reticulated by growth lines. Aperture ovate, anterior end weakly notched; columella bent to left near anterior end, bearing 2 plaits near posterior end, the upper one the stronger, and a 3rd much weaker one on twist. Fasciole low, rounded. Inner lip callus spreading, moderately thick, with 1 or 2 weak, irregular ridges or denticles near plaits. Outer lip thickened and strongly lirate within.
Comparison: Marwick (1931, p. 121) considered Aphera scopalveus to be based on a juvenile Maorivetia brevirostris, but as Laws (1933, p. 328) correctly pointed out, there are considerable differences between the two species. A. scopalveus is more slender than M. brevirostris, and has a smaller protoconch, an unexcavated last whorl, and a shallower, less oblique anterior notch. A. scopalveus differs from the type species of Aphera, A. tessellata (Sowerby, 1832) (Recent, tropical western America) in having a mamillate rather than a dome-shaped protoconch, and in its much finer teleoconch sculpture, but the protoconch characters are unimportant in phylogeny, and the two species are very similar in shape and, more importantly, in apertural characters, and they are considered to be congeneric. There are no other records of the genus from New Zealand.
Distribution: Altonian; Target Gully Shellbed (type); Ardgowan Shellbed, 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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Zealand)