Bensonella mitochondria Gojšina, Vermeulen & Páll-Gergely, 2025

Bensonella mitochondria Gojšina, Vermeulen & Páll-Gergely sp. nov.

Figs 103 C View Figure 103 , 105 View Figure 105 , 107 View Figure 107

Type material.

Holotype. Laos • 1 shell (SH: 1.21 mm; SW: 1.27 mm); Khammouane Province, Thakhek Distr., Ban Nakok , base of forested limestone hill; 17°25.993'N, 105°07.880'E; 222 m a. s. l.; 14 Nov. 2006; A. Schuiteman leg.; locality code JJV 15157 ; CUMZ 14449 View Materials GoogleMaps . Paratypes. Laos • 9 shells; same data as for holotype; coll. JJV GoogleMaps .

Additional material examined.

Laos • 2 shells (juveniles, not paratypes); same data as for holotype; coll. JJV GoogleMaps .

Type locality.

Laos, Khammouane Province, Thakhek Distr., Ban Nakok, base of forested limestone hill; 17°25.993'N, 105°07.880'E; 222 m a. s. l.

Diagnosis.

A colourless Bensonella species with shouldered last whorl and spirally striated teleoconch and nearly heart-shaped aperture. Apertural barriers numerous and almost all equally strong, umbilicus moderately wide.

Description.

Shell conical-ovoid, colourless. Whorls 3.5, initial whorls rounded, last two strongly shouldered, separated by a deep suture. Protoconch consisting of ~ 1 whorl, very finely pitted, with signs of indistinct and widely spaced spiralling pattern. Teleoconch with coarse spiral striae which are crossed by stronger, coarse, not numerous, and almost regularly spaced radial growth lines. Approximately 25 widely spaced spiral striae present on the last whorl in standard apertural view. Last whorl adnate to the penultimate, slightly ascending near the aperture (~ 10–15 ° compared to the shell axis). Peristome continuous, strong, and expanded, especially at the parietal side where it leans on the penultimate whorl. Aperture nearly heart-shaped, equipped with a strong angular lamella, which is curved and almost merges with the prominent palatal tubercle, thus nearly enclosing the small sinulus (which makes it strongly separated from the rest of the aperture). Angular lamella reaches the peristome. There are eight to nine other barriers situated deep in the aperture and not reaching the peristome. Additional two lamellae at the parietal side (equally strong parietal and infraparietal), one columellar lamella, one subcolumellar, one basal plica, two palatal plicae (sometimes with additional, weak infrapalatal plica) and a palatal tubercle. Upper and lower palatal plicae strong, the former is situated slightly above the palatal tubercle. Palatal tubercle quite strong and elevated. Basal plica weaker than the palatals but stronger than the subcolumellar lamella. Columellar lamella slightly stronger than them but weaker than upper and lower palatal plica. Surface of all apertural barriers is finely granulated. Umbilicus moderately wide, measuring ~ 1 / 5 of the shell width and showing only the penultimate whorl.

Differential diagnosis.

This species differs from B. cardiostoma sp. nov. most clearly by the spirally striated shell and a wider umbilicus.

Measurements

(in mm, n = 5). SH = 1.21–1.33; SW = 1.21–1.37; AH = 0.57–0.62; AW = 0.58–0.67.

Etymology.

The appearance of the apertural barriers when the last whorl is broken behind them resembles the morphology of a mitochondria (Fig. 105 F View Figure 105 ), hence the specific epithet which is to be used as a noun in apposition.

Distribution.

This species in known only from the type locality.