When it comes to big fossil finds, China is full of surprises. The latest dinosaur discovery, announced today in Nature, is a bizarre chicken-sized animal with a delightfully short scientific name, Yi qi, Mandarin for “strange wing” (pronounced “yee chee”).
Illustration shows what the dinosaur, Yi qi, may have looked like. Photo / AP
Yi is a new type of scansoriopterygid, a family of small feathered dinosaurs with unusually long fingers, including forms like Epidexipteryx.
The extensively feathered fossil of Yi
hails from the Middle-Late Jurassic (160-165 million years old) of
Hebei Province, in northern China. It preserves a rod-like prop
extending from the wrist along with patches of bare, featherless tissue
around the hands.
The most likely explanation is that the digits and
bony rod supported membranous wing like in modern bats or mythical
dragons. It is unclear if Yi was capable of powered flight or simply glided.
The first palaeontologists to hear about the discovery were taken back by the oddness of the bony rod or styliform element. Dr Thomas R Holtz Jr, a palaeontologist at the University of Maryland, unconnected with the study, told us via email that:
[and others] were suspicious that it wasn’t really part of the animal,
but instead maybe a plant branch or other object that coincidentally was
right under the wrist. But chemical analysis of it shows it really is
derived from bone.
extinct flying reptiles with a wing membrane supported by a single
elongated finger, are not dinosaurs although they lived at the same
time. Yi is definitely not a pterosaur due to its skull
structure and forelimb anatomy. It is a true dinosaur that seems to have
evolved its own unique kind of wing. Holtz adds:
[…] in case anyone thinks otherwise, this [discovery] has zero to do with the origin of pterosaurs!
We’ve discovered a bizarre new flying dinosaur, with bat-like wings and feathers – Yi qi. http://t.co/3FGdq8Yy56 pic.twitter.com/RsOaIlgL3P
— The Conversation (@ConversationEDU) April 29, 2015
Feathers emerge when?
The first feathered dinosaur known to science was the famous Archaeopteryx,
described in 1861 from the Jurassic of Germany although for over a
century it was, by convention, called a bird simply because it had
This view was challenged by the discovery
of feathered dinosaurs from Liaoning, China, beginning in 1996 with the
announcement of Sinosauropteryx from the Early Cretaceous, about 125 million years old.
Numerous fossils from China, Canada, Germany and Russia
prove that many groups of dinosaurs sported feathers or feather-like
structures. These ranged from simple hair-like filaments to the complex
pennaceous true feathers of modern birds, the latter used primarily for
We found out about this new dinosaur when were both visiting the Institute of Vertebrate Palaeontology and Palaeoanthropology (IVPP) in Beijing. We paid a courtesy call to our colleague Professor Xu Xing.
Excitedly, he showed us his remarkable new find on his computer, as the original specimen was recently returned to the Shandong Tianyu Nature Museum. I asked him why it represents such an important discovery to which he replied:
This is the most unexpected discovery I have ever made, even though I have found a few really bizarre dinosaurs in my career.
know the complexity of the dino-bird transition but this new find
shocks me. It demonstrates some of the extreme early experimentation as
dinosaurs began to take to the air.
When dinosaurs took flight
illustrates that the transition from dinosaur to bird wasn’t as
straight forward as previously thought. A great deal of innovation took
place in animals close to the origin of birds, ranging from the
membranous wings of Yi to the four feathery wings of Microraptor.
evolved multiple times within the dinosaurs. The configuration in
modern birds, with a single pair of feathered wings, would ultimately
prove to be the winning formula.
The fossil of Yi is part of an extraordinary assemblage called the Daohugou Biota
from Hebei, Liaoning and Inner Mongolia. These Jurassic sites display
the same superb preservation as the better-known Early Cretaceous Jehol Biota of Liaoning Province. Both these assemblages have produced the vast majority of feathered dinosaur and early bird specimens.
One objection against the dinosaurian origin of birds was the supposed absence of feathered dinosaurs in rocks older than Archaeopteryx (the 150 million year old “first bird”). The Daohugou removes this paradox, revealing a community of feathered creatures that lived over 10 million years before Archaeopteryx.
Corwin Sullivan is a Canadian scientist based at IVPP who was involved in the study. He told us:
of the most exciting things about this animal is the way it seems to
have independently hit on a type of flight apparatus, consisting of an
aerodynamic membrane supported partly by a rod of bone or cartilage,
that is also seen in pterosaurs, bats and many gliding mammals. In that
respect Yi really showcases the power of evolutionary convergence.
appears repeatedly in evolution when functional constraints produce
similar body forms in unrelated lineages. It explains why marsupial thylacines and placental wolves and dogs look alike although they evolved independently over tens of millions of years on different continents.
Convergent evolution: the recently
extinct marsupial thylacine resembles a wolf but they are not closely
related. Photo / Getty Images
The unexpected discovery of Yi once again highlights the stunning diversity of fossils that have been unearthed in China.
From the oldest well-preserved enigmatic jawed fishes like Entelognathus
to the world’s most complete series of feathered dinosaurs, early
mammals and first birds, Chinese palaeontology is full of unique