Plumalexius is a genus of wasp in the extinct monotypic family Plumalexiidae, containing a single species, Plumalexius rasnitsyni. The species is known only from the Late Cretaceous White Oaks Pit in Sayreville, New Jersey, USA.
Species taxanomy provided by GBIF Secretariat (2022). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2023-06-13; License: CC BY 4.0