PDF(Pubmed)
Abstract：
The Emu Bay Shale (EBS) of South Australia is anomalous among Cambrian Lagerstätten because it captures anatomical information that is rare in Burgess Shale-type fossils, and because of its inferred nearshore setting, the nature of which has remained controversial. Intensive study, combining outcrop and borehole data with a compilation of >25,000 fossil specimens, reveals that the EBS biota inhabited a fan delta complex within a tectonically active basin. Preservation of soft-bodied organisms in this setting is unexpected and further underscores differences between the EBS and other Cambrian Lagerstätten. Environmental conditions, including oxygen fluctuations, slope instability, high suspended sediment concentrations, and episodic high-energy events, inhibited colonization of the lower prodelta by all but a few specialist species but favored downslope transportation and preservation of other largely endemic, shallow-water benthos. The EBS provides extraordinary insight into early Cambrian animal diversity from Gondwana. These results demonstrate how environmental factors determined community composition and provide a framework for understanding this unique Konservat-Lagerstätte.
摘要：
南澳大利亚州的Emu湾页岩（EBS）在寒武纪Lagerstätten中异常，因为它捕获了在Burgess页岩型化石中罕见的解剖信息，由于其推断的近岸环境，其性质仍然存在争议。深入研究,将露头和钻孔数据与>25,000个化石标本的汇编相结合，揭示了EBS生物群在构造活跃的盆地内居住着扇三角洲复合体。在这种情况下保存软体生物是出乎意料的，这进一步突显了EBS与其他寒武纪Lagerstätten之间的差异。环境条件,包括氧气波动，边坡失稳,高悬浮泥沙浓度，和周期性的高能事件，除少数专业物种外，所有物种都抑制了下游前三角洲的定殖，但有利于下坡运输和其他主要特有物种的保护，浅水底栖动物.EBS提供了对冈比亚早期寒武纪动物多样性的非凡见解。这些结果证明了环境因素如何决定社区组成，并为理解这种独特的Konservat-Lagerstätte提供了框架。
