The first crabronid wasps (Hymenoptera, Apoidea) from the Crato Formation (Northeastern Brazil) and implications for the evolution of apoid wasps and bees during the Early Cretaceous

In the present study, we describe a new extinct lineage of the hymenopteran family Crabronidae from the Crato Formation of northeastern Brazil. The new taxon represents the oldest crabronid and extends the occurrence of the lineage about 20 million years into the Early Cretaceous. We describe a new species in a new crabronid genus, †Exallopterus spectabilis gen. et sp. nov. Despite the similarities with living members of the subfamily Crabroninae, the new taxon cannot be placed in any of the existing subfamilies or tribes, and therefore we propose a new tribe, †Exallopterini trib. nov. and leave it as incertae sedis in Crabronidae. The discovery of crabronid wasps in the Crato formation sheds light on the understanding of the paleoenvironment and biogeography of apoid wasps and bees during the Early Cretaceous of Gondwana. Apparently, during their early evolution, crabronids occupied a much wider range of environments and exhibited a broader paleobiogeographic distribution compared to bees.