Illustration of Australian aborigine confronting Megalania.
The other day, I labored for hours cleaning out a closet and in the process discovered an old issue of Scientific American that featured an article about Komodo dragons. Few people are aware of a now extinct Pleistocene relative of Komodo dragons that formerly dominated the continent of Australia. Even scientists know little about Megalania priscus (the giant ripper lizard) because a complete skeleton has yet to be found, though disarticulated remains have been recovered from south Australia, New South Wales, and Queensland, proving that it was a widespread top predator on the continent during the Pleistocene. This monster grew up to 18-23 feet long and a full grown adult weighed between 800-1200 pounds. It would have easily destroyed and consumed any of the Australian megafauna, such as diprotondontid (a marsupial rhino), giant kangaroos, and marsupial lions.
Megalania became extinct about the time man appears in Australia’s archaeological record 40,000 years ago. The extinction of Australia’s megafauna is closely tied to man–both overhunting and anthropogenic fires disrupted the ecology of the continent. Fortunately, for scientific knowledge, the Komodo dragon still survives on a few islands in Indonesia, and because it’s a close relative, it affords us an otherwise impossible opportunity to understand how megalania survived.
Komodo dragons (Varanus komodoensis) are a member of the varanid family of lizards which includes monitor lizards from Africa and goannas from Australia. The varanid family is more closely related to snakes than other lizards are, and they’re probably close cousins to the aquatic mosasaurs that swam the Cretaceous seas off Georgia’s coast. The varanid lizards first evolved late in the Eocene. During the latter part of this era and throughout the Oligocene, monitor lizards even colonized North America, where it’s possible an undiscovered extinct species as large as the Komodo dragon may have lived in Georgia, but the paucity of land fossil sites in state may keep our knowledge of such a species in the dark.
Giant ripper lizards were much larger and bulkier than Komodo dragons, and they had better vision, but otherwise were similar Most of the following interesting facts, gleaned from the rediscovered issue of Scientific American about Varanus komodoensis, were probably true for megalania as well.
–Komodo dragons grow up to 6-9 feet long and up to 300 pounds, making them about 1/3 the size of megalania.
–They may have evolved their large size as an adaptation to hunt the now extinct pygmy elephant (stegodon) that used to live on isolated Indonesian islands.
–Komodo dragons hunt deer, wild boar, water buffalo, feral goats, and other Komodo dragons. This cannibalism keeps juveniles in the trees most of the time because adults are too heavy to climb.
–They have poor vision and are only able to hear sounds in the 400-2000 hertz range compared to the human ability to hear sounds in the 20-20,000 hertz range. This means they can’t hear low sounds or high pitched screams. Instead, Komodo dragons find their prey with their long forked tongue which along with their Jacobson’s organ helps them locate potential meals.
–Komodo dragons are ambush predators, staying still in heavy brush until their prey practically stumbles upon them. Then, they rush their victims, bowl them over, and go for the neck. Formerly, scientists believed the fifty kinds of toxic bacteria that infest their saliva facilitated the deaths of their intended meals, because oftentimes a deer or buffalo will regain footing and run away, but die of septic shock within days while the lizard follows it around. But a recent study by Australian scientist, Bill Fry, discovered that Komodo dragons actually have poison glands. (Megalania also had poison glands.) Dr. Fry compared the biting power between Komodo dragons and salt water crocodiles and determined that the former has relatively weak jaws, like saber-tooth cats. When they bite, Komodo dragons use their powerful bodies to pull and tear, causing damage, also like saber-tooth cats. The injection of an anti-coagulant poison keeps the blood from the gaping wound from clotting, and the prey animal dies from loss of blood. The low blood pressure keeps them from escaping, as the animal usually lays down and goes into shock.
–Komodo dragons can eat up to an incredible 80% of their body weight in one sitting, and they’re able to unhinge their jaws like snakes (and mosasaurs) to help gobble down their meal. They eat the whole animal, abstaining only the feces within the intestines which they vigorously shake loose.
–Komodo dragons can go for as long as 8 months without water, and they mostly drink from hog wallows.
–Reptiles have lower metabolism than mammals. This gives Komodo dragons a competitive advantage over mammalian carnivores on islands because they can survive in an ecosystem with lower prey densities.
–Komodo dragons battle over mates by biting and pushing up against each other. They have forked penises known as hemipenes. When they mount a female from her left hip, the right fork is inserted and vice versa.
–The European legend of the dragon is likely not based on this species for it wasn’t discovered by Western science until 1910. Legends of dragons in western culture are probably based on the existence of dinosaur fossils for which they had no logical explanation.
–I have two words for cryptozoologists’ claims that megalania still exists: No Way. There’s no way an 18 foot lizard with a poisonous bite could still exist in our modern overpopulated world without people knowing about it.
Scientific American March 1999
Fry, B. et. al (2009) “A central role for venom in predation by Varanus Komodoensis (Komodo dragon) and the extinct giant Varanus (megalania) prisca.” PNAS 10.1073/pnas.0810883106