Tube growth patterns and microbial mat-related lifestyles in the Ediacaran fossil Cloudina, Gaojiashan Lagerstatte, South China
Tube growth patterns and microbial mat-related lifestyles in the Ediacaran fossil Cloudina, Gaojiashan Lagerstatte, South China
复制标题
华南高家山拉格斯塔特埃迪卡拉化石Cloudina的管状生长模式和微生物席相关生活方式
DOI：
10.1016/j.gr.2012.12.027
复制
发表时间：
2014-04-01
影响因子：
6.1
通讯作者：
Yuan, Xunlai
中科院分区：
文献类型：
--
作者：
Cai, Yaoping;Hua, Hong;Yuan, Xunlai
Cloudina是埃迪卡拉纪重要的指标化石，因为它们具有一致的新元古代末期年龄和全球分布。云蝶属的形态学主要是根据中国和西班牙的三维标本重建的，但围绕其系统发育位置的问题仍然存在。了解Cloudina古生态学是解释这些神秘生物的一个重要方面。虽然他们的古生态动力学仍然没有解决，一个可能的“垫贴”生活模式已经找到了支持最近的埋藏学调查的Meskayan Cloudina标本。在这里，从埃迪卡拉纪灯影组上部（高家山和李家沟剖面，宁强地区，陕西南部，中国南部）的化石材料的分析，我们文件复杂的管生长模式的Cloudina除了这些化石与保存微生物引起的沉积结构（特别是matgrounds）的密切关系。高家山剖面含C/oudina碳酸盐岩层序的沉积学和埋藏学资料显示了Cloudina与微生物席的关系，并进一步证实了直立保存的Cloudina管。结合巴拉圭材料的观察，这里描述的灯影化石为古生态学解释Cloudina作为微生物结合的碳酸盐基质的居民提供了支持性证据。管（或锥体）的最顶端部分可能充当附着装置，位于微生物垫内或下方。对李家沟剖面Cloudina的三维磷化管进行了研究，发现单个管具有多个生长方向，这是由于管壁的弯曲生长（圆锥形和漏斗形）造成的。由于这些生物表现出固着，底栖生活模式，观察到的可塑性，在生长方向和方向可能是一个竞争驱动的适应，以确保更广泛地获得可用的食物来源和潜在的更高的喂养效率。尽管已发现Cloudina与生物层和生物丘（例如，沉积学和埋藏学特征表明，宁强云顶属的沉积环境为层状碳酸盐岩底质，具席状特征，但不存在生物礁和生物层。(C)2013年国际冈瓦纳研究协会。Elsevier B. V.出版，保留所有权利。
Cloudina are important Ediacaran index fossils, as they have a consistent terminal Neoproterozoic age and a worldwide distribution. The morphology of Cloudina has been reconstructed primarily on the basis of three-dimensionally preserved Chinese and Spanish specimens, but questions remain surrounding their phylogenetic placement. Understanding Cloudina paleoecology is an important aspect for the interpretation of these enigmatic organisms. Although their paleoecological dynamics remain unresolved, a possible "mat sticker" life mode has found support from recent taphonomic investigation of Paraguayan Cloudina specimens. Here, from analysis of fossil material from the upper part of the Ediacaran Dengying Formation (Gaojiashan and Lijiagou sections, Ningqiang area, southern Shaanxi Province, South China), we document complex tube growth patterns of Cloudina in addition to a close association of these fossils with preserved microbially induced sedimentary structures (specifically matgrounds). Sedimentological and taphonomic data of C/oudina-bearing carbonate sequences at the Gaojiashan section show a relationship between Cloudina and microbial mats, and further document erectly preserved Cloudina tubes. In conjunction with observations from the Paraguay material, the Dengying fossils described here provide supportive evidence for the paleoecological interpretation of Cloudina as inhabitants of a microbially bound carbonate substrate. The apical-most part of the tube (or cone) may have served as an attachment apparatus, situated within or beneath a microbial mat. Three-dimensionally phosphatized tubes of Cloudina from the Lijiagou section reveal that single tubes often have multiple growth orientations, which is demonstrated to have resulted from the curved growth of the tube walls (both cones and funnels). As these organisms exhibited a sessile, epibenthic life mode, the observed plasticity in growth direction and orientation may have been a competition-driven adaptation to ensure wider access to available food sources and potentially greater feeding efficiency. Although Cloudina have been found to co-occur in some deposits with biostromes and bioherms (e.g., stromatolites and thrombolites), sedimentological and taphonomic features of the Ningqiang Cloudina suggest that they inhabited a stratified carbonate substrate exhibiting matground features, but where biostromes and bioherms were absent. (C) 2013 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.