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. 14d): GS4901, I40/H515, Sister's Creek, Hakataramea Valley, Waitakian (GNS) |
Beu & Maxwell (1990): Chapter 10; p. 163; pl. 14 d.
Synonymy: Tubena olsoni Maxwell 1969, p. 180-181; Gegania (Tubena) olsoni, Beu & Maxwell, 1990, p. 163, pl. 14d.
Classification: Mathildidae
Description: Moderately large for family (height 15-18 mm), turbiniform, spire 0.7 total height. Protoconch heterostrophic, inverted, of c. 1.5 smooth whorls. Teleoconch of 5 strongly convex whorls, last whorl capacious, with a moderately wide umbilicus. Spiral sculpture rather variable, commencing as 2 or 3 narrow cords, which in some shells remain dominant throughout growth, but in others are rivalled by other cords appearing during growth. Last whorl with 11-15 low, rounded or flattened cords, some with interstitial threads, more crowded on base. Axial sculpture of fine growth ridges, varying considerably in strength and spacing, even on an individual, finely crenulating or nodulating spiral cords. Aperture subcircular, inner lip slightly expanded over umbilicus; edge of outer lip finely crenulate.
Comparison: Tuba viola (Altonian, Kakanui) — the type species of Tubena Marwick, 1943 — differs from T. olsoni in having biangulate teleoconch whorls and narrower spiral cords. Bieler (1995, p. 627) synonymised Gegania Jeffreys, 1884 and Tubena Marwick, 1943 with Tuba Lea, 1833, and is followed here. Another synonym of which he was apparently unaware is Kaitangata Finlay & Marwick, 1937, type species K. hendersoni (Wangaloan, Wangaloa). This appears to be merely a large, robust species of Tuba, although the protoconch remains unknown. Tuba has a recorded range of Wangaloan (Paleocene) to Recent in New Zealand. Bieler (1995, p. 628) placed the Recent species Gegania valkyrie Powell, 1971 in Tuba, and recorded it from NE New Zealand, New Caledonia and the Loyalty Islands, and off Réunion in the Indian Ocean.
Distribution: Bortonian-Otaian; Otekaike Limestone, Sister's Creek, Hakataramea Valley, Waitakian (type); Brother's Stream; Waihao Downs; Waihao Greensand, McCulloch's Bridge; Waiareka Volcanic Formation, Lorne; Wharekuri; Bluecliffs, Otaio River. Uncommon to rare.
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)