Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990)
(Pl. 22e): GS11154, J39/f26, holotype, foot of Mt Horrible, Pareora River, South Canterbury, Otaian (GNS)
Beu & Maxwell (1990): Chapter 11; p. 214; pl. 22 e.
Synonymy: Turehua lividorupis Beu & Maxwell 1987, p. 19
Classification: Cancellariidae: Plesiotritoninae
Description: Small for genus (height up to 13 mm), ovate, spire about half total height. Protoconch mamillate, of 1.5 smooth whorls. Teleoconch of 3 whorls, broadly angled near middle on spire, last whorl excavated, with short, broad neck. Axial sculpture of slightly opisthocline costae that are not parallel to outer lip of aperture (i.e. they are non-collabral), becoming shorter as shell grows so last whorl of large shells bears only peripheral nodules, crossed at a low angle by numerous, fine growth lines. Spiral sculpture of low, rounded, widely spaced primary cords, 2 or 3 on sides of spire whorls, 5 or 6 on last whorl, and numerous low, narrow threads, 10-20 on sutural ramp and 4-6 between primary cords, and many more on base and neck. Aperture narrowly oval; columella subvertical, almost straight except for bend near anterior end defining a short siphonal canal, bearing 2 prominent plaits near middle; no fasciole. Inner lip callus thin, spreading laterally, outer edge raised. Outer lip narrowly reflected over low terminal varix (previous varices not retained), bearing 4-8 very low indistinct nodules on its inner edge.
Comparison: Turehua lividorupis is easily recognised by being much the smallest and most weakly sculptured New Zealand species of the genus. The non-collabral axial sculpture is characteristic of the genus (and of the subfamily). Other New Zealand species (reviewed by Beu & Maxwell 1987) are T. dubia (Bortonian, Hampden) the type species of Turehua Marwick, 1943 which is larger than T. lividorupis, and has a concave sutural ramp, a prominent fasciole and a wide inner lip, and narrower, more numerous spiral cords; T. crassispiralis (Kaiatan, McCulloch's Bridge), a short, strongly inflated species with few, large, rounded, closely spaced spiral cords; T. ponscuspidis (Runangan, Bridge Point), a small species shaped like T. dubia but shorter, with fewer spiral cords and a shorter siphonal canal; and T. tenuispiralis (Duntroonian, Wharekuri), a large shell with prominent, clearly opisthocline axial costae but weak spiral sculpture. An unnamed species from the Chatham Islands (Opoitian-Waipipian, Momoe-a-Toa and Whenuataru Tuff), close to T. ponscuspidis and known from only a few broken specimens, is much the youngest known species in the world. Species of Turehua occur widely in Paleogene (and a few in Late Creataceous) rocks in Europe, and the genus probably was cosmopolitan, but is now extinct.
Distribution: Waitakian-Otaian; Mount Harris Formation, foot of Mt Horrible, Pareora River, Otaian (type); Bluecliffs, Otaio River; Brother's Stream, Hakataramea Valley; upper Tengawai River; not common at any locality.
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)