Feathers Before Flight

@article{Clarke2013FeathersBF,
  title={Feathers Before Flight},
  author={Julia A. Clarke},
  journal={Science},
  year={2013},
  volume={340},
  pages={690 - 692}
}
Fossil data indicate that feathers and their precursors may have evolved over a much longer span than previously thought. Feathers are branched structures consisting of β-keratin—a rigid protein material formed by pleated β sheets—with a hollow central shaft. They are strikingly different from other forms of vertebrate integument such as scales, skin, and hair. Until recently, evolutionary hypotheses envisioned their origin through elongation of broad, flat scales driven by selection for aerial… 
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References

SHOWING 1-10 OF 15 REFERENCES
Hind Wings in Basal Birds and the Evolution of Leg Feathers
TLDR
Together these fossils show that early avialans possessed four wings, rather than two, and provide solid evidence for the existence of enlarged leg feathers on a variety of basal birds, and suggest that extensively scaled feet might have appeared secondarily at an early stage in ornithuromorph evolution.
A new feather type in a nonavian theropod and the early evolution of feathers
TLDR
Congruence between the full range of paleontological and developmental data strongly supports the hypothesis that feathers evolved and initially diversified in nonavian theropods before the origin of birds and the evolution of flight.
Development and evolutionary origin of feathers.
  • R. Prum
  • Biology
    The Journal of experimental zoology
  • 1999
TLDR
A functionally neutral model of the origin and evolutionary diversification of bird feathers based on the hierarchical details of feather development is proposed, predicting that feathers originated with the evolution of the first feather follicle-a cylindrical epidermal invagination around the base of a dermal papilla.
Reconstruction of Microraptor and the Evolution of Iridescent Plumage
TLDR
This finding and estimation of Microraptor feathering consistent with an ornamental function for the tail suggest a centrality for signaling in early evolution of plumage and feather color.
Plumage Color Patterns of an Extinct Dinosaur
TLDR
This work has reconstructed the appearance of a theropod dinosaur by mapping features of its well-preserved feathers and comparing them with modern samples from birds, and indicates that the body was gray and dark and the face had rufous speckles.
An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures
TLDR
Tianyulong extends the geographical distribution of heterodontosaurids to Asia and confirms the clade’s previously questionable temporal range extension into the Early Cretaceous period, and represents the first confirmed report, to the authors' knowledge, of filamentous integumentary structures in an ornithischian dinosaur.
Paleohistological estimation of bone growth rate in extinct archosaurs
TLDR
It is concluded that crocodiles may have retained the capacity of growing at high rates on the basis of recent evidence for unidirectional airflow in the lungs of alligators, and a paleobiological model constructed to estimate bone growth rate from bone histological traits.
The soft tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathinae) and the structure of the pterosaur wing membrane
TLDR
Although the understanding of the mechanical properties of the wing membrane is hampered by the lack of knowledge regarding the composition of the actinofibrils, the configuration observed in Jeholopterus might have allowed subtle changes in the membrane tension during flight, resulting in more control of flight movements and the organization of the wings when the animal was at rest.
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