描述产自辽宁北票上园地区黄半吉沟上侏罗统义县组下部膜翅目昆虫化石1新属新种Trematothoracoides liaoningensis gen. et sp. nov., 归入葬茎蜂科(Sepulcidae)中的陷胸茎蜂亚科(Trematothoracinae)。这是首次在我国发现可靠的陷胸茎蜂化石，也是该亚科在侏罗纪的首次报道。分支分析结果表明Trematothoracinae为一单系类群。Thoracotrema与Prosyntexis进化程度较高，构成一对姊妹群，同时又是Trematothorax的姊妹群；Trematothoracoides最为原始，为Thoracotrema+Prosyntexis+Trematothorax的姊妹群。“,”A new genus and new species, Trematothoracoides liaoningensis gen. et sp. nov., is described here from the lower part of the Upper Jurassic Yixian Formation at Huangbanjigou Village near Shangyuan Town, Beipiao, Liaoning Province, China. This is the first reliable trematothoracin sawfly discovered in China and in the Jurassic Period. The cladistic analysis of Trematothoracinae shows that the subfamily is monophyletic. Trematothoracoides is relatively primitive and forms the sister group to a clade that includes Thoracotrema, Prosyntexis and Trematothorax. Thoracotrema and Prosyntexis are a closely related sister group, which is also the sister group to Trematothorax.rn