Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 29a): paratype, GS1037, S28/f6446, Hurupi Stream, Palliser Bay, southern Wairarapa, early Tongaporutuan (GNS)
Beu & Maxwell (1990): Chapter 13; p. 256; pl. 29 a.
Synonymy: Dosinia (Kereia) cottoni Marwick 1927, p. 590
Classification: Veneridae: Dosiniinae
Description: Size moderate for genus (42-50 mm high), subcircular, moderately inflated, with narrow, strongly protruding umbones, weakly winged posteriorly by weakly convex dorsal margin and weakly angling ridge from umbo to postero-ventral margin. Lunule large, narrow, deeply impressed, particularly in front. Escutcheon well marked, bounding ridge slightly more sharply keeled in left valve than in right. Sculpture of regular, very narrow, widely spaced, commarginal lamellae, normal to disc surface over central and anterior areas but more inclined outward over postero-dorsal area. Hinge visible on very few specimens (almost all are articulated shells); considerably wider and with thicker, more upright teeth than in D. greyi Zittel; teeth strongly divergent; right hinge with very short, high, lamellar anterior cardinal tooth close to valve margin, short, widely triangular median cardinal tooth close to anterior cardinal, very broad, grooved, weakly curved posterior cardinal, and short, wide, shallow, anterior lateral socket; left hinge with long triangular anterior cardinal tooth, broadly triangular, grooved median cardinal tooth, long, high, lamellar, weakly curved posterior cardinal tooth, and short, thick, low anterior lateral tubercle, rugose on its lower face; ligamental nymph long, smooth, with wide, bevelled, finely striated resilial surface above. Pallial sinus narrow, deep, with pointed apex, directed at top of anterior adductor muscle scar.
Comparison: Dosinia cottoni is closely similar to D. greyi (Kapitean-Recent), type species of D. (Kereia) Marwick, 1927, but differs in its larger size, its more posteriorly winged shape, its less prominent lunule, its lesser inflation, its wider hinge with thicker teeth, and in having a clearly defined escutcheon.
Distribution: Tongaporutuan (and Waiauan?); Hurupi Stream and nearby localities in Palliser Bay, southern Wairarapa (type), early Tongaporutuan, very common in shallow-water assemblages with diverse Mollusca; widespread in North Taranaki, Gisborne district, throughout Wairarapa, in Marlborough, North- Canterbury, and Westland; ? Fox River, Westland (Waiauan); similar shells occur in other Waiauan localities (Paparoa Rapids, Wanganui River; southern Wairarapa).
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)