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. 20f): GS9500, J41/f8028, excavation for Oamaru Borough Council septic tank, south Oamaru, Altonian (GNS) |
Beu & Maxwell (1990): Chapter 11; p. 192; pl. 20 f.
Synonymy: Natica notocenica Finlay 1924b, p. 450; Cochlis notocenica; Tanea notocenica; Taniella (Taniella) notocenica, Beu & Maxwell 1990, p. 192, pl. 20f
Type species of Taniella Finlay and Marwick, 1937
Classification: Naticidae: Naticinae
Description: Rather small for family (height 7- 12 mm), ovate, solid; spire low, conical, 0.15 total height. Protoconch depressed, of 2.5 smooth whorls with distinctly impressed suture. Teleoconch of 1.5-2.5 almost flush whorls, with only feebly impressed suture on spire, base with moderately wide umbilicus. No sculpture except for weak growth lines, well preserved shells polished. Umbilicus largely filled by prominent, smooth funicle of variable development but invariably separated from parietal region by deep groove or chink. Aperture semilunular, inner lip almost straight; parietal callus moderately thick. Outer lip thin, almost straight, inclined at about 20° from vertical.
Comparison: Taniella notocenica is readily distinguished from Tanea consortis (see above), with which it occurs at many localities, by its ovate shape with almost flush sutures on spire whorls and its larger funicle. T. notocenica has a very long stratigraphic range; its presumed successor, T. planisuturalis (Pl. 41n), differs in its larger size and in having the funicle more widely separated from the umbilical wall. Finlay (1924b, p. 450) considered T. notocenica to extend down to the Kaiatan (McCulloch's Bridge) but specimens from that locality belong in a distinct species, Taniella intermedia Maxwell, 1992; they are on the whole broader in relation to height than T. notocenica, have a smaller funicle, and have a shallower notch separating the funicle from the parietal callus. T. bacca (Marwick, 1924) (Bortonian, Hampden Beach) is smaller then T. intermedia (to only 6 mm high) and has a still smaller funicle and an even narrower groove between the funicle and the parietal callus. This appears to be a simple evolutionary lineage.
Taniella notocenica occurs in a wide range of lithofacies and seems to have had a considerable bathymetric range (inner shelf to uppermost bathyal zone). A deeper-water habitat (upper bathyal zone) seems to have been favoured by such species as T. motutaraensis (Altonian, Motutara, Auckland), T. mima (Clifdenian-Waiauan, Westland) and T. poliniciformis (Tongaporutuan, Wairarapa); these species differ from T. notocenica in having a tuberculate rather than a smooth funicle, and in having the umbilicus more or less completely filled.
Distribution: Duntroonian-Opoitian; Mount Harris Formation, Awamoa Creek, Oamaru, Altonian (type) and other Altonian localities near Oamaru, and numerous localities in North and South Islands.
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
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