Genus Edgbastonia Ponder, 2008

Type species: Edgbastonia allanwillsi Ponder, in Ponder et al. 2008 (by original designation).

Edgbastonia Ponder, in Ponder et al. 2008: 90.

Description. Shell small to moderate in size, elongate-conic to depressed trochiform, whorls convex (angled in one species), aperture subpyriform, peristome slightly to moderately thickened, inner lip usually separated from parietal wall, attached in one species; narrowly to moderately umbilicate; one species non-umbilicate. Columella usually smooth but bears a fold in type species. Sculpture of growth lines only or weak axial ribs present. Protoconch of 1.1–1.5 whorls, minutely to moderately punctate to granulate. Operculum yellowish to reddish, subpyriform, paucispiral with last whorl large, nucleus acentric; inner surface usually without white smear (present in one species), usually without weak protuberance or thickening. Radula with median cusp of central teeth longer and about equal to much wider than adjacent cusps; lateral margins moderate to narrow; innermost of two (rarely one) basal cusps short to moderate, usually narrow; basal tongue narrow U-shape. Male with prostate gland pyriform to bean-shaped, with about third to slightly more than half of length in pallial wall. Pallial vas deferens strongly undulating to coiled. Penis variable, distal end usually tapering, expanded in few species, sometimes with short to long papilla; glands absent. Female with coiled oviduct rather short, forming simple vertical arch or loop. Bursa copulatrix lies mostly behind or beneath albumen gland. Vestibule simple to greatly expanded; genital opening terminal to subterminal opening ventrally to laterally; sometimes with associated cowl or gutter.

Distribution. Discharge springs in the Barcaldine Supergroup in the eastern part of the GAB (Fig. 1).

Contained species. Edgbastonia alanwillsi Ponder, 2008, E. edgbastonensis (Ponder & Clark, 1990), E. pallida (Ponder & Clark, 1990), E. colmani (Ponder & Clark, 1990), E. corrugata (Ponder & Clark, 1990), E. jesswiseae (Ponder & Clark, 1990), E. coreena (Ponder & Clark, 1990), E. zeidlerorum (Ponder & Clark, 1990), E. acuminata (Ponder & Clark, 1990) and six new species and two new subspecies.

Remarks. When the genus Edgbastonia was named it contained a single species that differed from other taxa in the Queensland spring radiation in several features; namely the columellar fold, ratchet-like shell formation on the columella and an unusual female reproductive system. While the shell differences and female reproductive system are distinctive, the molecular results clearly show that Ed. alanwillsi clusters with other taxa in the Barcaldine Supergroup. Consequently, we use this name for the entire group of species in the Barcaldine Supergroup springs, while continuing to recognise the morphological distinctiveness of the type species by including the other species in a new subgenus described below.

While our new concept of Edgbastonia forms a distinct clade in the Perez et al. (2005) analysis and in our molecular phylogeny (see molecular results below), it is difficult to define morphologically. It is similar to the other genus-group taxa recognised herein, other than Eulodrobia, in having the coiled oviduct forming a more or less vertical U that mostly lies anterior to the bursa copulatrix. Some other female reproductive features are variable, with, for example, the vestibule being absent to highly-developed. The female opening usually lies subterminally and the seminal receptacle (absent in one species) lies on the anterior inner face of the bursa copulatrix.

The genus as here interpreted contains species from the Barcaldine Supergroup in the north-eastern part of the Great Artesian Basin and three additional species located in the Einasleigh Uplands at the base of Cape York from non-GAB springs. While two of these species closely resemble some species of Edgbastonia, another is only tentatively placed in that genus.