Thursday, July 16, 2015

Another 'Missing Link' Between Dinosaurs and Birds

the skull shows teeth of Zhenyuanlong
Dragons exist in legend and myth, but scientists in China have found a six-foot adolescent dragon that actually lived 125 million years ago. A nearly perfectly preserved siltstone fossil contains the detailed remains of an ancestor of Velociraptor that had wings. Because the wings are relatively small it is not likely the dinosaur named Zhenyuanlong suni (Zhenyuan's dragon) could fly, but it had carnivorous teeth and undoubtably could rapidly chase prey on its long legs. One scientist called the find the "most beautiful fossil [he] had the privilege to work on." It was originally discovered by a farmer who donated it to the Jinzhou Paleontological Museum. Investigators say the fossil is rare compared to other dromaeosaurids found in Liaoning Province, northeast China due to its large body size and tiny forearms. Most other dromaeosuarids found to date, such as Microraptor, are the size of a domestic cat. The results of a scientific collaboraton between the University of Edinburgh and the Chinese Academy of Geological Sciences are reported in the journal, Scientific Reports.

artist Z. Chuang
Early critics of Darwin & Wallace pointed out that evolution was not supported by the developing fossil records of the time because they did not reveal intermediate species expected if the theory was accurate. Since then many intermediate fossils have been found and studied. This spectacular piece of limestone is one such find. It shows a dramaeosaurid on the cusp of becoming something entirely different--a bird. Feather impressions are clearly visible in the fossil and cover the animal's body as well as forelimbs that eventually evolved into functional wings. Forelimb and tail feathers are true pin feathers--coverts, primaries and secondaries--used by modern birds for flight. This latest find from the epicenter of palentology, Liaoning Province, is as important as the discovery of Archaeopteriyx, the first complete ancient bird fossil ever found. It is generally thought that Archaeopteriyx could fly or glide short distances.  Biomechanical analysis of Zhenyaunlong's dragon is necessary before a definitive conclusion on its ability to fly is reached.