Mesoproterozoic coiled megascopic fossil Grypania spiralis from the Rohtas Formation, Semri Group, Bihar, India

摘要

The present communication records rare megascopic coiled impressions present on a shale slab collected during the recent field work on the Early Mesoproterozoic Rohtas Formation of the Semri Group, Vindhyan Supergroup exposed in the Rohtas District, Bihar. The fossil Grypania is considered as an important evidence in understanding the evolution of oxygen in the early atmosphere and early experimentation in the biosphere. The present paper also traces the appearance of Grypania to the lower part of the Rohtas Formation and adds to our knowledge about the distribution of Grypania in the Rohtas Formation.