古巨蜥

古巨蜥; 化石时期：1.5–0.04 Ma PreЄ Є O S D C P T J K Pg N ▼ 更新世
科学分类
界：	动物界 Animalia
门：	脊索动物门 Chordata
纲：	爬行纲 Reptilia
目：	有鳞目 Squamata
科：	巨蜥科 Varanidae
属：	巨蜥属 Varanus
种：	古巨蜥 V. priscus
二名法
	Varanus priscus; (Owen, 1859)
异名
	原用名 Megalania prisca Owen, 1859（互用名）; ; 主观异名 Notiosaurus dentatus Owen, 1884; Varanus dirus de Vis, 1889; Varanus warburtonensis Zeitz, 1899; ;

古巨蜥（学名：Varanus priscus）又名巨齿蜥，是一种已灭绝的巨型巨蜥。牠们生存于更新世的南澳洲，约于4万年前消失。最早到达的澳洲原住民可能曾与之一同生活。^[3]

科学分类

四种巨蜥的体型比较（3A与3B者）。

分类及命名

古巨蜥是由理查·欧文（Richard Owen）所描述，并取命名为Megalania prisca，意为“古代巨型的流浪者”。^[1] 欧文最初将古巨蜥分类在自己的属中，但此属的有效性却被受质疑，认为是巨蜥属的异名。^[4] 由于Megalania及巨蜥属的性别不同，种小名也由prisca改为priscus。^[5]

系统发生学

多项研究都尝试找出古巨蜥在巨蜥属内的系统发生学位置。其中一个指牠们的头颅骨顶形态与眼斑巨蜥相似，认为与之相近。^[6] 另一项较近期的研究则指牠们与科莫多龙的脑颅结构相似，故与之应为姊妹分类，而树巨蜥则为其最近亲。^[7]

体型

古巨蜥的骨骼结构重构。

古巨蜥的头颅骨。

古巨蜥没有留下完整或接近完整的骨骼，故很难确定其大小。^[4] 早期估计牠们最大约有7米长，及重600-620公斤。^[8] 于2002年，斯蒂芬·罗（Stephen Wroe）就认为古巨蜥最多只有4.5米长及重331公斤^[9]，而平均则长3.5米及重97-158公斤。^[9]^[10] 他认为早期的计算是基于错误的方法及夸大了其体型。^[9]

不过，Ralph Molnar于2004年基于脊骨及总体长的研究，指古巨蜥的体长有几种可能性。^[4] 若古巨蜥像树巨蜥般拥有幼长的尾巴，牠们有可能长达7.9米；若牠们的尾巴与体型的比例像近亲科莫多龙，则体长约等于7米。以7米的体长来计算，牠们可以重达1940公斤．而平均重320公斤。^[4]

古生物学

古巨蜥是已知最巨型的陆上蜥蜴(海中最大的蜥蜴则是沧龙)，牠们的四肢及身体强壮，头颅骨很大，眼睛间有细小的冠，颚骨上长满锯齿状的牙齿。^[5] 从其体型来推断，牠们主要猎食中型至大型的动物，包括任何巨型的有袋类（如双门齿兽）、爬行类、细小的哺乳动物及鸟类。

斯蒂芬·罗等人怀疑古巨蜥是否澳洲巨型动物群的主要掠食者。^[11] 他们发现袋狮曾残杀非常巨型的更新世哺乳动物，但古巨蜥却没有。他们也发现古巨蜥的化石并不普遍，与袋狮的分布相形见绌。

提姆·富兰纳瑞（Tim Flannery）认为要重构澳洲原住民到达澳洲前的生态系统，最理想的方法是以科莫多龙来取代古巨蜥。^[12]

毒素

研究发现其他巨蜥属的成员，如科莫多龙，沿颚部都有毒腺。^[13] 所以有指古巨蜥也可能有类似的毒腺。^[14] 若真是这样，古巨蜥将会是最巨大的有毒脊椎动物。

参考文献

^ ^1.0 ^1.1 Owen R. Description of Some Remains of a Gigantic Land-Lizard (Megalania Prisca, Owen) from Australia. Philosophical Transactions of the Royal Society of London. 1859, 149: 43–48. JSTOR 108688. doi:10.1098/rstl.1859.0002.
^ Lydekker R. Catalog of the fossil Reptilia in the British Museum (Natural History) Cromwell Road S.W. Pt. 1: The Orders Ornithosauria, Crocodilia, Squamata, Rhynchocephalia, and Proterosauria. London: The Trustees. 1888. Cited in Molnar RE. The long and honorable history of monitors and their kin. King, Ruth Allen; Pianka, Eric R.; King, Dennis (编). Varanoid lizards of the world. Bloomington: Indiana University Press. 2004: 45. ISBN 0-253-34366-6. )
^ Megalania, giant ripper lizard Archive.is的存档，存档日期2012-05-26, BBC - Science & Nature
^ ^4.0 ^4.1 ^4.2 ^4.3 Molnar, R.E. Dragons in the Dust: The paleobiology of the giant monitor lizard Megalania. Indiana University Press. 2004.
^ ^5.0 ^5.1 Molnar, R.E. History of monitors and their kin. Pianka, E.R., King, D. and King, R.A. (Editors) (编). Varanoid lizards of the world. Indiana University Press. 2004: 588 pp.
^ Lee MSY. Possible affinities between Varanus giganteus and Megalania prisca. Memoirs of the Queensland Museum. 1996, 39: 232.
^ Head, JJ.; Barrett, PM.; Rayfield, EJ. Neurocranial osteology and systematic relationships of Varanus (Megalania) prisca Owen, 1859 (Squamata: Varanidae). Zoological Journal of the Linnean Society. 2009, 2009 (155): 445–57.
^ Hecht, M. 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. 1975, 87: 239–50.
^ ^9.0 ^9.1 ^9.2 Wroe, S. 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 (PDF). Australian Journal of Zoology. 2002, 50: 1–24 [2009-09-28]. （原始内容 (PDF)存档于2003-12-10）.
^ Wroe S, Field J, Fullagar R, & Jermiin LS. Megafaunal extinction in the late Quaternary and the global overkill hypothesis. Alcheringa. 2004, 28: 291–331.
^ Wroe S, Myers TJ, Wells RT & Gillespie, A. 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. 1999, 47: 489–98.
^ Flannery T. The Future Eaters. 1994: pp. 384–5. ISBN 0-8021-3943-4.
^ Fry, B.; et al. Early evolution of the venom system in lizards and snakes. Nature. February 2006, 439: 584–8 [2009-09-28]. doi:10.1038/nature04328. （原始内容存档于2009-04-19）.
^ Komodo Dragons Kill With Venom, Researchers Find （页面存档备份，存于互联网档案馆） (National Geographic)

外部链接

Prehistoric Life - Museum Victoria
The UnMuseum （页面存档备份，存于互联网档案馆）

[Owen1859-1] 1.0 ^1.1 Owen R. Description of Some Remains of a Gigantic Land-Lizard (Megalania Prisca, Owen) from Australia. Philosophical Transactions of the Royal Society of London. 1859, 149: 43–48. JSTOR 108688. doi:10.1098/rstl.1859.0002.

[Lydekker1888-2] Lydekker R. Catalog of the fossil Reptilia in the British Museum (Natural History) Cromwell Road S.W. Pt. 1: The Orders Ornithosauria, Crocodilia, Squamata, Rhynchocephalia, and Proterosauria. London: The Trustees. 1888. Cited in Molnar RE. The long and honorable history of monitors and their kin. King, Ruth Allen; Pianka, Eric R.; King, Dennis (编). Varanoid lizards of the world. Bloomington: Indiana University Press. 2004: 45. ISBN 0-253-34366-6. )

[3] Megalania, giant ripper lizard Archive.is的存档，存档日期2012-05-26, BBC - Science & Nature

[Molnar,_2004-4] 4.0 ^4.1 ^4.2 ^4.3 Molnar, R.E. Dragons in the Dust: The paleobiology of the giant monitor lizard Megalania. Indiana University Press. 2004.

[Molnar,_2004;_in_Pianka_''et_al.'',_2004-5] 5.0 ^5.1 Molnar, R.E. History of monitors and their kin. Pianka, E.R., King, D. and King, R.A. (Editors) (编). Varanoid lizards of the world. Indiana University Press. 2004: 588 pp.

[Lee,_1999-6] Lee MSY. Possible affinities between Varanus giganteus and Megalania prisca. Memoirs of the Queensland Museum. 1996, 39: 232.

[Head_''et_al.'',_2009-7] Head, JJ.; Barrett, PM.; Rayfield, EJ. Neurocranial osteology and systematic relationships of Varanus (Megalania) prisca Owen, 1859 (Squamata: Varanidae). Zoological Journal of the Linnean Society. 2009, 2009 (155): 445–57.

[Hecht,_1975-8] Hecht, M. 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. 1975, 87: 239–50.

[Wroe,_2002-9] 9.0 ^9.1 ^9.2 Wroe, S. 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 (PDF). Australian Journal of Zoology. 2002, 50: 1–24 [2009-09-28]. （原始内容 (PDF)存档于2003-12-10）.

[Wroe_''et_al.'',_2004-10] Wroe S, Field J, Fullagar R, & Jermiin LS. Megafaunal extinction in the late Quaternary and the global overkill hypothesis. Alcheringa. 2004, 28: 291–331.

[Wroe_''et_al.'',_1999-11] Wroe S, Myers TJ, Wells RT & Gillespie, A. 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. 1999, 47: 489–98.

[12] Flannery T. The Future Eaters. 1994: pp. 384–5. ISBN 0-8021-3943-4.

[Fry2006-13] Fry, B.; et al. Early evolution of the venom system in lizards and snakes. Nature. February 2006, 439: 584–8 [2009-09-28]. doi:10.1038/nature04328. （原始内容存档于2009-04-19）.

[14] Komodo Dragons Kill With Venom, Researchers Find （页面存档备份，存于互联网档案馆） (National Geographic)

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