Early Evolution of Beetles of the Suborder Polyphaga (Insecta: Coleoptera) at the Permian–Triassic Boundary

A brief overview of the research history of the early stages of Polyphaga evolution is given. Reasons for the unparalleled evolutionary success of Polyphaga, which allowed them to become the dominant suborder from the Early Cretaceous to the present time, is analyzed on the basis of published data. Morphology of early findings of crown group beetles (family Ademosynidae, genera Archosyne Ponomarenko et al., 2014 and Ponomarenkium Yan et al., 2018) from the Middle and Late Permian and Triassic (family Peltosynidae) are evaluated morphologically, and their key apomorphies are highlighted. Phylogenetic hypotheses based on molecular analysis, which aimed at reconstructing the appearance and lifestyle of the earliest Polyphaga, are evaluated. Basal branching is shown in Polyphaga, which produced a wide spectrum of forms, no less than in other infraorder-level taxa of Holometabola, and helped them to survive three out of the five mass extinctions of Phanerozoic.