Chocolate is practically money

The Aztecs had bags of cacao beans that were used in trading, and also as a metaphorical reference for value. Due to their base-20 counting systems, they had bags with 400 beans (the Zontli) and bags with 8,000 beans (the Xiquipilli).

Charles R. Knight: The Artist Who Saw Through Time, by Richard Milner

It's a handsome coffee table book that covers the life and art of Charles Knight, known for his murals of dinosaurs and other prehistoric life. Somewhat loosely (dis)organized in parts, it's still quite a treat of text and images.

One of my favorite images from the book is not by Knight, but somewhat inspired by him... dinosaur statues floating on a barge on the Hudson River...
( on their way to the 1963 World's Fair )