Bird display both clearly traditional reptilian characteristics: teeth, clawed fingers, and a long, lizard-like tail, as well as wings with flight feathers similar to those of modern birds. It is not considered a direct ancestor of birds, though it is possibly closely related to the true ancestor. The earliest known avialan fossils come from the Tiaojishan Formation of China, which has been dated to the late Jurassic period (Oxfordian stage), about 160 million years ago. The avialan species from this time period include "Anchiornis huxleyi", "Xiaotingia zhengi", and "Aurornis xui". The well-known early avialan, "Archaeopteryx", dates from slightly later Jurassic rocks
Specimens of Archaeopteryx Pohl, who was able to find an anonymous donor willing to offer up the funds. After an initial period of display and scientific study in Germany, the specimen would then be given to the WDC on a long-term loan. After a period of research (Mayr et al. 2005, 2007), the fossil was transferred to the Wyoming Dinosaur Center of Thermopolis, Wyoming, where it has remained since June 2007. The export out of Germany of this specimen—widely considered to be one of the best "Archaeopteryx" fossils known—has caused some concern among German paleontologists and the public. Though no formal legality was