Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 34e, f): paratype, GS1457, V22/f6498, main highway south of Pakipaki, Hawke's Bay, Waipipian (GNS)
Beu & Maxwell (1990): Chapter 14; p. 281; pl. 34 e,f.
Synonymy: Lucinoma galathea Marwick 1953, p. 111; Lucinoma marwicki Dell 1953b, p. 39
Description: Moderately large for family (28-50 mm high), subcircular, thin, weakly inflated, slightly longer than high; posterior outline slightly quadrate because of weak sulcus in outline caused by radial flexure marking off posterior area (or "wing"); posterior area a little less inflated than remainder of disc, relatively wide and prominent (e.g., more prominent than in Pteromyrtea and Miltha). Anterior area or "pseudolunule" very narrow, only weakly defined by a slight change in direction of sculpture. Lunule excavated for most of depth of hinge, relatively long and narrow. Sculpture of high, thin, widely spaced commarginal lamellae, the most prominent of any large New Zealand lucinid, up to 1 mm high and 2-4 mm apart over the outer area of large specimens. Hinge plate narrow, with 2 small, curved cardinal teeth in each valve, and a very small, obscure anterior lateral tooth at front edge of each valve, in front of lunule (a second one present in some left valves); ligamental nymph prominent, long and narrow, occupying lower half of hinge plate behind umbo; ligamental groove wide, moderately deep, completely below valve margin, but not enclosed above by valve margins as in Miltha and Pteromyrtea. Anterior adductor scar very tall and narrow, almost straight, largely inside and free from pallial line; posterior adductor scar much smaller, oval; pallial line without sinus. Central area bounded by muscle scars and pallial line weakly radially wrinkled.
Comparison: Lucinoma galathea is commonly dredged buried deeply in fine sediment in moderately deep water (150-300 m) in the Southland fiords and in the upper bathyal zone around much of New Zealand, and the fossils clearly inhabited the same environment. L. galathea is easily recognised by its relatively large size and coarse commarginal lamellae for a New Zealand Pliocene-Pleistocene lucinid. The relationship needs to be investigated to the living Chilean to Magellanic Lucinoma lamellata (E. A. Smith, 1881); we can see no significant differences between New Zealand specimens and Chilean specimens of L. lamellata in NMNZ.
Distribution: Opoitian to Recent; Recent, "Galathea" station 614, Milford Sound, in 268 m (type); Shakespeare Cliff Siltstone, Wanganui, Castlecliffian, and mudstone in cuttings on main highway south of Pakipaki, Hastings, Waipipian (paratypes); widespread but uncommon in deep-water siltstone facies in Wanganui basin, Wairoa district, southern Hawke's Bay, southern Wairarapa (moderately common in some localities in bathyal Mangapanian or, more probably, early Nukumaruan mudstone beneath Pukenui Limestone on the Maungaraki Range, east of Gladstone), and in North Canterbury.
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)