Anoxia can increase the rate of decay for cnidarian tissue: Using Actinia equina to understand the early fossil record
Anoxia can increase the rate of decay for cnidarian tissue: Using Actinia equina to understand the early fossil record
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DOI：
10.1111/gbi.12370
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发表时间：
2020-01-28
期刊：
影响因子：
3.7
通讯作者：
Antcliffe, Jonathan B.
中科院分区：
文献类型：
--
作者：
Hancy, Anthony D.;Antcliffe, Jonathan B.
为刺胞动物模型生物开发了一种实验衰减方法，以与之前许多关于两侧对称动物的此类研究进行比较。这可以检查针对刺胞动物组织化石化及其诊断特征的固有偏差，这些偏差在什么条件下发生以及以什么方式发生。在一系列受控条件下检查了马海葵的腐烂顺序。这些实验表明，刺胞动物的腐烂始于表皮的最初破裂，随后可识别的内部形态特征迅速丧失。这表明细菌在表皮上的作用比自溶在内部解剖结构上的作用更快。数据还表明，双胚层组织在缺氧或还原条件下的腐烂并不普遍比在有氧条件下更慢。事实上，一些刺胞动物的特征在缺氧条件下比在有氧条件下衰退得更快。这表明作用的腐烂途径可能与影响两侧对称动物软组织（例如软表皮和内脏器官）的腐烂途径不同。在软息肉解剖结构的腐烂中最重要的是微生物群落，其可以以好氧或缺氧细菌为主。不同的拉格施塔特，即使是同一类型，其细菌群落也不可避免地存在细微的差异，这可能是对软息肉保存的控制因素，导致要么缺乏引人注目的软珊瑚虫（伯吉斯页岩），要么数量惊人（清江生物群）。
An experimental decay methodology is developed for a cnidarian model organism to serve as a comparison to the many previous such studies on bilaterians. This allows an examination of inherent bias against the fossilisation of cnidarian tissue and their diagnostic characters, under what conditions these occur, and in what way. The decay sequence of Actinia equina was examined under a series of controlled conditions. These experiments show that cnidarian decay begins with an initial rupturing of the epidermis, followed by rapid loss of recognisable internal morphological characters. This suggests that bacteria work quicker on the epidermis than autolysis does on the internal anatomy. The data also show that diploblastic tissue is not universally decayed more slowly under anoxic or reducing conditions than under oxic conditions. Indeed, some cnidarian characters decay more rapidly under anoxic conditions than they do under oxic conditions. This suggests the decay pathways acting may be different to those affecting soft bilaterian tissue such as soft epidermis and internal organs. What is most important in the decay of soft polyp anatomy is the microbial community, which can be dominated by oxic or anoxic bacteria. Different Lagerstatte, even of the same type, will inevitably have subtle difference in their bacterial communities, which among other factors, could be a control on soft polyp preservation leading to either an absence of compelling soft anthozoans (Burgess Shale) or an astonishing abundance (Qingjiang biota).