IS25025Cryptic species, mitochondrial phylogenomics and historical biogeography in the endemic genus Schistodesmus (Bivalvia, Unionidae) from China
An integrative taxonomic approach, including morphological and molecular data, revealed three new cryptic species: Schistodesmus luqiaoensis, Schistodesmus tongpenensis, and Schistodesmus xinyuensis. Maternal mitochondrial genomes of the first two species and Schistodesmus lampreyanus were sequenced, and interspecific relationships elucidated based on mitochondrial phylogenomics. Molecular clock analysis and biogeographical reconstruction based on fossil-calibrated dating indicated that the ancestor of Schistodesmus originated in the paleo-Yangtze River Basin during the Eocene (c. 50.74 Ma) and began diversifying c. 18.68 Ma in the Neogene. (Photography by Kaiyu Hou.)