The Caudipteryx fossil
Caudipteryx has enlarged, more bird-like, feathers on its hands and tail tip than Sinosauropteryx. They may have played a role in courtship, but might also have enhanced mobility and stability in a two-legged runner. It's certainly clear that Caudipteryx couldn't fly: its arms were far too short and its flight feathers far too small to support its body weight. Moreover, the "flight" feathers in Caudipteryx were like those of today's non-flying birds, with straight shafts and symmetrical vanes.
THE GEOLOGICAL MUSEUM OF CHINA