While watching an episode of "The Quilt Show" online this afternoon, I saw a sort-of Zentangle© image that just floored me.
The episode guest was Susan Carlson, who makes fabulous fabric collage quilty creations. One of her most stunning pieces is a pink rhinoceros. When asked what her inspiration was for this piece, she showed a drawing made by Albert Durer. The drawing is dated 1515! Google "Durer rhinoceros" and you will see it - the link was too long and complicated to post here - not exactly a tangle, but the detail is so similar to some of the patterns in use now.