When dinosaurs gave way to the birds

In the autumn if 1995, I spent several days in Beijing's Institute of Vertebrate Palaeontology and Paleoanthropology, working on a story about dinosaur hunting. Though I heard tales of finding dinosaur bone beds, and saw fossils including a stegosaur tail club casually left on a sofa, my greatest surprise came as a professor offered to show me some new discoveries.

Weeks earlier, a new bird fossil from China had become world news. Known as the "holy Confucius bird", it was said to be almost as old as the first known bird, Archaeopteryx, but differed partly as its beak had no teeth. Just eight specimens of Archaeopteryx were known since the first was discovered in 1861, and this was only the second kind of bird from the Jurassic.

So I was startled when the professor took me to his room, opened a small box, and showed me another Confucius bird. Then he reached onto his shelves, and took down two new Jurassic bird fossils - one of which was the size of a warbler with a ridge along its breastbone indicating it was a far better flier than Archaeopteryx or the Confucius bird. Elsewhere in the institute, a technician was preparing another Confucius bird specimen, meticulously removing fine-grained rock to expose tiny bones, and feathers.

The professor, Hou Lianhai, had previously studied thousands of recent bird fossils from Zhoukoudian , the Peking Man site. With these new discoveries, he was shifting focus to what has proved to be one of the world's greatest fossil areas, yielding specimens including feathered dinosaurs and early birds.

The fossil beds are in Liaoning province in the mainland's northeast. Here, during the age of dinosaurs, the climate was temperate, and the landscape was dotted with lakes: excellent conditions for a rich variety of creatures. Volcanoes in Inner Mongolia sometimes erupted, showering the area with fine ash that preserved plants and animals in astonishing detail.