Prof. Kenichiro Sugitani and Associate Prof. Koichi Mimura at the Graduate School of Environmental Studies, Nagoya University, with their research groups at the University of Liège, Belgium, and Lille University, France, discovered remarkable microfossils in sedimentary rocks in the Pilbara Craton of Western Australia that were deposited ~3.4 billion years ago. Compared to the contemporaneous typical ones, the microfossils were anomalously large, characterized by unusually complex morphologies and had acid-resistant cell walls; therefore, after separation and extraction of the microfossils, it was possible to observe the complicated forms, and even their internal structures, by using scanning and transmission electron microscopies. The researchers concluded that identified microfossils were more diverse and complex than expected. This means that elaborated ecosystems composed of varieties of microorganisms were already established 3.4 billion years ago. This evidence could lead to a paradigm shift in the earth sciences in terms of our understanding of early life.
This study was published online, Geobiology, on June 13, 2015.