Megalania
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| Varanus priscus (Owen, 1859 [1]) |
Megalania ("great roamer"; Greek Μέγας "great" + ἀλαίνω "roam"), the giant goanna is an extinct giant monitor lizard. It was one of the megafauna that roamed southern Australia, and appears to have disappeared around 40,000 years ago along with many other species of Australian megafauna. The first aboriginal settlers of Australia may have encountered living Megalania[citation needed].
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[edit] Taxonomy
[edit] 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" [1]. To do this Owen used a modification of the Greek word: plaina ("to roam about"). The close similarity of Owen's truncated plaina to the Latin word: lania (femine form for: butcher), resulted in numerous taxonomic and popular descriptions of Megalania mistranslating the name as: Ancient Giant Butcher.
[edit] 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 [2], 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.) [3].
[edit] Size
The lack of complete, or nearly complete fossil skeletons has made it difficult to determine the exact dimensions of Megalania[2]. Early estimates placed the length of the largest individuals at 7 meters (23 ft), with a maximum weight of approximately 600-620 kg [4]. 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 m and a weight of 331 kg [5], while its average length would have been around 3.5 m, and mean body weight would have been between 97-158 kg [5][6].He concluded[5] the earlier estimates reaching lengths of 6 meters or more (20ft) and a weight of several tons (see [7][8]) were exaggerations based upon flawed methodologies.
However, Ralph Molnar [2] 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 m, while if its tail-to-body proportions were more similar to that of the Komodo dragon, then a length of around 7 m is more likely. Taking the maximal 7 m length, he estimated a weight of 1,940kg, with a leaner 320kg being the average[2].
[edit] 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[citation needed]. 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 [3]. Due to its size and similarities to the Komodo dragon, a relationship between the two species has been suggested[citation needed]. In reality however, Megalania's closest living relative is the Perentie, Australia's largest living lizard, not the Komodo dragon[citation needed].
Wroe et al. (1999)[9] regard the contention that Megalania was the only, or even principle, 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.
[edit] 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[10]. 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[11]. In 1979 Gilroy made what he claimed were plaster casts of enormous lizard-like footprints found by a farmer in Queensland.
The possibility of a surviving population of the giant lizards in the Australian Outback is not accepted by mainstream scientists[12], as reports of giant lizards only began after Megalania was first described.
[edit] References
- ^ a b 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.
- ^ a b c d Molnar, R.E. 2004. Dragons in the Dust: The paleobiology of the giant monitor lizard Megalania. Indiana University Press.
- ^ a b 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.
- ^ 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.
- ^ a b c 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.
- ^ Wroe S, Field J, Fullagar R, & Jermiin LS. 2004. Megafaunal extinction in the late Quaternary and the global overkill hypothesis. Alcheringa 28: 291-331.
- ^ Rich, T & Hall, B. 1984. In: Vertebrate Zoogeography and Evolution in Australasia (eds Archer, M. & Clayton, G.). Pg. 391-394.
- ^ Martin, P.S. & Kline, R.G. 1984. Quaternary Extinctions. University of Arizona Press, Tuscon.
- ^ 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 mpoverishment ofAustralian marsupial carnivore faunas. Australian Journal of Zoology 47: 489-498.
- ^ http://www.cryptozoology.com/cryptids/megalania.php
- ^ http://www.mysteriousaustralia.com/australian_giant_reptilian_monsters-qld.html
- ^ http://www.cryptomundo.com/cryptozoo-news/megalania/
