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. 49c): Te Piki, near East Cape, Haweran (oxygen isotope stage 7, 200 000 years B.P.) (GNS, from a private collection) |
Beu & Maxwell (1990): Chapter 16; p. 364; pl. 49 c.
Synonymy: Buccinum nodosum Martyn 1784, fig. 5 (non-binominal); Drupa glans Röding 1798, p. 368; Buccinum raphanus (not of Lamarck) Quoy & Gaimard 1835, p. 428; Buccinum triton Lesson 1841, p. 37; Austrofusus glans agrestior Finlay 1927a, p. 486; Austrofusus glans tragulatus Iredale 1937, p. 107; possibly also = Austrofusus chathamensis Finlay 1928b, p. 253; Siphonalia nodosa; Fusus nodosus; Neptunea nodosa; Verconella (Aethocola) nodosa; Austrofusus (Austrofusus) glans, Beu & Maxwell 1990, p. 364, pl. 49c.
Type species of Aethocola Iredale, 1915, but NOT of Austrofusus Kobelt, 1879
Classification: Buccinulidae
Description: Large and tall for genus (50-80 mm high), with stepped spire and long canal that is weakly twisted for genus, and so with weakly developed fasciole. Sculpture of many narrow, prominent spiral cords and fine axial costellae; 2 peripheral rows of nodules are highly variable, moderate to large and sharp and forming 2 prominent angulations in most specimens, but absent in some, allowing evenly convex whorls (form chathamensis). Protoconch small, conical, of 3.5 smooth whorls.
Comparison: The Aethocola glans-A. chathamensis complex is poorly understood. The A. chathamensis form (with evenly convex whorls, and sculpture without nodules or with many small, closely spaced nodules) occurs commonly now on beaches at the Chatham Islands, and similar specimens occur in late Nukumaruan faunules in Wanganui and Wairarapa (where it seems to intergrade with the A. cottoni-A. marshalli complex). The typical A. glans form (with two rows of sharp peripheral nodules, forming angulations around the whorls) is unknown before Castlecliffian time, and differs from earlier relatives (A. taitae, Nukumaruan, Pl. 42k; A. pagoda, Opoitian- Mangapanian, Pl. 37g) in its markedly larger size, sharper nodules, and more elongate, narrower shape; it differs further from A. pagoda in its markedly finer spiral sculpture, lacking the consistent, prominent basal spiral cords of A. pagoda. On this evidence, it appears possible that A. glans and A. chathamensis are distinct species with different ancestors. However, the modern population around central New Zealand is highly variable in the prominence and number of peripheral nodules, and specimens indistinguishable from Chatham Islands specimens of A. chathamensis wash ashore on Wellington beaches not uncommonly, intergrading with the variably nodulose specimens of A. glans. The complex needs re-evaluation by modern biochemical or genetic techniques, but it seems very likely that A. chathamensis is part of the variation of A. glans. Aethocola has been known incorrectly since 1926 as Austrofusus, on the basis of an invalid type species designation cited by Finlay (1926); the type species of Austrofusus is a Recent western South American species, Fusus fontainei Orbigny, 1841, resembling Aeneator (Buccinulidae); Beu & Marshall (2009) showed that its usage in New Zealand must be replaced by Aethocola Iredale, 1915.
Distribution: Late Nukumaruan (?); Castlecliffian-Recent; Recent, New Zealand (types of all names in the synonymy list, above). Abundant on the inner to outer continental shelf at present all around New Zealand, and cast ashore on beaches — much the most abundant buccinulid of the New Zealand modern fauna. Aethocola glans is a very common fossil in Castlecliffian and younger rocks throughout New Zealand, most commonly in inner-shelf, soft-bottom facies such as sandstone and mudstone, and particularly at Castlecliff, Wanganui.
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)