Mexican beaded lizard Mexican beaded lizard The Mexican beaded lizard ("Heloderma horridum") is a species of lizard in the family Helodermatidae, one of the two species of venomous beaded lizards found principally in Mexico and southern Guatemala. It and its congener (member of the same genus) the Gila monster ("Heloderma suspectum") are the only lizards known to have evolved an overt venom delivery system. The Mexican beaded lizard is larger than the Gila monster, with duller coloration, black with yellowish bands. As it is a specialized predator that feeds primarily upon eggs, the primary use of its venom is still a source of
Mexican Plateau horned lizard wide range of primary (dry scrubland, pine-oak forest, oak forest, juniper forest) and secondary habitats (agricultural land, and agave and "Opuntia" fields). Five subspecies of "P. orbiculare" are recognized as being valid, including the nominotypical subspecies. "Nota bene": A trinomial authority in parentheses indicates that the subspecies was originally described in a genus other than "Phrynosoma". The subspecific name, "cortezii", is in honor of Spanish "conquistador" Hernán Cortés. The subspecific name, "dugesii", is in honor of French-born Mexican naturalist Alfredo Dugès, who is considered the "father" of Mexican herpetology. Mexican Plateau horned lizard The Mexican Plateau horned lizard (Phrynosoma orbiculare)