Hypselostoma geckophilum Gojšina, Hunyadi & Páll-Gergely, 2025

Hypselostoma geckophilum Gojšina, Hunyadi & Páll-Gergely sp. nov.

Figs 111 W View Figure 111 , 143 View Figure 143 , 144 View Figure 144 , 154 View Figure 154

Type material.

Holotype. Thailand • 1 shell (SH: 2.92 mm; SW 1: 2.74 mm); Chanthaburi Province, Kaeng Hang Maeo district, Tham Khao Wongkot ; 12°53.236'N, 101°49.065'E; 60 m a. s. l.; 08 Mar. 2023; A. Hunyadi leg.; CUMZ 14451 View Materials GoogleMaps . Paratypes. Thailand • 105 shells; same data as for holotype; coll. HA GoogleMaps • 1 shell; same data as for holotype; coll. VG GoogleMaps .

Additional material examined.

Thailand • 14 shells (juveniles / damaged, not paratypes); same data as for holotype; coll. HA GoogleMaps .

Type locality.

Thailand, Chanthaburi Province, Kaeng Hang Maeo district, Tham Khao Wongkot; 12°53.236'N, 101°49.065'E; 60 m a. s. l.

Diagnosis.

Shell concave-conical, last whorl shouldered, previous whorls weakly convex. Teleoconch with raised spiral striae and strong whitish streaks. Last whorl detached from the penultimate, slightly turned downwards. Aperture equipped with five barriers (angulo-parietal, upper palatal, lower palatal, basal, and columellar). Umbilicus initially narrow but suddenly expanding at the last whorl.

Description.

Shell concave-conical (due to the strongly expanded last whorl), light brown, weakly glossy, opaque. It is consisting of 4.5–5 step-like, regularly increasing whorls separated by a very deep suture. All whorls except for the last one are rounded, convex. Protoconch slightly lighter than the rest of the shell, spirally striated (~ 25 densely arranged spiral striae) and consisting of ~ 1.25 whorls. Boundary between protoconch and teleoconch not particularly clear but visible as stronger spiral striation and darker surface. Teleoconch densely and strongly spirally striated, especially on the last whorl. Spiral striae slightly almost regularly spaced, leaving the space between the two striae up to the width of three or rarely two striae. Spiral striae get more densely arranged at the lower part of the last whorl than those at the centre of the periphery. There are ~ 33 spiral striae on the last whorl in standard view. Strong and wide radial white streaks cross the spiral striae. These streaks vary in number and are mostly present on the last three whorls. Last whorl shouldered, slightly detached from the penultimate and slightly descending near the aperture (~ 5–10 ° compared to the shell axis). Peristome of the same colour as the rest of the shell, or very slightly lighter. It is expanded and not reflected. Aperture equipped with four main barriers (angulo-parietal, upper palatal, lower palatal and columellar). Angular part of the angulo-parietal lamella reaching the peristome, very small and pointed, leaned towards the upper palatal plica. Parietal part of the angulo-parietal lamella is much stronger and high, blade shaped. Upper palatal plica moderately developed, slightly curved towards the lower palatal and similarly strong. Lower palatal plica high and narrow, making it particularly slender. Columellar lamella strong as the palatal plicae, almost horizontal and very slightly leaned towards the lower palatal plica. Between these main barriers, only a small and weak basal one is additionally observed. Surface of all apertural barriers is smooth. Sinulus wide, not strongly separated from the rest of the aperture. Umbilicus initially very narrow, suddenly expanded at the last whorl, measuring between 1 / 3 and ¼ of the shell width. A deep groove is running from the columellar side of the peristome towards the inner walls of the umbilicus.

Differential diagnosis.

See under H. platybasis sp. nov.

Measurements

(in mm, n = 5). SW 1 = 2.48–2.74; SW 2 = 1.68–1.75; SH = 2.62–2.92; AH = 1.09–1.21; AW = 1.12–1.25.

Etymology.

The specific epithet is due to the fact that there were many geckos at its habitat.

Distribution.

This species is known only from the type locality.

Remarks.

The concrescent angulo-parietal lamella can have the appearance of the typical form (with strong parietal and weaker, pointed angular part) or can have the appearance of only a single, parietal lamella with a very slightly visible swelling which represents the angular part. Infrapalatal lamella can be well visible or very weakly developed.