Pravonitor ferrugineus Stanisic, 2010

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 : 1780-1782

Pravonitor ferrugineus Stanisic, 2010

( Figures 4 , 14 (d), 17)

Pravonitor ferruginea [sic!] Stanisic, 2010: 300–301.

Material examined

Holotype. QM MO12752 , East Claudie River , Iron Range , Far North Qld, Australia, monsoon rainforest, 26 July 1981, A. Green.

Paratypes. AM C .122987, AM C.432173, AM C.432174.

Other material. See Table 1 .

Diagnosis

External morphology. Shell ( Figure 14 (d)) medium-sized (SW 10.2–13.6 mm), pale cream to golden brown, with an orange-brown supraperipheral band, 5.2–6.4 whorls, discoidal with a low conical spire, whorls rounded, umbilicus very narrow. Protoconch and teleoconch sculptured with very fine spiral grooves. Body cream (in alcohol). Mantle lobes moderately large; shell lappets moderately long, wide at base, tapering to a point. Caudal horn moderately long.

Genital anatomy. Genitalia ( Figure 17 ) with moderately short vagina; bursa copulatrix moderately long, duct slightly broader at base, tapering, bursa not distinct, internally sculptured with longitudinal ridges. Penis moderately long, tubular, swollen just before epiphallic boundary with a small blind tip; internally with long, pointed, conical pustules, becoming larger in swollen portion; fine ridges in blind tip; approx. 75% enclosed in penial tunica. Epiphallus enters penis through simple pore; epiphallus longer than penis; epiphallus 2 longer than epiphallus 1; long epiphallic caecum present, with medial attachment of the penial retractor muscle; flagellum long, slender, tightly coiled, with tiny internal cryptae.

Remarks

Pravonitor ferrugineus was introduced for a medium-sized, banded snail from the Iron Range ( Stanisic et al. 2010). It was described as differing from P. kreffti by its flatter shell and the presence of a strong supraperipheral reddish-brown band.

We found two morphospecies in material identified as P. ferrugineus , similar in genital morphology but differing in the size, shape and internal sculpture of the penis and in their flagellum (and presumably spermatophore) shape. In particular, there is a marked difference in the penis interior, which is sculptured with very fine longitudinal pilasters in one species and with pointed, conical pustules in the other species. Both had pale cream shells with a strong reddish-brown band, differing slightly in size and shape. However, the sequences available (a single sequence from each morphospecies) showed a genetic divergence of only 2.5%.

Given the very distinct differences seen in the genitalia, we treat these morphospecies as distinct despite the low genetic differentiation. Through comparison with photographs of the holotype, we identified the smaller, higher-spired shell as P. ferrugineus . The second species is described below as P. stuarti sp. nov.

Pravonitor ferrugineus is recorded only from the Iron Range, Far North Qld, where it is found in rainforest, in and under logs ( Stanisic et al. 2010). Herein we expand the known distribution to include Heathlands National Park, 120 km to the north ( Figure 4 ). It is possible that P. ferrugineus is sympatric with P. stuarti , which is recorded from High Range, only 30 km south-east of the type locality of P. ferrugineus , but at present there is insufficient data to clarify this. Another population with the same distinctive colouring as P. ferrugineus and P. stuarti is known: Helicarionidae CY 7 from Black Mountain, south of Cooktown. The only material available for examination was a single adult shell and a spirit-preserved juvenile specimen, so species identity could not be confirmed.

Pravonitor ferrugineus can be distinguished from most of its congeners and by members of Geminitor and Malandena by its cream-coloured shell with a distinct reddishbrown supraperipheral band, and from P. stuarti by its smaller size and higher, conical rather than concave spire.

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 17. Genitalia of Pravonitor ferrugineus, QM MO21506, Heathlands. a) Reproductive system. b) Penis interior. Scale bars: 1 mm.