4-Winged Dinosaur or bi-plane
Microraptor gui (drawing in National Geographic), was shown to Mark Norell shortly after Gao Ke-Qin, Ji Qiang, and he had submitted a paper that was published in Nature magazine (under the heading, "Brief Communications") in 2002. Microraptor gui is important since this speciman is better preserved and has unquestionable distribution of long feathers on the hind legs. It also has potential for implications for the beginning of powered flight (Unearthing the Dragon, p. 191).
The 2002 Nature article speciman [not shown and is nicknamed "Chong" and also is referred to as the "four-finger theropod" due to misinterpertaion of a feather impression as a fourth finger (p. 188)] has distinct feathers, but it is hard to interpret due to the arms being folded back across the body. While a process of tracing out every single feather led to the conclusion that "long feathers were present both on the fore and hind limb" (p. 189), there were several paleontologists who questioned the presence of the distribution on the hind limb.
Viewing of new specimens, including Microraptor gui (shown above), removed that question with strong evidence of feathers on the hind limb as is evident in the photo above. Norell was shown the new fossils by Xu Xing at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. (related information on fossils in China)
The Microraptor gui specimen were from a closely related animal similar to "Chong," but from a formation (Yixian - between 130 and 110 million years ago which is Early Cretaceous age) which is a few million years older. "Dave" has the suggestion of modern aspect feathers. Both "Chong" and Microraptor gui specimen have conclusive evidence of modern aspect feathers.
The fossil speciman is now on exhibit in the new dinosaur exhibit at the American Museum of Natural History, New York that opened on May 14, 2005. These photos are from the members preview and reception on May 13, 2005. Much of the data is from Liaoning Provice in northeast China. Mark Norell's book, Unearthing the Dragon, gives details not only about current thinking regarding dinosaurs, but also about the meeting of the American and Chinese cultures in the process of science.