Fifteen new species of freshwater snail fossil Viviparidae (Gastropoda: Architaenioglossa) from the Neogene and Quaternary of the Yunnan Province, China

Abstract Yunnan Province, China, harbors numerous ancient plateau lakes, some of which have dried up. Recent research has uncovered a wealth of gastropod fossils from these desiccated lake basins, with most representing Yunnan-endemic species. For the family Viviparidae, these subfossils and fossils typically possess large shells, a trait that facilitates their preservation in deeper clay layers. This study investigated ancient lake basins in Qujing, Mengzi, and Zhaotong cities, Yunnan Province. Viviparidae specimens were collected from different stratigraphic layers to explore the evolutionary patterns of shell morphology in endemic species of these ancient lakes. The study describes fifteen new species: Anularya bengu H.-Q. Xiang, B.-Y. Wang, Y.-M. He & A.-S. Lv sp. nov., Cipangopaludina somnumbra H.-Q. Xiang, B.-Y. Wang, Y.-M. He & T.-X. Xie sp. nov., Dalipaludina zhanglejiai H.-Q. Xiang, B.-Y. Wang, Y.-M. He & H. Chen sp. nov., Dalipaludina zhaolu H.-Q. Xiang, B.-Y. Wang, Y.-M. He & H. Chen sp. nov., Tchangmargarya ashimaae H.-Q. Xiang, B.-Y. Wang, Y.-M. He & H. Chen sp. nov., Tchangmargarya buhou H.-Q. Xiang, B.-Y. Wang, Y.-M. He & L.-R.-X. Chen sp. nov., Tchangmargarya cunshan H.-Q. Xiang, B.-Y. Wang, Y.-M. He & A.-S. Lv sp. nov., Tchangmargarya sparkleae H.-Q. Xiang, B.-Y. Wang, Y.-M. He & H. Chen sp. nov., Tchangmargarya laojin H.-Q. Xiang, B.-Y. Wang, Y.-M. He & H. Chen sp. nov., Tchangmargarya liyoufui H.-Q. Xiang, B.-Y. Wang, Y.-M. He & H. Chen sp. nov., Tchangmargarya luyizhii H.-Q. Xiang, B.-Y. Wang, Y.-M. He & H. Chen sp. nov., Tchangmargarya mohou H.-Q. Xiang, B.-Y. Wang, Y.-M. He & L.-R.-X. Chen sp. nov., Tchangmargarya yangjizhoui H.-Q. Xiang, B.-Y. Wang, Y.-M. He & H. Chen sp. nov., Tchangmargarya yumi H.-Q. Xiang, X.-C. Zha, Y.-M. He & H. Chen sp. nov., Tchangmargarya zhangxianmingi H.-Q. Xiang, X.-C. Zha, Y.-M. He & H. Chen sp. nov. The species previously known as Tulotomoides tulotomoides (Yen, 1935), Idiopoma tingi (Yen, 1935) and Idiopoma chutsingensis (Yen, 1935) are moved to Tchangmargarya J. He, 2013 genus; Idiopoma wangi (Yen, 1935) syn. nov. being assigned as a junior synonym of Tchangmargarya tingi comb. nov.; Vivipara margaryaeformis Mansuy, 1918 is moved to the Anularya Zhang & Chen, 2015 genus.