Although the three species are all part of the reptile group of the Schuppenkriechtiere, but are only remotely related. They do not come from the same line of development, each species reinvented the ribs fly. "An amazing example of convergent evolution, " the researchers write. The shape of the flies differed significantly among the three reptiles. For example, Xianglong had wings that are sometimes similar to those of active flyers. The aerodynamic values were quite favorable, the researchers write.
The new fossil comes from a young and is excellently preserved: In addition to the extended ribs including the skin, the 9.5 centimeters long tail and the claws of the lizard are still clearly visible. They show that Xianglong was able to climb trees. The fossil comes from the famous Yxian Formation, where many feathered dinosaurs and mammals from the Middle Ages have been found.Pi-peng Li (Shenyang Normal University, China): PNAS, online pre-release, DOI: 10.1073 / pnas0609552104 Ute Kehse advertisement