GNS Science

Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)

New Zealand Cenozoic Mollusca

Comitas allani Powell, 1942


(Pl. 42p): GS10849, V20/f8572, Devil's Elbow mudstone, top of north face of Devil's Elbow hill, north of Napier, Nukumaruan (GNS)

Beu & Maxwell (1990): Chapter 15; p. 327; pl. 42 p.

Synonymy: Comitas allani Powell 1942, p. 59

Classification: Turridae: "Cochlespirinae" clade 3 or 4 (Puillandre et al. 2008)

Description: Small for genus (26-33 mm high), tall and narrow, with tall stepped spire and long, almost straight canal without fasciole (canal incomplete on most specimens). Axial sculpture of short, only slightly opisthocline costae at and below shoulder, 12-14 per whorl, prominent and extending whole whorl height on early whorls but shorter lower down, reduced or absent on last half-whorl of large shells; crossed by relatively prominent, coarse, rounded spiral cords, 5-7 on spire and about 25 on last whorl and canal, with 1 lower cord filling each interspace on whorl sides; sutural ramp almost smooth, apart from weak subsutural fold. Anal sinus narrowly rounded, relatively deep, occupying narrow zone on sutural ramp below subsutural fold. Protoconch of 2 smooth whorls, apex dome-shaped; ending in a few axial costae.

Comparison: Comitas allani has weaker axial sculpture and more prominent spiral cords than other New Zealand species. Also, it is much smaller than the widespread Oligocene-Miocene species C. fusiformis and the Pliocene-Recent species C. onokeana.

Distribution: Opoitian-Nukumaruan; "Devil's Elbow, Napier-Wairoa Road", Nukumaruan (type); uncommon in Opoitian-Waipipian blue-grey mudstone in the Wairoa district, northern Hawke's Bay; widespread but uncommon in Nukumaruan blue-grey mudstone throughout central and southern Hawke's Bay. At Devil's Elbow, C. allani is not uncommon in Devil's Elbow mudstone at the top of the north face of the road exposure, but we have not seen specimens from any other horizon, so Devil's Elbow mudstone is assumed to be the type horizon.

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
ISBN 978-0-478-19705-1
ISSN 1177-2441
(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)


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