Which came first, the chicken or the egg?

All the evidence we have indicates that birds are descended from dinosaurs. In the 1800’s Thomas Huxley noted that birds have skeletons that are almost identical to some dinosaurs, other than the beak, of course. There are some striking anatomical similarities.
But if I asked you to tell me what makes birds different from all other animals, I’m guessing you’d tell me feathers. So how can we say that birds are descended from dinosaurs? Where did the feathers come from?
Well, it turns out that there were feathered dinosaurs! How do we know? Because we’ve found fossils with feathers.
So we have critters that aren’t birds, but that have skeletons very similar to birds. With feathers. And of course reptiles lay eggs. As time goes on, they get less and less like reptiles and more and more like a bird, until we end up with something almost, but not quite, a bird. It laid an egg in which the final mutation had occurred, and from which the first bird hatched. So our answer is – the egg!
Or you could go to a restaurant and order two sandwiches, egg salad and chicken salad, and see which comes first. :P