[N] 2012 Feathered Non-Avian Dinosaurs from North America Provide Insight into Wing Origins
Previously described feathered dinosaurs reveal a fascinating record of feather evolution, although substantial phylogenetic gaps remain. Here we report the occurrence of feathers in ornithomimosaurs, a clade of non-maniraptoran theropods for which fossilized feathers were previously unknown. The Ornithomimus specimens, recovered from Upper Cretaceous deposits of Alberta, Canada, provide new insights into dinosaur plumage and the origin of the avian wing. Individuals from different growth stages reveal the presence of a filamentous feather covering throughout life and winglike structures on the forelimbs of adults. The appearance of winglike structures in older animals indicates that they may have evolved in association with reproductive behaviors. These specimens show that primordial wings originated earlier than previously thought, among non-maniraptoran theropods.
Zelenitsky et al (2012) Feathered Non-Avian Dinosaurs from North America Provide Insight into Wing Origins. Science 26 October 2012: Vol. 338 no. 6106 pp. 510-514 DOI: 10.1126/science.1225376