By the early 1980s, a monographic description of the main groups of organic remains from the Chergak series of Tuva had been largely completed and published: stromatoporates, tabulates, rugosas, bryozoans, crinoids.

Upper Ordovician and Lower Silurian sediments are widespread in the Altai-Sayan folded region. They have been studied to varying degrees, paleontologically characterized differently, and have different relationships with each other.