Abstract
A molecular phylogenetic study was conducted on genus Tropidauchenia, based on COI and 16S sequences. A total of six out of 18 species in the genus, as well as three species of Grandinenia and eight species of subfamily Synprosphyminae and Phaedusinae were sequenced. The phylogenetic results supported the monophyly of three Clausiliid subfamilies distributed in East Asia and demonstrated that Tropidauchenia was divided into two clades that corresponded to its two main distribution areas. A new species, Tropidauchenia jiangjilini Z.-G. Chen, Z.-Y. Chen & R.-X. Lin, sp. nov., from Guangdong, southern China, has been identified and described based on morphological comparison and molecular phylogeny. The discovery expanded the distribution range of Tropidauchenia and revealed the potential species diversity of land snails in the karst region of Guangdong.