GNS Science

Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)

New Zealand Cenozoic Mollusca

Aethocola (Aethocola) acuticostata (Suter, 1917)


(Pl. 6m): GS11216, J40/f068, South Branch Waihao River, near Waihao Downs, Bortonian (GNS)

Beu & Maxwell (1990): Chapter 7; p. 108; pl. 6 m.

Synonymy: Siphonalia nodosa acuticostata Suter 1917, p. 81; Austrofusus (Austrofusus) acuticostatus, Beu & Maxwell 1990, p. 108, pl. 8m.

Classification: Buccinulidae

Description: Rather small for genus (height 25-30 mm), broadly fusiform, spire half height. Protoconch conical, of about 4 whorls, last 0.5 whorl with narrow opisthocyrt costellae. Teleoconch whorls 6 or 7, angled medially on spire, last whorl with well developed peribasal angulation, strongly excavated below with a short, curved neck. Axial sculpture of prominent rounded costae, slightly tubercular at angulations, reaching from lower suture to upper part of sutural ramp on spire whorls, dying out rapidly on upper part of base; 11 or 12 on penultimate whorl. Spiral sculpture of numerous narrow cords with interstitial secondary and tertiary threads, finely crenulated by growth lines. Aperture ovate, with narrow siphonal canal sharply bent to left; outer hp somewhat thickened internally, bearing about 15 narrow lirate within.

Comparison: Aethocola acuticostata has also been recorded from McCulloch's Bridge (Kaiatan) but the species occurring there is distinct, differing in its larger size, less slender shape, more strongly angled teleoconch whorls and coarser spiral sculpture. Except for a doubtful record from the Waipawan of Chatham Island, this is the oldest known species of Aethocola, an endemic New Zealand genus that includes numerous species, many of them highly distinctive and having short stratigraphic ranges. A. acuticostata differs from younger species in its relatively small size, slender shape, fine spiral sculpture and somewhat thickened, distinctly lirate outer lip.

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 (in press) showed that its usage in New Zealand must be replaced by Aethocola Iredale, 1915. We follow Harasewych & Kantor (2004) in placing almost all New Zealand "Buccinidae" in Powell's (1929) family Buccinulidae, on anatomical grounds. Of New Zealand taxa, probably only Cantharus, and possibly Euthria pangoides (Beu), belong in family Buccinidae.

Distribution: Bortonian, Waihao Greensand, Waihao Downs (type) (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
(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)


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