Bensonella obex Gojšina, Hunyadi & Páll-Gergely, 2025

Bensonella obex Gojšina, Hunyadi & Páll-Gergely sp. nov.

Figs 39 S View Figure 39 , 77 View Figure 77 , 78 View Figure 78 , 97 View Figure 97

Type material.

Holotype. Myanmar • 1 shell (SH: 1.8 mm, SW: 1.5 mm); Shan State, 5.7 km south-southwest from Pinlaung, Wingabar Taung ; 20°4.152'N, 96°46.232'E; 1510 m a. s. l.; 04 Oct. 2018; A. Hunyadi, K. Okubo & J. U. Otani leg.; CUMZ 14441 View Materials GoogleMaps . Paratypes. Myanmar • 32 shells; same data as for holotype; coll. HA GoogleMaps .

Additional material examined.

Myanmar • 12 shells; Shan State, Pinlaung centre N 7.5 km, Tar Kge , near ” Big Bang Cave ”; 20°10.273'N, 96°47.442'E; 1540 m a. s. l.; A. Hunyadi, K. Okubo & J. U. Otani leg.; coll. HA GoogleMaps • 4 shells; Shan State, Pinlaung centre SSW 11 km – Laneli Bridge, Nam Pam , near “ Upper Spider Cave ”; 20°2.114'N, 96°45.728'E; 1420 m a. s. l.; 04 Oct. 2018; A. Hunyadi, K. Okubo & J. U. Otani leg.; coll. HA GoogleMaps .

Type locality.

Myanmar, Shan State, 5.7 km south-southwest from Pinlaung, Wingabar Taung; 20°4.152'N, 96°46.232'E; 1510 m a. s. l.

Diagnosis.

Bensonella species with a pitted protoconch and conical-ovoid shell. Last whorl slightly ascending near the aperture. Peristome usually wrinkled due to several tubercles. Transversal plica strong and very weakly concave.

Description.

Shell conical-ovoid, consisting of 4.5–5 rounded, convex, regularly increasing whorls separated by a deep suture. Shell colour slightly weathered in the holotype but probably light brownish. Protoconch consisting of 1.75 whorls, finely pitted or sometimes spirally striated, especially terminally. Teleoconch finely pitted, with a pasty sculpture and without visible spiral striae but with coarsely and irregularly spaced radial growth lines. Last whorl enlarged, adnate to the penultimate and slightly ascending near the aperture (~ 20–25 ° compared to the shell axis). Aperture profile opisthocline to the shell axis. Peristome white and expanded (at columellar but especially at the parietal side where it forms a distinct callus) but not reflected. Aperture equipped with numerous barriers. Parietal lamella strong and high, almost reaching the expanding peristome. It sometimes has a heart-like appearance due to the distinct sinuation in the middle. Angular lamella weakly wavy, slightly weaker than the parietal but longer, reaching the expanding peristome. It also has a sinuation as in the parietal lamella but weaker. Upper palatal plica very short and moderately strong. Transversal plica strong, slightly concave on the front surface. A strong palatal tubercle is sitting in front and between the upper palatal and transversal plica. Below this tubercle, there are several more tubercle-like swellings which give the peristome a wrinkled appearance. Infrapalatal plica elongated and low. Basal plicae number ranging from one to four, similarly shaped as the infrapalatal plica. Subcolumellar lamella (if present) shares the same appearance as the former two. Columellar lamella moderate, ~ ½ as strong as the parietal. Supracolumellar lamella present but can be strong or quite weak. Infraparietal lamella slightly weaker than the columellar or even half as strong. Surface of all apertural barriers is finely granulated. Sinulus relatively narrow, small, and distinctly separated from the rest of the aperture. Umbilicus very narrow, measuring ~ 1 / 10 of the shell width, slightly elongated.

Differential diagnosis.

Bensonella nordsiecki has a smooth protoconch and more ovoid shell. The transversal plica in B. nordsiecki is without a concave frontal surface. Bensonella dracula sp. nov. is less ovoid, does not have a wrinkled peristome (but two palatal tubercles) and has a wider umbilicus.

Measurements

(in mm, n = 10). SH = 1.42–1.8; SW = 1.36–1.5; AH = 0.61–0.81; AW = 0.63–0.70.

Etymology.

The specific epithet comes from a Latin word for a barricade (obex), which refers to the transversal palatal plica in the form of a barrier / obstacle. To be used as a noun in apposition.

Distribution.

This species is known from three localities around Pinlaung, Shan State.