CAMPECHE, MEXICO—Mexico News Daily reports that a digital reconstruction of a charcoal mural discovered inside a cave-like, arched vault at the Maya site of Calakmul has revealed early examples of calendrical writing. Daniel Salazar Lama of Mexico’s National Institute of Anthropology and History (INAH) said that the mural shows Juun Ajaw, one of the mythical Maya hero twins, hunting a creature in water. A symbol corresponding to a day marker in …