Called Cratonavis zhui, the strange hybrid died some 150 million years ago and was uncovered by paleontologists from the Chinese Academy of Sciences in Beijing. Cratonavis most likely behaved like a raptor, flitting from tree to tree and pouncing on prey with its sharp claws. It's a remarkable find that illustrates mosaic evolution, or the slow transition of some traits while others remain the same.
The evolutionary history of birds is nothing short of spectacular. The diversity of feathers, beaks, claws, diet and preferred geography is broad, not to mention the ability to majestically fly better than any other animal. But the differences between birds and dinosaurs are substantial, and experts still aren't entirely sure how this transition happened.
There are other features of the Cratonavis skeleton that are a bit strange. It has an atypically long shoulder blade, a bone called the scapula, as well as longer bones in the feet.
Evolution is a dynamic, not a logical process, and the transition from dinosaurs to birds involved dramatic changes in morphology — it didn't happen all in one single jump. For example, dinosaurs evolved feathers, which became a defining trait of birds, but feathers appeared millions of years before the necessary bone structures for flight. That marks another example of mosaic evolution.
