A 120 million-year-old fossil helps paleontologists to bridge the ‘phantom’ evolutionary leap between feathered dinosaurs and trendy birds.
Dubbed “the dancing dragon”, or Wulong bohaiensis, this newly described species is an odd combine between fowl and dinosaur, historical and new.
First found in China greater than a decade in the past, in one of many world’s richest fossil deposits, the traditional animal’s superbly preserved bones have solely not too long ago acquired nearer inspection.
The Jiufotang Formation, the place the fossil was discovered, belongs to the Jehol group – identified for its unimaginable number of animals, it is thought-about one of many earliest habitats the place dinosaurs, birds, and bird-like dinosaurs co-existed. However even amongst stiff competitors, the Wulong fossil is certainly one of a sort.
Specialists from China and the US now assume this dancing specimen is without doubt one of the earliest family members of velociraptors, and an important stepping stone within the obscure dinosaur-to-bird transition.
Smaller than a raven however bigger than a crow, this new species would have appeared considerably like a tiny feathered raptor, outfitted with 4 wing-like limbs and an excellent lengthy, double-plumed tail. And but, there was one thing unusual about its age.
“The specimen has feathers on its limbs and tail that we affiliate with grownup birds, but it surely had different options that made us assume it was a juvenile,” says paleontologist Ashley Poust from San Diego Pure Historical past Museum.
The mix was puzzling. Feathers had been as soon as thought distinctive to birds, however because of latest discoveries – a lot of which got here from the identical Chinese language province – it now seems many of those key avian options developed a lot earlier on, perhaps even earlier than dinosaurs.
The truth is, velociraptor embryos are mentioned to look “virtually similar” to the world’s first birds.
Inspecting a number of bones from the Wulong specimen, Poust and colleagues decided that regardless of its mature-looking feathers, this specific dancing dinosaur was, in actual fact, a juvenile – roughly a yr outdated.
“The presence of such elaborate buildings within the equally sized, comparatively somatically immature Wulong demonstrates that non-avian dinosaurs had a really totally different technique of plumage growth than their dwelling family members,” the authors write.
Most trendy birds, as an illustration, don’t develop their plumage fairly that rapidly, particularly these cumbersome tail-feathers often reserved for mating. Wulong’s tail, however, virtually doubles the dinosaur’s size, and its feathers seem to have developed properly earlier than sexual maturity.
“Both the younger dinosaurs wanted these tail feathers for some operate we do not learn about, or they had been rising their feathers actually in a different way from most dwelling birds,” explains Poust, who now works on the San Diego Pure Historical past Museum.
To work out the small print, the crew in contrast the stays to samples of a dinosaur from the Sinornithosaurus genus. These bones had been additionally massive and adult-looking, however turned out to not be totally grown both. Collectively, the crew warns in opposition to making determinations of age based mostly on commentary alone.
Whereas bone histology will be harmful to a skeleton, the researchers argue it’s also one of the crucial reliable strategies and one of the best ways for us to know key discoveries.
“The brand new dinosaur suits in with an unimaginable radiation of feathered, winged animals which might be intently associated to the origin of birds,” says Poust.
“Learning specimens like this not solely reveals us the generally stunning paths that historical life has taken, but in addition permits us to check concepts about how necessary fowl traits, together with flight, arose within the distant previous.”
The research was printed in The Anatomical File.