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. 8 q): GS9508, J40/f8803, McCulloch's Bridge, Kaiatan (GNS) |
Beu & Maxwell (1990): Chapter 8; p. 125; pl. 8 q.
Synonymy: Columbarium maorum Marshall and Murdoch 1923a, p. 127; Vesanula maorum; Parasyrinx finlayi Allan 1926, p. 344; Tahusyrinx finlayi; Cochlespira (Tahusyrinx) maora, Beu & Maxwell 1990, p. 125; Cochlespira maora, Maxwell 1992, p. 152
Type species (as P. finlayi) of Tahusyrinx Powell, 1942
Classification: Turridae: Cochlespirinae
Description: Rather small for subfamily (height 15-26 mm), fusiform-pagodiform, spire about half total height. Protoconch conical, of about 4 or 5 whorls, last 2 whorls keeled above middle, last whorl with very small, sharp peripheral tubercles, other whorls smooth. Teleoconch of up to 7 whorls, sharply and prominently keeled near middle on spire; last whorl with much less prominent peribasal keel, contracted gradually below, shallowly excavated, with a long, slender neck. Axial sculpture of small, sharply triangular serrations on peripheral keel, short, narrow ridges bordering upper suture and, particularly evident on last whorl, numerous growth lines. Spiral sculpture commencing on about 2nd whorl as a narrow suprasutural cord, joined on 4th or 5th whorl by a similar though weaker cord between it and peripheral keel; sutural ramp smooth except for occasional weak threads. Suprasutural cord emerging on last whorl as peribasal keel, accompanied by up to 20 somewhat weaker cords, some with interstitial threads, on base and neck. All spirals on last whorl (and to some extent on earlier whorls) gemmulated by growth lines. Aperture narrowly pyriform, with a moderately long, narrow siphonal canal. Outer lip thin, with a deep U-shaped anal sinus, its apex near middle of sutural ramp.
Comparison: Cochlespira maora is the only species of Cochlespira to have been described from New Zealand, although other species are known from the upper Waihao River (Mangaorapan), Greymouth (Clifdenian and Waiauan) and Parengarenga Harbour (Altonian) (Maxwell 1988a, p. 62). Recent species of Cochlespira are recorded only from tropical or subtropical regions and mostly at bathyal depths, although there are a few records from the outer shelf (Powell 1969, p. 396-404). Maxwell (1992, p. 151) pointed out that the recognition of Tahusyrinx was based solely on protoconch (i.e., developmental) characters, and justifiably synonymised it with Cochlespira.
Distribution: Kaiatan; "Pukeuri" (type locality of C. maorum — actually from McCulloch's Bridge (Maxwell 1966, p. 455)); Waihao Greensand, McCulloch's Bridge (type locality of P. finlayi) (uncommon).
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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copy of New Zealand Geological Survey Paleontological Bulletin 58 in CD version
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