Eulodrobia, 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 : 8

Genus Eulodrobia n. gen.

Type species: Jardinella eulo Ponder & Clark, 1990 .

Description. Shell small to moderate in size, very variable in shape from depressed conic to near discoidal, tightly to openly coiled, whorls convex (keeled in one species, angled in another); aperture subpyriform to circular, peristome thin to moderately thickened, inner lip adhering to parietal wall posteriorly (except in one openly coiled species), moderately to widely umbilicate. Sculpture of growth lines and (rarely) weak spiral rugae. Protoconch of 1.2–1.5 whorls, minutely to moderately irregularly punctate. Operculum yellowish to brownish, subpyriform to circular, slightly concave in most species; paucispiral with last whorl large, nucleus acentric, subcentric to central; inner surface without white smear, with or without weak thickening or protuberance at nucleus. Rectum with or without arch. Radula with median cusp of central teeth wider and longer than adjacent cusps; lateral margins narrow, innermost basal cusps heavy, triangular; basal tongue U-shaped. Male with prostate gland mostly visceral, with about quarter to third in front of posterior pallial wall. Pallial vas deferens simple or with one or two bends. Penis with distal swelling forming non-glandular lobe(s) in most species; glands absent. Female with renal oviduct long; initial part with anteriorly-orientated arch then forming posterior loop extending onto most of width of bursa copulatrix, making complete oval. Seminal receptacle an ovoid sac when present (absent in some taxa); lies within posterior loop of renal oviduct. Bursa copulatrix small to large, mostly to completely posterior to albumen gland or ventral to it. Pallial oviduct with simple ventral channel and opening simple and anterior (terminal to slightly subterminal).

Distribution. Discharge springs of the Eulo Supergroup, SW Queensland ( Fig. 1 ).

Contained species. Eulodrobia eulo and six new species described below, all from the Eulo Supergroup.

Etymology. Eulo—the township of Eulo, Queensland; -drobia—derived from the genus Hydrobia . Gender feminine.

Remarks. This genus has a very diverse shell morphology and is restricted to the Eulo Supergroup situated in the southern part of the GAB in Queensland in the vicinity of the small town of Eulo. Although the shell is highly variable in shape, it is never high-spired. Unlike species of Jardinella, the peristome is not noticeably thickened, and the operculum is flat and usually colourless to yellowish or in a few species, brownish. The opercula of two species are, uniquely in the Queensland spring tateids, circular with a central nucleus.

The prostate gland differs from most other taxa described herein in being mostly visceral, although this feature is shared with some species included below in Edgbastonia from the Barcaldine Supergroup. The penis often bears a distal lobe and, in this respect, resembles that of species of Fluviopupa Pilsbry, 1911 (Haase et al. 2006; Ponder & Shea 2014).

A unique anatomical character of Eulodrobia is a feature of the coiled oviduct, where the initial loop is pointed anteriorly and then it extends posteriorly, making an oval loop not seen in other Queensland spring taxa. Also, uniquely, when the seminal receptacle is present it lies within this loop. Unlike several other Queensland spring tateids, the pallial oviduct, lacks any significant elaboration of the ventral channel or genital opening.

In the molecular analysis of Perez et al. (2005) and in our analysis, species in this genus form a monophyletic group (see Fig. 31 ).

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.

FIGURE 31. Phylogram of Australian tateid spring taxa and selected outgroups with Bayesian posterior probability values (shown above nodes) and RAxML bootstrap support values (shown below nodes). Posterior probability values below 0.85 and bootstrap support below 70% are not shown, and asterisks indicate optimal support. Two parallel diagonal lines on branches indicate those branches have been shortened. Bayesian tree is shown. The grey box indicates the clade encompassing all Queensland spring taxa, the monotypic Nundalia from New South Wales, and the coastal, riverine genus Jardinella from northern Queensland. All taxa included in this clade are illustrated to the right and where possible aligned with their respective placement in the phylogram. Abbreviations: C—Carnarvoncochlea; E. (B.)—Edgbastonia (Barcaldinia); E. (E.) -Edgbastonia (Edgbastonia); NQ—North Queensland (coastal); NSW—New South Wales; S—Springvalia. Names of imaged taxa are indicated, next to the illustrations, by the three first letters in their species (or subspecies) name, or, when identical, the four first letters. For details of superscript numbers 1–40, see Table 20.