Feathers Before Flight

  title={Feathers Before Flight},
  author={Julia A. Clarke},
  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… 
From baby birds to feathered dinosaurs: incipient wings and the evolution of flight
These findings provide a quantitative, biologically relevant bracket for theropod performance and suggest that protowings could have provided useful aerodynamic function early in maniraptoran history, with improvements in aerodynamic performance attending the evolution of larger wings, more effective feathers, and faster angular velocities.
A Mesozoic aviary
According to this story, the development of flight was chaotic, with different dinosaurs experimenting with different airborne behaviors using different airfoil and feather arrangements, until ultimately only modern birds survived.
Beyond the rainbow
These results contribute to an emerging understanding of why pennaceous feathers may have been superior to filamentous protofeathers and insights into body size evolution in dinosaurs along the line to birds are contributed.
Flight, symmetry and barb angle evolution in the feathers of birds and other dinosaurs
It is shown that extant taxa, including strong flyers (e.g. some songbirds), show convergence on trailing barb angles and barb angle asymmetry observed in Mesozoic taxa that were proposed not to be active fliers, challenging the notion that barb angle and barb angles ratios in extant birds directly inform the reconstruction of function in extinct stem taxa.
Feather evolution exemplifies sexually selected bridges across the adaptive landscape
Feathers illustrate how sexual selection can generate complex novel phenotypes, which are then available for natural selection to modify and direct toward novel functions.
Barb geometry of asymmetrical feathers reveals a transitional morphology in the evolution of avian flight
The findings suggest that the fully modern avian flight feather, and possibly a modern capacity for powered flight, evolved crownward of Confuciusornis, long after the origin of asymmetrical flight feathers, and much later than previously recognized.
Aerodynamics from Cursorial Running to Aerial Gliding for Avian Flight Evolution
Among the different models that have been proposed to explain the origin of avian flightfrom terrestrial predators, the cursorial and arboreal hypotheses remain the most discussed.However, the fossil
How birds became birds
  • M. Benton
  • Biology, Environmental Science
  • 2014
Evidence for sustained miniaturization for 50 million years before Archaeopteryx evolved is provided, showing that sustained size reduction was essential for the origin of birds and avian flight.
Exceptional preservation and the fossil record of tetrapod integument
It is suggested that among-integument variation in preservation can bias the reconstructed first origins of integumentary novelties and has implications for predicting where, and in what depositional environments, to expect further discoveries of exquisitely preserved tetrapod integument.


Narrow Primary Feather Rachises in Confuciusornis and Archaeopteryx Suggest Poor Flight Ability
Analysis of the flight feathers of early Mesozoic birds Archaeopteryx and Confuciusornis shows that the rachises were much thinner and weaker than those of modern birds, and thus the birds were not capable of flight.
Hind Wings in Basal Birds and the Evolution of Leg Feathers
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
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
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
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
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.
Oviraptorosaur Tail Forms and Functions
Three-dimensional digital muscle reconstructions reveal that, while oviraptorosaur tails were reduced in length relative to the tails of other theropods, they were muscularly robust and, despite overall caudal length reduction, the relative size of the M. caudofemoralis in most ovirptorosaurs was comparable with those of other non-avian theropod.