Pseudoiglica phonsavanica, Grego, Jozef, 2018

Grego, Jozef, 2018, First record of subterranean rissoidean gastropod assemblages in Southeast Asia (Mollusca, Gastropoda, Pomatiopsidae), Subterranean Biology 25, pp. 9-34 : 15

Pseudoiglica phonsavanica sp. n. Figs 11-12

Type locality.

Laos; Xianghouan Province, Ban Nadom Village, 18 km SE of Phonsavan, 3 km N of Ban Kaua cement factory at highway 1D (9 km ENE of Xiang Khouang), small spring at eastern foot of limestone hill, 19°23.142'N; 103°17.630'E, 1196 m a.s.l., fine sand directly at spring zone.

Type material.

Holotype: type locality: J. Grego leg. 22 February 2017 (NHMUK 20180004).

Measurements.

Holotype: H 3.05 mm; W 1.30 mm; BW 1.00 mm; BH 1.71 mm; AH 0.93 mm; AW 0.79 mm; H/W 2.35; AH/AW 1.18; W/BW 1.30; H/BH 1.78; H/AH 3.28; W/AW 1.65.

Diagnosis.

Similar to Pseudoiglica kameniari sp. n. (Khammouane Province), from which it differs by its more robust shell with a more prominent umbilicus and a proportionally smaller aperture. The robust shape differentiates the species from all other members of the genus.

Description.

The light orange, silky shell has five tumid convex whorls with a weak suture and a blunt apex. The smooth shell surface is covered by sparse rusty incrustations. The shell is elongated conical, with a prominent body whorl. Umbilicus is slit-like. In frontal view, the aperture is aligned with the shell periphery outline. Aperture is ear-shaped, separated from the body whorl by a weak sulcus. The peristome margin is blunt, not reflexed and slightly callous internally. The labral lip has a straight profile in lateral view, scooped backward from the columellar axis. The elongate ellipsoidal spiral operculum is light yellowish corneous with submarginal nucleus.

Etymology.

Named after the city of Phonsavan, Laos, capital of Xianghouan Province, which is the closest large city to the type locality.

Distribution.

Only known from the type locality.

Ecology.

The locality is a small karstic spring rising at the foot of a rounded cone-shaped limestone hill at the boundary between limestone beds and a sandy slate substrate just a few meters above the road. The spring is connected to a small waterworks to supply water to the nearby village Ban Nadom. The water supply seems to be permanent throughout all seasons.

Remarks.

The body whorl of P. phonsavanica sp. n. is proportionally larger than that of all other species of the genus. The more teardrop-shaped aperture suggests that this geographically distant species could represent a new genus distinct from Pseudoiglica gen. n. Anatomical and molecular data are needed to confirm such a possible distinction.