Rhaphisotostoma asztalosi Pall-Gergely & Neubauer 2026, gen. et sp. nov.

Rhaphisotostoma asztalosi Páll-Gergely & Neubauer, gen. et sp. nov. urn:lsid:zoobank.org:act: D5287478-C4BE-4C64-BE44-6E4C24C9142F Figs 4A–L Type material: Holotype: HNHM PAL 2026.123.1, 1 shell, pit-heap of Ármin-bánya [Ármin mine], 47°05’17.2”N 17°35’21.5”E, G. Asztalos leg. 2025. Paratypes: HNHM PAL 2026.124.1, 1 broken shell, pit-heap of Jókai-bánya [Jókai mine], 47°04’35.5”N 17°34’00.6”E, G. Asztalos leg., 2025. GA, 3 compressed shells, pit-heap of Ármin-bánya [Ármin mine], 47°05’17.2”N 17°35’21.5”E, G. Asztalos leg. August 2026. Diagnosis: Shell ca. 4.4 mm, high conical (mean spiral angle: 18°); whorl sides nearly flat, slightly concave below suture. Teleoconch surface matte with fine, undulating, irregular radial growth lines and weaker spiral striation. Aperture suboval-triangular with expanded lower palatal part and pointed parieto-palatal angle; in lateral view with rounded, sinus-like concavity at upper quarter of aperture. Description: Shell small, high conical, widest at its base; consists of 7 whorls, which increase slowly in diameter after slightly inflated apex. Teleoconch whorls widest at approx. mid-height. Each whorl faintly bulging just above, and to lesser extent, just below suture. Subsutural bulges are followed below by shallow, broad concavity, resulting in slightly undulating whorl profile. Between last and penultimate whorl blunt keel and angulation delimit whorl profile and base, resulting in an area that is triangular in apertural view between keel and parietal callus. Protoconch consists of approx. 1 whorl; surface very finely pitted, with weak, irregular growth lines on last ca. quarter whorl; transition to teleoconch marked by weak growth rim and onset of faint teleoconch sculpture. Teleoconch surface matte, with fine, undulating, irregularly spaced growth lines and weak spiral striation (weaker on the body whorl). Aperture suboval-triangular with widely expanded basal part and pointed parieto-palatal angle. Palatal margin of peristome expanded, ear-shaped. Peristome continuous, parietal lip thickened, faintly detached from base of penultimate whorl, nearly straight apart from weak convexity near columella; no umbilicus. In lateral view, aperture orthocline, with characteristic, rounded, sinus-like concavity at upper quarter. Shell light brownish, irregularly patterned, particularly on last 3 whorls. Measurements: AH: 1.3 mm, AW: 0.9 mm, SH: 4.4 mm, SW: 1.15 mm (holotype, only complete specimen). Etymology: This new species is named after Gábor Asztalos, the collector. Remarks: The new genus is remarkably distinct in its characters, distinguishing it clearly from co-occurring and other Cretaceous taxa. Particularly the eponymous needle-like appearance and expanded but orthocline aperture, paired with undulating growth lines are unique. In fact, these features even cast doubt on its placement in Hydrobiidae. On the other hand, the size and shape of the protoconch plus the typically retracted upper part of the peristome are typical for hydrobiids, which is why we preliminarily maintain the genus in Hydrobiidae s.l. Parateinostoma manum differs in its more ovoid, glossier shell, the rounded whorls, and the more typical hydrobiid-like aperture. Slender morphotypes of the co-occurring potamidid Hadraxon csingervallensis (Tausch, 1886) shows a similarly stacked morphology with low-convex whorls and basal keel (e.g. Oppenheim 1892, pl. 35, fig. 17; Bandel & Riedel 1994, pl. 6, figs 5–6). However, the species as well as other representatives of Hadraxon are conical and ornamented with axial ribs or distinct spiral keels (Oppenheim 1892; Bandel & Riedel 1994). Moreover, H. csingervallensis bears a distinctly wrinkled protoconch that consists of two whorls (Bandel & Riedel 1994, pl. 7, figs 1–3), reflecting a different juvenile lifestyle. Both the holotype and, to a lesser extent, the paratype exhibit a light brownish shell colouration, which is not found in other specimens from Ajka. The excellent preservation of the material suggests that the colouration could be original, however given the pattern’s irregular nature it remains speculative.