Monitor Lizard 15cm long x 6cm high
Monitor lizards also known as bayawak or goannas, genus Varanus, are members of the family Varanidae. Varanus is a group of carnivorous lizards which includes the heaviest living lizard, the Komodo dragon and the crocodile monitor which is the longest lizard in the world. The closest living relatives are the anguid and helodermatid lizards. Monitor lizards are generally large reptiles, although some can be as small as 12 centimetres in length. They have long necks, powerful tails and claws, and well-developed limbs. Most species are terrestrial, but arboreal and semi-aquatic monitors are also known. Almost all monitor lizards are carnivorous, although Varanus prasinus and Varanus olivaceus are also known to eat fruit. They are oviparous, laying from 7 to 37 eggs, which they often cover with soil or protect in a hollow tree stump.
Monitor lizards differ greatly from other lizards in several ways, possessing a relatively high metabolic rate for reptiles and several sensory adaptations that benefit the hunting of live prey. Recent research indicates that the varanid lizards, including the Komodo dragon, may have weak venom. This discovery of venom in monitor lizards, as well as in agamid lizards, led to the Toxicofera hypothesis: that all venomous lizards and snakes share a common venomous ancestor.
The Lace Goanna or Lace Monitor (Varanus varius) is the second largest Australian goanna and can grow to two metres. Its range is restricted to eastern Australia, where it is found from Melbourne in the far south all the way up to Cape York in the north.