Four-winged dinosaurs from China.
Although the dinosaurian hypothesis of bird origins is widely accepted, debate remains about how the ancestor of birds first learned to fly. Here we provide new evidence suggesting that basal dromaeosaurid dinosaurs were four-winged animals and probably could glide, representing an intermediate stage towards the active, flapping-flight stage. The new discovery conforms to the predictions of early hypotheses that proavians passed through a tetrapteryx stage.
Xu
Xing
X
Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, P.O. Box 643, Beijing 100044, China. xing_xu@sina.com
Zhou
Zhonghe
Z
Wang
Xiaolin
X
Kuang
Xuewen
X
Zhang
Fucheng
F
Du
Xiangke
X
D000818:Animals; D005075:Biological Evolution; D001717:Birds / Q000033:anatomy & histology* / Q000145:classification / Q000502:physiology; D002681:China; D025061:Dinosaurs / Q000033:anatomy & histology* / Q000145:classification / Q000502:physiology; D005241:Feathers / Q000033:anatomy & histology / Q000502:physiology; D005426:Flight, Animal; D005580:Fossils; D008954:Models, Biological; D014921:Wings, Animal / Q000033:anatomy & histology* / Q000502:physiology