By THE PULSE NEWS MEXICO STAFF     The National Anthropology Museum in Mexico City’s Chapultepec Park opened an exhibition on pre-Columbian Gulf of Mexico cultures on Wednesday, Jan. 30. The exhibit, composed of 1,354 pieces, covers a variety of pre-Hispanic societies, from 1600 B.C. up until the 1518 Spanish Conquest, when it is believed that tat least 20 distinct cultures existed