Description of the second European Cenozoic roproniid (Hymenoptera: Roproniidae) from the earliest Eocene Fur Formation, Denmark, with remarks on the family diagnosis

Roproniidae are treated here as a small family of approximately 25 extant species in four genera, apparently closely related to Proctorenyxidae. Clarifying the phylogenetic position of these two lineages within Proctotrupoidea remains a difficult and pressing task requiring broad, integrative analyses. The family is most diverse in eastern Asia, continental China (Shaanxi, Hunan, Fujian, Zhejiang, Guizhou, Sichuan, and one species near the Kachin border), Taiwan, Japan (Honshu, Hokkaido), Kunashir and southern Sakhalin (Townes, 1948; Yasumatsu, 1956, 1958; Lin, 1987; He & Chen, 1991; Yang, 1997; He & Xu, 2015). Three Nearctic species occur in the USA (both coasts) and southern Ontario (Townes, 1948; Porter, 2002). In the Western Palaearctic, two species are known from southern Turkey (Hatay and Karatepe; Madl, 2001). The first European fossil was described from the Paleocene of Menat, France (Garrouste et al., 2016). Named earlier fossil representatives of Roproniidae are otherwise limited to the Cretaceous Kachin amber (Engel & Huang, 2017) and four genera with five species in the extinct subfamily Beipiaosiricinae Hong, 1983 (Middle Jurassic–Early Cretaceous of China and Eastern Siberia) (Rasnitsyn, 1990; Zhang & Zhang, 2001). The present study adds a new roproniid from the Ypresian Fur Formation of the Limfjord region (Northern Jutland, Denmark), constituting the second Cenozoic and youngest European fossil representative of the family.