Pincerna (?) maolanensis ( Luo, Zhang & Zhuo, 2009 ), 1907

Páll-Gergely, Barna, 2023, Revision of the Alycaeidae of China, Laos and Vietnam (Gastropoda: Cyclophoroidea) II: The genera Alycaeus and Pincerna, Zootaxa 5249 (2), pp. 253-276 : 266

Pincerna (?) maolanensis ( Luo, Zhang & Zhuo, 2009)

( Fig. 5F–I )

Dioryx maolanensis Luo, Zhang & Zhuo, 2009: 862–864 , figs 1–6.

Pincerna maolanensis — Páll-Gergely, 2017: 10.

Pincerna? maolanensis — Páll-Gergely et al., 2020: 180 , Fig. 41.

Type material. Mao-Lan Town , Libo County, Qian-Nan Prefecture, Guizhou Province, China, leg. Luo Tai-Chang, 2001.7.9., IZCAS TM 047081 (holotype, Fig. 5F–I ) .

Diagnosis. A small alycaeid species with a shell that is higher than wide, R1 strongly, regularly ribbed, long, smooth, R3 or normal length, with low swelling, its ribs density is similar to that of R1.

Remarks. Pincerna vanbuensis is the species most similar to P. maolanensis in terms of shell size and the ratios or shell regions, however, it has a denser R1 ribbing. Although the rib density of P. vanbuensis is variable across populations, it is never as widely-spaced as that of P. maolanensis . Moreover, between the main ribs of P. maolanensis , there are additional, thinner, lower riblets, while the area between the R1 ribs of P. vanbuensis is smooth. It would be important to examine several samples from northern Guangxi and southern Guizhou provinces to see whether these traits are stable across populations of P. maolanensis and P. vanbuensis , or if the two species are connected by intermediate forms.

Distribution. This species is known only from its type locality ( Fig. 6 ).

Figures

FIGURE 5. Shells of Pincerna Preston, 1907 species.A–E: Pincerna acroptychia n. sp. (holotype); F–I: Pincerna maolanensis (Luo, Zhang & Zhuo, 2009) (holotype); J–M: Pincerna yaanensis Z.-G. Chen, 2022, holotype; N–R: P. yaanensis, locality 2015/53, coll. HA. Photos: Kaibaryer Meng (F–I), B. Páll-Gergely (A–E, N–R), photos from the original description (J–M). White lines indicate length of suture.

FIGURE 6. Distribution of Pincerna Preston, 1907 species. Circles: Pincerna costulosus (Bavay & Dautzenberg, 1912) (yellow circle indicates the type locality of Pincerna vallis Z.-Y. Chen & M. Wu, 2020); Yellow triangle: Pincerna acroptychia n. sp.; Green rhomb: Pincerna yaanensis Z.-Y. Chen, 2022. The map was made using Google Earth Pro.