Ediacara fossils represent some of the earliest, complex macroorganisms in the late Ediacaran Period (approximately 580-540 million years ago). They were first discovered in Newfoundland in 1872, and have later been found in Namibia, Australia, Russia, Siberia, England, North America, and South China. Despite their importance in understanding the early evolution of macroscopic life, their wide geographic distribution, and their long history of being targeted for scientific investigation, the morphological, paleoecological, and phylogenetic interpretation of Ediacara fossils has not been completely resolved. A key challenge has to do with the way most Ediacara fossils are preserved: almost all Ediacara fossils are preserved as casts and molds in sandstone or siltstone, making it difficult to reconstruct the morphologies. This project is designed to study an unusually preserved Ediacara assemblage from bituminous limestone of the Dengying Formation (551-542 million years ago) in the Yangtze Gorges area of South China. Preliminary investigation has recovered at least five new Ediacara forms. The fossils appear to have been preserved in three dimensions and in situ. Some of them show remains of degraded organic walls, and morphological reconstruction indicates that they lived procumbently at or near the water-sediment interface. The immediate objective of this project is to carry out systematic field investigation and collection of the Dengying Formation in the Yangtze Gorges area, and to carefully study the Dengying Ediacara fossils using serial thin section, light microscopy, SEM, and electron microprobe techniques. The long-term goal of this research is to address questions related to the biodiversity, bodyplan, taphonomy, and paleoecology of the Dengying Ediacara assemblage. Thus, the scientific significance of this research is to advance our knowledge about the evolution of the earliest complex macroorganisms - the Ediacaran biota.
