Come on, people, we can clear this up right now! For years, designers and editors of articles and books about the Maya have mistakenly used the Aztec calendar round (the one with the face and four directions in its middle) to represent the Maya calendar. Not only is the physical appearance of the two calendar rounds different, but so were the Maya and Aztec calendar systems and the time spans represented in the graphics above (which, by the way, I found on the Museum of Belize facebook page [2]). For one excellent explanation of the difference between the two, and to learn more about why they are so often confused, read Master Mayanist David Stuart's book,The Order of Days: The Maya World and the Truth About 2012 (Harmony, 2011) [3]. In the meantime, study the graphic above, head out into the wild world of publishing to see if you can find the Aztec calendar erroneously labeled as Maya—then let the editor know.
Links:
[1] http://www.moon.com/files/blog-entry-images/558974_491664520877680_1309413841_n.jpg
[2] http://www.facebook.com/MOBNICH
[3] http://www.amazon.com/Order-Days-World-Truth-About/dp/0385527268