Claim: Porthidium nasutum (horned hog-nosed viper) inhabits the Atlantic lowlands from Mexico, in the Pacific lowlands, it occurs in southwestern Costa Rica.
Evidence: Common names: rainforest hognosed pitviper, horned hog-nosed viper. Inhabits the Atlantic lowlands from Mexico (Tabasco and Chiapas) through Belize, Guatemala, Honduras, Nicaragua and Costa Rica to eastern Panama and northwestern Colombia. In the Pacific lowlands, it occurs in southwestern Costa Rica, central and eastern Panama, continuing on to northwestern Ecuador.