New mecopteran insects from the Middle Jurassic Yangshuzhuang Formation of Jiyuan Basin, China

The Middle Jurassic Yangshuzhuang Formation in the Jiyuan Basin is rich in fossil insects; however, mecopterans have not been previously reported from this formation. Herein, we describe and illustrate five new species and two new genera of the ‘Orthophlebiidae’ sensu lato from the Yangshuzhuang Formation: Protorthophlebia gracilis sp. nov., Protorthophlebia curvata sp. nov., and Jiyuanphlebia incompleta gen. et sp. nov. of Protorthophlebiidae, as well as Orthophlebia picta sp. nov., and Quadrivena jiyuanensis gen. et sp. nov. of Orthophlebiidae. Additionally, four new specimens are assigned to Orthophlebia quadrimacula Lin, 1982, as they share same coloured markings and similar venational pattern. Ten hindwing specimens of ‘Orthophlebiidae’ are also described and illustrated, representing eight distinct wing forms. Seven forewings and one possibly forewing of incompletely preserved are illustrated as at least five wing forms of ‘Orthophlebiidae’. A fragmentary specimen is assigned to Mesopsychidae, although it can only be identified at familial level. Our findings indicated that the ‘Orthophlebiidae’ sensu lato were diverse in Jiyuan Basin during the Middle Jurassic, increasing the palaeodiversity of this group during the Jurassic. Moreover, the discovery of the same species in both the Yangshuzhuang Formation and the Zhiluo Formation suggests a potential stratigraphic correlation between these two formations.