I know someone who is a Thiffault and has done extensive research and has a huge database of Thiffeaults. He says there are 30 or so different spellings and all Thiffeaults and their different spellings are all linked to one of two brothers who came from France. No other Thiffeault lines survive in France. If you would like contact information please let me know and I can pass it along for you. He and his wife travel across Canada and the U.S. in serch of relatives, and I think also have travelled overseas looking for more information