A new tribe of fossil digger wasps (Insecta: Hymenoptera, Crabronidae) from the Rovno amber, Eocene of Ukraine

A new tribe of digger wasps, Protomicroidini trib. nov. (Hymenoptera, Crabronidae), including a single known species Protomicroides sororius gen. et sp. nov. is described from the Upper Eocene Rovno amber, Ukraine. The new tribe combines features characteristic of several tribes of the Crabroninae and is a sister group of the extant tribe Oxybelini. The most distinctive characters of the new tribe include nonelongate propodeum with strongly developed lateral keel and enclosed dorsal area; semioval postscutellum with a lamellate border; absence of pygidial plate, psammophores, and digging tarsal rakes; and considerably reduced forewing venation.