Pincerna yaanensis, Z.-G. Chen, 2022

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 : 274

Pincerna yaanensis Z.-Y. Chen, 2022

( Figs 5J–R )

Pincerna yaanensis Z.-Y. Chen, 2022: 118.

Type locality. “ Bifengxia scenic spot [ AEIJ ẈṃḆḢ], Bifengxia town [ AEIJ Ẉffi ], Yaan City [Bdzm], Sichuan Province [Ɓffl ẘ], China, 102°59′23″E, 30°04′26″N ” .

Additional material examined. CHINA, Sichuan, Chengdu Shi, Dujiangyan Shi, Qingcheng Shan , Fangningqiao 200 m towards Zushidian , 1130 m a.s.l., 30°54.337′N, 103°33.282′E (locality code: 2015/53), leg. Hunyadi, A., 6 June 2015, HA/1 ( Fig. 5N–R ) .

Distribution. This species is known from two closely situated localities in central Sichuan. Here I report this species from another site ca. 100 km north from the known localities ( Fig. 6 ).

Remarks. Pincerna yaanensis is a recently described species from central Sichuan. According to the original description, it is larger than P. costulosus , it has a ribbed R3 (smooth in P. costulosus ), has a more convex body whorl, denser ribs, and an umbilicus completely covered by the reflected peristome. After examining several P. costulosus shells belonging to multiple populations, the differences between P. costulosus and P. yaanensis do not seem to be convincing. The difference in size between P. yaanensis and P. costulosus is only minimal; the difference regarding R3 is not correct, because some P. costulosus shells (even syntypes, see Fig. 8E–H ) have ribs on R3; the rib density is also variable across populations of P. costulosus (although probably still denser than in any P. costulosus shell); and the umbilicus is completely covered in some P. costulosus shells (see Fig. 8E–H ). Pincerna yaanensis should be kept as an independent species because of the R3 of P. costulosus has a central swelling, whereas it is shifted towards the aperture in P. yaanensis .

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.

FIGURE 8. Shells of Pincerna costulosus (Bavay & Dautzenberg, 1912).A–D: MNHN-IM-2000-31786 (syntype); E–H:Phong Tho, MNHN-IM-2012-27043 (probable syntype); I–L: Northern Laos, MNHN-IM-2012-27218.