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 beaded lizard is used to store fat so it can survive during months of estivation. Unlike many other lizards, this tail does not autotomize and cannot grow back if broken. The beaded lizard has a forked, pink tongue which it uses to smell, with the help of a Jacobson's organ; it sticks its tongue out to gather scents and touches it to the opening of the organ when the tongue is retracted. Beaded lizards are found in the Pacific drainages from southern Sonora to southwestern Guatemala and two Atlantic drainages, from central Chiapas to southeastern Guatemala. Their habitats are primarily in the