In the center of the monolith is the face of the solar deity, Tonatiuh,[REF] which appears inside the glyph for "movement" (Nahuatl: Ōllin), the name of the current era.
The top left square shows 4 Wind (Nahuatl: Nahui Ehēcatl'), the date on which, after 364 years, hurricane winds destroyed the earth, and humans were turned into monkeys.