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: 120

publication ID 10.1111/zoj.12051

persistent identifier

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scientific name

Nanotrachia undetermined




Australia, WA, EK, Osmond Range , 17 km northeast of Palm Yard, narrow limestone and sandstone ridge, with steep open slopes, talus, and Spinifex   , in litter under rocks, 17°12′13″S, 128°24′50″E (coll. V. Kessner, 29 August 2009); dissected specimen ( WAM S66301 View Materials ). GoogleMaps  


Same as holotype; one wet ( WAM S49181 View Materials ), 11 dry ( WAM S49086 View Materials )   .

Other material: Table 1.


In reference to the crown-like appearance of the peripheral keel because of the axial ribs continuing onto it, derived from ‘coronatus’ (Latin = bearing a crown), adjective of feminine gender.


Shell ( Figs 4C View Figure 4 , 5C, D View Figure 5 ): Large; 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, widely spaced axial ribs, not interrupted on keel; apertural lip reflected, moderately expanded; yellowish brown.

Genitalia: Epiphallus very short, one-quarter of penial length; no muscle fibres connect epiphallus and penial apex. Vas deferens entering penial sheath almost halfway up. Penial wall thin, with two longi- tudinal 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 (identical to N. carinata   sp. nov.; Fig. 6C View Figure 6 ).

Comparative remarks

Largest species of genus. Shell similar to N. carinata   sp. nov., but axial ribs continuing on keel; N. levis   sp. nov. differing by absence of keel; N. orientalis   with stronger ribs, other congeners with weaker keel. Genitalia identical to N. carinata   sp. nov.


Western Australian Museum