冀北滦平盆地大北沟组叶肢介化石研究新进展

系统研究了采自滦平盆地火斗山乡张家沟剖面大北沟组(J3d)的叶肢介化石4属22种(包括11个新种)。其中,Nestoria属占绝对优势,并贯穿整个大北沟组,故大北沟组可称为Nestoria群。在该剖面大北沟组首次发现了Jibeilim-nadia属和Keratestheria属,分别产于该组下部和上部,可将Nestoria群进一步划分为下部Nestoria-Jibeilimnadi组合(带)和上部Nestoria-Keratestheria组合(带)。另外,在张家沟剖面大北沟组上部首次发现了中侏罗统土城子组中的重要分子cf.Pseudograpta属,进一步证明了大北沟组的叶肢介动物群与土城子组的叶肢介关系密切,具有重要的时代意义。

New progress in the study of conchostracon fossils from the Dabeigou Formation in the Luanping basin, northern Hebei Province of China

Abundant conchostracon fossils were discovered in the Dabeigou Formation at the Zhangjiagou section,Huodoushan Village,Luanping County,Hebei Province.They include4genera and22species.Among these,the species of Nestoria predominate and occur throughout the Dabeigou Formation,so they can be called the Nestoria fauna.In the Dabeigou Formation the authors for the first time found Jibeilim-nadia and Keratestheria,which occur in the lower and upper parts of the formation respectively.The two genera divide the Nestoria fauna into two assemblage zones:the Nestoria-Jibeilimnadia assemblage zone in the lower part and the Nestoria-Keratestheria assemblage zone in the upper part.In addition,the genus cf.Pseudograpta,an important element in the Middle Jurassic Tuchengzi Formation,was for the first time found in the upper part of the Dabeigou Formation at the Zhangjiagou section,which further proves that the conchostracon fauna in the Dabeigou Formation is closely related to that in the Tuchengzi Formation and has great age significance.