Discovery of a new Isonychia species with distinctive characters from southwestern China, and preliminary exploration of its phylogenetic status (Ephemeroptera, Isonychiidae)

The genus <i>Isonychia</i> Eaton, 1871 is widely distributed across the Holarctic and Oriental regions. However, no representatives of this genus have been reported from southwestern China, a region known for its high biodiversity. Here, we described and illustrated <i>Isonychialatias</i> <b>sp. nov.</b>, a new species recently collected from Guizhou Province, southwestern China, across all developmental stages. The imagos of this new species exhibit some uncommon characters within <i>Isonychia</i>, such as brown mid- and hindlegs, and pale stripes on the thorax. To explore the phylogenetic status of this new species within <i>Isonychia</i>, a multigene phylogenetic analysis was conducted.