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New Bird-Like Dinosaur Took to the Jurassic Air on“Strange Wings”
Beijing – Anewdinosaur from Jurassic rocks in northeast China shows that some cousins of birds had wings that were made of skin instead of feathers, according to a team of scientists led by Professors Xu Xing ofthe Institute of Vertebrate Paleontology and Paleoanthropology (IVPP)in Beijing and ZhengXiaotingof Linyi University in Shandong Province. The recently discovered specimen from Hebei Province, whose name Yi qi is pronounced roughly “eechee” and means “strange wing” in Mandarin, would have moved through the air using membranesa bit like those of a flying squirrel.
Yi qi belongs to an enigmatic group of small dinosaurs, called the scansoriopterygids, that is so far known only from China. Scansoriopterygids are closely related to primitive birds such as the famous Archaeopteryx, but there was previously no evidence that they could take to the air themselves.
At first, Yi qi also looked flightless to the China-based scientists who carried out the new research, published in this week’s issue of Nature. Feathers were preserved along with the skeleton, but they seemed too narrow and filament-like to form useful flight surfaces. However, the researchers eventually realized that another unusual feature of the specimen, a long, rod-like bone extending from each wrist, suggested a completely different type of wing was present.
Several other animals, including bats and flying squirrels, are already known to have similar rods of either bone or cartilage associated with one pair of limb joints. The function of these structures is always the same – to help support an aerodynamic membrane. Sure enough, patches of membranous tissue are also preserved in Yi qi, although the shape and size of the entire membrane are uncertain. While this type of flight apparatus has evolved in other groups, it has never previously been found in a dinosaur, and Yi qi may represent a bizarre evolutionary experiment that ultimately failed.
“We thought giving this animal a name meaning ‘strange wing’ was appropriate, because no other bird or dinosaur has a wing of the same kind,” explained Professor Xu. “We don’t know ifYi qi was flapping, or gliding, or both, but it definitely evolved a wing that is unique in the context of the transition from dinosaurs to birds.” Professor Xu also noted that Yi qi is the shortest name ever given to a dinosaur.
The researchers expect their reconstruction of the wings of Yi qi to be controversial, but say they believe they have come up with the best interpretation of the available evidence. Colleagues have joked that Yi qi could have used its rod-like wrist bones as ski poles or giant chopsticks, but so far haven’tbeen able to think of a plausible function for them that doesn’t involve flight or gliding.
“At first we just didn’t know what the rod-like bones were,” said Dr. Corwin Sullivan, a Canadian palaeontologist based at the IVPP and involved in the study. “Then I was digging into the scientific literature on flying and gliding vertebrates for a totally different project, and I came across a paragraph in a textbook that said flying squirrels have a strut of cartilage attached to either the wrist or elbow to help support the flight membrane. I immediately thought, wait a minute – that sounds familiar!”
However, Yi qi might not have been a champion flyer. Even if it had some ability to flap, rather than only glide, it may have been limited to short flights between trees, or from elevated perches to the ground.
“Yi qi lived in the Jurassic, so it was a pioneer in the evolution of flight on the line to birds,” said Professor Zheng. “It reminds us that the early history of flight was full of innovations, not all of which survived.”
For further details, to obtain high-resolution (and/or unlabelled) versions of the images below, or to arrange an interview with any of the authors, please contact Dr.Corwin Sullivan (, +86 136-2132-4250) or Professor Xu Xing (, +86 136-9357-9209).
Only known specimen of the new dinosaur Yi qi. Photo may be used freely to accompany an article on the discovery of Yi qi, but should be credited to Mr. ZangHailong. Future requests for use should be directed to Prof. Xu Xing.
Skull of the new dinosaur Yi qi. Photo may be used freely to accompany an article on the discovery of Yi qi, but should be credited to Mr. ZangHailong. Future requests for use should be directed to Prof. Xu Xing.
Right rod-like bone (labelled) of the new dinosaur Yi qi, with membranous tissue preserved around the tip of the bone and filament-like feathers preserved elsewhere in the image. Photo may be used freely to accompany an article on the discovery of Yi qi, but should be credited to Mr. ZangHailong. Future requests for use should be directed to Prof. Xu Xing.
Artist’s impression of the new dinosaur Yi qi. Image may be used freely to accompany an article on the discovery of Yi qi, but should be credited to DinostarCo. Ltd. Future requests for use should be directed to Prof. Xu Xing.