【作者】 王约；

【导师】 王训练；

【作者基本信息】 中国地质大学（北京） ， 古生物学与地层学， 2009， 博士

【摘要】 宏体生物广泛地生活于扬子地区伊迪卡拉纪陡山沱期古海洋中,描述了产自渝东南和黔东北伊迪卡拉系陡山沱组的宏体生物(包括宏体植物、后生动物和遗迹化石)共30属,23种,4个不明固着器,其中包括4个新属,5个新种,2个新修正属和1个新修正种。渝东南陡山沱期早期宏体生物群可与华北地区青白口期中-晚期Longfenshania植物群可进行比较,而与陡山沱期晚期宏体生物群有较大的区别,它表明了早期的宏体生物能够穿越过“雪球事件”。黔东北陡山沱期晚期瓮会生物群不但含鄂西庙河生物群和皖南蓝田植物群的分子,也有南澳大利亚伊迪卡拉生物群和俄罗斯White Sea生物群的分子,而且有别于其它伊迪卡拉期生物群。瓮会生物群中宏体植物已有组织、器官和功能的明显分化,并出现了原始的维管植物Wenghuiphyton。瓮会生物中宏体后生动物有海绵类、栉水母类、刺胞类和三叶类等两胚层辐射对称动物以及环节类和可能的软体类等三胚层两侧对称动物。瓮会生物群生活于的温暖清澈、相对平静、有一定含氧量、光照充分、富有无机营养盐、并具正常盐度的浅海环境,其基底为富含水份的粥性基底,且生物群的生活周期与周期性的洋流事件存在一定的相关性。瓮会生物群在空间上可分为“挺立群落”、“沉积表层群落”和“水体上层群落”,而构成了一个原始而相对完整的生态系统。在时间纵向上可依次分为Globusphyton , Sectoralga-Longifuniculum , Cucullus , Beltanelliformis ,Baculiphyca-Gesinella等5个群落,反映出生物群落与环境的相关性以及宏体后生动物与植物之间的相关性和规律性。陡山沱期的宏体藻类多分枝并直立固着于海底,提高了光合作用的效率,增加了海中水体中的含氧量,不仅改善了环境,为依赖一定氧而生活、生长和繁殖的后生动物给予了必要的支持,而且作为生态系统中的必要基础,为宏体后生动物的快速发展和演化提供了一个新的食物源。在生命演化的早期,生态系统的演化主要表现为生物从被动地接受环境因子到对环境因子需求的竞争,从依赖环境到参与对环境的改造,生物的环境空间分布从二维到三维,生物的能量传递方式从生物体外到体内。伊迪卡拉纪陡山沱期晚期“原始立体生态系统”的出现,生物在三维空间中开始了对环境因子需求的竞争和生物体内能量传递的食物链结构,同时增强了参与和对环境演化的贡献力度,是生物迅速演化和其后寒武纪生命大辐射的重要转折。另外,扬子地区在陡山沱期晚期是地震构造运动的活跃期,地震构造活动可引起磷等无机营养盐和海水温度的升高,而有利于多细胞生物的起源和发展。伊迪卡拉纪陡山沱期是Rodinia超大陆裂离的重要地质时期,是化学、气候和环境变化的剧烈时期和磷质聚集时期,也是多细胞生物起源和发展的重要转折时期。更多还原

【Abstract】 The macro-organisms lived widely in the Yangtze Sea during the Doushantouian of the Ediacaran. The macro-organisms, including macro-plants, metazoans and trace fossils, 30 species of 23 genera and 4 macroalgal holdfasts, which are collected from Southeast Zhongqing and Northwest Guizhou, are described herein. The macro-biota of the early Doushantuoan from Southeast Zhongqing can compare with the Longfenshania Flora in the middle-late Qingbaikouian in North China, but differs from the late Doushantuoan biotas. It indicates that the macroscopic organisms were able to go through and had gone through the Snowball Event. The Wenghui Biota of the late Doushantuoan in Northeast Guizhou not only contains some elements of the Miaohe Biota from West Hubei, the Lantian Flora from South Anhui, the Ediacara Funa from South Australia, and the White Sea Biota from Russia, but also has its own characters to distinguish other Ediacaran biotas. The macro-plants in the Wenghui Biota have born the differentiation of tissue, organ, and their functions, and had emerged a primordial vascular plant Wenghuiphyton. The metazoans in the Wenghui Biota had radiate symmetrical animals, including Porifera, Ctenophora, Cnidaria, and Trilobozoas, and bilateral symmetrical animals, including Annelida and possible Mollusca. This biota lived in a shallow sea environment with warm-water, low-energy, poor-oxygen, enough-sunlight, rich-nutrition, well-balanced salt, and soupground. The life cycle of this biota was relationship with the seasonal events of ocean currents. In living space, the Wenghui Biota can be redivided into“Upright Community”,“Depositional Surface Community”, and“Super-water Community”, to form a primordial tri-dimension ecosystem. On the section, the Wenghui Biota can be redivided into Globusphyton,Sectoralga-Longifuniculum,Cucullus,Beltanelliformis,and Baculiphyca- Gesinella Communities, from below to above. The change and evolution of these communities show the relation the biota and microenvironment, and indicates the relationship macro-plants with metazoans. The numerous macro-plants during the Doushantuoian were branching and semi-floated and erected on seafloor. They advanced the photosynthetic efficiency and increase oxygen in water to improve in environment for metazoans; and they served as a primary producer in the paleoecosystem to provide an alternative and new food of metazoan. In the early life evolution, the evolution of ecosystem mainly exhibited the development what was from passive accepters to active competitors in life demands for environment factors, from dependence on to reform in the environment, from two-dimension to three-dimension in the spatial distribution, and from outside to inside of organism in the style of energy transformation. The emergence of primordial tri-dimension ecosystem in the late Doushantuoan of the Ediacaran imply that organisms began to compete for environment factors demanded by them, to form a food chain that energy transferred in inner organism body, and to enhanced contribution for environmental evolution. Therefore, the Doushantuoan is a key period in the history of life evolution, and a transition period of the big radiant of life. In addition, the late Doushantuoan was an active period in seismotectonism. The seismotectonism might cause the increase of phosphorous inorganic-salt and seawater warming to help for the origin and development of mulicellular organisms. The Doushantuo Period of the Ediacaran is not only an important epoch of the Rodinia supercontinent cracked and a tempestuous epoch of the chemical, climatic, and environmental changes, but also an important epoch of the mulicellular organismal origin and development.更多还原