叶牙龙

叶牙龙属; 化石时期：晚侏罗纪
保护状况
	无效状况
科学分类
界：	动物界 Animalia
门：	脊索动物门 Chordata
纲：	蜥形纲 Sauropsida
总目：	恐龙总目 Dinosauria
目：	†鸟臀目 Ornithischia
演化支：	†颌齿类 Genasauria
演化支：	†新鸟臀类 Neornithischia
属：	†叶牙龙属 Phyllodon; Thulborn, 1973
模式种
	汉氏叶牙龙 Phyllodon henkeli; Thulborn, 1973

叶牙龙属（属名：Phyllodon）意为“叶状的牙齿”，是种小型鸟臀目恐龙，化石发现于葡萄牙莱里亚区的Guimarota地层，生存年代为上侏罗纪的启莫里阶。

叶牙龙的化石只有牙齿与可能的部分下颌。叶牙龙的属名Phyllodon也被一种现代苔藓使用中，但因为两个属分别属于不同的界，不会造成使用上的问题。叶牙龙的亲缘关系可能接近于同时代的北美洲恐龙。

历史

叶牙龙的模式标本（编号MGSP G5）是一个部分齿骨牙齿，发现于莱里亚市附近的褐煤矿层。Richard Thulborn叙述了叶牙龙，并加了一个前上颌骨牙齿（编号MGSP G2）。Thulborn认为叶牙龙属于棱齿龙科，并且主要根据牙齿来推测、重建^[1]。数年后，彼得·加尔东（Peter Galton）重新研究侏罗纪晚期的北美洲棱齿龙科恐龙，发现叶牙龙的牙齿与侏儒龙的牙齿最相符，并根据叶牙龙的下颌牙齿前后侧并不对称，来确定叶牙龙属于棱齿龙科^[2]。

因为化石数量稀少，叶牙龙过去常被认为是基础鸟脚下目恐龙的一个疑名，而且是分类不明属^[3]^[4]。然而，在原本地点新发现的化石可能属于叶牙龙，包含超过120颗牙齿，以及四个部分下颌。奥利佛·劳赫（Oliver Rauhut）叙述了这些新化石，因为当地并没有发现其他恐龙，所以暂时将牠们归类于叶牙龙。这些牙齿非常小，宽约3毫米，可能来自于幼年体。他同时发现叶牙龙的独有衍征，包含非常高的下颌牙齿，显示牠们为有效属。劳赫拿这些牙齿与其他棱齿龙类比较，发现牠们与约同时代的北美洲莫里逊组的德林克龙最为相符，许多特征显示牠们有接近亲缘关系^[5]。在2006年，加尔东也发现这些牙齿类似德林克龙与侏儒龙的牙齿^[6]。

古生物学

身为棱齿龙类或是基础鸟脚类恐龙，叶牙龙应该是二足、草食性恐龙。目前还没有估计过叶牙龙的身长，但大部分棱齿龙类的成年个体身长为1到2米（3.3到6.6呎）^[4]，因此叶牙龙可能拥有类似大小的体型。叶牙龙与北美洲的德林克龙、侏儒龙的相似处，提供了晚侏罗纪时期，葡萄牙的恐龙生物群与莫里逊组之间的连结证据^[7]。

参考资料

^ Thulborn, Richard A. Teeth of ornithischian dinosaurs from the Upper Jurassic of Portugal, with description of a hypsilophodontid (Phyllodon henkeli gen. et sp. nov.) from the Guimarota lignite.. Memória Serivoços Geológicos de Portugal (Nova Série). 1973, 22: 89–134.
^ Galton, Peter M. The cranial anatomy of Dryosaurus, a hypsilophodontid dinosaur from the Upper Jurassic of North America and East Africa, with a review of hypsilophodontids from the Upper Jurassic of North America. Geologica et Palaeontologica. 1983, 17: 207–243.
^ Sues, Hans-Dieter; and Norman, David B. Hypsilophodontidae, Tenontosaurus, Dryosauridae. Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.) (编). The Dinosauria 1st. Berkeley: University of California Press. 1990: 498–509. ISBN 0-520-06727-4.
^ ^4.0 ^4.1 Norman, David B.; Sues, Hans-Dieter; Witmer, Larry M.; and Coria, Rodolfo A. Basal Ornithopoda. Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.) (编). The Dinosauria 2nd. Berkeley: University of California Press. 2004: 393-412. ISBN 0-520-24209-2.
^ Rauhut, Oliver W.M. Herbivorous dinosaurs from the Late Jurassic (Kimmeridgian) of Guimarota, Portugal. Proceedings of the Geologists' Association. 2001, 112: 275–283.
^ Galton, Peter M. Teeth of ornithischian dinosaurs (mostly Ornithopoda) from the Morrison Formation (Upper Jurassic) of the western United States. Carpenter, Kenneth (ed.) (编). Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs. Bloomington and Indianapolis: Indiana University Press. 2006: 17–47. ISBN 0-253-34817-X.
^ Mateus, Octávio. Late Jurassic dinosaurs from the Morrison Formation (USA), the Lourinhã and Alcobaça Formations (Portugal), and the Tendaguru Beds (Tanzania): a comparison. Foster, John R.; and Lucas, Spencer G. (eds.) (编). Paleontology and Geology of the Upper Morrison Formation. New Mexico Museum of Natural History and Science Bulletin (36). Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. 2006: 223–231.

外部链接

恐龙.NET——中国古生物门户网站。
Phyllodon on Thescelosaurus!, under Ornithopoda i.s.

[RAT73-1] Thulborn, Richard A. Teeth of ornithischian dinosaurs from the Upper Jurassic of Portugal, with description of a hypsilophodontid (Phyllodon henkeli gen. et sp. nov.) from the Guimarota lignite.. Memória Serivoços Geológicos de Portugal (Nova Série). 1973, 22: 89–134.

[PMG83-2] Galton, Peter M. The cranial anatomy of Dryosaurus, a hypsilophodontid dinosaur from the Upper Jurassic of North America and East Africa, with a review of hypsilophodontids from the Upper Jurassic of North America. Geologica et Palaeontologica. 1983, 17: 207–243.

[SN90-3] Sues, Hans-Dieter; and Norman, David B. Hypsilophodontidae, Tenontosaurus, Dryosauridae. Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.) (编). The Dinosauria 1st. Berkeley: University of California Press. 1990: 498–509. ISBN 0-520-06727-4.

[NSWC04-4] 4.0 ^4.1 Norman, David B.; Sues, Hans-Dieter; Witmer, Larry M.; and Coria, Rodolfo A. Basal Ornithopoda. Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.) (编). The Dinosauria 2nd. Berkeley: University of California Press. 2004: 393-412. ISBN 0-520-24209-2.

[OR01-5] Rauhut, Oliver W.M. Herbivorous dinosaurs from the Late Jurassic (Kimmeridgian) of Guimarota, Portugal. Proceedings of the Geologists' Association. 2001, 112: 275–283.

[PMG06-6] Galton, Peter M. Teeth of ornithischian dinosaurs (mostly Ornithopoda) from the Morrison Formation (Upper Jurassic) of the western United States. Carpenter, Kenneth (ed.) (编). Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs. Bloomington and Indianapolis: Indiana University Press. 2006: 17–47. ISBN 0-253-34817-X.

[OM06-7] Mateus, Octávio. Late Jurassic dinosaurs from the Morrison Formation (USA), the Lourinhã and Alcobaça Formations (Portugal), and the Tendaguru Beds (Tanzania): a comparison. Foster, John R.; and Lucas, Spencer G. (eds.) (编). Paleontology and Geology of the Upper Morrison Formation. New Mexico Museum of Natural History and Science Bulletin (36). Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. 2006: 223–231.

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