MORPHOLOGICALLY COMPLEX ORGANIC-WALLED MICROFOSSILS (OWM) FROM THE LATE PALAEOPROTEROZOIC - EARLY MESOPROTEROZOIC CHITRAKUT FORMATION, VINDHYAN SUPERGROUP, CENTRAL INDIA AND THEIR IMPLICATIONS ON THE ANTIQUITY OF EUKARYOTES

Three complex Organic-Walled Microfossils (OWM) viz. Shuiyousphaeridium echinulatum Yin and Gao, 1999; Cymatiosphaeroides kullingii Knoll et al., 1991 and Trachysphaeridium sp. are recorded from the chert streaks of the Chitrakut Formation of the Semri Group, Vindhyan Supergroup. This assemblage has been attributed to eukaryotic remains and discussed on various possible criteria to establish their affinity. The present record is the third occurrence of such eukaryotic forms from the Late Palaeoproterozoic - Early Mesoproterozoic succession after the report of the Roper Group, Australia and the Ruyang Group, China. The Chitrakut assemblage represents the first comprehensive report of the acritarchs including Shuiyousphaeridium type acritarch from the Vindhyan Supergroup.