Natdanai LikhitrakarnSergei I. GolovatchEkgachai JeratthitikulRuttapon SrisonchaiChirasak SutcharitSomsak PanhaA.N. Severtsov Institute of Ecology and Evolution Russian Academy of SciencesChulalongkorn UniversityMaejo UniversityKhon Kaen UniversityMahidol University2020-05-052020-05-052020-01-01ZooKeys. Vol.2020, No.925 (2020), 55-7213132970131329892-s2.0-85083578043https://repository.li.mahidol.ac.th/handle/123456789/54449© Natdanai Likhitrakarn et al. A new, giant species of Trachyjulus from a cave in southern Thailand is described, illustrated, and compared to morphologically closely related taxa. This new species, T. magnus sp. nov., is much larger than all other congeners and looks especially similar to the grossly sympatric T. unciger Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2012, which is widespread in southern Thailand. Phylogenetic trees, both rooted and unrooted, based on a concatenated dataset of the COI and 28S genes of nine species of Cambalopsidae (Trachyjulus, Glyphiulus, and Plusioglyphiulus), strongly support the monophyly of Trachyjulus and a clear-cut divergence between T. magnus sp. nov. and T. unciger in revealing very high average p-distances of the COI gene (20.80-23.62%).Mahidol UniversityAgricultural and Biological SciencesArticleSCOPUS10.3897/zookeys.925.49953