Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 24m): GS11182, D45/f8819, Fouraye Siltstone, Clifden, Altonian (GNS)
Beu & Maxwell (1990): Chapter 11; p. 224; pl. 24 m.
Synonymy: Murexsul scobinus Finlay 1930b, p. 74
Classification: Muricidae: Muricopsinae
Description: Size moderate for genus (height 30-60 mm), broadly fusiform, spire 0.35-0.4 total height. Protoconch imperfectly known, conical, of about 3 whorls. Teleoconch whorls 5-7, prominently shouldered at 0.5-0.6 whorl height on spire; last whorl elongate, broadly excavated with moderately long neck. Axial sculpture of prominent broadly triangular costae with broad interspaces, reaching from suture to suture on early whorls, almost obsolete on sutural ramp on later whorls, extending across base and onto neck of last whorl; penultimate whorl with 8-10 costae. Spiral sculpture of prominent narrow cords with interstitial threads, less prominent on ramp than below, neck with 2 cords noticeably stronger than those above. Hollow triangular spines formed at intersections of stronger spirals with costae, the most prominent on shoulder angle; and fine scales produced where spirals are crossed by growth lamellae, giving the shell a distinctly file-like appearance. Aperture ovate; siphonal canal long, slightly curved, fasciole prominent with a deep pseudumbilicus between it and inner lip. Inner lip moderately callused, smooth except for low ridge at base of columella; outer lip finely crenulated along margin, finely denticulate within.
Comparison: Murexsul scobinus is distinguished from other New Zealand species of Murexsul by its relatively slender shape and its densely scaly sculpture. M. proavitus (Altonian, Target Gully and Ardgowan Shellbeds, Oamaru) has similar sculpture, but is less elongate and has evenly convex or only weakly shouldered teleoconch whorls.
Distribution: Altonian; Calamity Point Sandstone, Calamity Point, Clifden (type); Fouraye Siltstone, Clifden, moderately common. Also recorded by Finlay (1930b, p. 74) from Long Beach Shellbed, Clifden.
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)