A team of researchers have conducted a study of the remains of a chicken-sized dinosaur that lived in China about 161 million years ago, during the Jurassic period. Their analysis of the exquisitely-preserved fossil, published January 15, 2018, in the journal Nature Communications, suggests that the small dinosaur had a shaggy ruff of iridescent rainbow feathers.
The scientists think the dinosaur – named Caihong juji, “rainbow with the big crest” in Mandarin — used its flashy neck feathers and a bony crest on its snout to attract mates.
Julia Clarke, a professor in the Department of Geological Sciences at the Univeristy of Texas Jackson School of Geosciences, helped describe the new species. She said in a statement:
Iridescent coloration is well known to be linked to sexual selection and signaling, and we report its earliest evidence in dinosaurs.
The dinosaur is interesting because it has features that are both ancient and modern, said co-author Xing Xu, a professor at the Chinese Academy of Sciences. The bony crest is a feature usually seen in dinosaurs from earlier eras, while its neck feathers show evidence of melanosomes – microscopic, wide pigment-containing packages – that may represent the first known occurrence of iridescence similar to that found in many of today’s hummingbirds.
A farmer discovered the slab of rock containing the dinosaur fossil in northern China’s Hebei Province in 2014. The rock contained a nearly complete skeleton surrounded by impressions made by feathers. The impressions preserved the shape of the melanosomes. The researchers compared the melanosome impressions to melanosomes found in living birds and found that they most closely resembled those in the iridescent, rainbow feathers of hummingbirds.
Caihong is also the earliest known dinosaur with asymmetrical feathers, the feather type found on the wingtips of modern birds that helps control flight, said the researchers. But unlike birds today, Caihong’s asymmetrical feathers were on its tail, not its wings — a finding that suggests that early birds may have had a different steering or flight style.
Caihong stands out from the other small, bird-like dinosaurs that lived in China during the Jurassic, the researchers say. While the other dinosaurs had triangular skulls and longer forearm bones than today’s birds, Caihong had a long and narrow skull, and unlike many of these other dinosaurs, its short forelimbs show proportions more like modern birds. Clarke said:
This combination of traits is unusual. It has a rather velociraptor-looking low and long skull with this fully feathered, shaggy kind of plumage and a big fan tail. It is really cool… or maybe creepy looking depending on your perspective.
Bottom line: Researchers have described a small dinosaur with rainbow feathers that lived in China about 161 million years ago.
Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.