ScienceAlert has a story about the discovery of a dinosaur with iridescent feathers. The new dinosaur named Caihong juji, which means "rainbow with a big crest" in Mandarin, lived about 161 million years ago in China, during the Jurassic period. The research appeared in the journal Nature.
"Iridescent colouration is well known to be linked to sexual selection and signalling, and we report its earliest evidence in dinosaurs," said researcher Julia Clarke of the University of Texas Jackson School of Geosciences.
"The dinosaur may have a cute nickname in English, Rainbow, but it has serious scientific implications."
The research team determined the possibility of iridescent feathers, coloured like those of a hummingbird, by the fossil. The slab of rock, found by a farmer in 2014, contained nearly a complete skeleton.
While the feathers themselves had long since decayed, they left impressions in the rock around the fossilised bones.
"I was shocked by its beautifully preserved feathers, even though I had seen many feathered dinosaur fossils previously," co-author Xing Xu of the Chinese Academy of Sciences told National Geographic.
It's difficult to tell for certain what colour the feathers were, but the fossil was so detailed that it preserved the shape of the melanosomes, the organelles inside cells responsible for pigmentation.
And when the team compared these melanosomes to those of living birds, they most closely resembled melanosomes found in the iridescent, rainbow-hued feathers of hummingbirds.
