Abstract

An assemblage of microbial remains consisting two types of preservations are being recorded for the first time from the phosphoritic chert intercalated in Tirohan Limestone (Rohtas Limestone Formation) of Semri Group, Vindhyan Supergroup, exposed in Chitrakoot, Madhya Pradesh. The uniquely preserved, cryptic forms are multicellular, bilaterally symmetrical, monoecious, cylindrical elongated coiled body with clitellum and ornamented structures (setae). This assemblage shows possible biomineralized novel post embryonic developmental stages of the juvenile and young forms of the annelids. The dark brown organic-walled microfossils (prokaryote and protists) are sparse, cellularly preserved, distorted, small sized, simple sphaeromorphs. The present explored preliminary results are based on the Mesoproterozoic stray fossils of two bioentities in limited material, and are the authentic key events to consider remarkable potential value in understanding the evolution and divergence of the metazoan in India along with status of Indian subcontinents (geographic position) in geological past of world history. It is a team effort of the earth scientists (geologists, botanist, and zoologist) based on the extinct and extant annelids in present brief communication.

Key words: Soft bodied metazoan, annelid, clitellum, Mesoproterozoic, Tirohan limestone, Vindhyan.