End-Permian and end-Triassic mass extinctions reshaped the diversity of Odonata

The analysis of the morphological diversity of dragonfly wings over an interval of 150 million years shows that their diversity was considerably renewed during the late Permian and late Triassic mass extinctions. This unexpected result sheds new light on the history of insects and continental ecosystems.

Until then, the evolution of the number of known fossil species suggested a constant increase in dragonfly diversity since the Carboniferous, coeval to a progressive acquisition of modern characters. The wing shape diversity records traces of the selective disappearances of many groups and of a rapid recovery of diversity after the crises. The paleontological archives of insects being very fragmentary and the sites being dated with little precision, the simple count of fossil biodiversity does not make it possible to read the rapid fluctuations in the number of species. The study of the diversity of forms, also called disparity, partly compensates for these limitations. The application of disparity methods to other groups would make it possible to reconsider the extent of past mass extinction in continental ecosystems.

Reference

• Deregnaucourt I., Bardin J., Villier L., Julliard R., Béthoux O. 2023. Disparification and extinction trade-offs shaped the evolution of Permian to Jurassic Odonata. iScience 26, 107420. https://doi.org/10.1016/j.isci.2023.107420