Abstract: During a field work on stratigraphy Mr. Yang Youshi et al., the geologists from •the Regional Geology and Mineral Resources Survey Institute of Hebei Province, discovered some well-preserved fossil sturgeons from the Yixian Formation in Fengning County, northern Hebei Province. These specimens, characterized by an extraordinarily long dorsal fin, represent a new form Yanosteus longidorsalis gen. et SP. nov. of the order Acipenseriformes. Yanosteus is stratigraphically concurrent with two known acipenseriform genera Peipiaosteus Liu et Zhou and Protopsephurus Lu in northern Hebei and western Liaoning. The fishbearing strata of Yixian Formation have long been thought to be Late Jurassic (Liu & Zhou 1965, Lu 1994), but additional evidence suggests an Early Cretaceous age (Li et al. 1994).