The prehistoric creature researchers have dubbed as the “rainbow” dinosaur was just about as large as a crow, with analysis pointing to iridescent feathers on its head, neck, and chest. And, as the scientists behind the discovery described it, this possible ancestor of modern-day birds points to a “more colorful Jurassic World than we previously imagined.”
In a study published Monday in the journal Nature Communications, the researchers detailed their new discovery, which was first spotted by a local farmer from Hebei Province in northeastern China. The so-called “rainbow” dinosaur, which was given the name Caihong juji, or “rainbow with the big crest,” is believed to have existed during the Jurassic Era, approximately 161 million years ago.
As noted in a report from Reuters, Caihong’s fossil was found near-intact and well preserved, and analysis of the dinosaur’s remains suggested that it stood out for the iridescent feathers found on its head, neck, and chest. The colors of these feathers are believed to have “shimmered and shifted in the light,” much like in the case of modern-day hummingbirds.
The story of how the scientists discovered that Caihong might have been a rainbow-colored dinosaur of sorts began when Hebei Province farmer Yang Jan first spotted its fossil, with the Paleontological Museum of Liaoning acquiring it in February 2014, according to National Geographic. Analysis of the fossil revealed that Caihong’s feathers had traces of pigmentation through the remnants of melanosomes, which are the organelles that provide color and photoprotection to animal tissues. With this in mind, the researchers took the melanosomes they found in Caihong’s fossil and compared them against those found in present-day bird feathers.
Based on the researchers’ findings, Caihong had melanosomes that were very similar to those found in the iridescent throat feathers of hummingbirds. These long and flat melanosomes were found primarily in the creature’s head and chest, and in some parts of its tail.
Although the scientists were not able to absolutely confirm that Caihong was a “rainbow” dinosaur, as they weren’t able to reconstruct the exact colors of its feathers, they believe that the pigments found in those feathers gave them a rainbow-like effect. This is a similar effect to what was observed in the fossil of the dinosaur Microraptor, as researchers discovered in 2012 that its feathers “glinted blue in the sun” like present-day crows and grackles do, wrote National Geographic.
Unlike Microraptor, Caihong was not a purely iridescent creature, as most of its body was covered in dark feathers. And while the colorful, “rainbow” part of the creature’s plumage may have most likely been used to attract potential mates, the researchers are unsure whether Caihong’s feathers would have allowed it to fly.
A newly discovered dinosaur likely had iridescent feathers that gave it a rainbow appearance. ???? Caihong juji (“rainbow with the big crest” in Mandarin) was a duck-sized dino living 161 million years ago. https://t.co/Yv17q6i4wQ pic.twitter.com/g0AdU9HHoS
— The Field Museum (@FieldMuseum) January 15, 2018
Interestingly, the dinosaur was cited by Reuters as the earliest known animal with asymmetrical feathers, which are used by today’s birds to maneuver themselves while airborne. But while birds use their arm feathers to steer themselves, Caihong’s asymmetrical feathers were found on its tail, which could hint at tail feathers being the first ones used to control airborne movement.
According to Chinese Academy of Sciences paleontologist and study co-author Xing Xu, the above trait made Caihong very similar to Archaeopteryx and other early birds.
“Its forelimbs were configured like wings. To be honest, I am not sure what function the feathers have, and I don’t think that you can completely exclude the possibility that the feathers helped the animal to get in the air.”
At the present, there are still many unanswered questions about the “rainbow” dinosaur Caihong. According to National Geographic, more research on feathered dinosaurs may be needed to fully confirm what the iridescent feathers were actually for, or if this was a trait found in males and/or females of the species.