I've seen birds. Isn't Archaeopteryx "just a modern bird?"
Aside from the fact that it had feathers, we do not know what it was. While feathers are the distinguishing characteristic of modern birds, we cannot say that Archaeopteryx was a bird. We cannot even say whether it could fly or not. Modern birds have quite a few adaptations for flight such as totally different lungs from all other animals and very light bones. We have no evidence of such in Archaeopteryx. Further, to put Archaeopteryx in the line of descent of birds is pretty desperate of evolutionists considering that while we have found many examples of Archaeopteryx, we have not found any examples of anything which could be considered its predecessor, nor anything like it for some 50 million years afterwards. So it is no proof of evolution at all.