The animal would have been around 4 feet long in life, and its fossil shows that it was covered in feathers -- including, as in its smaller cousin Microraptor, a pair of "leg wings" represented by long paired pennaceous feathers on the metatarsals and tibiotarsus. One of Changyuraptor's most unique features is its voluminous tail feathers, and these feathers constitute the longest of any known non-avian dinosaur, with the most distal retrices reaching around 30 cm in length.
Changyuraptor is also by far the largest "four-winged" dinosaur known, and while this might not be as big of a deal as it sounds (given that there aren't very many "four-winged" dinosaurs), it does show that small size wasn't necessarily the gatekeeper to certain volant adaptations. I personally doubt that this animal was doing anything approaching powered flight, but the long tail feathers and multiple sets of long, well-developed lifting surfaces may have been a boon to gliding and controlled descent. The exceptionally long tail feathers therefore might have been used as a sort of "pitch control" device, wherein a large, relatively heavy animal would have needed especially fine-tuned control over rapid falls onto prey or in safe landings from higher ground. As Buzz Lightyear would say, "This isn't flying, it's falling with style!"
Gouache/watercolor paint on A3-size hot-pressed illustration board, approx. 5-6 hours.
Gang Han et al. 2014. "A new raptorial dinosaur with exceptionally long feathering provides insights into dromaeosaurid flight performance". Nature Communications. 5: 4382.
Great work on the feathers, as always!
By the way, was he four feet long with or without the tail feathers? And is it possible for a raptor even larger than him to be a good glider?
And thank you greatly for clarifying/answering!!! It's really appreciated!
The "biplane" model makes more sense in an evolutionary way beyond the obvious as well. Many bird species tuck their feet up under their bellies when they fly, herons being one of the most obvious exceptions. The "biplane" positioning of a Microraptor is more in line with developing muscles to bring the feet forward and up than the "sprawling" model that reverses joint evolution towards reptilian positioning.
But behavior is just as much a response to environment as it is to genetics. A pheasant or hawk or goose will still display the typical behaviors of their species associated with posture, including mating/breeding behaviors, even if they're raised in captivity. However, if they're imprinted on humans/captive living, then they typically will not develop the skills associated with survival instincts related to procuring food or avoiding predation. The reason why a pure-blooded, captive but wild bird ends up with damaged feathers is based primarily on inadequate (cramped or dirty/damp) living conditions. But fully-domesticated birds have other factors hindering their behavior and/or ability to maintain their feathers.
Animals that are heavily artificially selected for specific physical traits cannot behave in a manner that is in accordance with possession of those artificially-selected physical traits. Just as dogs bred for short faces (pugs, bulldogs, etc) suffer breathing problems for their distorted anatomy, pigeons and chickens can suffer for their distorted anatomy. And feather-footed pigeons are possessed of distorted anatomy. Fantail pigeons, one of several breeds to possess "leg-wings," are bred to be short-legged and pudgy, leaving most of them unable to fly due to weight/lack of range-of-movement of their wings. They would have trouble walking even without the additional long feathers on their legs and feet.
And that's why they shouldn't be used as a reference for leg-feather placement in extinct animals... artificial breeding has distorted both their skeletal structure as well as their plumage.
In any case, I get what you're saying and I don't really disagree. In my first really meticulous illustration of Microraptor that was informed almost entirely by published data, I painstakingly reconstructed the legwings in a way that seemed - both on evolutionary and morphological grounds - most reasonable, and this way was based very loosely on the position of these feathers in fancy pigeons. My logic at the time was that the legwings facing directly backwards, as they're usually reconstructed, would impede the animal's ability to sit, lay down, and stand at certain angles, so they'd need to be held in a different way. Out to the side would make more sense. However, other artists, most notably Matt Martyniuk, have reconstructed the legwings of microraptorines to sort of "fold" in a similar way to regular wings, which could pick them up off the ground for these positions. This is how I've attempted to paint Changyuraptor above, though I don't feel strongly which position is the correct one (and they may not be mutually exclusive). I wrote more about this idea here.
The tail finally looks very similar to that of Archaeopteryx.
Just imagine the difference in style between the shrink-wrapped naked raptors of 2 decades ago and this...
A picture for the Featured folder