Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 7n): GS12418, J32/f31, Leah Creek, Westland, Runangan (GNS)
Beu & Maxwell (1990): Chapter 8; p. 115; pl. 7 n.
Description: Size moderate for genus (length 50 mm), apex moderately elevated, corroded on only example, situated at about 0.3 anterior-posterior distance. Radial sculpture of 25 simple, rounded costae, strongest posteriorly and weakening towards front. No secondary radials. Commarginal sculpture of growth lines and ridges. Internal features not known.
Comparison: This limpet is included to demonstrate the fortuitous nature of much fossil preservation. Extant species of Cellana are intertidal rock-dwellers and the genus therefore has a very poor fossil record. The Leah Creek specimen is the oldest recorded from New Zealand, the next oldest being C. taberna Powell, 1973 from Curiosity Shop, Rakaia River (Waitakian). Its preservation apparently is the result of mass debris-flow of shallow-water sediments into a deeper-water environment.
Cellana is primarily an Indo-Pacific genus at the present day, but its distribution extends southwards to New Zealand and the subantarctic islands (Powell 1973; Lindberg & Hickman 1986). The Runangan species is remarkably similar to the southernmost living species, C. strigilis (Hombron & Jacquinot, 1841), which has been subdivided into several subspecies by Powell (1955; 1973); Powell's classification was largely supported by the molecular phylogenetic study by Goldstien et al. (2006). The unnamed fossil species differs from these mainly in having no secondary costae, but as only one specimen has been collected, its range of variation is unknown.
Distribution: Runangan, Omotumotu Member (Kaiata Formation), Leah Creek, Westland.
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
(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)