GNS Science

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

New Zealand Cenozoic Mollusca

Rugobela tenuilirata (Suter, 1917)


(Pl. 22q): GS9685, J41/f9499B, Pukeuri road cutting, Oamaru, Altonian (GNS)

Beu & Maxwell (1990): Chapter 11; p. 213; pl. 22 q.

Synonymy: Ptychatractus tenuiliratus Suter 1917, p. 26

Type species of Rugobela Finlay, 1924

Classification: Conidae: Raphitominae

Description: Size moderate for subfamily (height 7-9.5 mm), elongate-ovate, spire a little more than half total height. Protoconch conical, of about 5 whorls, last quarter whorl with opisthocyrt costellae, remainder smooth. Teleoconch of 4-4.5 whorls, convex except for a narrow, shallowly concave sutural ramp; last whorl weakly excavated. Axial sculpture of low, rounded, almost orthocline costae with wider interspaces, reaching from lower suture almost to upper suture on spire, barely extending onto upper part of base on last whorl, in some shells becoming obsolete on later part of last whorl; 12-13 costae on penultimate whorl. Spiral sculpture of numerous fine, low cords, usually most prominent on neck. Aperture narrowly pyriform, columella convex with 4-6 narrow, low oblique plaits anteriorly; siphonal canal short, scarcely differentiated, shallowly notched. Inner lip with parietal callus pad, narrowly callused below; outer lip somewhat thickened internally near the shallow, assymetric anal notch, thin below.

Comparison: Rugobela semilaevigata (Waitakian, Otiake) is similar to R. tenuilirata but has a larger protoconch, and has axial costae absent from the last whorl of the teleoconch. Other species of Rugobela either have axial costae almost completely absent, or have strongly shouldered teleoconch whorls. Rugobela is one of the most characteristic turrid genera in the mid-Cenozoic of New Zealand, with a recorded range of at least Kaiatan (possibly Mangaorapan-Porangan) to Waiauan. One species, R. humerosa, originally described from Lome (Kaiatan), has been recorded from the Late Eocene of Victoria, Australia (Long 1981, pp. 46-47). The genus as a whole seems to have been bathymetrically tolerant, some species having been recorded from shallow-water assemblages, others from mid to outer shelf or upper bathyal faunules.

Distribution: Altonian-Waiauan; Target Gully Shellbed, Oamaru, Altonian (type); Pukeuri; Ardgowan Shellbed; Waitiiti Formation, Hokianga district, Northland; Nissen Shellbeds, Clifden.

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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