Lincoln Park Zoo

Common name: Mexican beaded lizard
Latin Name: Heloderma horridum

Class: Reptiles & Amphibians
Order:    Sauria

Description
30 inches from head to tail, the Mexican beaded lizard's head is broad and flat with poison glands at the lower jaw. Body is long and heavy, but not quite as stout as that of the gila monster. Scales are bead-like and form a pattern of yellow and black stripes; one subspecies is completely black.

Range
Throughout western Mexico

Status
Protected under the Convention on International Trade in Endangered Species.

Habitat
Found in dry, open forests with abundant rocks and sparse vegetation. Burrows to avoid the midday heat.

Niche
Carnivorous: eats insects, spiders, other small invertebrates, lizards, snakes, rodents, birds and eggs. Primarily terrestrial. They are frequently found in abandoned mammal burrows and near sources of permanent water. Preyed upon by large mammals and birds of prey.

Life History
Mating occurs mostly in the spring. Between 3-13 eggs laid in mid-to-late summer and buried in sand at a depth of about 5 inches. Incubation is 117-130 days.

2

Special Adaptations

  • Paired salivary glands produce a venom injected through a groove in the teeth that paralyzes prey.
  • Must chew their victim in order to inject poison.
  • The tail is used to store energy for times when food is scarce.
  • Long claws are used for digging.
  • Tongue used as a sense organ.