The mesoraphidiid genus Siboptera Ponomarenko, 1993 is one of the most distinguishable snakeflies in the absence of stem MA from the forewing, with only two Early Cretaceous species from the Zaza Formation of eastern Siberia, Russia and Yixian Formation of western Liaoning, NE China, respectively. We herein describe and illustrate the third species of the genus, Siboptera lata sp. nov., based on a forewing from the Lower Cretaceous Baiwan Formation of Zhenping, southwestern Henan, China. The present data indicate that this genus has an Aptian age, and is a component of the Jehol Biota in East Asia.