|Name Meaning||Ancient great roamer||Length||4-7 meters (13.1-23 feet)|
|Pronunciation||Meg-ah-lay-knee-ah||Weight||100-1,940kg (220.5-4,277 lbs)|
|Era||Cenozoic – Quaternary Period||Location||Australia|
|Classification||Reptilia, Squamata & Varanidae|
The Megalania was a giant monitor lizard living in Pleistocene Australia.
It is now considered the largest known terrestrial lizard and an important piece of our world’s evolutionary history.
Considering its gigantism and hunting abilities, the Megalania may have been an apex predator in its habitat.
It was strong enough to subdue even the largest marsupials.
Besides its size, another distinctive characteristic of this species is the small crest located between the eyes.
Before diving into more details, we must mention that the Megalania term is now considered only a common name, and the creature is scientifically called Varanus priscus.
The Megalania snout was equipped with a distinctive crest similar to the one known in Varanus giganteus.
The snout also featured some osteoderms growing from the skin and extending to the nape of the neck, and the teeth were quite sharp.
The Megalania may have had a highly forked tongue like other monitor lizards and a long, thin tail.
In short, it resembled modern species, except that it was larger, and its body proportions were slightly different.
For example, the upper arm bone may have been remarkably wide at the far end.
Extant monitor lizards, on the other hand, have the far end of their upper arm bone just as wide as the near end.
Additionally, Megalania differed from the other Varanus species by the form of their teeth.
More precisely, they were more curved and replaced at a different frequency.
Many studies focused on establishing their size, which is by far the most distinctive characteristic of the species.
However, since complete skeletons are lacking, size estimations have never been confirmed.
Estimations based on the comparison between the Megalania and Varanus komodoensis show a length of 2.2–2.4 meters (7.2–7.9 feet), although these are average numbers and do not include the tail.
Other estimations suggest lengths of 2.6–2.7 meters (8.5-8.9 feet) and 4.5 meters (14.8 feet).
The tail would have added ½-⅓ of the Megalania’s body length.
As such, if an individual had a body length of 4.5 meters (14.8 feet), the tail would have added around 2-2.5 meters (6.5-8.2 feet), and the total length would be approximately 7 meters (23 feet).
However, since the morphology of the Megalania’s tail is unknown, these numbers may differ slightly.
The weight was initially estimated at 600–620 kilograms (1,323–1,367 pounds), then downsized to 91–158 kilograms (201-348 pounds), and later changed again to 575 kilograms (1,268 pounds).
Naturally, the proposed weight numbers depend on the proposed length numbers.
If a scientist argues that the Megalania measured only 4.5 meters (14.8 feet) and not seven meters (23 feet), the weight numbers would be lower.
Can you imagine that an estimation based on a 7-meter (23-foot) length resulted in a weight of 1,940 kilograms (4,277 pounds)?
In short, all these numbers are quite confusing, and, in the end, no one is sure how long the Megalania was.
There’s a noticeable gap between these estimations, and future paleontological findings are a must to satisfy our curiosities.
Habitat and Distribution
The Megalania was an inhabitant of Pleistocene Australia.
The best and most important Megalania material was discovered in Kings Creek, eastern Darling Downs.
The first known remains were recovered from the bed of a tributary of the well-known Condamine River, which drains the northern part of the Darling Downs.
Other fossils were recovered from New South Wales, South Australia, and other Queensland localities.
During the Pleistocene, our planet was marked by repeated glacial cycles that affected all parts of the world, including Australia.
The continent was already close to where it is today, and the sea levels were low, thus revealing land bridges between Tasmania and New Guinea.
Its climate shifted back and forth from cold, dry weather to warm, wet weather.
The sea levels typically fell once the cold, dry conditions (something known as icehouse) settled in.
Behavior and Diet
As you’ve probably already guessed, the Megalania was a terrestrial creature and probably a very capable predator.
In addition to its sturdy limbs and serrated teeth, the Megalania may have possessed toxin-secreting oral glands inside the jaw.
The glands released a potent venom containing haemotoxin that acted as an anticoagulant once in the bloodstream, thus increasing the bleeding rate of the wounds delivered by the Megalania.
At the same time, the blood pressure of the subdued prey would increase.
This, in turn, would lead to systemic shock.
If the Megalania possessed toxin-secreting glands, it would now be the world’s largest venomous vertebrate.
Studies suggest the Megalania may have held a major ecological role in Pleistocene Australia, filling a missing carnivore component of the continent’s megafauna.
While some suggest it was among the largest predators of the Australian megafauna or maybe even an apex predator, others disapprove of this theory.
The Megalania may have gone for medium- to large-sized prey.
The Megalania preyed on the Diprotodon, an extinct marsupial living in Pleistocene Australia.
Like the Megalania, the Driptodon was the largest of its kind, measuring 1.6–1.8 meters (5.2–5.9 feet) tall at the shoulder and 2.75–3.4 meters (9–11.2 feet) long.
This large marsupial is thought to have been quite difficult to subdue, so if the Megalania succeeded in doing this, it was undoubtedly a ferocious predator, and its venom was of much help.
Although it had enough qualities to be the strongest predator in its habitat, the Megalania was quite slow, reaching a sprinting speed of only 2.6-3 m/s, or 9.4–10.8 km/h (mph).
Don’t go to the next part yet, as we’ve got one more interesting thing to note about this reptile’s behavior!
If the Megalania did have the typical forked tongue seen in monitor lizards, then it used its tongue to smell the environment.
The tongue collected the air molecules and transmitted them to the reptile’s sensory organ! How fascinating is this?
As a monitor lizard, the Megalania was oviparous, meaning it reproduced by laying eggs.
As such, no embryonic development occurred within the female.
This creature laid between 7 and 38 eggs on the ground or in tree hollows.
If laid on the ground, the eggs were covered with soil.
Komodo dragons, which are most often compared with Megalania, are known to have adapted to parthenogenesis, a kind of asexual reproduction, although these cases are rare.
As such, we cannot rule out the possibility that the Megalania may have also engaged in this reproductive behavior.
Male Komodo dragons are also known to engage in fights over females and territories, while the females are known to resist mating, forcing the males to restrain them to make copulation possible.
The incubation period of Komodo dragons lasts between 7 and 8 months.
The hatchlings are born defenseless and, therefore, require adult help.
Unfortunately, although the Megalania is typically compared to the Komodo dragon in terms of physical characteristics and ecological role, it remains unknown how much of the Komodo dragon’s reproductive behavior applies to the extinct monitor lizard.
The growth rate and lifespan of monitor lizards also differ between species.
Since few studies mention anything on this aspect related to the Megalania, we cannot provide a clear answer yet.
Evolution and History
The oldest known member of the Varanidae family, which Megalania is part of, dates from China and Mongolia in the Late Cretaceous.
As such, Megalania’s ancestors probably date from that period.
The closest relative of the Varanus genus is the Archaeovaranus.
It dates from the Early Eocene, roughly 53 million years ago. It lived in East Asia, so it is now generally recognized that the members of the Varanus genus have Asian origins.
The earliest known fossils belonging to the Varanus genus were found in Europe and northern Africa. They date from the early Miocene.
The Varanus priscus species, also known as Megalania, was first described in 1859.
The description was based on three vertebrae discovered among several marsupial bones.
They had been recovered from eastern Australia, from the bed of a Condamine River tributary.
At first, however, the species was not called Varanus priscus.
The fossils were attributed to the Megalania genus, and the species was called Megalania prisca, which translates to the ancient great roamer.
Today, this genus is no longer recognized, and instead, the creature is known under the name Varanus priscus.
The specific name is the male form of prisca, inspired by the original species’ name.
Upon the discovery, scientists concluded that the Megalania lived roughly 1.5–0.04 million years ago during the Late Pleistocene.
Its extinction has been associated with the appearance of early human settlements in Pleistocene Australia.
Scientists came to this conclusion after studying the hindlimb muscles of varanids and how musculoskeletal stress affected their ability to move.
They concluded that larger lizards experienced an increase in musculoskeletal stress.
As such, the giant Megalania likely could not outrun its biggest predator, humans.
However, humans may have contributed only partly to the disappearance of these giant monitor lizards.
Interactions with Other Species
During the Pleistocene, Australia was home to large birds, reptiles, and mammals.
As such, the Megalania may have shared its habitat with the following creatures, many of which are still alive:
- Red kangaroos
- Eastern gray kangaroos
- Antilopine kangaroos
- More than 20 types of other now-extinct marsupials, including Diprotodon and Palorchestes
- Mammals like Obdurodon and Murrayglossus
- Common wombats
- Southern cassowaries
- Birds like Dromornis and Genyornis
- Saltwater crocodiles
- Freshwater crocodiles
- Turtles like Meiolania
- Crocodiles like Quinkana
While the territory was undoubtedly rich in large animals, there’s poor evidence confirming which of them interacted with the Megalania.
It has been suggested, though, that this giant monitor lizard preyed on medium- to large-sized animals, including large marsupials like the Diprotodon.
Since the Megalania is often seen as an apex predator in its habitat, it remains unknown whether it had any predators.
Nevertheless, the Quinkania crocodiles were also excellent predators and may have competed for the title.
The association between the Megalania and Aboriginal Australians is believed to have inspired the appearance of the fearsome mythological creature known as Whowie.
Supposedly, it resembled a monitor lizard, measuring approximately seven meters (23 feet) long.
However, it had six legs instead of four and a frog-shaped head.
The Whowie was so strong and ferocious that it could eat a whole tribe for a single meal.
This is not the only piece of culture that Megalaia served as inspiration for.
Many documentaries and books focus on describing this creature in detail.
Moreover, a Megalania skeletal reconstruction can be seen at the Museum of Victoria.
Additionally, Megalania can be seen in the following media productions:
- Mega Beasts
- Monsters We Met
- Jeff Corwin’s Giant Monsters
- Lost Tapes
- Jurassic Park Builder video game
- ARK: Survival Evolved video game
The Megalania is an important creature in the scientific universe as well.
Its discovery aroused the interest of paleontologists and scholars from around the world.
Considering that it may have been an apex predator in Pleistocene Australia, the discovery of the Megalania marked a turning point in understanding our world’s prehistory and how it shaped the fauna of today’s Australia.
Moreover, the Megalania may have been among the few creatures that interacted with the earliest human settlements.
Therefore, its importance in our world’s evolutionary history is indisputable.
The Megalania, scientifically known as Varanus priscus, was a giant monitor lizard living in Australia.
It was alive during the Pleistocene and probably went extinct approximately 40,000 years ago.
It is now regarded as the world’s largest terrestrial lizard, having filled an ecological niche similar to that of the extant Komodo dragon.
The Megalania may have been an apex predator in its habitat, especially if it possessed the venom known to other living monitor lizards.
Since many physical characteristics of this creature remain unknown due to limited fossil discoveries, we hope that future findings will shed light on other aspects of its appearance and lifestyle.
Did Megalania exist with dinosaurs?
In that case, the answer is no, because most dinosaurs went extinct approximately 65 million years ago, whereas the Megalania inhabited Australia much later.
However, we can safely state that it lived among dinosaurs on the Avialae lineage, meaning birds.