Carnarvoncochlea, Zhang, 2019

Zhang, - H., 2019, New taxa of Tateidae (Caenogastropoda, Truncatelloidea) from springs associated with the Great Artesian Basin and Einasleigh Uplands, Queensland, with the description of two related taxa from eastern coastal drainages, Zootaxa 4583 (1), pp. 1-67 : 47

Genus Carnarvoncochlea n. gen.

Type species: Jardinella carnarvonensis Ponder & Clark, 1990

Description. Shell small to tiny, conical to depressed trochiform, whorls convex, aperture subpyriform, peristome slightly thickened, inner lip loosely attached or separated from parietal wall; narrowly to moderately umbilicate. Sculpture of growth lines only. Protoconch of 1.2–1.4 whorls, minutely punctate. Operculum subpyriform, paucispiral with last whorl large, nucleus acentric; inner surface lacking white smear, with or without weak protuberances. Radula with central teeth with median cusp wider and longer than adjacent cusps; lateral margins usually narrow; innermost basal cusps short to moderate, broad; outer pair very small to absent; basal tongue narrow U-shape. Rectum with prominent arch. Male with pallial vas deferens simple or with undulations or coils. Prostate gland (known in only one species), broad, tapering rapidly anteriorly and posteriorly, slightly more than half in mantle roof. Penis with slightly tapering to slightly swollen distal end and short papilla; glands absent. Female with coiled oviduct with one arch-like vertical loop not overlapping bursa. Bursa copulatrix mostly posterior to albumen gland, absent in one species. Vestibule moderately to significantly expanded; genital opening terminal to subterminal, short to slit-like, with or without associated gutter.

Distribution. Recharge springs in the Springsure Supergroup ( Fig. 1 ) in the south-eastern part of the Queensland GAB.

Contained species. Carnarvoncochlea carnarvonensis ( Ponder & Clark, 1990) and C. exigua ( Ponder & Clark, 1990) .

Remarks. This genus does not possess any unique anatomical characters but differs from other Queensland species in the ‘Jardinella radiation’ in that the rectum forms a prominent arch in the mantle roof. Otherwise, the anatomy is plesiomorphic for the group.

Some specimens of members of this genus are unusual in having a rudimentary penis present in females ( Ponder & Clark 1990), a feature not observed in the material described below.

The origin of the water in the Carnarvon Gorge springs is from local sandstone aquifers which are part of the recharge zone of the GAB (Fensham & Fairfax 2003).

Figures

FIGURE 1. Map of the spring supergroups associated with the Great Artesian Basin (GAB) in Queensland, showing the main non-town locations mentioned in the text (squares) and some of the towns in the area (ovals). The pale grey shading is the discharge part of the GAB, the dark grey the recharge part. The inset map of Australia shows the area illustrated. The approximate location of Conondale is indicated by a triangle and Nundle by a star. The spring supergroups are outlined with dotted lines and are as follows: A, Mulligan River; B, Springvale; C, Flinders River; D, Hughenden; E, Barcaldine (see inset at upper right for details); F, Springsure; G, Eulo.