Short communicationFirst record of the subfamily Archinemestriinae in the family Nemestrinidae (Diptera: Brachycera) from Upper Cretaceous Burmese amber

Mesonemestrius caii gen. et sp. nov. is the first record of Archinemestriinae (Nemestrinidae) to be described from Upper Cretaceous Burmese amber. Mesonemestrius caii can be attributed to the subfamily Archinemestriinae by the following characters: M1 ending posterior to the wing tip and supernumerary crossveins absent. Mesonemestrius is characterized by M1 bifurcating after the conjunction of M1+2+3 and a long straight R1. The discovery not only adds to the diversity of tangle-veined flies in Burmese amber, but also represents the youngest record of the ancient subfamily Archinemestriinae.