Mesoamerican ballgame many Caribbean islands including Cuba, Puerto Rico, and the West Indies, has been proposed as a descendent of the Mesoamerican ballgame, perhaps through the Maya. Mesoamerican ballgame The Mesoamerican ballgame was a sport with ritual associations played since 1400 BC by the pre-Columbian people of Ancient Mesoamerica. The sport had different versions in different places during the millennia, and a newer more modern version of the game, "ulama", is still played in a few places by the indigenous population. The rules of the game are not known, but judging from its descendant, ulama, they were probably similar to racquetball, where
Mesoamerican calendars menstrual period and birth, unlike Naegele's rule which is 40 weeks (280 days) between the "last" menstrual period and birth. It is postulated that midwives originally developed the calendar to predict babies' expected birth dates. A third theory comes from understanding of astronomy, geography and paleontology. The mesoamerican calendar probably originated with the Olmecs, and a settlement existed at Izapa, in southeast Chiapas Mexico, before 1200 BCE. There, at a latitude of about 15° N, the Sun passes through zenith twice a year, and there are 260 days between zenithal passages, and gnomons (used generally for observing the path of