I can't believe I didn't share this... This is one of my favorite videos. Hopefully everyone had heard of Trance Around the World... This one of the very few videos that made me kinda cry when I first saw it...
I saw that on the Science Channel Brain Games. Fascinating.
The brain is hard wired to make sense of anything that looks like a face (it doesn't matter what animal, the brain knows a face when it sees one), so even the concave, inside aspect of the dinosaur's face is regarded as convex and three dimensional despite the fact that it is nothing more than folded cardboard.