Ferrusquía-Villafranca, Ismael, Shelton P. Applegate, and Luis Espinosa-Arrubarrena. 2018. “First Paleogene Selachifauna of the Middle American-Caribbean Antillean Region, La Mesa De Copoya, West-Central Chiapas, Mexico—Geologic Setting”. Revista Mexicana De Ciencias Geológicas 17 (1):1-23. https://rmcg.geociencias.unam.mx/index.php/rmcg/article/view/1014.