热河生物群凌源东方叶肢介的软体构造及其分类意义  

SOFT BODY PRESERVATION IN THE CONCHOSTRACAN EOSESTHERIA LINGYUANENSIS CHEN FROM THE JEHOL BIOTA AND ITS TAXONOMIC SIGNIFICANCE

作　　者：沈炎彬[1] 

机构地区：[1]中国科学院南京地质古生物研究所,南京210008

出　　处：《古生物学报》2011年第3期275-283,共9页Acta Palaeontologica Sinica

基　　金：国家自然科学基金(40902004);中国科学院知识创新工程方向性项目(KZCX-2YW-QN104)联合资助

摘　　要：东方叶肢介(Eosestheria)是著名热河生物群中最为常见的一类甲壳动物,关于它的形态、壳瓣结构及微细纹饰特征的研究已相当详尽,但一直没有关于其软体构造的报道。本文描述的凌源东方叶肢介(Eosestheria lingyuanensis)采自辽宁北票市尖山沟村,产于下白垩统义县组的尖山沟夹层。这些软体构造包括:头部形态、眼、闭壳肌痕、雄性执握肢、体节、消化道及尾节等。通过与现生叶肢介软体形态构造比较,显示其与刺尾亚目的蚌壳虫科的代表最为亲近。从而为探讨化石与现生叶肢介之间的演化关系及建立高一级的统一分类,提供了有价值的依据。The clam shrimp Eosestheria is an extraordinarily abundant and important member of the conchostracan fauna from the famous Jehol Biota.Here the occurrence of partial soft body preservation in E.lingyuanensis is reported for the first time,occurring as impressions,inside the valve,of the head,eye,adductor muscle scar,male claspers,digestive tube,and telson.The exceptionally preserved specimens were found in the Lower Cretaceous Yixian Formation at Jianshangou village,near Beipiao,in Liaoning Province of NE China.The preservation of soft parts in conchostracans is significant partly because its occurrence is very rare-known previously only from about 16 species worldwide and several of which are actually much less complete than the present material.Soft body characteristics are also important for accurate taxonomic determination and assessment of relationships.For example,all conchostracan males have the first pair of trunk limbs modified to form so called ＇claspers＇,which hold to the female during mating.Some modification of the second pair of trunk limbs is seen in laevicaudatan conchostracans,two species of which are also known as fossils with soft body parts,but the second pair appears not to be clasper-like in form.Eosestheria lingyuanensis on the other hand has two pairs of clearly defined claspers as in spinicaudatan conchostracans.Furthermore in its more distinct growth lines and acute rostrum as well as its two pairs of claspers it clearly belongs to the suborder Spinicaudata.Within that group,although it is similar to the Cyzicidae in its rostrum lacking an apical spine and in its short stout telson,it differs in its less developed occipital notch and larger palp with a row of pores.Although the name Conchostraca is commonly used in fossil and extant literature, recent molecular and morphological analyses show that the ＇Conchostraca＇ appears not to be a monophyletic group.As such it has no taxonomic meaning.It has therefore been abandoned as a taxonomic unit by many authors.However,Shen et al.（2

关 键 词：热河生物群 东方叶肢介 甲壳类 叶肢介 软体化石 分类 

分 类 号：Q915[天文地球—古生物学与地层学]