黔东北江口陡山沱组庙河生物群中的革辛娜藻Gesinella Steiner et al.,1992  

THE GESINELLA STEINER ET AL., 1992 FROM THE MIAOHE BIOTA(EDIACARAN) OF JIANGKOU, GUIZHOU PROVINCE

作　　者：伍孟银[1,2] 赵元龙[2] 彭进[2] 傅晓平[3] 

机构地区：[1]贵阳学院政教系,贵阳550005 [2]贵州大学资源与环境工程学院,贵阳550003 [3]深圳仙湖植物园,深圳518004

出　　处：《微体古生物学报》2012年第3期312-319,共8页Acta Micropalaeontologica Sinica

基　　金：国家自然科学基金(40672018;41172005);贵州省科技基金项目(黔科合J字[2012]2018);贵州省国际科技合作项目(黔科合外G字[2010]7001);贵州省省长基金(黔省专合[2011]37);深圳市仙湖植物园基金联合资助

摘　　要：贵州江口埃迪卡拉纪的江口庙河生物群是一个极为重要的早期后生生物群,不仅含有大量的宏观藻类化石,还发现了可靠的、重要的动物化石。宏观藻类化石数量丰富,保存完整,类型多样,提供了早期后生植物研究的极好材料。本文研究的江口庙河生物群中的大量碳质压模保存的湖南革辛娜藻Gesinella hunanensis,与产于湖南留茶坡组的模式标本相比,整体形态特征虽然一致,两者却存在一些差异,如江口的Gesinella hunanensis叶状体表面较光滑,碳膜厚度从基部向上逐渐变薄,边缘较中部厚,未见乳状突起及侧枝,但可见明显的碳膜压叠现象;叶状体周期性生长明显,一个生长周期形成的叶状体中部较宽,两端较窄;宽度从几个毫米至几十毫米,变化较大;固着结构分为须根状和盘状两种形态,固着器与叶状体之间为加厚的固着蒂,固着蒂之上的叶状体边缘呈波状。与带状棒形藻Baculiphyca taeniata明显不同,尽管整体均呈棒状,但度量相差一个数量级以上,且具独特的周期性生长方式,碳膜中部薄且时有叠压现象、而端部和边缘厚的特征显示其叶状体可能是中空的囊状,与Baculiphyca taeniata的叶状体碳膜极厚乃至保存为块状的特征明显不同。研究结果表明Gesinella hunanensis的形态趋于多样性,证实了Gesinella hunanensis与Baculiphyca taeniata是完全不同的另一类宏观藻类。Miaohe Biota of Jiangkou is a very important early biota, which not only has reliable animal fossils but also has abundant macroalgae with great variety and good preservation. The macroalgal fossils are important for the research on the composition and evolution of the early metaphytes. In this paper, we studied more than 130 pieces of specimens of the Gesinella hunanensis. Comparing with the holotype of Gesinella hunanensis from the Liuchapo Formation in Taoyuan County, Hunan Province, the Gesinella hunanensis from the Doushantuo Formation in Jiangkou County, Guizhou Province has some different characteristics although its overall morphological characteristics is consistent with the former. The thallus of Gesinella hunanensis from Jiangkou Biota is smooth, and the carbon film gra-dually become thinner from the base upward and from the edge to central. No papillae and lateral branches can be found on the thallus but its carbon membrane shows pressure fold phenomenon. The thallus can be obviously found single-or multi-staged bladder-like stages and the width vary considerably from a few millimeters to dozens of mm. The holdfast is divided into two forms, the rhizoids and the disk. There is a thickened pedicle connecting the thallus and the holdfast. The edge of the thallus above the pedicle is wavy. Gesinella hunanensis is markedly different from Baculiphyca taeniata although their club-like morphology is similar. The size of Gesinella hunanensis-like is over one order of magnitude larger, with a unique way of episodic growth. It is suggested that the thallus may be hollow since the carbon film is thin and folded in central, the end and the edge thick. Meanwhile the carbon film of the thallus of Baculiphyca taeniata is so thick as massive. All marked differences between the Gesinella hunanensis and the Baculiphyca taeniata indicate that they are two different type of macroalgae. This study also shows diverse form of Gesinella hunanensis.

关 键 词：Gesinella hunanensis 宏观藻类 庙河生物群 陡山沱组 埃迪卡拉纪 江口 贵州 

分 类 号：Q913[天文地球—古生物学与地层学]