A new tribe of Diamesinae (Diptera: Chironomidae) from the Lower Cretaceous of Mongolia

A new tribe of Diamesinae, Eugenodiamesini tr. nov. (Diptera: Chironomidae), is described based on a single pupa from Khutel Khara (lower part of the Tsagan Tsab Formation, Lower Cretaceous of Mongolia). The most distinctive characters of the new taxon are numerous multibranched lateral setae on tubercles along entire margins of abdominal segments II–VIII, and a unique setation of the anal lobes, with two multibranched anal macrosetae on each side and one simple near the apex. The fossil is the oldest known member of Diamesinae.