The discovery of new fossil species in the Yimen region,central Yunnan

Through 1:50 000 regional geological survey, a large number of well-preserved multicellular macrosomal fossils were discovered for the first time in the grayish black carbonaceous muddy slates of the Etouchang Formation of the Mesoproterozoic Dongchuan Group in the Yimen region, central Yunnan. It is inferred from the zircon U-Pb age data that these fossils may be dated at ca. 2200 Ma. The microscopic analysis, electron probe analysis and electron microscopic scanning analysis have confirmed that these fossils are the largest multicellular macrofossils with the most complete biological structures, and fills up the blank of non-biofossil records in the Precambrian strata in Yunnan. This discovery is of great scientific signicance and scientific values in the study of the evolution of the Earth's environments and life during the early periods of the Earth's history.