A gliding, four-winged dinosaur’s feathers:
Dinosaurs, such as Anchiornis, had shaggy, primitive feathers prior to the evolution of highly adapted feathers in modern birds.
Study: Saitta et al. 2017. Palaeontology
Media: New York Times, Smithsonian Magazine, Live Science, Der Spiegel (German), briefly discussed in I Know Dino
Structures in dinosaur fossils are feathers, not collagen:
A likely final blow against the argument that filaments around the bones are collagen fibers from the skin. They are feathers, based on overwhelming evidence.
Study: Smithwick et al. 2017. Palaeontology
Psittacosaurus tail bristles resemble those of modern birds:
External and internal structural similarities suggest shared ancestry of basic developmental processes in feathers deep into archosaur evolution. Bristles possibly functioned in sexual display.
Study: Mayr et al. 2016. Palaeontology
Media: Discover Magazine, Inverse, le Scienze (Italian)