Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 33a): holotype (right valve only), GS5240, Q21/f6501, Waihi Beach, Hawera, South Taranaki, Waipipian (TM2714, GNS)
(Pl. 33e): GS11886, R21/f01, left valve, Larsen shellbed, north of road end, Waitotara Valley, Wanganui Basin, Opoitian (GNS)
Beu & Maxwell (1990): Chapter 14; p. 275; pl. 33 a,e.
Synonymy: Chlamys (Phialopecten) triphooki marwicki Beu 1970a, p. 115; Phialopecten ongleyi, Beu & Maxwell 1990, p. 276, pl. 33e.
Description: Very large for family (97-175 mm high), calcitic, most specimens equidimensional or slightly longer than high; left valve moderately to markedly more inflated than right; ears large, almost equal in the 2 valves, anterior slightly longer and more notched at base than posterior; with very shallow byssal sinus but no ctenolium on right anterior ear. Sculpture of 25-35 (28-30 on most specimens) prominent, narrow, closely spaced radial costae, almost equal in width on 2 valves, those on left valve consistently bearing 3 (or 4 on a few specimens) low, narrow costellae on their surfaces; only 1 secondary costella in most interspaces. Internal features visible in very few specimens.
Comparison: See under Phialopecten thomsoni for comparison and discussion. The specimen illustrated by Beu & Maxwell (1990, pl. 33e) is an Opoitian specimen of Phialopecten marwicki.
Distribution: Waipipian-Opoitian; Waihi Beach, Hawera, South Taranaki, Waipipian (type); abundant in Te Aute limestone facies and near-shore sandstone and shellbeds in Wanganui basin and throughout east coast North Island.
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)