Anauchen turritus Gojšina, Hunyadi & Páll-Gergely, 2025

Anauchen turritus Gojšina, Hunyadi & Páll-Gergely sp. nov.

Figs 10 P View Figure 10 , 32 View Figure 32 , 33 View Figure 33 , 34 View Figure 34 , 37 View Figure 37

Type material.

Holotype. Vietnam • 1 shell (SH: 4.7 mm, SW: 3.2 mm); Thanh Hoa Province, 23.7 km south from centre of Ngoc Lac, Phuc Thinh, Lang Mieng , rock above the village; 19°55.869'N, 105°22.196'E; 65 m a. s. l.; 13 Feb. 2020; A. Hunyadi, H. V. Luong, J. U. Otani & S. V. Pham leg.; IEBR _LS_Anauchen.001 H GoogleMaps . Paratypes. Vietnam • 1 shell; same data as for holotype; CUMZ 14432 View Materials GoogleMaps • 79 shells; same data as for holotype; coll. HA GoogleMaps • 1 shell; same data as for holotype; coll. VG GoogleMaps • 29 shells; Thanh Hoa Province, Nhur Thanh District, Hai Van, Hang Lo Cao Khang Chien , near cave; 19°37.079'N, 105°34.629'E; 22 m a. s. l.; 14 Feb. 2020; A. Hunyadi, H. V. Luong, J. U. Otani & S. V. Pham leg.; coll. HA GoogleMaps .

Additional material examined.

Vietnam • 13 shells (juveniles, not paratypes); same data as for holotype; coll. HA GoogleMaps • 7 shells (juveniles / damaged, not paratypes); Thanh Hoa Province, Nhur Thanh District, Hai Van, Hang Lo Cao Khang Chien , near cave; 19°37.079'N, 105°34.629'E; 22 m a. s. l.; 14 Feb. 2020; A. Hunyadi, H. V. Luong, J. U. Otani & S. V. Pham leg.; coll. HA GoogleMaps .

Type locality.

Vietnam, Thanh Hoa Province, 23.7 km south from centre of Ngoc Lac, Phuc Thinh, Lang Mieng, rock above the village; 19°55.869'N, 105°22.196'E; 65 m a. s. l.

Diagnosis.

Shell conical, consisting of 7.5–8 whorls. Teleoconch densely spirally striated. Last whorl adnate to the penultimate. Aperture equipped with four main barriers (parietal, upper palatal, lower palatal and columellar), supra-angular and additional two smaller barriers (basal and infraparietal).

Description.

Shell conical to weakly concave-conical, light brown-yellowish in colour, opaque. It is consisting of 7–8 regularly increasing whorls separated by a moderately deep suture. All whorls rounded, weakly convex. Protoconch lighter than the rest of the shell, slightly translucent, consisting of ~ 1.25–1.5 weakly spirally striated whorls. Teleoconch finely and densely spirally striated, especially on the last ~ 3 whorls. Spiral striae strong, irregularly spaced, curved,> 40 on the last whorl in a standard view. The space between two spiral striae ranges from the width of one to the width of two or even three spiral striae. These striae are occasionally crossed by a few radial whitish streaks, randomly positioned, but mostly present on the last and the penultimate whorl. Last whorl adnate to the penultimate, slightly ascending (~ 5 ° compared to the shell axis) and making the apertural profile slightly opisthocline to the shell axis. Peristome thick, the same colour as the rest of the shell, expanded and not reflected, very finely pitted. It is especially strongly expanded at the parietal side where it leans against the penultimate whorl and forms a thick callus. Aperture equipped with four main barriers (parietal, upper palatal, lower palatal, and columellar) and several smaller ones. Parietal lamella very strong and high, directed towards the lower palatal plica. Upper palatal plica very strong, developed equally as parietal lamella and slightly leaning towards the lower palatal plica. Parietal lamella and upper palatal plica are closely positioned, leaving a narrow spacing between them. Lower palatal plica is strong but weaker than the upper palatal, directed towards the embayment between columellar and parietal lamellae. Columellar lamella slightly oblique, directed towards the lower palatal plica and developed to the same extent. Between these main barriers, smaller number of minor ones are also observed. Supra-angular lamella present, small, and short, leaning towards the palatal wall. Interpalatal plica sometimes present, positioned rather obliquely. Subcolumellar lamella present as weak or absent. Basal plica present, short. A very slight thickening (swelling) like infraparietal lamella is present. This lamella is sometimes much stronger. Surface of all apertural barriers is finely granulated. Sinulus large, distinctly separated from the rest of the aperture due to the strong angulo-parietal lamella and upper palatal plica. Umbilicus narrow, measuring ~ 1 / 8 of the shell width and with almost perpendicular walls, not showing previous whorls.

Differential diagnosis.

This species is similar to various congeners such as A. rochebruni and A. messageri . However, it can be clearly separated from them by the separate lamellae on the parietal side (angular and parietal) and a generally more elongated shell with slightly more pronounced spiral threads. Anauchen turritus sp. nov. has spiral striation, more apertural barriers and a wider umbilicus than A. jokaii sp. nov. See also under H. annamiticum .

Measurements

(in mm, n = 5). SH = 4.05–4.7; SW = 2.72–3.43; AH = 1.54–1.88; AW = 0.7–0.87.

Etymology.

This species is named after the tower-shaped (turreted) shell.

Distribution.

This species is known from two localities in Thanh Hoa Province, Vietnam.

Remarks.

We have observed significant intraspecific variability in this species. Shell can be high conical or conical (even weakly concave-conical). Some specimens (Fig. 32 View Figure 32 ) have only six apertural barriers (supra-angular, parietal, columellar, basal, upper, and lower palatal) while others can have up to nine (including interpalatal, infraparietal and subcolumellar) (Fig. 34 View Figure 34 ). Colouration is usually pale brown but colourless specimens also occur.