Movement is a key ecological function that greatly influences an organism’s body structure. New ways of moving can lead to significant changes in body form, which can drive species diversification. Despite new fossil discoveries, it is unclear if flying evolved once or multiple times among dinosaurs. The flight abilities of these dinosaurs are also disputed. For modern birds, flight evolved through modifications of feathered limbs and tails.

By examining number and shape of flight feathers in modern birds, Kiat et al. found that these features are closely linked to flight ability, showing important functional constraints. Traits evolve at different rates, with some reflecting ancient conditions and others current flight capabilities. Mesozoic birds and Microraptor have feather structures similar to modern flying birds, while anchiornithines have different feather structures, suggesting they could not fly.

These findings support the idea that flight in dinosaurs originated once and that early feathered wings are not well-represented in the current fossil record.

Read the full article in Proceedings of the National Academy of Sciences of the USA 121 e2306639121 https://doi.org/10.1073/pnas.2306639121