Megalania (Wikimedia Commons).


Megalania (Greek for "giant roamer"); pronounced MEG-ah-LANE-ee-ah


Plains of Australia

Historical Epoch:

Pleistocene-Modern (2 million-40,000 years ago)

Size and Weight:

Up to 25 feet long and 2 tons



Distinguishing Characteristics:

Large size; powerful jaws; splayed legs


About Megalania

Aside from crocodiles, very few prehistoric reptiles after the age of dinosaurs achieved enormous sizes--one notable exception being Megalania, also known as the Giant Monitor Lizard.

Depending on whose reconstruction you believe, Megalania measured anywhere from 12 to 25 feet from head to tail and weighed in the neighborhood of 500 to 4,000 pounds--a wide discrepancy, to be sure, but one that would still put it in a heftier weight class than the largest lizard alive today, the Komodo Dragon (a relative lightweight at "only" 150 pounds). See a slideshow of 10 Recently Extinct Reptiles

Even though it was discovered in southern Australia, Megalania was described by the famous English naturalist Richard Owen, who in 1859 also erected its genus and species name (Megalania prisca, Greek for "great ancient roamer"). However, modern paleontologists believe that the Giant Monitor Lizard should properly be classified under the same genus umbrella as modern monitor lizards, Varanus. The result is that professionals refer to this giant lizard as Varanus priscus, leaving it to the public to wield the "nickname" Megalania.

Paleontologists speculate that Megalania was the apex predator of Pleistocene Australia, feasting at leisure on mammalian megafauna like Diprotodon (better known as the Giant Wombat) and Procoptodon (the Giant Short-Faced Kangaroo). The Giant Monitor Lizard would have been relatively immune from predation itself, unless it happened to spar with two other predators that shared its late Pleistocene territory: Thylacoleo, the Marsupial Lion, or the Quinkana, a 10-foot-long, 500-pound crocodile.

(Given its splay-legged posture, it seems unlikely that Megalania could have outrun more fleet-footed mammalian predators, especially if these furry assassins decided to gang up for the hunt.)

One interesting fact about Megalania is that it's the largest identified lizard ever to have lived on our planet. If that makes you do a double-take, remember that Megalania technically belongs to the order Squamata, placing it on an entirely different branch of evolution than plus-sized prehistoric reptiles like dinosaurs, archosaurs and therapsids. Today, Squamata is represented by close to 10,000 species of lizards and snakes, including Megalania's modern descendants, the monitor lizards.

Megalania is one of the few giant Pleistocene animals the demise of which can't be traced directly to early humans; the Giant Monitor Lizard was probably doomed to extinction by the disappearance of the gentle, herbivorous, oversized mammals that early Australians preferred to hunt instead. (The first human settlers arrived on Australia about 50,000 years ago.) Since Australia is such a huge and uncharted landmass, there are some people who believe that Megalania still lurks in the interior of the continent, but there isn't a shred of evidence to support this view!

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Your Citation
Strauss, Bob. "Megalania." ThoughtCo, Jan. 24, 2017, Strauss, Bob. (2017, January 24). Megalania. Retrieved from Strauss, Bob. "Megalania." ThoughtCo. (accessed January 22, 2018).