Argemiones stupeflip gen. et sp. nov., a new spathiopterygid wasp (Hymenoptera: Diaprioidea) from the mid-Cretaceous Kachin amber

Although infrequent in the fossil record, the extinct wasp family Spathiopterygidae have been suggested to be diverse and globally distributed during the Cretaceous, being documented in seven major amber deposits. In the present study, I describe and figure Argemiones stupeflip gen. et sp. nov. from the rich early Cenomanian Kachin amber (Myanmar). The new monotypic genus is characterized by the compound eyes with numerous ommatidia, the first four flagellomeres distinctly thinner and longer than followings, a distinctive fore wing venation, a fringe of long setae along the apical margin of fore wing, a much reduced but present hind wing, and a conspicuous petiolate first metasomal segment. The presence of Spathiopterygidae in the endemic fauna of the Burma Terrane suggests their antiquity, with a possible origin in the Upper Jurassic to the earliest Cretaceous, and dispersion between the Gondwana and the Southern and Western Laurasia during the Lower Cretaceous. I propose an updated version of the key to genera and species of the family.