Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
| | Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990) |
|
  (Pl. 47u): Castlecliff, Wanganui (apparently from Tainui Shellbed), Castlecliffian (GNS, from an early collection) |
Beu & Maxwell (1990): Chapter 16; p. 351; pl. 47 u.
Synonymy: Buccinum vermis Martyn 1784, vol. 2, pl. 53 (valid, ICZN Opin. 479); Murex australis Gmelin 1791, p. 3542; Struthiolaria inermis G. B. Sowerby I 1821, pl. 222, fig. 3, 4; Struthiolaria crenulata Lamarck 1822, p. 148; Struthiolaria tricarinata Lesson 1841, p. 256; Struthiolaria acuminata Marwick 1924a, p. 185; Struthiolaria media Marwick 1924a, p. 187; Struthiolaria convexa Marwick 1924a, p. 188; Struthiolaria fossa Marwick 1924a, p. 189; Pelicaria mangaoparia Vella 1953, p. 40; Pelicaria rotunda Vella 1953, p. 41; Struthiolaria (Pelicaria) vermis flemingi Neef 1970, p. 462; Struthiolaria (Pelicaria) vermis grahami Neef 1970, p. 465; Struthiolaria (Pelicaria) vermis powelli Neef 1970, p. 465; Struthiolaria (Pelicaria) vermis bradleyi Neef 1970, p. 467; Struthiolaria (Pelicaria) vermis vellai Neef 1970, p. 468; Struthiolaria (Pelicaria) wellmani Neef 1970, p. 472.
Type species of Pelicaria Gray, 1857
Classification: Struthiolariidae
Description: Moderate-sized for genus (40-65 mm high), with moderately short to moderately tall spire, short last whorl without anterior canal, and narrow, flat or, in some forms, deeply channelled subsutural ramp. Sculpture of many fine spiral threads and weak growth ridges; most specimens with 2 (or, in a few specimens, 3) low, wide, rounded, weakly nodulous cords on spire whorls, fading out before last whorl of many specimens, remaining as 3 prominent, wide, convex-crested spiral cords on others; several weker cords on base. Aperture nearly circular, lips thickened and reflected but much less so than in Struthiolaria papulosa; outer lip weakly sinuous. Outer lip meets columella at shallow anterior notch. Protoconch a low, wide, smooth, irregular dome of 1 whorl, reflecting direct development.
Comparison: The sections here on Pelicaria vermis form acuminata (Pl. 42e), P. vermis form convexa (Pl. 42b), and P. vermis form fossa (Pl. 42a) should be consulted in combination with the present section, as these are all considered (along with the many other names in the synonymy) to be synonyms of Pelicaria vermis. This is interpreted by Beu (2009) as a single early Nukumaruan-Recent direct-developing, highly variable species. The early P. vermis acuminata form seems to have evolved in earliest Nukumaruan time from P. canaliculata through the series of species - an anagenetic series? - recognised by Neef (1970) in the Mangahao distrct, NW Wairarapa, by the adoption of direct development, as it is at this time that the great range of variable forms appears in the fossil record. The strongly sculptured P. vermis acuminara form dominated early populations in South Wairarapa (i.e., it seems to have been a cool-water form) and intergrades with the P. vermis convexa form (so that this, in turn, seems to indicate warm water) in early beds of the Nukumaruan succession in central Hawke's Bay. The P. vermis acuminata form thereafter faded from the record, except that a few specimens in the Recent fauna from deep water (up to 300 m or more) have the same prominent spiral cords - the form sometimes identified as P. vermis tricarinata. Late Nukumaruan and Castlecliffian-Recent forms are highly variable; some of the variation is discussed under individual Nukumaruan forms elswhere here. However, there are no hard divisions between the many forms, and they clearly behave as variants of a single species. Most have 2 or 3 weak spiral cords on the last whoel, a narrow, flat, horizontal surural ramp, and a moderate spire. Relatively few specimens have low, angular nodules on the peripheral spiral cord.
Pelicaria vermis has direct development (Morton 1950) and so the segregation of regional forms into local populations and many complex variants is to be expected. Neef (1970) pointed out the occurrence of variants of P. vermis around New Zealand at present, although the forms intergrade and we do not consider them to be geographical subspecies. Pelicaria vermis forms in Castlecliffian rocks at Wanganui reflect changing temperature regimes: P. vermis specimens in the Kai-Iwi siltstone beds have many low, closely spaced spiral cords as in specimens living offshore on the continental shelf along the east coast from East Cape to Oamaru at present, and presumably indicate both offshore deposition and a relatively cool temperature. Specimens in most higher beds rsemble those along the Paraparaumu-Waikanae coast or in Auckland and Northland at present, and indicate temperature much like those near Wanganui at present, whereas the occurrence of P. vermis specimens like those in the Bay of Plenty at present, but also inseparable from the P. vermis convexa form in Hawke's Bay Nukumaruan rocks (together with the return of the otherwise Nukumaruan Stiracolpus waikopiroensis) in the Kupe Formation indicate a temperature a little higher than that near Wanganui now.
Distribution: Earliest Nukumaruan-Recent; Recent, New Zealand (types of Buccinum vermis, Murex australis, Struthiolaria inermis, S. crenulata, S. tricarinata, S. vermis bradleyi, S. vermis flemingi, S. vermis grahami, S. vermis powelli, and S. vermis vellai); Pukenui Limestone, early Nukumaruan, Te Awaite cutting, Makara River, Wairarapa (type of S. acuminata); Castlepoint, E Wairarapa, early Nukumaruan (type of S. media); Okauawa Formation, late Nukumaruan, Okauawa Stream, Kereru Road, Hawke's Bay (type of S. convexa); "Shrimpton's", Kikowhero Stream, Hawke's Bay, late Nukumaruan (type of S. fossa); Managaopari Stream 120 m upstream from Makara River junction, South Wairarapa, early Nukumaruan (type of P. mangaoparia); Whakarua Stream, tributary of Whangaehu River, South Wairarapa, early Nukumaruan (type of P. rotunda); Marima Sandstone, early Nukumaruan, Mangahao River 350 m NE of Marima, NW Wairarapa (type of S. wellmani). A common fossil in Nukumaruan and Castlecliffian shallow-water shellbeds and siltstone and less common in limestone in Hawke's Bay, Wanganui, Wairarapa, Marlborough, and North Canterbury. Abundant in the Haweran Te Piki bed, Cape Runaway; known also from Castlecliffian rocks in the Bay of Plenty, at Cape Kidnappers, and near Parnassus, North Canterbury, but very rare in Haweran terrace cover deposits.
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)