High-status women often filed their teeth into points.
Outside of the Babylonian systems, the Mayans were probably the first civilization using the number 0 as a place holder. Afterwards Indian mathematicians started to use it as a mathematical value in computations.
Nobody knows how the Mayan Empire decayed. Well ahead of the Spanish came many of the great cities had already been abandoned and lay in ruins. There are a lot of hypothesized reasons ranging from drought and famine to overpopulation and climate change.
Mayans use a different calendars in order to track longer periods of time, and for the inscription of calendar dates. There are three Calendars: the 260-day long Tzolk’in Calendar referenced for the divination of the supernatural; the Haab’ Calendar, a 360-day long calendar with five “lucky” or “dark” days at the end (depending on interpretation) to make 365 days; and the Long Count Calendar, which measures longer periods of times and contains the mystical “zero date”. None of them predicted the world would end in 2012.
The Mayan Civilization had one of the most advanced writing systems (called hieroglyphics) of any ancient civilization and wrote on almost anything, including their buildings.