At a farm in north-eastern China’s Hebei Province, a fossil of Caihong juji (C. juji), which is Mandarin for ‘rainbow with a big crest’, was discovered.
This is a fitting name for a 161 million-year-old dinosaur with a Velociraptor-like skull that has iridescent feathers on its head, wings and tail. Scientists discovered the dinosaur’s colourful nature by examining its feathers using a scanning electron microscope, which showed evidence of melanosomes. This is the part of cells that contain pigment.
Despite the colour having long faded away over time, the structure of the cell still remains intact. The dinosaur, C. juji, is not the first of its kind to sport such a feature.
The Microraptor, a four-winged dinosaur also had gleaming features. However, it existed 40 million years after C. juji, which makes the newly identified dinosaur the oldest to have shimmering feathers. It would have also had asymmetrical feathers, a trait that is shared by modern birds and helps them steer while flying.
While C. juji may have sported these feathers on its tail, they could have been used for early flight control, warmth and to attract mates. Not all of C. juji’s features are unusual for a dinosaur though. It had a bony head crust, but the body of an avian.
This combination of new and old traits is an example of mosaic evolution, the concept of change occurring in some parts of an animal but not others.