New xyelydid sawflies from the Lower Cretaceous of China

One new genus and three new species, Fissilyda compta gen. et sp. nov., F. alba sp. nov., and F. parilis sp. nov., and a new species, Novalyda decora sp. nov., are described and figured on the basis of five well-preserved fossils from the Lower Cretaceous Yixian Formation of China. All of these well-preserved new fossil specimens have a desclerotized pterostigma which is pale at the base, while F. alba sp. nov. has the crossvein cu-a linearly aligned with vein a in the hind wing, both are rather unusual and important characters in Hymenoptera. These new taxa broaden the diversity of Xyelydidae in the Early Cretaceous and their new morphological characters enhance our understanding of the evolution and relationships of this small extinct family.