Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990) |
(Pl. 49a): Te Piki, near East Cape, Haweran (oxygen isotope stage 7, 200 000 years B.P.) (M49092, National Museum of N.Z.), a topotype of the form named P. edita by Powell (1934), |
Beu & Maxwell (1990): Chapter 16; p. 361; pl. 49 a.
Synonymy: Fusus sulcatus Lamarck 1816, pl. 424, fig. 3, "Liste des objets", p. 6; Fusus dilatatus Quoy & Gaimard 1833, p. 498; Fusus zelandicus Quoy & Gaimard 1833, p. 500; Fusus adustus Philippi 1845 (in 1845-1847), p. 21; Verconella adusta mandarinoides Powell 1927b, p. 558; Verconella accipitris Finlay 1930b, p. 68; Verconella allani Finlay 1930b, p. 71; Verconella falsa Finlay 1930b, p. 71; Austrosipho (Verconella) edita Powell 1934, p. 271; Verconella adpressa Powell 1947a, p. 168; Siphonalia mandarina of Suter 1913c, p. 370 (not of Duclos, 1831)
Type species of Penion Fischer, 1884, and of Verconella Iredale, 1914
Classification: Buccinulidae
Description: Large for family (120-170 mm high), tall and narrow, with spire slightly shorter than aperture and long, narrow, weakly twisted and recurved, widely open anterior canal. Whorls evenly convex to strongly angled (angled medially on spire whorls), with or without large, antero-posteriorly compressed nodules (present on shoulder angle of angled specimens only; highly variable). Sculpture of many prominent spiral cords, highly variable in size, number and spacing, 1 large, high one and 1 low, narrow one alternating regularly on many specimens. Low fasciole and very shallow pseudumbilicus present on most large shells. Aperture large, oval, lips smooth and simple, with low parietal callus pad. Protoconch large (3-4 mm high), subcylindrical, of 2.5-3 smooth, weakly inflated whorls, with bluntly rounded apex.
Comparison: Powell (1927b, 1947a) accepted relatively little variation in Penion species and named several forms as species that are now considered to be sculptural variants of one species, although recently (Powell 1979) he listed the same names as we have (based on Recent specimens) as synonyms of P. sulcatus. Finlay (1930b) similarly named several fossil forms that in our opinion are merely part of the variation of P. sulcatus. Penion has a large, heavy embryonic shell (several in each large, horny egg capsule) and direct development, producing subtle genetic differences between populations around the country, but there is no evidence that the variation is regular in any geographical pattern. Ponder (1973, p. 416) showed that P. mandarina (Duclos) applies to an Australian species, and the earliest name for the New Zealand one is P. sulcatus (Lamarck). He later (Ponder 1975) illustrated the holotype of P. dilatatus, showing that this name applies to the nodulose, adustus form of P. sulcatus. He therefore selected P. cuvierianus as the name for the species previously known as P. dilatatus. P. cuvierianus reaches a considerably larger size than P. sulcatus (to at least 250 mm high), has a thinner and more elongate shell, consistently finer spiral sculpture (although the extremes of the two species overlap), biangled nodules around the periphery on the most common, coarsely nodulose form (biangled nodules are rare in P. sulcatus), and a taller protoconch of 3.5-4 whorls. It seems likely that P. cuvierianus has a similar range of sculptural variation to P. sulcatus, and that P. ormesi (Powell) is based on specimens of P. cuvierianus lacking shoulder nodules. Penion includes the common large buccinoidean "whelks" of the New Zealand area, and P. sulcatus is common from intertidal to outer shelf depths on a variety of hard to soft substrates, whereas P. cuvierianus occurs only on soft substrates on the continental shelf. Fossils of P. sulcatus are common at Castlecliff (particularly small specimens, in Tainui Shellbed) and are easily distinguished from Buccinulum, Aeneator and Glaphyrina species by their much larger, subcylindrical protoconch. P. cuvierianus is much less common as a fossil, although it, too, occurs at Castlecliff.
Distribution: Mangapanian-Recent. Recent, New Zealand (types of Fusus sulcatus, F. dilatatus, F. zelandicus, F. adustus, Verconella adusta mandarinoides, V. adpressa); Castlecliff, Wanganui, Castlecliffian (type of V. falsa); Okauawa Stream, Kereru Road, central Hawke's Bay (type of V. accipitris); Nukumaru, "papa band", i.e., probably Tewkesbury Formation, Nukumaru Beach, west of Wanganui, Nukumaruan (type of V. allani); Te Piki, Cape Runaway, near East Cape, Haweran (oxygen isotope stage 7) (type of Austrosipho edita). Widespread but never common in shallow-water to mid-shelf formations throughout New Zealand of Mangapanian to Haweran age.
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
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ISSN 1177-2441
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