Birds evolved from dinosaurs

All birds evolved from the raptor family of therapod dinosaurs.

AnswerPossibly none. Birds do have many features in common with theropods (bipedal carnivorous dinosaurs) which suggests that they had a common ancestor. We dont know that this common ancestor was a dinosaur though. It may well have been a bird (see related links).

Looking back in time through the theropod fossil record, these dinosaurs appear to be more bird-like the further back in time you look. Raptors are known to have had feathers and were fairly bird-like, but Archaeopteryx was much more bird-like and lived much earlier and may have been an ancestor of the raptors. There is also a controversial fossil called Protoavis that was dated even earlier and was more bird-like still, with hollow bones like modern birds.

So birds may have been around throughout the mesozoic era and pre-date the dinosaurs. We have little record of them though because their hollow bones mean that few fossils survive to the present day.