Found in a cave in Mexico in 2012, the 10th- through 13th-century bones may have been displayed in a ritual tower of craniumsA decade ago, a large, jumbled mass of human remains was found in a cave in Frontera Comalapa, a town in the southern state of Chiapas, Mexico, near the Guatemalan border. Given the state’s struggles with drug cartels, violent infighting, and reported human trafficking and forced prostitution, authorities opened up an investigation into the apparent gruesome crime. The results are finally in—and it turns out the cave wasn’t actually a crime scene. Instead, the 150 skulls found there...