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, are paleontologically characterized differently, and have different relationships with each other.