Phylogenomics of Tanypodinae (Diptera: Chironomidae) redefines relationships in Procladiini and Tanypodini and supports a new tribe.

The phylogenetic relationships between Procladiini and Tanypodini (Chironomidae, Tanypodinae) remain unresolved. Here, we recovered an average of 2,432 universal single-copy orthologous genes (USCOs) per species from 29 taxa and used occupancy-filtered USCO datasets to reconstruct their phylogenetic relationships, providing the first USCO-based phylogenomic framework for Tanypodinae. Maximum likelihood and multispecies coalescent analyses recovered consistent and strongly supported topologies. Djalmabatista was recovered as a distinct lineage within Procladiini and as sister to Procladius, supporting its status. as a valid genus. In contrast, Saetheromyia was recovered as sister to Tanypus, rather than within Procladiini. Independent morphological evidence indicates that Saetheromyia exhibits a unique combination of characters absent in other tribes, supporting the establishment of a new tribe, Saetheromyiini Xiao, trib. nov.. Divergence time estimation using fossil calibrations indicates that major Tanypodinae tribes originated in the Early Cretaceous (ca. 123.9-104.0 million years ago, Ma), with the split between Procladiini and Tanypodini in the Late Cretaceous (ca. 96.1-78.2 Ma), followed by diversification of Procladiini from the Late Cretaceous to the Eocene and of Tanypodini primarily during the Miocene. These results provide a robust phylogenomic framework for understanding the evolutionary history and higher classification of Tanypodinae.