“…Archaeological bitumen samples were acquired from Early Preclassic contexts at eight Olmec sites e El Remolino, El Azuzul, Isla Alor, Loma del Zapote, Paso los Ortices, San Lorenzo, El Macayal, and La Nueva Abundancia (Fig. 1, Table 2) [7e 10,32,33,39,41,42].…”