埃迪卡拉化石组成了全球埃迪卡拉纪地层中最具代表性的大型软躯体生物群落。根据其时代、化石种类以及岩性等, 埃迪卡拉化石被划分为阿瓦隆、白海、纳玛三个不同组合。产自我国三峡地区埃迪卡拉纪晚期的石板滩生物群是为数不多保存在海相碳酸盐岩中的埃迪卡拉化石生物群。本文利用多元统计分析和网络分析等定量古生物方法划分出四个化石组合, 检验并探讨了石板滩生物群所属的组合类型, 以及初步探讨了石板滩生物群的生态空间利用情况。聚类分析和网络分析的结果, 均倾向于将石板滩生物群划归于纳玛组合。然而在非度量性多维标度变换(NMDS)分析中, 石板滩生物群因其化石属种组成的独特性和复杂性, 离其他典型的纳玛组合化石产地的点位相距较远。石板滩生物群的生活方式以底栖固着和底栖移动类型为主, 其独有的实体化石和丰富、复杂的遗迹化石属种, 拓展了人们关于该时期生物对生态空间利用的认识。从生态空间利用的角度来看, 石板滩生物群要远高于阿瓦隆组合, 接近甚至略高于典型的纳玛组合和白海组合。
Ediacara-type fossils constitute the most representative Ediacaran macroscopic and soft-bodied biotic assemblages (i.e., Ediacara biotas). Ediacara biotas have been classified into three different assemblages—the Avalon, White Sea, and Nama assemblages mainly based on their ages, taxonomic compositions, and lithologies. The late Ediacaran Shibantan biota from the Yangtze Gorges area is a rare example of Ediacara-type fossil assemblages preserved in carbonate rocks. In this study, we applied quantitative approaches, including multivariate and network analyses, to recognize four different assemblages, as-signed the Shibantan biota to one of these assemblages, and preliminarily discussed ecospace occupancy in the Shibantan bi-ota, as compared with the three classic and broadly accepted assemblages mentioned above. The results of cluster and net-work analyses are inclined to classify the Shibantan biota as a member of the Nama assemblage. It is also worth noting that the placement of the Shibantan biota is deviated from other typical fossil localities of Nama assemblage in the result of NMDS analysis, possibly caused by the uniqueness and complexity of the Shibantan taxonomic composition. The Shibantan biota is dominated by sessile and mobile benthic organisms, whose unique body fossils and abundant and complex trace fos-sils expand our understanding of ecospace occupancy during this time interval. From the perspective of ecospace occupancy, the Shibantan biota is more complex than the Avalon assemblage, similar to or slightly more complex than typical Nama and White Sea assemblages.