New Findings of Udokania in the Udokan Complex of West Siberia

Based on the results of investigations in stratigraphy, structural geology and biostratigraphy obtained during last years the traditional notion on the Early Proterozoic age of the Udokan complex is suggested to be revised. Udokania problematica from the Butunian Formation, the Chiney series of the Udokan complex, is first proved to belong to highly developed skeletal forms typical of Early Paleozoic fauna. Brief preliminary description is given to the morphology and some skeleton elements of the problematica. The following alternative conclusions are suggested: 1) the udokanias are insuffciently studied species of the skeletal organisms which have been existing as long ago as Proterozoic; 2) sedimentary-metamorphic rocks of the Chiney series are of Early Paleozoic age and their present spatial position in the structure of the Kodar-Udokan zone is a consequence of tectonic piling-up.