India, Jan. 31 -- If we could wander through a Jurassic Age forest from 160 million years ago, at least a few species would seem oddly familiar (and no, not from the movies).

Amid the strange undergrowth, we would see small, raptor-like dinosaurs (some as little as 2 ft tall) scurrying around, covered in fuzzy coats. With their slender bodies, three-toed feet and curved claws, these dinosaurs mark the point in evolutionary history where the story of birds begins.

Over the next 70 million years, the fuzzy filaments would evolve into complex feathers; tails would shrink; arms would widen into wings; snouts would narrow and curve into beaks; bones would lighten; teeth would fall away; diets would change. oh, it would take so much, before t...