title: Feathered non-avian dinosaurs from North America provide insight into wing origins.
abstract: 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.
authors.affiliation: Department of Geoscience, University of Calgary, Calgary, Alberta T2N 1N4, Canada. dkzeleni@ucalgary.ca
authors.forename: Darla K
authors.initials: DK
authors.lastname: Zelenitsky
authors.forename: François
authors.initials: F
authors.lastname: Therrien
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Erickson
authors.forename: Christopher L
authors.initials: CL
authors.lastname: DeBuhr
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: David A
authors.initials: DA
authors.lastname: Eberth
authors.forename: Frank
authors.initials: F
authors.lastname: Hadfield
mesh_terms: D000818:Animals; D005075:Biological Evolution; D025061:Dinosaurs / Q000033:anatomy & histology* / Q000145:classification*; D005241:Feathers / Q000033:anatomy & histology*; D009656:North America; D010802:Phylogeny; D014921:Wings, Animal / Q000033:anatomy & histology*