Metlapilcoatlus mexicanusMetlapilcoatlus mexicanus is a pit viper species endemic to Mexico and Central America.DescriptionImage:Atropoides-nummifer-2.jpg|left|thumb|240px|M. mexicanus, Dominical, Costa Rica. Adults grow to an average of 50–70 cm in total length. The maximum total length is for males and for females. The body is extremely stout.Geographic rangeFound in the Atlantic drainage from Mexico south to the Canal Zone in Panama, both slopes of Costa Rica and Panama. Occurs at elevations of. The type locality given is "Coban, capitale de la province de la Véra-Paz, ".TaxonomyRegarded as a full species, Metlapilcoatlus mexicanus, by Campbell and Lamar.