Diverse biomineralizing animals in the terminal Ediacaran Period herald the Cambrian explosion
Diverse biomineralizing animals in the terminal Ediacaran Period herald the Cambrian explosion
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埃迪卡拉纪末期的多种生物矿化动物预示着寒武纪大爆发
DOI：
10.1130/g45949.1
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发表时间：
2019-04-01
期刊：
影响因子：
5.8
通讯作者：
Hua, Hong
中科院分区：
文献类型：
--
作者：
Cai, Yaoping;Xiao, Shuhai;Hua, Hong
生物矿化后生动物的起源和辐射代表着生命史上一项重要的进化创新。已知的最早的骨骼后生动物在埃迪卡拉纪末期(约550-539 Ma)由四个属主导，随后在早寒武世(约539-510 Ma)出现了新的多样化的壳化石。因此，埃迪卡拉纪末期骨骼化石和早寒武世壳化石通常被认为是两个截然不同的组合，在地层分布和分类组成上几乎没有重叠，这意味着在埃迪卡拉纪-寒武纪界线可能发生了灭绝事件和随后的辐射事件。然而，最近的研究表明，一些埃迪卡拉纪的骨骼类群可能已经延伸到早寒武世，表明这两个组合之间存在演化连续性。在这里，我们记录了中国南部埃迪卡拉纪登营组末期的不同骨骼化石组合。该组合以埃迪卡拉纪末期的Cloudina和Sinotublites等类群为主，但也含有形态上与早寒武世壳体化石相似的稀有元素。这一发现表明，埃迪卡拉晚期骨骼动物比之前认为的更加多样化，并进一步加强了埃迪卡拉纪-寒武纪过渡期间生物矿化动物的进化连续性。
The origin and radiation of biomineralizing metazoans represents an important evolutionary innovation in the history of life. The earliest known skeletal metazoans are dominated by four genera in the terminal Ediacaran Period (ca. 550-539 Ma), followed by the diversification of new and diverse shelly fossils in the early Cambrian Period (ca. 539-510 Ma). Thus, terminal Ediacaran skeletal fossils and early Cambrian shelly fossils are commonly regarded as two distinct assemblages, with little overlap in stratigraphic distribution and taxonomic composition, implying a possible extinction event and a subsequent radiation event at the Ediacaran-Cambrian boundary. However, it has been shown recently that some Ediacaran skeletal taxa may have extended into the early Cambrian, indicating evolutionary continuity between these two assemblages. Here we document an assemblage of diverse skeletal fossils from the terminal Ediacaran Dengying Formation in South China. This assemblage is dominated by terminal Ediacaran taxa such as Cloudina and Sinotubulites, but also contains rare elements that morphologically resemble early Cambrian shelly fossils. This finding suggests that terminal Ediacaran skeletal animals are more diverse than previously thought and further reinforces the evolutionary continuity of biomineralizing animals across the Ediacaran-Cambrian transition.