Caihong juji

Discovered in the Tiaojishan Formation in Liaoning Province, China and described in 2018, Caihong juji, or "rainbow big crest" was a anchiornithid avialae theropod dinosaur that lived 161 million years ago in the Oxfordian stage of the Late Jurassic period. The fossilized feathers of Caihong possessed nanostructures which were analyzed and interpreted as melanosomes, showing similarity to organelles that produce a black iridescent color in modern birds like crows, while feathers found on the head, chest, and the base of the tail preserve flattened sheets of platelet-like melanosomes very similar in shape to those which create brightly colored iridescent hues in the feathers of modern hummingbirds, likely used for sexual display.