Spencer's Monitor aka Spencer's Goanna (Varanus spenceri), STANCED!!!, family Varanidae, Australia
photograph by Rob Sorrentino
I've seen 19th century taxidermy made by people who had never even been on the same continent as a monitor lizard, let alone seen how one is able to move, that looks more realistically posed than this thing. Monitors have a shape and we cannot quantify what shape that is.
this is actually a VERY good question and it's related to several interesting pieces of monitor lizard anatomy!
- The throat is doing that because monitor lizards are in possession of an expandable pharyngeal space, also known as the gular pouch. In laymen's terms, it's a throat balloon. They can inflate this structure as part of their threat displays, and it's also related to the gular pumping that occurs as part of their respiration. (I'll spare you the details but the way lizards breathe is weird.)
- The neck is doing that because arching the neck is also part of the threat display- it's thought that it makes the gular pouch look bigger and helps prime the neck muscles for a quick lash-out and bite.
- The legs are doing that because the classic monitor "I am going to fight you now" pose involves getting as tall as possible. Monitors, like all lizards, have highly mobile shoulder joints and a sprawl stance, and we're used to seeing them in that sprawl position. But their limbs are much longer than we give them credit for! They just can't... walk... when they're doing this. Which is why this is the "I am going to fight you now" pose and not the "I'm going to run away from you very, very fast" pose.
- The tail is doing that because it's a weapon. Both ends of the monitor are sharp and can do some damage, but their first defense is usually to lash out with the tail... because their brain isn't in it. When a lizard bites, it's exposing its head to a potential threat. But if the threat goes for their tail? Way less dangerous. In some species (not monitors), they can even drop the tail and are more likely to escape. Cocking the tail like that is what you see before it hits you. To do that, the tail has some extremely powerful muscles at its base; at the tip, it's just bone, connective tissue, and hard scales. Kind of what you'd expect at the tip of a whip.








