After the Permian–Triassic extinction event, the fossil record of insects is poor, but there are some beetles from the Lower Triassic. At the Babiy Kamen site in the Kuznetsk Basin, there are many beetle fossils, including entire specimens of the infraorders Archostemata (e.g. Ademosynidae, Schizocoleidae), Adephaga (e.g., Triaplidae, Trachypachidae) and Polyphaga (e.g. Hydrophilidae, Byrrhidae, Elateroidea).