† Camelosphecia gen. nov., lost ant-wasp intermediates from the mid-Cretaceous (Hymenoptera, Formicoidea)

Abstract

Fossils provide primary material evidence for the pattern and timing of evolution. The newly discovered “beast ants” from mid-Cretaceous Burmite, † Camelosphecia gen. nov., display an exceptional combination of plesiomorphies, including absence of the metapleural gland, and a series of unique apomorphies. Females and males, represented by † C. fossor sp. nov. and † C. venator sp. nov., differ in a number of features which suggest distinct sexual biologies. Combined-evidence phylogenetic analysis recovers † Camelosphecia and † Camelomecia as a clade which forms the extinct sister group of the Formicidae . Notably, these genera are only known from alate males and females; workers, if present, have yet to be recovered. Based on ongoing study of the total Aculeata informed by the beast ant genera, we provide a brief diagnosis of the Formicoidea . We also provide the first comprehensive key to the major groupings of Mesozoic Formicoidea , alongside a synoptic classification in which † Zigrasimeciinae stat. nov. and † Myanmyrma maraudera comb. nov. are recognized. Finally, a brief diagnosis of the Formicoidea is outlined.