One smoggy afternoon in the summer of 2010, I took a walk down Xi Zhi Men Wai Avenue in Bejing. The ten-lane thoroughfare was packed with cars, buses, pedalos, and bicycles. But even here, in China's hyperurbanized core, there were birds to keep me company. Sparrows shot around the roadside trees. Black and white magpies perched in the treetops, issuing their rattling calls. I was walking down Xi Zhi Men Wai Avenue to pay a visit to a museum, where I could take a close look at the fossilized remains of some ancient cousins to the magpies. I was going to see some feathered dinosaurs.
Feathers are one of the marvels of animal evolution--a combination of extreme beauty and extreme usefulness--but for over a century their fossil record stopped with the 145-million-year-old Archaeopteryx. It was a mix of bird anatomy such as wings and older vestiges of a reptilian origins, ...
