GNS Science

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

New Zealand Cenozoic Mollusca

Cominella (Cominella) excoriata (Finlay, 1926)


(Pl. 42h): GS10849, V20/f8572, Devil's Elbow hill, Napier-Wairoa highway, central Hawke's Bay, Nukumaruan (GNS)

Beu & Maxwell (1990): Chapter 15; p. 324; pl. 42 h.

Synonymy: Eucominia excoriata Finlay 1926b, p. 241

Classification: Buccinulidae

Description: Moderate-sized for genus (33-40 mm high), moderately tall, with moderately tall spire, large last whorl, and short, widely open, strongly twisted canal, forming wide fasciole bordering narrow umbilical chink. Sculpture of very prominent, narrow, widely spaced, weakly sinuous axial costae of rounded cross-section, 12 on penultimate whorl, unique among those of New Zealand Cominella species in being strongly opisthocline, not collabral; crossed at an angle of 10°-15° by regular, microscopic growth ridges; crossed (without forming nodules) by low, wide, indistinct, strap-like, widely spaced spiral cords, 4 to 6 on spire whorls and about 9 on last whorl. Aperture wide, oval, with smooth, thickened lips. Protoconch large, dome-shaped, of 2.5 smooth whorls.

Comparison: Cominella excoriata is a member of a group of warm-temperate species of relatively large Cominella, containing also the modern eastern North Island species C. tolagaensis Ponder (a distinct species with coarser spiral cords and wider and less markedly opisthocline axial costae than C. excoriata) and the modern southern Australian species C. eburnea (Reeve).

Distribution: Nukumaruan; "Shrimpton's", i.e., Kikowhero Stream, Matapiro Station, north side of Ngaruroro River, central Hawke's Bay (type); common in offshore mudstone facies in central Hawke's Bay, but we are not aware of specimens from any other district.

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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