The subject has come up often, on all the artifact forums, over the years. This earlier thread we are currently posting to is one of the more informative dealing with the subject on TNet...
I found another informative post, by someone whose opinion I really value, and he has done some research on the subject. Unfortunately, it is located on a different forum, and I believe it is frowned on to post links to other artifact forums. Too bad, he did his research....
A couple of things are generally accepted. Flint thunderbirds have been faked since about the 1880's. Also often cited by collectors is the fact that flint thunderbirds have never been found in a controlled archaeological excavation in North America. That is often cited by collectors to support their doubts. It is often stated that archaeologists working in North America regard them as fake. I'm not judging these statements, just noting them, as flint thunderbirds, like flint fishhooks, are common fakes, and archaeologists regard them as fakes. FWIW.....
When somebody finds one, in non-suspicious circumstances, diplomacy is in order....
