A deep root for the Cambrian explosion: Implications of new bio- and chemostratigraphy from the Siberian Platform
A deep root for the Cambrian explosion: Implications of new bio- and chemostratigraphy from the Siberian Platform
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DOI：
10.1130/g38865.1
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发表时间：
2017-05
期刊：
影响因子：
5.8
通讯作者：
--Manuscript Draft;Maoyan Zhu;A. Zhuravlev;R. Wood;Fangchen Zhao;Sergey Sokhov
中科院分区：
文献类型：
--
作者：
--Manuscript Draft;Maoyan Zhu;A. Zhuravlev;R. Wood;Fangchen Zhao;Sergey Sokhov
埃迪卡拉纪和寒武纪生物群之间的时间关系仍然存在很大的不确定性，但这对我们理解后生动物的兴起至关重要。在这里，我们提出了新的高分辨率的碳同位素化学地层学和生物地层学的终端埃迪卡拉纪寒武纪继承东西伯利亚地台，俄罗斯，这表明存在一系列不同的化石组合开始之前，寒武纪基底负碳同位素偏移（BACE）。软体埃迪卡拉生物群（Beltanelliformis）发生在埃迪卡拉纪晚期正碳同位素高原（EPIP）开始之前，是埃迪卡拉纪和寒武纪的混合骨骼生物群（Cloudina，Anabarites，Cambrotubulus）出现在EPIP中，以及多种寒武纪类型的小壳化石，包括Protohertzina和其他protocondonts，halkieriids，chelloriids，hyoliths，hyolithelminthes，在BACE的开始出现了穴居遗迹化石Diplocrafish。这些综合数据表明，分类群归因于所谓的埃迪卡拉纪和最早的寒武纪骨骼生物群实际上重叠没有显着的生物营业额，从而反驳了存在的一个大的同位素漂移与大规模灭绝的埃迪卡拉纪生物群。我们提出了一个新的生物带，Cloudina - Namacalathus - Sinotubulites组合带，在已知的小壳化石（SSF）带之前。这些观察结果引起了人们对埃迪卡拉纪和寒武纪骨骼生物群之间是否存在任何真正的分离的怀疑，并表明寒武纪后生动物大爆发有着深刻的根源。
Much uncertainty remains as to the temporal relationship between the Ediacaran and Cambrian biotas, yet this is critical to our understanding of the rise of metazoans. Here we present new high-resolution carbon isotope chemostratigraphy and biostratigraphy for a terminal Ediacaran to Cambrian succession on the eastern Siberian Platform, Russia, which shows the presence of a succession of diverse fossil assemblages before the start of the basal Cambrian negative carbon isotope excursion (BACE). Soft-bodied Ediacaran biota ( Beltanelliformis ) occur before the start of the late Ediacaran positive carbon isotope plateau (EPIP), a mixed Ediacaran and Cambrian skeletal biota ( Cloudina , Anabarites , Cambrotubulus ) appears within the EPIP, and diverse Cambrian-type small shelly fossils including Protohertzina and other protocondonts, halkieriids, chancelloriids, hyoliths, hyolithelminthes, and the burrowing trace fossil Diplocraterion appear at the beginning of the BACE. These integrated data show that taxa attributed to so-called Ediacaran and earliest Cambrian skeletal biotas in fact overlap without notable biotic turnover, and thus refute the presence of a large isotope excursion coincident with mass extinction of all Ediacaran biota. We propose a new biozone, the Cloudina - Namacalathus - Sinotubulites Assemblage Zone, to precede the known small shelly fossil (SSF) zones. These observations raise doubts as to whether there is any true separation between the Ediacaran and Cambrian skeletal biotas, and suggest that there is a deep root for the Cambrian explosion of metazoans.