A creepy Mayan ballgame that turned dead people into the insides of rubber balls has fascinated researchers.
"The ballgame", as scholars call it, is thought to be one of the most important religious and cultural aspects of Mayan society, which began shortly after the start of the last millennium around 250 AD.
Although the rules of the game aren't known, scholars know that the game was played by two opposing teams on court shaped like the letter 'I', with a rubber ball, and is thought to have been a violent game, the Daily Beast reports.
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Players would wear protective gear to prevent injury, especially as the game was played between stone walls, and some have even theorised the losers of the game were sacrificed at the end - although most researchers don't believe this was an integral, or even common, part of the game.
It's likely, instead, that the people who died during the game were captives, or killed incidentally as the violent ballgame was played.
Plenty of courts have been discovered in ancient Mayan cities, and the game was played from modern-day Arizona and New Mexico to as far south as Colombia, uniting huge parts of Central and South America.
But a creepy discovery has led scholars to believe that "the ballgame" was far eerier than first thought.
In 2020 a team, led by archaeologist Juan Yadeun Angulo of Mexico's National Institute of Anthropology and History, discovered crypt dating back more than 1000 years beneath a Pyramid in Toniná in Chiapas, Mexico - one of many pyramids likely from the sixth or seventh overlooking a central plaza, where two ball courts were located.
Inside the crypt, the archaeologists discovered a maze of stairways and small chambers.
The team found about 400 vessels there that had once contained materials such as charcoal, ash, plant roots and natural rubber.
Angulo and his companions noticed that the materials that were kept there were similar to those needed for the vulcanisation - or hardening - of rubber, and they hypothesised that the ashes were the remains of cremated rulers.
Angulo believes the ancient rulers were turned to ash and used as an ingredient in the balls, and that this "transformation of the body" allowed rulers to be immortalised in ball form.
In the neighbouring site of Yaxchilán archaeologists discovered artwork carved onto sculptures there showing players throwing balls containing human captives, fuelling the theory that the balls contain human remains.
Some scholars disagree with Angulo's theory, saying more research is needed to connect the balls used in the game with the ancient rulers' ashes.