LAUSR

Abstract Four new genera and species of long-proboscid Paradoxosisyrinae (Neuroptera: Sisyridae) are described from the Upper Cretaceous amber from northern Myanmar: Buratina truncata gen. et sp. nov., Sidorchukatia gracilis gen. et sp. nov., Protosiphoniella anthophila gen. et sp. nov. and Khobotun elephantinus gen. et sp. nov. Presence of an elongated labrum is confirmed for Paradoxosisyrinae for the first time. 3D modelling was used to demonstrate how the mouthparts of B. truncata were assembled together during feeding. We show that there is considerable diversity in the morphology of mouthparts, wing venation and wing patterns of Paradoxosisyrinae. Nectar-feeding habits are suggested for Paradoxosisyrinae on the basis of microscopic examination of their stylet-like mouthpart structures. Possible reasons for evolutionary failure of long-proboscid Neuroptera are discussed.