The Paper's reporter Lu Xinwen
Flapping flight, which uses wings, has long been one of the most iconic features of birds. Although some fossils of non-avian dinosaurs suggest that they may have had flight patterns similar to those of birds, the evolution of flapping wing flight in birds and their close relatives remains to be studied.
Recently, the journal Current Biology published online the latest research results of Xu Xing's team at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences. This result uses the suggestive weight method to systematically analyze and update the phylogenous tree of plesiosaurs, and on this basis, quantitative analysis shows that flapping wing flight may have had three or more independent origins in near-avian dinosaurs.
Near bird phylogeny trees and partial flight-related feature evolution research team Courtesy of the team
There is multiple evolutionary convergence in the evolutionary history of small theropod dinosaurs in the Mesozoic Era, resulting in certain uncertainties in the results of their phylogenetic analysis. As a framework for exploring evolutionary questions, phylogenetic uncertainty limits accurate analysis of the evolutionary history of morphological functions such as the origin of bird flight. On the basis of expanding the evolution matrix of plesiosaurs, this study uses the suggestive weighting method for morphological features in systematic analysis, and reduces the uncertainty of the analysis results caused by evolutionary convergence by assigning weights to different features. The results of this systematic analysis re-support the monophyletic dinosaurs of the Chironidae and the Family " Pterosodondae " , while the Prototylodontidae are at the base of the ornithoptera , and members of the Chinese Early Cretaceous Rehe biota of Chiosaurus and the North American Hesperonychus are classified as monophyletic petty poachosaurs.
Wing loading and take-off dynamics of small theropod dinosaurs Research team Courtesy of the team
Based on the newly created phylogenetic tree, the research team quantitatively analyzed the dynamic flapping flight potential of winged early birdwings with wings and closely related birds. Two indicators, namely wing loading and specific lift, were selected to numerically estimate and reconstruct the relevant fossil species and ancestral nodes. The analysis results showed that most of the early bird winged birds and some non-avian dinosaurs (Microparaptor and Rahonavis theodonosaurus) met the reference numerical criteria for wing load and take-off power of living flying birds, that is, they had the potential for dynamic flapping wing flight. In addition, the wing load of some small non-avian dinosaurs reached the reference value of living flyable birds, but the take-off power was insufficient, while other taxa, including larger theropod dinosaurs, did not meet the standard of living flyable birds.
The study supports multiple independent wing-flapping origins of theropod dinosaurs, identifying at least two possible power flight origin events (Microraptor and Rahonavis) outside of bird-winged dinosaurs, and the wing payload and take-off dynamics of a series of non-avian dinosaurs are close to the reference numerical standards for living birds. The results suggest that many non-avian theropod dinosaurs are likely already exploring modes of movement assisted by two wings at the same time as birds first took off, and that some of them have also successfully flapped their wings and flew into the sky, and the specific details and patterns of the independent origin of these flights need to be further studied.
This study was conducted by the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences in collaboration with researchers from the University of Hong Kong and Argentina, the United States and the United Kingdom.
Editor-in-Charge: Xu Di