At the dawn of megadiversity – Protoitidae, a new family of Chalcidoidea (Hymenoptera) from Lower Cretaceous Lebanese amber

The earliest representatives of Chalcidoidea are described from Barremian age Early Cretaceous Lebanese amber and classified in Protoitidae Ulmer & Krogmann, fam. nov. (Hymenoptera: Chalcidoidea). Protoitidae exhibits a high morphological diversity of the terminal metasomal tergum which may indicate a broad spectrum of oviposition capabilities and the ability to occupy a diverse range of ecological niches. Protoitidae comprises two genera, Protoita Ulmer & Krogmann, gen. nov. , and Cretaxenomerus Nel & Azar, 2005 based on C. jankotejai Nel & Azar, 2005, which is transferred from Scelionidae (Hymenoptera: Platygastroidea) to Protoitidae. Together, 10 new species, all by Ulmer and Krogmann, are described in the two included genera– Protoita bidentata , P. istvani , P. noyesi , P. petersi , Cretaxenomerus brevis , C. curvus , C. deangelis , C. mirari , C. tenuipenna , and C. vitreus . Keys to the genera and species of Protoitidae are provided. In addition, we examine the postulated plesiomorphies and apomorphies within Chalcidoidea with respect to the fossil record, and provide additional hypotheses on their biogeographic origins.