The Mexican howler (Alouatta palliata mexicana) is a subspecies of the mantled howler, A. palliata. Its range includes southeastern Mexico and Guatemala. The Mexican howler is sympatric with the Guatemalan black howler, A. pigra, in Tabasco, Mexico. The Mexican howler differs from the golden-mantled howler, A. palliata palliata, primarily in aspects of skull morphology, and in some differences in pelage. The golden-mantled howler's range includes parts of Guatemala and Honduras, and it is not clear if the Mexican and golden-mantled howler's ranges currently are in contact.
^ abcdRylands, Groves, Mittermeier, Cortes-Ortiz & Hines (2006). "Taxonomy and Distributions of Mesoamerican Primates". In Estrada, A.; Garber, P.A.; Pavelka, M.S.M.; Luecke, L. New Perspectives in the Study of Mesoamerican Primates. pp. 50–51. ISBN978-0-387-25854-6.