Geminitor macveae, Hyman & Köhler, 2022

Hyman, Isabel T. & Köhler, Frank, 2022, Homoplasy in shells discombobulated the taxonomy: revision of the larger helicarionid land snails of northern Queensland, Australia (Stylommatophora: Helicarionidae), Journal of Natural History 56 (41 - 44), pp. 1727-1799 : 1768

Geminitor macveae sp. nov.

( Figures 4 , 6 (e), 12)

Etymology

Named for Tracey McVea, in acknowledgement of her tireless efforts as Grants and Research Support Officer at the Australian Museum Research Institute.

Material examined

Holotype. QM MO85999 , Rifle Ck , c. 1 km NW of Mt Molloy, north-eastern Qld, Australia (15 57’ S, 145 19’ E), 10 September 1988, J. Stanisic, D. Potter.

Paratype. QM MO20694 (same data as holotype) .

Other material. See Table 1 .

Diagnosis

External morphology. Shell ( Figure 6 (e)) small (SW 6.6 mm), golden amber, 5.2 whorls, subdiscoidal with a low conical spire, whorls rounded; umbilicus narrow; protoconch and teleoconch with fine spiral grooves. Body white (in alcohol). Mantle lobes moderately small; shell lappets long, triangular, tapering. Caudal horn moderately large.

Genital anatomy. Genitalia ( Figure 12 ) with short vagina; bursa copulatrix of moderate length, duct broad, internally with fine, longitudinal, anastomosing ridges; bursa elongate. Penis short, slender, internally with two chambers, distal portion sculptured with one main longitudinal pilaster and a second, shorter and narrower pilaster; proximal portion sculptured with longitudinal ridges; penial verge absent;penis 100% enclosed in penial tunica.Epiphallus longer than penis, similar in width to penis; two arms of epiphallus approximately equal in length; long epiphallic caecum present, with basal attachment of the penial retractor muscle; flagellum moderately short, slender, coiled, without obvious internal cryptae.

Remarks

Geminitor mvceae (preliminarily identified as P. villaris ‘Rifle Creek’) is only known from the holotype and paratype, from Rifle Creek near Mt Molloy ( Figure 4 ). This species was previously subsumed within G. villaris , which it closely resembles. However, G. macveae is significantly smaller than G. villaris , with a much smaller and narrower penis and distinctly different internal penial sculpture. It is the smallest and most southerly distributed of all Geminitor species.

Figures

Figure 4. Distribution map. Grey symbols: Geminitor. Blue symbols: Pravonitor. Red symbols: Elatonitor. Biogeographic barriers are marked in black; A = Normanby Basin, B = Black Mountain Corridor, and C = Atherton Tableland.

Figure 6. Shells of Geminitor. a) Geminitor laura, AM C.474954, Lakeland Downs. b) Geminitor villaris, QM MO20887, Mt Cook. c) Geminitor villaris, QM MO21256, Starcke. d) Geminitor kullaensis, QM MO30875, McIlwraith Range. e) Geminitor macveae, QM MO20694 (paratype). f) Geminitor wenlockensis, QM MO86000 (H), Wenlock River. Scale bar: 5 mm. Photographs by F. Köhler ((a-b), d, f), J. Caiza (c), and G. Thompson (e).

Figure 12. Genitalia of Geminitor macveae. a, b) QM MO85999 (holotype), Rifle Creek. a) Reproductive system. b) Penis interior. Scale bars: 1 mm.