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An extinct freshwater molluscan fauna has been discovered from Quaternary lacustrine deposits of a recently vanished group of lakes and surrounding lacustrine deposits in the Luliang Basin, Yunnan Province, China. Three species of Tchangmargarya He, 2013 are dominant and distributed sympatrically here. One of them is new to science. Here we describe the three Tchangmargarya species from the Luliang Basin, including the new species, Tchangmargarya cuan n. sp., and compare the species composition of this fauna with the other extant lacustrine mollusc fauna of Yunnan. The vanished lakes group in Luliang is the first case of sympatric distribution within Tchangmargarya. It is considered to have once been a diversity hotspot of Tchangmargarya and represents a vanished Quaternary lacustrine habitat in Yunnan. [ABSTRACT FROM AUTHOR]

The species of Satsuma are mostly endemic to East Asia except for one species distributed in Batan Island of the Philippines. More than 99% of the known species of this genus are endemic to the island environment. Only three species are currently known to occur on the mainland. Here we describe a new sinistral Satsuma species from China, Satsuma guandi n. sp. We studied the shell morphology and genital anatomy of the new species and reconstructed the molecular phylogeny of the genus based on partial nucleotide sequences of the mitochondrial gene cytochrome c oxidase subunit I and nuclear markers from the ribosomal RNA cistrons (the internal transcribed spacer and the external transcribed spacer regions). The new species differs from other sinistral Satsuma species by having a strongly angulated shell and an open dark brownish-red umbilicus. The new species also differed from all other sinistral congeners in details of its reproductive anatomy. The molecular analysis supports the validity of the new species within the genus Satsuma. [ABSTRACT FROM AUTHOR]

Habitat loss poses a grave threat to endemic species with narrow distributions. Some species become extinct even before scientific identification due to habitat destruction. Here, a probable example is reported based on some recent and subfossil shells from an almost disappeared wetland lake in Yunnan Province, China. A new ornamented freshwater snail species,Tchangmargarya ziyin. sp., is recognised and described based on morphological comparison with the otherTchangmargaryaspecies. The subfossil specimens of the new species show a great similarity toTchangmargrya yangtsunghaiensis(Tchang & Tsi, 1949), indicating their potentially close relationship. The discovery of the new species demonstrates that the plateau lakes of Yunnan, even the small ones, have a high biodiversity and endemism. Furthermore, it enriches the knowledge of the distribution ofTchangmargaryaand provides further evidence that the Liangwang Mountains are a significant biogeographic barrier to three endemic viviparid genera (Margarya,Anularya andTchangmargarya) of Yunnan. Since the only known habitat of this species has been mostly landfilled due to the construction of a golf course and villas, this species possibly has already gone extinct. In order to implement conservation measures more efficiently, more comprehensive surveys should be conducted in all plateau lakes of Yunnan, including those that might seem insignificant. [ABSTRACT FROM PUBLISHER]