CLASSIFICATION OF HELODERMA (GILA MONSTER)
PHYLUM :- CHORDATA (Notochord, dorsal tubular nerve cord present and gill slits present)
GROUP :- CRANIATA (Definite head. Cranium with brain present)
SUB-PHYLUM :- VERTEBRATA (vertebral column present)
DIVISION:- GNATHOSTOMATA (Jaws and paired appendages present)
SUPER CLASS :- TETRAPODA (Paired limbs, lungs, bony skeleton and cornified skin)
CLASS :- REPTILIA (Scaly vertebrates with right and left aortic arches. Single condyle, pulmonary respiration. Embryo with amnion and allantois).
SUB CLASS :- DIAPSIDA (Skull with two temporal openings separated by postorbital and squamosal).
ORDER :- SQUAMATA (Lizards and snakes with horny epidermal scales or shields. Quadrate bone movable. Vertebrae procoelous. Anal opening transverse).
SUB ORDER :- SAURIA (Lizards. Body slender, limbs 4. Pterygoid in contact with quadrate. Eyelids movable).
FAMILY :- HELODERMATIDAE (Poisonous lizard. Fleshy bifid tongue).
Genus :- Heloderma
Heloderma is found in deserts of Mexico and U.S.A.
HABIT AND HABITAT
Heloderma lives in dry places under rocks and in burrows. It is a clumsy, sluggish animal which feeds on snake eggs and lizards.
GENERAL CHARACTERSTICS OF HELODERMA (GILA MONSTER)
- Commonly called as Gila monster or Hella monster.
- Body measuring about 60 cm, is covered with ugly tubercles and divided into head, neck, trunk and tail.
- Body contains black and orange scales forming coloured patches. Dorsal scales are bead-like over bony tubercles (osteoderms). Ventral scales flat.
- Head is short, stout having eyes, nostrils and a wide mouth. External ear opening present behind eyes.
- Teeth pleurodont, fang-like and contain labial poison glands which open on outer ‘gum’ of lower jaw. Tongue is fleshy and bifid.
- Trunk and tail stout and rounded.
- Forelimbs and hind limbs are short, powerful and well developed. It is capable of swift movement. Digits are clawed.
- Heloderma lays eggs in the nest formed in sandy soil.
- Heloderma is the only poisonous lizard. The poison apparatus comprises of a modified sublingual salivary gland that secretes a poisonous fluid. Poison glands open on outer gum of lower jaw. Venom is potent; bite is fatal to small animals, and rarely to man.
- This lizard has bead-like scales, tubercles, coloured patches, stout trunk and above features, hence it is Heloderma.