Saturday, July 17, 2010
Creature Feature: Lizard Week- Komodo Dragon
I just got back from a 3-D movie about Sue, the world's largest most complete T-Rex skeleton. It rocked harder than the animatronic dinosaurs did. Besides a bunch of other awesome thunderlizards, the movie mentioned a sort of prehistoric varanid lizard that threatened Sue's eggs.
Strangely, this week had yet to touch varanid lizards (AKA monitors). These are the lizards that look like dragons (unlike the agamids dubbed "dragons" by goodness-knows-who), with long necks, forked tongues, and a largely carnivorous diet.
The Komodo Dragon is the world's largest extant lizard. As its name implies, it is native to only a few Indonesian islands (Komodo among them). There are a number of theories surrounding its abnormally-large size, including insular gigantism and the Komodo being a living fossil. Its diet consists entirely of meat, whether it be living or dead flesh.
The Komodo, like the T-Rex, is not only a large predator, but a lazy one; it feeds primarily on carrion. Several experts have suggested that the T-Rex, too, was mainly a scavenger, even though it could take large chunks out of living prey as well.
THIS is how you film a Komodo Dragon HUNTING, Animal Planet!
In part because of its scavenging diet, the Komodo Dragon's jaws are filled with virulent bacteria. Some venom has been found in Komodo jaws as well, leading experts to wonder which is the real culprit. The venom contains anticoagulants and other things to, perhaps, make the bacteria's work easier. A single bite will kill regardless, leaving the giant lizard to scavenge away at its new feast.
As if to add salt to the poisoned wounds, the scavenging Komodo's teeth are serrated like saws. If they lose one, it grows right back. Komodos do not chew their food; they tear it off in huge, bloody chunks.
Unless you saw the dragons actually KILLING this, assume it was scavenged.
The Komodo Dragon has one more, far more bizarre trick up its sleeve: Should the need arise, the female can give birth to all-male babies without the aid of a male. This is because they, unlike mammals, have been blessed with the ZW sex chromosomes.
They have two different letters than we do. So what? Shouldn't parthenogenesis lead to clones? Like, exact clones?
Not so in the case of ZW species. The Z is the male and the homozygote in Komodo dragons. When two of a female's egg's fertilize each other, ZZ is inevitable (WW is deleterious). This leads to all of the offspring being male. More on that here.
It also makes an excellent case for Raptor Jesus.
This is sounding more and more likely. Also, check out the poppies in that picture...