Megalania

*Varanus priscus*

### Name Means

"Great roamer (common name/former generic name) Ancient Monitor lizard/Lizard beast (specific name) Ancient Great roamer (former specific name) Monitor lizard/Lizard beast (generic name)"

### Time

Pleistocene (Calabrian to Tarantian), 1.5-0.04 Ma

### Taxon

Squamata,Varanidae, Varanus

***Megalania*** is an extinct large monitor lizard that lived in Australia during the Pleistocene Epoch, about 2.5 million years ago. The massive reptile was about 23 feet (7 meters) long, the size of a Saltwater Crocodile, the largest reptile alive today, making it the largest lizard of its time. It also had a venomous bite just like its relative, the Komodo Dragon.

## Taxonomy

Sir Richard Owen described the first known remains of Megalania in 1859, from three vertebrae amongst a collection of primarily marsupial bones purchased by the British Museum, collected from the bed of a tributary of the Condamine River, west of Moreton Bay in eastern Australia.

### Naming confusion

The name *Megalania prisca* was coined by Sir Richard Owen to mean "Ancient Great Roamer." A name he made "in reference to the terrestrial nature of the great Saurian" . To do this Owen used a modification of the Greek word ἠλαίνω *ēlainō* ("I roam"). The close similarity to the Latin word: *lania* (birdsfemine form of "butcher"), resulted in numerous taxonomic and popular descriptions of *Megalania* mistranslating the name as: Ancient Giant butcher.

### *Megalania* vs *Varanus*

*Megalania prisca* was originally classified in its own monotypic genus. Its status as a valid genus remains controversial, with many authors preferring to consider it a junior synonym of *Varanus* , which encompasses all living monitor lizards. As the gender of the genera *Megalania* and *Varanus* are different (feminine and masculine, respectively), the epithet *prisca* changes to *priscus* (in alignment with the Code of the I.C.Z.N.)

## Size

The lack of complete, or nearly complete fossil skeletons has made it difficult to determine the exact dimensions of *Megalania*. Early estimates placed the length of the largest individuals at 7 metres (23 ft), with a maximum weight of approximately 600–620 kilograms (1,300–1,400 lb). However, more recent and more rigorous studies give very different results from one another.

In 2002, Stephen Wroe determined that *Megalania* had a maximum length of 4.5 metres (15 ft) and a weight of 331 kilograms (730 lb), while its average length would have been around 3.5 metres (11 ft), and mean body weight would have been between 97–158 kilograms (210–350 lb). He concluded that the earlier estimates reaching lengths of 6 metres (20 ft) or more and a weight of several tons were exaggerations based upon flawed methodologies.

However, Ralph Molnar  in 2004 determined a range of potential sizes for *Megalania* (made by scaling up from dorsal vertebrae, after he determined a relationship between dorsal vertebrae length and total body length). If it had a long thin tail like the Lace monitor (*Varanus varius*), then it would reached a length of 7.9 metres (26 ft), while if its tail-to-body proportions were more similar to that of the Komodo dragon, then a length of around 7 metres (23 ft) is more likely. Taking the maximal 7 m length, he estimated a weight of 1,940 kilograms (4,300 lb), with a leaner 320 kilograms (710 lb) being average.

## Palaeobiology

*Megalania* is the largest terrestrial lizard known to have existed. Judging from its size, *Megalania* would have fed mostly upon medium to large sized animals, including any of the giant marsupials like *Diprotodon* along with other reptiles, small mammals, and birds and their eggs and chicks. It had heavily built limbs and body and a large skull complete with a small crest in between the eyes, and a jaw full of serrated blade-like teeth.

Several studies have attempted to establish the phylogenetic position of *Megalania* within the Varanidae. An affinity with the Perentie, Australia's largest living lizard, has been suggested based on skull-roof morphology . The most recent comprehensive study  proposes a sister-taxon relationship with the Komodo Dragon based on neurocranial similarities, with the Lace Monitor as the closest living Australian relative. Conversely, the Perentie is considered more closely related to the Gould's and Argus Monitors.

Wroe *et al.* (1999) regard the contention that *Megalania* was the only, or even principal, predator of the Australian Pleistocene megafauna with skepticism. They note that the marsupial lion (*Thylacoleo carnifex*) has been implicated with the butchery of very large Pleistocene mammals, while *Megalania* has not. In addition, they note that fossils of *Megalania* are extremely uncommon, in contrast to *Thylacoleo carnifex* with its wide distribution across Australian Pleistocene deposits.

The Australian biologist Tim Flannery suggested that if one wanted to reconstruct the ecosystems that existed before the arrival of the humans on Australia, it may be desirable to introduce Komodo dragon as a replacement for *Megalania*.

## Claims of surviving remnants

There have been numerous reports and rumors of living *Megalania* in Australia, and occasionally in New Guinea, as recently as the late 1990s. Australian cryptozoologist Rex Gilroy has stated that *Megalania* is still alive today, and it is only a matter of time until one is discovered alive.

The possibility of a surviving population of the giant lizards in the Australian Outback is not accepted by mainstream scientists, as reports of giant lizards only began after *Megalania* was first described.

## Feeding Habits

*Megalania* would normally prey on on Australia's large marsupials, such as *Diprotodon* and *Procoptodon* and large fightless birds like *Bullockornis* and *Genyornis* and the massive herbivorous turtle *Meiolania*. It would have used its veneomous bite to take down these large animals. *Megalania* shared it's habitat and rivaled with the marsupial lion *Thylacoleo*, crocodiles like *Quinkana*, snakes like *Wonambi*, and other monitor lizards. A study of modern-day Monitor Lizards prove that *Megalania* was most likely very noisy when it walked or moved, so chasing down prey likely wasn't an option. What it most likely did was, like modern lizards, lay in wait for prey to pass by, and then jump out in ambush and bite down using its powerful jaws and venom to take them down.

While modern day Monitor Lizards hunt this way, the Megalania may have also track and stealthily approach their prey like Komodo Dragons. They probably used the same hunting strategy of a Komodo Dragon, ambushing their prey, biting and injecting their venom, and running away and wait till the venom kicks in. Like Komodo Dragons and Lace Monitor, Megalania's venom probably killed its prey by shock, paralysis and coagulation that causes rapid blood loss. These venom acts quickly but its potency through various prey size. Normally a Komodo Dragon venom or bite can kill a medium sized prey like a boar or a deer outright, but will mostly 24 hours to kill a large water buffalo. Megalania's jaws were larger and can secrete more venom than a Komodo Dragon. Unlike monitor lizards, Megalania's teeth were more curved and serrated for better ripping off flesh.

## Extinction Theories

One theory of how *Megalania* became extinct is that after *Diprotodon* and *Procoptodon* died off, there was not enough food to sustain such a large reptile, and slowly the population died to extinction. Another theory is that the first humans who colonised Australia hunted the gigantic lizard to extinction. There's also a theory of the combined two, that early man burned the once plentiful forested areas to protect themselves from this mighty reptile, and doing so not only helped directly kill off *Megalania*, but also indirectly, since it ran out of places to hide in ambush and the prey animals it once fed on had no more food. There is one last, very unlikely theory that a small population of *Megalania* still lives on in the outback, stories of cattle savidged in the night by mysterious killers and large footprints in the sand. But as of yet, it cannot be proved and is highly unlikely that *Megalania* lives on.

## Appearance in other media

### *Jurassic Park*

* Megalania appears in the game *Jurassic Park: Builder* as a gold creature in the Glacier Park, even though as a cold-blooded animal that lived in the arrid outback, it would've died in the frozen island off the coast of Patagonia.

* It also appears in *Jurassic World: Alive* as an Omega

### *The Land Before Time*

*Megalania* is represented in *The Land Before Time Animated Moviebook*, in the tropical forest stage of 'The Great Fossil Hunting Grounds' minigame.

## References

1. ↑ Owen R. (1859). "Description of Some Remains of a Gigantic Land-Lizard (Megalania Prisca, Owen) from Australia". Philosophical Transactions of the Royal Society of London. 149: 43–48.
2. ↑ 2.0 2.1 2.2 2.3 Molnar, R.E. 2004. Dragons in the Dust: The paleobiology of the giant monitor lizard *Megalania.* Indiana University Press.
3. ↑ 3.0 3.1 Molnar, R.E. History of monitors and their kin. In: Pianka, E.R., King, D. and King, R.A. (Editors) 2004. Varanoid lizards of the world. Indiana University Press, 588 pp.
4. ↑ Hecht, M. 1975. The morphology and relationships of the largest known terrestrial lizard, *Megalania prisca* Owen, from the Pleistocene of Australia. *Proceedings of the Royal Society of Victoria* **87**: 239–250.
5. ↑ 5.0 5.1 5.2 Wroe, S. 2002. A review of terrestrial mammalian and reptilian carnivore ecology in Australian fossil faunas, and factors influencing their diversity: the myth of reptilian domination and its broader ramifications. *Australian Journal of Zoology* **50**: 1–24.
6. ↑ Wroe S, Field J, Fullagar R, & Jermiin LS. 2004. Megafaunal extinction in the late Quaternary and the global overkill hypothesis. *Alcheringa* **28**: 291-331.
7. ↑ Rich, T & Hall, B. 1984. In: *Vertebrate Zoogeography and Evolution in Australasia (eds Archer, M. & Clayton, G.). Pg. 391-394.*
8. ↑ Martin, P.S. & Kline, R.G. 1984. *Quaternary Extinctions*. University of Arizona Press, Tucson.
9. ↑ Lee MSY. 1996. Possible affinities between *Varanus giganteus* and *Megalania prisca*. Memoirs of the Queensland Museum 39: 232.
10. ↑ Head, JJ.; Barrett, PM.; Rayfield, EJ. 2009. Neurocranial osteology and systematic relationships of *Varanus (Megalania) prisca* Owen, 1859 (Squamata: Varanidae). Zoological Journal of the Linnean Society, 2009, 155, 445–457.
11. ↑ Wroe S, Myers TJ, Wells RT & Gillespie, A. 1999. Estimating the weight of the Pleistocene marsupial lion, *Thylacoleo carnifex* (Thylacoleonidae : Marsupialia): implications for the ecomorphology of a marsupial super-predator and hypotheses of impoverishment of Australian marsupial carnivore faunas. *Australian Journal of Zoology* **47**: 489-498.
12. ↑ Flannery T. 1994. *The Future Eaters*, pp. 384-385. ISBN 0802139434
13. ↑ Cryptozoology.com
14. ↑ Australian Giant Reptilian Monsters - Queensland Reports
15. ↑ Cryptomundo.com » Megalania