A quill is a pen made from a flight feather of a large bird, most often a goose.
From the en.wikipedia.org
The timing and progression of flight feather moult therefore varies among families.
From the en.wikipedia.org
We already have feather, flight feather and down feather as well as plumage.
From the en.wikipedia.org
Scientists have not yet determined the function of all flight feather modifications.
From the en.wikipedia.org
The edges of feather of birds incapable of flight, such as ostriches, are symmetrical.
From the sciencedaily.com
This feather anatomy, during flight and flapping of the wings, causes a rotation of the feather in its follicle.
From the en.wikipedia.org
The presence of colored feather patterns in a bird prior to the evolution of true flight, suggests that feather coloration may have evolved for reproductive or communication purposes.
From the scienceblogs.com
The hooked, interlocking barbs gave strength and flexibility to the feather and prevented air from passing through it in flight.
From the sciencedaily.com
A symmetrical feather lacks the aerodynamic qualities thought to be necessary for flight, so it is unlikely that Caudipteryx could fly.