Wanted, tracked down and identified: Mesozoic non-biting midges of the subfamily Chironominae (Chironomidae, Diptera)

Here we provide evidence for the presence of non-biting midges of the subfamily Chironominae in the Mesozoic, based on descriptions of exceptionally rare amber inclusions. The subfamily has already been reported, but based on a single and unspecified record from Late Cretaceous Taimyr amber (similar to 84 Mya). That record is here revised and confirmed. Moreover, a new find in Burmese amber locates the temporal boundary of the subfamily back to the mid-Cretaceous (probably similar to 100 Mya). We describe two new genera assigned to the tribe Pseudochironomini: Mesoacentron gen. nov. with the species Mesoacentron kaluginae sp. nov. (Taimyr amber) and Palaeocentron gen. nov. with the species Palaeocentron krzeminskii sp. nov. (Burmese amber), the oldest known representative of the subfamily. The systematic position of the new taxa is discussed, and a key to the identification of adult males of extinct and extant Pseudochironomini genera is presented. Insights in the phylogeny and diversification tempo of the Chironominae and Pseudochironomini in the past are also provided.

Automated summary

We present evidence for the existence of non-biting midges of the subfamily Chironominae in the Mesozoic era, based on rare amber inclusions. The subfamily was previously reported in Late Cretaceous amber, but we revise and confirm that record, and also discover a new find in Burmese amber that pushes back the subfamily's temporal boundary to the mid-Cretaceous. We describe two new genera and provide insights into the phylogeny and diversification tempo of the Chironominae and Pseudochironomini.