Although the study of extinct species is crucial for diversification and evolutionary history of Hymenoptera, the past diversity of Liadoxyelini (Xyelidae, Xyelinae) is relatively poorly documented. Herein, one new fossil genus with one species, Novoxyela bella gen. et sp. nov., and one species, Platyxyela elegans sp. nov., are described and figured from the Middle Jurassic Daohugou Beds of Inner Mongolia, China. N. bella gen. et sp. nov. differs from other Liadoxyelini by combination of traits including unusual large head, pterostigma only sclerotised basally, 1-Rs almost as long as 1-M and 1 m-cu slightly shorter than 2-Cu. P. elegans sp. nov. exhibits unique features hitherto unknown among species of the Platyxyela, viz., pterostigma of medium width, completely sclerotised and ovipositor sheaths widest subapically. The diversity of known fossil species of Liadoxyelini and new forewing characters, as well as a new key to species of Platyxyela, are presented.LSIDurn:lsid:zoobank.org:pub:874C3A78-2EA3-4877-AA5E-AC352A8AFCAE