The historical development of main ray-finned fish taxa in the Permian and Early Triassic of the Kuznetsk Basin has been traced. Three faunal assemblages of ray-finned fishes, successively changing and having no continuity, have been identified: Permian, Indian and Olenekian. The first one is subdivided into five subassemblages. During the Permian, endemism among the ray-finned fish assemblages increased. In the Triassic, the faunal assemblages changed completely twice (without any continuity with earlier assemblages) - at the Permian-Triassic boundary and at the boundary of the Indian and Olenekian Stages.
Bakaev et al. (2025) studied this question.