The Palaeontology Research On Ediacara Biotas From The Doushantuo Formation (635Ma-555Ma) On The East Of Yangtze Gorge, South China

In recent, geologists and biologists have been attached to the study of life and environment in the early history of our earth. There are available data which indicate that the Doushantuo Formation is older than the diverse Ediacaran assemblages of South Australia and northern Russia, and may older than all to known Ediacaran assemblages.During our fieldwork, we collected almost 200 specimens from the Doushantuo Formation in the Yangtze Gorges area in South China. We made thin rock sections and dissolved our specimens with acids. We also took some SEM photoes for some special fossils. Through our work we have got some important data: The first , We have identified some sponge skeletons in the lower part of the Neoproterozoic Doushantuo Formation that deposit in the Yangtze Gorges aera (South China), These skeleton systems consist of siliceous, four-pronged tetraxonal magascleres with axial canals, monaxonal microscleres and gemmoscleres. All of the four-pronged tetraxonal magascleres were broken and their new cross sections show that spicules have a concentric lamellar organization that can be divided into three parts: in the center is axial canal, around the canal an axial cylinder and finally the lamellar region lamellae. These microscleres and gemmoscleres are embedded in the outer coat of sponge gemmules. They are referred to as the Porifera, class Demospongiae. The three-dimensional preservation of possible sponge skeleton systems suggest that the sponges may have already appeared, 50 to 70 million years before the Cambrian Explosion, in terminal Proterozoic. The second, we have found the acritachs of Tianzhushania、embryo fossils and multicellular algal fossils from the Doushantuo Formation in the Yangtze Gorges area in South China. These fossils can be compared with Wengan biota. Our data suggests that the Wengan biota in Guizhou province is older than Miaohe biota in the Yangtze Gorges area. The last but not the least, we discovered a type of special fossil globular fossils which on the external appearance mostly several diameters for the small ball of 20μm come together to together, and forms particular morphology. That type of detection of fossil enriched the contents of the Ediacara Biotas.