GNS Science

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

New Zealand Cenozoic Mollusca

Polinices (Polinella) obstructus (Marwick, 1924)



scale

(Pl. 37i): lectotype of Natica ovata Hutton, 1873 (preoccupied) = Uber obstructus Marwick, 1924, GS227, J33/f7010, Lake Kaniere, Westland, Kapitean-Opoitian? (TM6813, GNS)

Beu & Maxwell (1990): Chapter 14; p. 294; pl. 37 i.

Synonymy: Natica (Mamilla) ovata Hutton 1873b, p. 9, in part (not of Klipstein, 1843); Polinices (Mamma) ovatus; Uber obstructus Marwick 1924d, p. 567 (new name for Natica ovata Hutton, preoccupied)

Classification: Naticidae: Poliniceinae

Description: Large for subgenus (30-40 mm high), relatively tall and narrow, with moderately tall, convex spire (0.3 height of aperture), large enveloping last whorl, and no anterior canal; smooth except for weak growth lines. Growth lines retracted to suture, without obvious axial grooves. Aperture simple, D-shaped; inner lip with prominent, relatively narrow parietal callus, merging into weakly lobed umbilical callus above a low funicle that fills most of umbilicus, leaving (in most but not all specimens) a moderately wide, deep umbilical groove; umbilical callus tapers gradually into lower part of inner lip. Left edge of parietal callus regularly, weakly convex, except for small, triangular, protruding lobe immediately above umbilicus; callus bears 1 wide, shallow, indistinct but consistently present groove opposite triangular lobe, and another shorter and slightly shallower one, not quite parallel to upper one, opposite widest lobe of umbilical callus, above funicle. Aperture inclined at an angle of about 20° to the coiling axis. Protoconch as in P. scalptus (Pl. 29 k), but slightly taller.

Comparison: Marwick (1924d, p. 568) referred specimens from Altonian to Waiauan formations at Clifden, Southland, to Polinices obstructus, but in view of the distinctive ontogeny described above for P. scalptus (Pl. 29k) the identity of these older specimens needs confirmation. P. obstructus is one of the larger and more distinctive species of subgenus P. (Polinella), recognisable by the two shallow, in most specimens diverging grooves in the inner-lip callus near the top of the umbilicus. Much larger, narrower, with weaker and more nearly parallel grooves on the callus, and with a narrower callus than P. scalptus (Pl. 29l).

Marwick (1924d, p. 565, 568) named as new species both Uber ovuloides and Uber obstructus, formerly included in the species previously named Natica (Mamilla) ovata Hutton (1873b, p. 9; not of Klipstein, 1843). He discussed the status and types of Natica ovata Hutton, pointing out that no lectotype had been formally designated, and then decided that, as Hutton's name is preoccupied, "we can start again with fresh specific names". However, Marwick's action constitutes the replacement of a preoccupied name, not the proposal of a new species, and a lectotype is still needed (and until 1990 had not been designated) for Natica ovata. Beu & Maxwell (1990) therefore designated as lectotype of Natica (Mamilla) ovata Hutton (1873b, p. 9) the specimen illustrated here, the "holotype" of Uber obstructus, the specimen from Lake Kaniere figured as Polinices ovatus "holotype" by Suter (1914, p. 21, pl. 17, fig. 1a, b), supposedly from "Shakespeare Cliff, Wanganui" (the locality confusion was clarified by Marwick 1924d, p. 565).

Distribution: Altonian(?)-Waipipian; GS227, Lake Kaniere, Westland, Kapitean or Opoitian? (type); widespread but uncommon in Kapitean to Waipipian blue-grey sandy mudstone along the Wanganui-South Taranaki coast (Waipipian), on the coast between Te Araroa and East Cape (Kapitean), in the Tauwhareparae area inland from Tolaga Bay (Opoitian), in the Awatere Valley, Marlborough (Kapitean- Opoitian), in Westland (Kapitean-Waipipian) and in Southland (Kapitean).


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)

References

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