Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 18j): GS9685, J41/f9499B, Pukeuri road cutting, Oamaru, Altonian (GNS)
(Pl. 18l): GS9685, J41/f9499B, Pukeuri road cutting, Oamaru, Altonian (GNS)
Beu & Maxwell (1990): Chapter 11; p. 182; pl. 18 j, l.
Synonymy: Myrtea valdesculpta Marwick 1943, p. 185
Description: Small for family (length 4-8 mm), subtrigonal-ovate, moderately inflated. Beaks sub-central, orthogyrous. Lunule and escutcheon lanceolate, strongly differentiated. Commarginal sculpture of distant, narrow lamellae raised into subtriangular spines along dorsal margins, particularly on posterodorsal margin. Spacing between lamellae very variable, but typically 3-4 per mm. Interspaces smooth apart from growth lines in some shells, but with fine, rather irregular radial ridges in others. Left hinge with very weak anterior and posterior lateral teeth, a narrowly triangular anterior cardinal and a similar posterior cardinal tooth. Right hinge with strong, distant anterior and posterior laterals and a narrow, triangular median cardinal tooth. Adductor muscle scars ovate, subequal. Internal margins smooth.
Comparison: Myrtea valdesculpta closely resembles M. staminifera (Duntroonian, Chatton), but differs in having a straighter anterodorsal margin. In view of the considerable variability present in New Zealand species of Myrtea, however, it is possible that these species are not really distinct. Myrtea has a recorded range of Duntroonian to Opoitian in New Zealand; elsewhere the genus has a wide bathymetric range (from about five metres down to mid-bathyal depths).
Distribution: Altonian; Target Gully Shellbed (type) and other North Otago and South Canterbury localities, where it is the most common lucinid.
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)