辽西义县组蝾螈类化石新发现

New discovery of salamander fossils from the Yixian Formation in western Liaoning

在辽西葫芦岛市附近的早白垩世义县组地层中发现1处新的蝾螈化石点。新台门一带出露的湖相沉积地层主要是一套灰绿色安山岩与紫色泥质粉沙岩的互层。该层中除了产蝾螈化石外,还有诸如Ephemeropsis,Eosestheria,Liaoningocladus等其他动植物化石。过去发现的Liaoxitriton化石点是在同一地区比新化石层稍高的层位中发现的。该类蝾螈化石曾报道产于早白垩世的九佛堂组,但是新近的野外调查表明,该化石点所在层位也属义县组。

Recent field work in the Xintaimen area near Huludao City,western Liaoning,resulted in the discovery of a new site for salamander fossils in lacustrine deposits of the Early Cretaceous Yixian Formation.The lacustrine deposits exposed in the Xintaimen area consist of interbedded grayish green andesite and purple muddy siltstones.The deposits yield Ephemeropsis,Eosestheria and Liaoningocladus in addition to salamander fossils.The site of fossils of Liaoxitriton discovered in the past is located in a horizon slightly above the new horizon.This salamander form was reported to occur in the Early Cre-taceous Jiufotang Formation,but recent field survey,including the stratigraphic section,has shown that the horizon of this fossil site also belongs to the Yixian Formation rather than to the Jiufotang Formation.