中文摘要：

云南虫是澄江生物群中最具争议的动物之一,其系统位置目前至少有6种不同的观点,不同研究组曾分别将其解释为分类位置不定的原口动物、头索动物、半索动物、有头类、后口动物的干支类群,或者两侧对称动物的基部类群等。争论的焦点主要集中在一些关键形态特征的解释,如轴部构造、背部分节以及鳃等。澄江生物群不同地区云南虫标本的详细对比显示,相同地点云南虫的保存有明显共性,而不同地点云南虫的保存特征差异很大。云南虫争议的主要根源在于不同研究组所研究标本的产地不同,标本保存特征不同,同时又缺少不同地点云南虫埋藏学的对比研究所致。埋藏学的初步研究表明,目前云南虫许多性状特征（尤其是关键的分类特征）的解释都存有疑问。背部发生叠覆和扭曲的标本显示云南虫的背部分节和肌节特征并不相同;腮腔外囊状突起的发现更对云南虫头部结构的推测提出质疑。进一步的生物学特性分析表明云南虫身体结构的同源性还远没有定论,云南虫系统分类有待于埋藏学、沉积学、地球化学以及分子系统学等多学科的综合研究。

英文摘要：

As one of the most controversial taxa of the Chengjiang Biota,yunnanozoans have hitherto been referred by different authors respectively to at least six different phylogenetic clades,including protostome,cephalochordate,hemichordate,craniates,the stem group of deuterostome,and basal bilaterian.These widely different viewpoints are mainly caused by the incongruence of the some key anatomical interpretations,such as dorsal segments,axis,and gill structures.Extensive investigation reveals that specimens of yunnanozoans from different localities and sections are taphonomically unique,which are illustrated and discussed in this paper respectively.Much controversy about yunnanozoans＇s morphology and phylogenenetic relationships is mainly due to the variation of preservations of the specimens from different localities and the absence of comparative study among those specimens.Preliminary taphonomic comparison indicates that some previous interpretations of morphological characters,especially some key characters,of yunnanozoans are questionable.For example,the folded and twist dorsal part of yunnanozoans forcefully contradicts the myomeres hypothesis.Saclike structure exterior to the gill also calls for question about previous head structure interpretation.In view of taphonomy,the verdict of most anatomical characters of yunnanozoans is far from set.This incertitude about morphology further suspends deciphering the phylogeny of yunnanozoans.Efforts from taphonomy,sedimentology,geochemisty,and molecular phylogeny are required in future research of yunnanozoans.