Edgbastonia? conjuboyensis, 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 : 45-47

Edgbastonia? conjuboyensis n. sp.

Material examined. Holotype: Queensland, W of Georgetown, S of Einasleigh, Conjuboy Station, Basalt Spring , 18° 40' 02" S, 144° 44' 36" E, on rocks, W.F. Ponder, J.B. Studdert, C. Slatyer & J.M. Ponder, 23 Aug 2004, C.479956 . Paratypes: Same data, 23 Aug 2004, C.445416, 20+ dry; QM MO85771 , 5 .

Shell ( Fig. 13H ). Spire outline slightly convex, normally coiled, translucent. Length 1.4–1.8 mm (mean 1.6 mm), width 0.9–1.1 mm (mean 1.0 mm). Protoconch of about 1.3 whorls, lacking punctate sculpture but with initial part with an irregular surface resembling uneven plastering, and the latter part with faint transverse wrinkles and extremely fine spiral striae. Teleoconch whorls moderately convex, evenly rounded, total number 3.5–4.1 (mean 3.7). Umbilicus represented by chink only. Aperture ovate or pyriform, inner lip narrow, thin or medium, slightly separated along whole length of parietal wall, outer lip thin or medium. Periostracum very thin and inconspicuous, white.

Operculum ( Fig. 14M, N ). Transparent, pale yellow, slightly concave. Inner side lacking white smear, with weak, smooth ridge near columellar edge of inner side.

Head-foot and external body. Snout, neck and opercular lobes pigmented, tentacles and dorsal and lateral foot unpigmented, mantle roof densely pigmented or black, visceral coil densely pigmented.

Mantle cavity. Ctenidium well-developed, filaments 13–15, broadly triangular, apex right edge. Osphradium narrowly oval, towards anterior end of ctenidium, length relative to gill 0.21–0.31. Hypobranchial gland not distinguishable (absent). Rectum with U-shaped bend, faecal pellets longitudinally orientated or orientated obliquely and longitudinally, anus at or very near mantle collar. Kidney extends for about third of length into mantle cavity roof, or half or more in roof of mantle cavity. Renal gland transverse. Pericardium extends for about third of length into mantle cavity roof, abutting posterior end of ctenidium.

Radula ( Fig. 19E, F ). Central teeth with cusp formula 4–5+1+4–5, basal cusps 2+2; median cusp narrow, sharp about twice as long as adjacent cusps. Lateral teeth with cusp formula 3–4+1+3–4; main cusp about twice as long as adjacent cusps, sharp to blunt. Inner marginal teeth with 19–21 cusps. Outer marginal teeth with 17–21 cusps.

Female reproductive system ( Fig. 16M, N ). Ovary simple sac. Renal oviduct makes tight, near vertical to anteriorly orientated loop, distinctly muscular. Seminal receptacle absent; orientated sperm located in renal oviduct. Bursa copulatrix behind albumen gland, elongately-oval or triangular, shorter than albumen gland, bursal duct enters bursa mid anteriorly, bursal duct joins coiled oviduct little behind posterior mantle cavity wall. Albumen gland partly in mantle cavity. Capsule gland with two distinct glandular zones, medium thickness in cross section, markedly indented by rectum. Anterior vestibule not defined, opening subterminal, short, cowl and/or gutter associated with oviduct opening absent.

Male reproductive system ( Fig. 17G , 18H, I ). Prostate gland half in mantle roof, bean-shaped, medium in cross section. Posterior pallial vas deferens slightly undulating, anteriorly strongly and tightly undulating near base of penis. Penis towards middle of head, distal end narrow, elongate, not tapering, blunt terminally.

Etymology. Named for Conjuboy Station.

Distribution and habitat. Known only from a non-GAB spring on Conjuboy Station ( Fig. 1 ) in north western Queensland, about 120 km south of Mt Garnet in the mid-eastern part of the Einasleigh Uplands.

Remarks. This species was found in a spring emanating from basalt rocks on Conjuboy Station and thus it is not from the Great Artesian Basin aquifers. It is the only tateid known to date from a ‘basal Tertiary spring’ ( Habermehl 1982) within the area occupied by the Queensland part of the GAB. Some of the basalts on Conjuboy Station are Murronga basalts formed around 120,000 to 180,000 years ago ( Griffin & McDougall 1975) which are slightly younger than the famous Undara Lava Tubes to the south which were formed a little earlier, around 190,000 years ago. However, other basalts on Conjuboy Station are much older, around 400,000 years and some 2.27 million years old, while others in the same region are in excess of 7 million years ( Griffin & McDougall 1975).

Regrettably our available material of this species was not able to be sequenced. It occurs well to the north of the Barcaldine Supergroup springs, in the same general area as Ed. (B.) chillagoensis and Ed. (B.) hufferensis . All the springs in this area (the Einasleigh Uplands) are not fed from water from aquifers making up the Great Artesian Basin ( Habermehl 1982). While the molecular data for the other two species appears to confirm their relationship with Edgbastonia , we include the present species in that genus only tentatively, pending confirmation. It differs from species included in any of the genera dealt with here in its more regularly conical shell. Anatomically, it mainly differs in the female lacking a bursal duct. Another unusual feature is its peculiar protoconch microsculpture, which is unlike that seen in any other Australian tateid. Despite the differences, the general anatomy, radula, and operculum do not show other substantive differences from many of the other species included here in the ‘ Jardinella radiation’.

Species of the SE Australian/Tasmanian genus Austropygrus Cotton have a similar shell morphology, but those all have a pegged operculum, more than two pairs of basal cusps and differ in some anatomical details (e.g., possessing a gastric caecum) and in protoconch microsculpture (see Clark et al. 2003). Some species of Fonscochlea Ponder et al., 1989 are generally similar but members of that genus differ markedly in female anatomy.

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 13. Shells of species of Edgbastonia (Barcaldonia) n. subgen. A. Edgbastonia (B.) hufferensis n. sp., holotype (C.479951). B. Edgbastonia (B.) cf. pallida (Ponder & Clark, 1990) (C. 479947). C, D. Edgbastonia (B.) routhensis n. sp., Routh Stn, C, holotype (C.479960). D. paratype (C.448850). E, Edgbastonia (B.) pagoda n. sp., holotype, Myross Stn (C.479948). F. Edgbastonia (B.) rugosa n. sp., holotype, Myross Stn (C.479949). G. Edgbastonia (B.) corrugata umbilicata n. sp., holotype, Myross Stn (C.479946). H. Edgbastonia? conjuboyensis, holotype, Conjuboy Stn (C.479956). I. Edgbastonia (B.) chillagoensis, holotype, Chillagoe Stn (C.479958). Scale bar 1 mm.

FIGURE 14. Opercula of species of Edgbastonia (Barcaldonia) n. subgen. A. Edgbastonia (B.) hufferensis n. sp., internal view (C.423238). B, C. Edgbastonia (B.) cf. pallida (Ponder & Clark, 1990). B. External view. C. Internal view (C. 457755). D, E. Edgbastonia (B.) routhensis n. sp. D. External view. E. Internal view (C438551). F, G. Edgbastonia (B.) pagoda n. sp. F. External view. G. Internal view (C.457756). H. Edgbastonia (B.) rugosa n. sp., internal view (C.457753). I, J. Edgbastonia (B.) corrugata umbilicata n. subsp. I. External view. J. Internal view (C.415845). K, L. Edgbastonia? conjuboyensis n. sp. K. External view. L. Internal view (C.445416). M, N. Edgbastonia (B.) chillagoensis n. sp. M. External view. N. Internal view (C.438557). Scale bar 200 µm.

FIGURE 16. Female reproductive system of species of Edgbastonia (Barcaldonia) n. subgen., shown from left side. A, B. Edgbastonia (B.) hufferensis n. sp. (C.423238). C, F. Edgbastonia (B.) cf. pallida (Ponder & Clark, 1990) (C.457755). D, E. Edgbastonia (B.) routhensis n. sp. (C.438551). G, H, Edgbastonia (B.) pagoda n. sp. (C.457756). I, L. Edgbastonia (B.) rugosa n. sp. (C.457753). J, K. Edgbastonia (B.) corrugata umbilicata n. subsp., (C.415845). M, N. Edgbastonia? conjuboyensis n. sp. (C.445416). O, P. Edgbastonia (B.) chillagoensis n. sp. (C.438557). Abbreviations: ag—albumen gland; bc—bursa copulatrix; cg—capsule gland; o—opening of oviduct; pw—posterior wall of mantle cavity; ro—renal oviduct; sr—seminal receptacle; vc—ventral channel. Scale bars 200 µm.

FIGURE 17. Prostate and vas deferens of species of Edgbastonia (Barcaldonia) n. subgen. A. Edgbastonia (B.) hufferensis n. sp. (C.423238). B. Edgbastonia (B.) cf. pallida (Ponder & Clark, 1990) (C.457755). C. Edgbastonia (B.) routhensis n. sp. (C.438551). D. Edgbastonia (B.) pagoda n. sp. (C.457756). E. Edgbastonia (B.) rugosa n. sp. (C.457753). F. Edgbastonia (B.) corrugata umbilicata n. subsp. (C.415845). G. Edgbastonia? conjuboyensis n. sp. (C. 445416). H. Edgbastonia (B.) chillagoensis n. sp. (C.438557). Abbreviations: avd—anterior vas deferens; pg—prostate gland; pvd—posterior vas deferens; pw—position of posterior wall of pallial cavity. Scale bars 200 µm.

FIGURE 18. Penis and vas deferens of species of Edgbastonia (Barcaldonia) n. subgen. A. Edgbastonia (B.) hufferensis n. sp. (C.423238). B, C. Edgbastonia (B.) cf. pallida (Ponder & Clark, 1990) (C.457755). D, Edgbastonia (B.) routhensis n. sp. (C.438551). E. Edgbastonia (B.) pagoda n. sp. (C.457756). F. Edgbastonia (B.) rugosa n. sp. (C.457753). G. Edgbastonia (B.) corrugata umbilicata n. subsp. H, I. Edgbastonia? conjuboyensis n. sp. (C.445416). J, K. Edgbastonia (B.) chilagoensis n. sp. (C.438557). Abbreviations: avd—anterior vas deferens; ngl—non-glandular lobe; p—papilla; pd—penial duct. Scale bars 200 µm.

FIGURE 19. Radulae of species of Edgbastonia (Barcaldonia) n. subgen. A, B. Edgbastonia (B.) rugosa n. sp. A. Half row. B. Lateral teeth (C.457753). C, D. Edgbastonia (B.) corrugata umbilicata n. subsp. C. Half row. D. Lateral and marginal teeth (C.415845). E, F. Edgbastonia? conjuboyensis n. sp. E. Half row. F. Marginal teeth (C.445416). G, H, I. Edgbastonia (B.) chillagoensis n. sp. G. Half row. H. Lateral and marginal teeth. I. Outer marginal teeth (C.438557). Scale bars 10 µm.