Therianthropes have been found through history in many cultures, legends, and myths. Almost every culture has them somewhere. The Eygyptions had a lot of them. The classic Werewolf myth comes from 1800's europe. The japanese have their kitsune and others, The native American have the skinwalkers, the Canadians have windigo (or wendigo), And so on.
Strangely enough, the Internet, information outlet as it is, has a lot of duplicated, outdated, or simply incorrect information. Plus, on something that most people take personally, opinion differ greatly. It's like the old joke, if you ask twelve different were creatures what their take on it is, you'll get twelve different answers. The sole commonality among them is that a transformation is involved somewhere along the line, either spiritual, mental, or physical. Probably the most complete source I saw was (I say was, as It's now offline) The Shapeshifter and Were-Wolf Handbook. It at least had the best collection of links out there. Now all that's left is probably google or one of the other search engines.
If you are looking for material for a paper (school or collage), I have some factual links here which may be of some assistance. or at least as factual as one can get when talking about this topic.