Origin of flight: Could ‘four-winged’ dinosaurs fly?

@article{Padian2005OriginOF,
  title={Origin of flight: Could ‘four-winged’ dinosaurs fly?},
  author={Kevin Padian and Kenneth P Dial},
  journal={Nature},
  year={2005},
  volume={438},
  pages={E3-E3}
}
Arising from: X. Xu et al. 421, 335–340 (2003); F. Zhang & Z. Zhou 431, 925 (2004); X. Xu et al. reply; F. Zhang et al. replyOur understanding of the origin of birds, feathers and flight has been greatly advanced by new discoveries of feathered non-avian dinosaurs, but functional analyses have not kept pace with taxonomic descriptions. Zhang and Zhou describe feathers on the tibiotarsus of a new basal enantiornithine bird from the Early Cretaceous of China. They infer, as did Xu and colleagues… 
A pre-Archaeopteryx troodontid theropod from China with long feathers on the metatarsus
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