Paraprososthenia bicarinata Xiang, He, Lu & Chen 2025, sp. nov.

Paraprososthenia bicarinata Xiang, He, Lu & Chen, sp. nov. https://zoobank.org/ urn:lsid:zoobank.org:act: 27968859-1552-4BAC-903D-6652708AA905 Fig. 2 B, Fig. 3 D-E Material examined. Holotype: XHQ 24010201, shell height 17.0 mm. Yanjiang Town [沿江Dz], Qilin District [dzǝ区], Qujing City, Yunnan Province, China, 25.48°N, 103.87°E, June 2024, collected by Yue-Ming He and Hong-Quan Xiang (Fig. 1). Paratypes: 1 specimen, XHQ 24010202, shell height 15.0 mm, June 2024, locality and habitat same as holotype. Diagnosis. Shell small, elongate conic, white, with eight whorls, the whorls with keels and axial ribs, aperture ovate, inner lip thickened, outer lip reflexed and thickened. Description. Shell small, but solid, elongate conic, white, with eight whorls, including two protoconch whorls; third to fifth whorls with two very week keels and shell surface smooth; sixth whorls with two week keels and very week axial ribs; other whorls with two very obvious keels and week axial ribs; body whorls not swollen. Shell surface with axial growth lines. Apex obtuse. Umbilicus narrow and small, base with one keel around umbilical area. Aperture ovate, inner lip thickened and smooth; outer lip thickened and reflexed. Differential diagnosis. Compared with P. costata and P. constricta, Paraprososthenia bicarinata sp. nov. shell surface lacks nodules and with two very obvious keels. Compared to Parapyrgula coggini and Paraprososthenia gredleri, Paraprososthenia bicarinata sp. nov. shell is larger, surface with week axial ribs. Compared with P. bronyaae sp. nov., Paraprososthenia bicarinata sp. nov. shell surface with week axial ribs and less whorls. Etymology. The species name " bicarinata " originates from the characteristic of having two keels on the whorls. We suggest the Chinese common name as " uAEḄ川ϐ ". Distribution and ecology. This species is only found in the lake sediments of Qilin District, Yunnan Province.