Margarya
Margarya is a genus of large operculate freshwater snails, aquatic gastropod mollusks in the family Viviparidae. Taxonomy. The genus "Margarya" was described by Nevill (1877) based on shells of the type species collected by A.R. Margary from Lake Erhai, the type locality of "Margarya melanioides". Based on shell and radular morphology, Tchang & Tsi (1949) revised this genus for the first time and recognized seven distinct species. He created two subgenera of "Margarya" , viz "Tchangmargarya" and "Mabillemargarya". The first molecular phylogeny showed that the genus "Margarya" is polyphyletic and divided into three distinct clades. Combining study of comparative morphology and  molecular phylogeny, Zhang "et al". revised the systematics of "Margarya" and recognized eight genuine extant species. However, only four species were found belonging to "Margarya" s. str., the rest species belonging to distinct genus "Tchangmargarya" or "Anularya". Distribution. This genus appear to be endemic to Dian Lake, Erhai Lake, Cibi Lake, Jianhu Lake, Xihu Lake, and Lugu Lake in Yunnan Province in the China. Species. There are 4 extant species and 4 fossil species of "Margarya" s. str. "Margarya bicostata" and "Margarya mansuyi" are transferred to "Anularya". "Margarya yangtsunghaiensis" is transferred to "Tchangmargarya". Species within the genus "Margarya" include 8  species: Species brought into synonymy: Cladogram. The cladogram based on sequences of mitochondrial 16S ribosomal RNA and cytochrome-c oxidase I (COI), and nuclear ITS2 genes showing the phylogenic relationships of the genus "Margarya" indicates that "Margarya" is polyphyletic. Margarya as traditionally delimited decayed into three distinct clades. The sister lineages of two of these clades are representatives from different viviparid genera, which are widely distributed in East and Southeast Asian rivers and lakes. These predominantly riparian viviparids also differ markedly in their shell morphology. Herein only genus-level phylogenic relationship is given, whereas relationship between lower taxonomic units deserve  further study.