Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 9c, d): GS9535, J42/f6031, beach below Everett's Quarry, Kakanui, Whaingaroan (GNS)
Beu & Maxwell (1990): Chapter 9; p. 131; pl. 9 c, d.
Synonymy: Cardita benhami Thomson 1908, p. 102-103; Venericardia benhami; V. (Fasciculicardia) benhami
Classification: Carditidae: Venericardiinae
Description: Small for genus (length 25-30 mm), subquadrate, beaks situated at about 0.2 anterior-posterior distance; strongly inflated; posterior area slightly concave. Lunule small, pouting. Radial sculpture of 28-31 prominent, narrow, strongly nodulose costae that are noticeably weaker in middle of posterior area than elsewhere. Some costae, particularly on posterior part of flanks and on posterior area, with a low ridge on each side. Commarginal sculpture of nodules and scales on costal crests, and numerous very fine ridges and wrinkles in between. Left hinge with a small, tubercular anterior lateral tooth at end of lunular groove, a broadly triangular anterior cardinal and a long, narrow, slightly curved posterior cardinal tooth. Right hinge with small anterior lateral socket and a curved, excavated median cardinal tooth. Ligament groove narrow, bounded by a thin ridge along margin of sunken escutcheon.
Comparison: Glyptoactis benhami is distinguished from G. acanthodes (Pl. 5g, h) and G. subintermedia (Pl. 23g) by its relatively small size, its less rounded outline and its more closely spaced, less obviously tripartite radial costae. The number of costae is similar to that in G. subintermedia; G. acanthodes, by contrast, has only 21-24 costae.
Distribution: Whaingaroan; Deborah Volcanic Formation, Everett's Quarry, Kakanui (type) (common); Gee's Point, Kakanui (rare).
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)