Angustopila dominikae Pall-Gergely & Hunyadi

Pall-Gergely, Barna, Hunyadi, Andras, Jochum, Adrienne & Asami, Takahiro, 2015, Seven new hypselostomatid species from China, including some of the world's smallest land snails (Gastropoda, Pulmonata, Orthurethra), ZooKeys 523, pp. 31-62 : 33

Taxon classification Animalia Pulmonata Hypselostomatidae

Angustopila dominikae Pall-Gergely & Hunyadi sp. n. Figure 1, 12

Type material.

China, Guangxi (广西), Hechi Shi (河池市), Bama Xian (巴马县), cliffs at the southern edge of Jiaole Cun (交乐村), 590 m, 24°7.045'N, 107°7.847'E, leg. Hunyadi, A. & Szekeres, M., 10.09.2013., HNHM 99435 (holotype).

Diagnosis.

A tiny, corpulent species with elongated aperture having a parietal and a single palatal tooth.

Description of the holotype.

Shell minute, light grey, corpulent, almost globular, the penultimate whorl is the widest from apertural view; protoconch consists of 1.5 whorls, protoconch microstructure finely pitted and granular with a powdery superficial texture, the granular microstructure collectively radiates from the nuclear whorl and ceases at the second; teleoconch finely ornamented with irregularly-spaced radial growth lines crossed by fine rows of equidistantly spaced microscopic spiral threads; the 4.75 whorls are separated by a deep suture; whorls shouldered; aperture slightly oblique to shell axis; umbilicus deep, very narrow; aperture elliptical; the sinulus is narrow; peristome slightly expanded, not reflected; the mid section comprising the parietal tooth is sinuous and slightly protruding (in side view); parietal callus well developed, its portion between the parietal tooth and the columella adnate to the penultimate whorl; the portion of the callus between the parietal tooth and the upper right sinulus edge is detached; parietal tooth well developed with a very small additional tubercle (may be homologous with the angular tooth), the palatal tooth is positioned deeper in the shell and directly opposite the parietal tooth.

Measurements

(in mm): SH = 0.86, SW = 0.8, AH = 0.3, AW = 0.37, SW/ SH× 100 = 93.02, AW/ AH× 100 = 123.33 (n = 1).

Differential diagnosis.

Angustopila tamlod from Thailand also possesses two teeth (parietal and palatal), but it has a conical shell, which is nearly globular in Angustopila dominikae sp. n. Moreover, Angustopila tamlod has a narrower umbilicus and a more rounded aperture. Angustopila huoyani is larger than Angustopila dominikae sp. n. It has a rather conical shell, more whorls, a narrower umbilicus, two apertural denticles and lacks the spiral thread-like lines (or has much weaker spiral striae) on the whole shell. The sympatric Angustopila subelevata sp. n. has a conical shell and lacks apertural dentition. See also under Angustopila fabella sp. n. and Angustopila szekeresi sp. n.

Etymology.

The new species is named after Mrs. Dominika Páll-Gergely, the wife of the first author.

Type locality.

China, Guangxi (广西), Hechi Shi (河池市), Bama Xian (巴马县), cliffs at the southern edge of Jiaole Cun (交乐村), 590 m, 24°7.045'N, 107°7.847'E.

Distribution.

The new species is known from the type locality only (Figure 13).

Ecology.

The single empty shell of this new species was found in a soil sample at the base of limestone rocks. It likely lives on limestone walls as do other similar hypselostomatid species recorded by Panha and Burch (2005).

Conservation status.

A single empty shell has been collected from a soil sample at the type locality. Therefore, knowledge is very limited for evaluating its conservation status. Since the species is known from one site only, it is evaluated as Critically Endangered (CR) under IUCN criteria ( IUCN 2014). Quarrying is quoted as the main threat to similar limestone habitats. However, no ongoing threats to the type locality are known at the moment.