Megascopic Biota From The Doushantuoian Of The Neoproterozoic (Ediacaran) In Guizhou And Zhongqing, South China

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.