From a central feather shaft extends a series of slender barbs, each sprouting smaller barbules, like branches from a bough, lined with tiny hooks. When these grasp on to the hooklets of ...

This image shows the magnified barbules of a white peacock's feathers, which feature long appendages that diffuse thermal radiation to keep the birds warm. Disclaimer: AAAS and EurekAlert!

cylindrical filaments that differ from modern feathers by lacking barbs and barbules. Initially, these structures may have provided thermal insulation and ornamentation before evolving under ...