On his NeuroLogica Blog, Dr. Steve Novella recently addressed creationist denial of transitional forms and provided a nice summary of a great little feathered dinosaur: Eosinopteryx brevipenna.
Eosinopteryx was just described in a January 2013 article in Nature Communications by Pascal Godefroit and colleagues. Eosinopteryx was a cursorial dinosaur, with bony teeth in its jaws and a long, bony tail, but it was also covered in short feathers, none of which show evidence of derived structure suitable for powered flight. With the fossil dated to about 140 million years ago, we have yet another example of an animal with apparently ancestral traits for a bird that appears later than Archaeopteryx. The phylogenetic bush that describes the evolution of birds is dense, and it will take more work and additional discoveries to identify its basal stem.