Pravonitor septentrionalis, 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 : 1786-1788

Pravonitor septentrionalis sp. nov.

( Figures 4 , 14 (h), 20)

Etymology

From septentrionalis (Latin = northern), referring to the species’ range at the northernmost tip of Cape York peninsula.

Material examined

Holotype. QM MO86001 . c. 4.0 km N of Lockerbie , Cape York Development Rd, Far North Qld, Australia; coll. 22 September 1988; J. Stanisic, D. Potter, J. Chaseling.

Paratypes. QM MO21832 , MO15621 , MO21629 .

Diagnosis

External morphology. Shell ( Figure 14 (h)) small (SW 7.7–9.3 mm), pale golden amber, 4.9–5.5 whorls, subdiscoidal to subglobose with a moderately raised spire, whorl profile rounded, sutures impressed; microsculpture of very fine spirals on protoconch and teleoconch, becoming obsolete on later whorls; umbilicus very narrow, lip reflected over opening, thickened columella with small notch. Body white (in alcohol). Right and median mantle lobes moderately small, left lobe small; shell lappets moderately long, narrow, tapering, left slightly shorter than right. Caudal horn moderately large.

Genital anatomy. Genitalia ( Figure 20 ) with very short to absent vagina; bursa copulatrix moderately long, duct slightly broader at base, sculptured internally with longitudinal ridges; bursa elongate. Penis long, bulging at base, tubular medially; internally with one pustulose longitudinal pilaster basally, internal wall sculptured with fine pustules; basal bulge with thickened folds; base not enclosed in penial tunica; tunica enclosing approx. 50–60% of penis. Epiphallus enters penis through a small verge; epiphallus shorter than penis; epiphallus 2 slightly longer than epiphallus 1; moderately short epiphallic caecum present, with medial attachment of the penial retractor muscle; flagellum long, slender, with L-shaped tip; very small internal cryptae visible. Spermatophore with soft capsule and elongate tail-pipe sculptured with small hook-like spines.

Remarks

Pravonitor septentrionalis sp. nov., initially designated as Pravonitor kreffti ‘Cape York’, is known only from a small area on the tip of Cape York peninsula, from just south of Bamaga to Punsand Bay. It is probably sympatric with P. kreffti near Punsand Bay, and in the past has been identified as this species, but comparison with the type images and early descriptions has shown that P. kreffti is significantly larger. Pravonitor septentrionalis also bears a close resemblance to Geminitor wenlockensis , which is found farther to the south between Weipa and the Portlands Rd crossing of Wenlock River. However, G. wenlockensis has a glossier shell surface, a sealed umbilicus partially covered by a reflected lip, and a weaker columellar thickening.

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 14. Shells of Pravonitor. a) Pravonitor insularum, AM C.170795 (paratype). b) Pravonitor annulus AM C.425415,Gabba Is. c) Pravonitor aquilonia, QM MO48285 (holotype). d) Pravonitor ferrugineus, QM MO12752 (holotype). e). Pravonitor kreffti, AM C.1352, Thursday Is. f) Pravonitor kreffti, AM C.425474, Simpson’s Bay, Utingu. g) Pravonitor monteithi, QM MO48587 (holotype). h) Pravonitor septentrionalis, AM C.425422. i) Pravonitor stuarti, QM MO80213 (paratype). Scale bar: 5 mm.

Figure 20. Genitalia of Pravonitor septentrionalis. a-c) QM MO86001 (holotype), Lockerbie. a) Reproductive system. b) Penis interior. c) Penial complex. d) QM MO15621 (paratype), Bamaga. Spermatophore. Scale bars: 1 mm.