Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 50b): Nucinella aff. maoriana (Hedley, 1904); GS9520, J41/f8029, Awamoa Creek, North Otago (Altonian) (right hinge showing ligamental fossette indenting posterodorsal margin).
(Pl. 50d): Nucinella aff. maoriana (Hedley, 1904); GS9520, J41/f8029, Awamoa Creek, North Otago (Altonian)
(Pl. 50e): Nucinella aff. maoriana (Hedley, 1904); GS9520, J41/f8029, Awamoa Creek, North Otago (Altonian)
Beu & Maxwell (1990): Chapter 17; p. 374; pl. 50 b,d,e.
Synonymy: Pleurodon Wood, 1840, not of Harlan, 1831
Description: Height typically 1-3.5 mm, a few species much larger (but not in N.Z. species), ovate, thin-shelled, smooth or with weak commarginal grooves. Hinge prominent, with several large cardinal taxodont teeth, and a large anterior lateral tooth in each valve. Ligament external, sitting in shallow fossette behind beaks.
Comparison: Nucinella superficially resembles some nuculids, but differs in being non-nacreous, in having lateral teeth as well as cardinal teeth, and in having an external ligament. Despite the great difference in shell morphology, manzanellids seem to be most closely related to solemyids (Allen & Sanders 1969). Nucinella is highly conservative in shell characters and there are only relatively minor differences between the known species.
Distribution: Duntroonian-Recent, New Zealand; cosmopolitan, recorded from early Jurassic to Recent.
© 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)