Remarkable insights into the paleoecology of the Avalonian Ediacaran macrobiota
Remarkable insights into the paleoecology of the Avalonian Ediacaran macrobiota
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DOI：
10.1016/j.gr.2014.11.002
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发表时间：
2015-06
影响因子：
6.1
通讯作者：
A. Liu;C. Kenchington;E. Mitchell
中科院分区：
文献类型：
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作者：
A. Liu;C. Kenchington;E. Mitchell
来自阿瓦隆地体(主要是纽芬兰东部和英国中部)的埃迪卡拉纪巨型化石记录了地球上一些最早的大型复杂多细胞生物。也许关于这些化石最大的未知数是它们与动物界早期进化史的相关性。近年来，新的数据和发现揭示了对埃迪卡拉纪古生物学、分类关系、古生态学和区位分类学的洞察，极大地完善了我们对阿瓦隆生态系统的理解。在这里，我们总结了最近的观测和定量研究，以及它们对当前对阿瓦伦底栖海洋生态系统的理解的影响。对阿瓦隆海洋组合生物组成的现有知识的审查表明，它们记录了人口稠密的生态系统，居住着各种各样的生物，可能代表着多个生物界。在考虑宏观演化与同时代的气候、构造和地球化学事件之间的关系时，对这种多样性及其给古生态研究带来的复杂性的认识是至关重要的。然后，我们总结了目前对阿瓦隆古生态学的认识。对移动、繁殖、摄食策略、群落结构和演替的研究表明，这些生态系统与显生动物环境有很大的不同。此外，我们认为阿瓦隆生态系统见证了新的营养源的出现，为底栖生物提供了新的机会和生态位。根据地化、形态和生物信息，对数字优势的地貌是渗透营养型的观点进行了综述和评价。最后，对现代生态计量学在埃迪卡拉纪化石组合研究中的应用进行了评估。根据目前的挖掘学和沉积学理解，概述了对古生态数据解释的关注，这使人们对以前关于阿瓦伦纪组合主要由后生动物组成的说法产生了怀疑。然而，我们强调，如果必要的谨慎处理，古生态数据可以在帮助确定埃迪卡拉纪晚期宏观生物的生物亲缘关系方面发挥重要作用。
Ediacaran macrofossils from the Avalon Terrane (primarily eastern Newfoundland and the central UK) record some of the earliest large and complex multicellular organisms on Earth. Perhaps the greatest unknown regarding these fossils is their relevance to the early evolutionary history of the Kingdom Animalia. In recent years, new data and discoveries have revealed insights into Ediacaran paleobiology, taxonomic relationships, paleoecology and taphonomy, significantly refining our understanding of Avalonian ecosystems. Here, we summarise recent observational and quantitative studies, and their bearing on the current understanding of Avalonian benthic marine ecosystems. A review of existing knowledge of the biological composition of Avalonian marine assemblages demonstrates that they record densely-populated ecosystems inhabited by a diverse range of organisms, likely representing multiple biological Kingdoms. Appreciation of this diversity, and of the complexities it introduces to paleoecological studies, is vital when considering the relationship between macroevolution and contemporaneous climatic, tectonic and geochemical events. We then summarise current understanding of Avalonian paleoecology. Studies into locomotion, reproduction, feeding strategies, and community structure and succession reveal that these ecosystems were considerably different to Phanerozoic settings. Furthermore, we suggest that Avalonian ecosystems witnessed the appearance of novel nutrient sources, offering new opportunities and niches for benthic organisms. The suggestion that the numerically dominant rangeomorphs were osmotrophic is reviewed and appraised in light of geochemical, morphological, and biological information. Finally, the use of modern ecological metrics in the study of Ediacaran fossil assemblages is assessed. Concerns regarding the interpretation of paleoecological data are outlined in light of current taphonomic and sedimentological understanding, and these cast doubt on previous suggestions that the Avalonian assemblages were largely composed of metazoans. Nevertheless, we emphasise that if treated with necessary caution, paleoecological data can play a significant role in assisting efforts to determine the biological affinities of late Ediacaran macroscopic organisms.