Euryachen seuzei, a new genus and species of Placusini (Coleoptera: Staphylinidae: Aleocharinae) from Brazil.

The tribe Placusini (Coleoptera: Staphylinidae) consists five genera with worldwide distribution. Despite great morphological diversity, the species are easily recognized by their 4-4-5 tarsal formula and the two-articulated labial palpi, along with a broad and rounded ligula. Several synapomorphies proposed by earlier authors, both for larvae and adults, have led to the conclusion that the tribe now is considered monophyletic within Aleocharinae. Herein, a new genus and species of Placusini from Brazil is described and illustrated. Euryachen seuzei gen. et sp. nov. presents all the proposed synapomorphies for the tribe, in addition to unique characters. An updated key for the genera in Placusini is also provided.