Yellow Spotted Monitor

Order:  Squamata (scaled reptiles)
Suborder:  Lacertilia (=Sauria) (lizards)
Family:  Varanidae (monitor lizards)
Genus:  Varanus (monitor lizards)
Also known as:  Yellow Spotted Goanna

Scientific Name:  Varanus panoptes

panoptes="all-seeing;" a reference to the eyelike spots on some specimens' backs

Habitat:  A variety of environments ranging from woodland to arid regions.

Length: About four feet total.
Food:  Insects and small vertebrates. Yellow Spotted Monitor Range

This monitor lizard (or "goanna," a corruption of the word "iguana") was leisurely crossing the road just north of Devil's Marbles Conservation Area in Northern Territory.  Unfortunately for me, it was at a bend in the road, and I didn't see it until I was VERY close to it, and I was traveling pretty fast.  In an effort to avoid running over the goanna, I swerved off the road and almost lost control of my car!  After regaining my composure, I returned to find the monitor departing the opposite side of the road (first picture), where it took refuge among the clumps of grass.

Goanna Crossing Road
At first, the goanna tried to lie motionless in the hopes that I wouldn't notice it (second picture).  Naturally, this was not the case.  As I approached closer, the lizard abruptly stood up high on all four legs, inflating its body and throat and sticking out its tongue to make itself appear more threatening (final picture).  After a few more seconds, it turned and ran back across the road on its hind legs. Goanna Hiding
This was the first wild lizard I found it Australia, and it was very exciting!  We don't have lizards this big in the United States! Threat Display
I had trouble identifying the particular species to which this goanna belonged, so I consulted Mr. John Fowler, who maintains the Reptiles of Australia web site along with John Hollister.  This species is easily confused with Gould's Monitor, also known as the sand goanna (Varanus gouldii).  In fact, there is still a debate over the actual identity of the "type specimen" of the sand goanna--it may actually be a yellow-spotted monitor!  This only adds to the confusion.  However, as Mr. Fowler notes, the sand goanna usually has a yellow tail tip, and the monitor I found did not, which means it is most likely a yellow-spotted monitor.  Many thanks to Mr. Fowler for his assistance!

Also, thanks to Michael Durbin for assisting with the etymology of the scientific name.