In the past discussions on Bigfoot, few have noticed the disappearance of the prognathism. The head and nose changed too, and the entire profile of the face changes with the vanishing of the projected lower facial features.
Patterson noted that one of the first articles that got him into the hunt for Bigfoot was by Ivan T. Sanderson. The cover art on that article shows the William Roe case, illustrated by Mort Künstler. Roger Patterson copied the art closely and then published Sanderson’s entire article in Patterson’s book. Many have commented on how the Künstler-Patterson art mirrors the P-G film Bigfoot.
I think the key is the changed face.
March 28, 2013
but here is some meta-analysis of changing portraits of Bigfoot over the years, by cryptozoologist Loren Coleman.