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. 50a): Linucula n.sp.; GS 9500, J41/f8028, excavation for Oamaru Borough Council septic tank, South Oamaru (Altonian) |
  (Pl. 50c): Linucula n.sp.; GS 9500, J41/f8028, excavation for Oamaru Borough Council septic tank, South Oamaru (Altonian) (showing characteristic crenulations on posterodorsal margin. |
 (Pl. 50f): Linucula n.sp.; GS 9500, J41/f8028, excavation for Oamaru Borough Council septic tank, South Oamaru (Altonian) |
Beu & Maxwell (1990): Chapter 17; p. 373; pl. 50 a,c,f.
Classification: Nuculidae: Nuculinae
Description: Height 2-5.8 mm, ovate to subcircular, some species almost smooth, others with fine radial and/or commarginal sculpture. Lunule and escutcheon areas with very fine subsurface prisms diverging from somewhat coarser radial prisms beneath surface of flanks, and finely crenulating dorsal margins. Hinge arched or broadly angled, chondrophore projecting.
Comparison: Distinguished from Nucula and other nuculids with ventral marginal crenulations (i.e. Nuculinae) in having divergent subsurface structural elements on lunule and escutcheon in addition to radial elements on flanks. The presence of dorsal crenulations is the simplest way of recognising species of the genus — other nuculines have smooth dorsal margins.
Distribution: Duntroonian-Recent, New Zealand; Recent, South America (Dell 1964b, p. 143- 144). Linucula is the most speciose nuculid genus in the New Zealand Cenozoic and is represented by shallow-water and upper bathyal species.
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)