GILA MONSTER

(Heloderma suspectum), one of only two species of venomous lizards, both of the family Helodermatidae and both similar in appearance and habits. The Gila monster was named for the Gila River Basin and occurs in the southwestern United States and northern Mexico. It grows to about 50 centimetres (about 20 inches), is stout-bodied with black and pink blotches or bands, and has beadlike scales. Its relative, the Mexican beaded lizard (Heloderma horridum), is slightly larger (to 80 cm) and darker. During warm weather the Gila monster feeds at night on small mammals, birds, and eggs. Fat stored in the tail and abdomen at this time is utilized during the winter months. Both species of Heloderma are sluggish in habit, but they have a strong bite. Most of the teeth have two grooves that conduct the venom, a nerve poison, from glands in the lower jaw. Fatalities to humans are rare.