A new fossil species of Nausibius (Coleoptera: Silvanidae) in Rovno amber: a beetle from Eocene forests with congeners thriving in warehouses today

A new species of silvanid flat bark beetle, Nausibius radchenkoi sp. nov., is described and illustrated based on a well-preserved inclusion in Eocene Rovno amber. It is the first fossil species of Nausibius, a cosmopolitan genus with representatives living worldwide today. The current finding confirms both the Eocene age of the genus and the presence of representatives of the genus in forest palaeoecosystems of Europe in that time. In addition, Austronausibius aenigmatista Alekseev & Bukejs, 2022, previously described from Rovno amber, is documented in Baltic amber for the first time. Thirteen common species of Coleoptera (including one newly recorded here) known from these two East European ambers are listed. The newly described species, as well as some other beetle taxa in Eocene European habitats (where Rovno and Baltic ambers were produced), have several congeners that live today in artificial synanthropic habitats, namely warehouses storing various food products.