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. 30f): GS3348, N33/f9114, Kaiwara River near former Ethelton School, North Canterbury, Tongaporutuan, specimen closely resembling King's incomplete holotype (GNS) |
Beu & Maxwell (1990): Chapter 13; p. 267; pl. 30 f.
Synonymy: Austrofusus speighti King 1934, p. 24 (not of Marwick, 1932); Austrofusus valedictus King 1935, p. 312 (new name for A. speighti King, 1934, preoccupied)
Classification: Buccinulidae
Description: Moderate-sized for genus (40-50 mm high), with conic, weakly stepped spire 0.6 height of aperture and canal; whorls with rounded angulation, median on spire whorls, forming weakly concave sutural ramp; sculpture subdued. Anterior canal short, unusually wide for genus, twisted to left, with prominent fasciole bordered by narrow ridge. Sculpture of low, narrow, widely spaced spiral cords, fairly even in spacing and size over most of shell, but slightly more closely spaced over shoulder nodules than elsewhere, and becoming slightly more prominent over base than higher up; crossing low, evenly rounded, widely spaced axial costae over peripheral area only, forming low, rounded nodules around shoulder angle and even lower ones on 2 prominent spiral cords on peribasal angulation. Protoconch not seen, presumably conical, of about 3 whorls, as in other A. (Austrofusus) species.
Comparison: The wide form, the long, only weakly concave sutural ramp, the subdued spiral cords and low, rounded nodules, the weakly contracted neck, and the relatively short canal bent to the left suggest the possibility that Aethocola valedicta was ancestral to A. (Zelandiella) conoidea (Kapitean-Opoitian, Waipipian?, Awatere Valley) (= A. allani) and A. (Zelandiella) pliocenica (Opoitian-Mangapanian; Pl. 37d). The origins of the group are obscure, but two possibilites are suggested: (a) A. valedicta resembles several Pareora-Southland Series species of typical Aethocola, so it possibly descended from this group, and species included in Zelandiella are polyphyletic; or (b) the resemblance to Pareora-Southland Series species is superficial, and the A. conoidea group is correctly referred to Zelandiella. Better collections and further research are required to resolve these possibilities, but inclusion of all these species in Zelandiella is the simpler classification and is adopted here. Adoption of Aethocola is discussed under A. acuticostata (Pl. 6m).
Distribution: Waiauan-Kapitean; most records are Tongaporutuan. Upper Medway River, Awatere Valley, Tongaporutuan (type); uncommon in southern Wairarapa, Marlborough, North Canterbury, and Westland, in diverse shallow-water assemblages that lived on soft substrates.
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)