GNS Science

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

New Zealand Cenozoic Mollusca

Protoginella (?) bellensis (Beu, 1970)


(Pl. 27l): paratype, GS10200, S27/f8945, Bell's Creek, Mangaopari Stream, South Wairarapa, middle Tongaporutuan (TM 4616, GNS)

Beu & Maxwell (1990): Chapter 12; p. 248; pl. 27 l.

Synonymy: Euliginella bellensis Beu 1970c, p. 226

Classification: Marginellidae

Description: Small for family (5.5 x 4.3 mm), short and very inflated, with low spire, rounded, polished whorls, no sculpture other than faint growth lines, and only thin external glaze, with clearly visible suture and distinct, thickened, relatively wide inner lip callus. Outer lip thickened, bevelled to thin, smooth inner edge. Inner lip callus extending full height of aperture, smooth except for 4 prominent plaits, highest plait slightly above centre of columella; plaits increase in obliquity downwards. Some specimens with shallow indistinct groove around outer (left) edge of basal area of inner lip callus.

Comparison: Specimens from several Opoitian localities in Mangapoike River, Wairoa district, Hawke's Bay were identified by Dr J. Marwick as "Marginella whitecliffensis" and appear inseparable from Protoginella(?) bellensis (although they were not recorded by Marwick 1965). The similar P.(?) whitecliffensis (Tongaporutuan, North Taranaki) has a slightly more conical spire, a shorter inner lip callus (extending only half the height of the lip), less prominent plaits, and a more marked basal groove than P.(?) bellensis. This species group appears to be widespread in Late Miocene-early Pliocene bathyal facies.

These species have previously been placed in Euliginella Laseron, 1957 (synonymised by Coan (1965, p. 190) with Cystiscus Stimpson, 1865, although in our opinion Euliginella and Cystiscus are distinct) but Euliginella species are markedly smaller and have many small denticles inside the outer lip that are lacking from the P. bellensis-whitecliffensis group.

Distribution: Tongaporutuan, Opoitian?; Bell's Creek, Mangaopari Stream (type); common at all southern Wairarapa bathyal mollusc localities (middle Tongaporutuan) and much the most common mollusc at the locality with the most diverse assemblage, Bell's Creek, a tributary of Mangaopari Stream.

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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