Nanotrachia undetermined

Köhler, Frank & Criscione, Francesco, 2013, Small snails in a big place: a radiation in the semi-arid rangelands in northern Australia (Eupulmonata, Camaenidae, Nanotrachia gen. nov.), Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 169 (1), pp. 103-123: 119-120

publication ID 10.1111/zoj.12051

persistent identifier

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scientific name

Nanotrachia undetermined




Australia, WA, EK, 40.6 km north-west of Nicholson Station Homestead , limestone area with numerous gullies, base of cliffs, Spinifex   , and talus, under rocks in loose soil, 17°49′30″S, 128°34′40″E (coll. V. Kessner, 1 September 2009); dissected specimen ( WAM S66300 View Materials ). GoogleMaps  


Same data as holotype; two wet ( WAM S49178 View Materials ), 85 dry ( WAM S49100 View Materials ) GoogleMaps   .


In reference to the peripheral keel of the shell, derived from ‘carinatus’ (Latin = possessing a keel), adjective of feminine gender.


Shell ( Figs 4B View Figure 4 , 5A, B View Figure 5 ): Average in size; periphery shouldered, strongly keeled; spire weakly elevated; umbilicus open, wide, not concealed by columellar reflection; protoconch and teleoconch with dense, pointed periostracal projections and fine axial growth lines; teleoconch with weak, blunt, narrowly spaced axial ribs, interrupted on keel; apertural lip reflected, moderately expanded; yellowish–horn.

Genitalia ( Fig. 6C View Figure 6 ): Epiphallus very short, onequarter of penial length; no muscle fibres connect the epiphallus and penial apex. Vas deferens entering penial sheath almost halfway up. Penial wall thin, with two longitudinal pilasters, one wide, irregular, comprising half of penial wall, second pilaster thinner, irregularly shaped, winding, with regularly spaced, pointed corrugations; penial pore surrounded by subcircular ridge. Vagina slightly shorter than penis, half to twice as long as free oviduct.

Comparative remarks

Shell similar to N. coronata   sp. nov., but smaller in size, axial ribs interrupted on keel. Differs from N. levis   sp. nov. by presence of keel, from all other congeners by less developed axial ribs. The largest shells of N. carinata   sp. nov. are similar to the smallest shells of O. elegans   , which differ by more elevated spire and weaker developed periostracal projections. Genitalia identical to N. coronata   sp. nov., N. levis   sp. nov. has three pilasters, and all other species have smooth pilasters.


Western Australian Museum