Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 3d): GS11650, J40/f6612, Waihao River, near "Pentland Hills", Mangaorapan ? (GNS)
(Pl. 3g): GS11650, J40/f6612, Waihao River, near "Pentland Hills", Mangaorapan ? (GNS)
Beu & Maxwell (1990): Chapter 6; p. 90; pl. 3 d, g.
Description: Size moderate for genus (height 25-35 mm), subtrigonal, known only by the thick, lamellar-shelled right valve. Sculpture of irregular, spinose radial costae, mostly abraded from available specimens. Hinge prominent, cardinal area very small, noted only on young, less-abraded shells. Resilifer narrowly tubular, bounded by and largely covered by low, divergent ridges. Crura prominent, rather narrow but high, transversely grooved, separated from resilifer by prominent sockets. Adductor muscle scar large, sub-circular, in posterior position. Internal margin irregularly crenulate.
Comparison: This is the only species of Plicatula so far recorded from New Zealand. The genus is confined to the tropics at the present day but it seems to have had a more cosmopolitan distribution in the past. The highly distinctive hinge, with lateral ridges and grooves on the 2 major teeth, makes this genus readily recognised. The disc of all species is thick and rather crudely corrugated.
Distribution: Same locality as Spondylus n. sp. (BM31) (moderately common, but rather poorly preserved).
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)