CHINESE palaeontologists have found a downy dinosaur that could flap its long
front limbs like a bird. The discovery implies that the first birds evolved from
fast-running two-legged predators called theropods.
The key evidence lies in the sturdy shoulders of the new discovery,
Sinornithosaurus, says Xiao-Chun Wu of the Institute of Vertebrate
Palaeontology and Palaeoanthropology in Beijing. “[The joint] allows the arm to
go up and down for flapping. From this point we can easily go to a flying
animal,” says Wu. Other feathered fossils have shoulders built for moving the
limbs back and forth. Wu reports the find in Nature (vol 401, p
262).
