倍甲龙属

倍甲龙属; 化石时期：晚白垩世; 76.5 Ma PreЄ Є O S D C P T J K Pg N ▼
	正模标本头骨
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
科：	†甲龙科 Ankylosauridae
亚科：	†甲龙亚科 Ankylosaurinae
属：	†倍甲龙属 Dyoplosaurus; Parks, 1924
模式种
	†锐鳞倍甲龙; Dyoplosaurus acutosquameus; Parks, 1924

倍甲龙（属名：Dyoplosaurus，意为“双倍装甲的蜥蜴”）是一属甲龙科恐龙，化石发现于加拿大亚伯达省晚白垩世（坎潘阶中期，约7650万至7500万年前）的恐龙公园层。^[1]与同地层的刺甲龙、无齿甲龙近缘，亦曾一度被认为是包头龙的异名。^[2]

研究史

1919年李维·斯腾伯格（Levi Sternberg）在加拿大亚伯达省红鹿河（英语：Red Deer River）附近的恐龙公园层底部10米处发现了倍甲龙的正模标本ROM 784，包括一个部分头盖骨、带有牙齿的下颌碎片、装甲、皮肤印痕、关节相连的后胸椎、部分胸肋、部分髂骨、成对坐骨、尾槌、桡骨、手部骨头、股骨、胫骨、腓骨、脚部骨头。现保存于皇家安大略博物馆。^[1]^[2]另两具标本ROM 7761和UA 47273也归入倍甲龙，都是部分尾槌。^[3]

模式种锐鳞倍甲龙（Dyoplosaurus acutosquameus）由古生物学家威廉·帕克斯于1924年发表、命名。属名Dyoplosaurus由古希腊语的dyo（双倍）加上hoplon（武器、盾、铠甲）及sauros（蜥蜴）组成，意即“两倍武装蜥蜴”；种名acutosquameus以拉丁语acutus（尖锐）与squama（鳞片）组成，意即“锐利的鳞片”。^[1]

1956年叶夫根尼·马列夫根据来自蒙古耐梅盖特层的PIN 551/29标本（一系列尾椎、跖骨、指骨、装甲、尾槌）命名了第二个种巨型倍甲龙（D. giganteus），鉴定特征包括前部尾椎短、与尾椎融合的大型人字骨、远端尾椎低矮且长、跖骨短而宽、蹄形趾爪、锋利的薄壁皮内成骨表面布满凹陷及沟槽。但2014年的研究指出其正模缺乏鉴定性特征，因为以上特征皆存在于所有甲龙亚科，于是将该物种视为疑名。^[4]

描述

正模标本的尾部化石照片（上）与骨盆至尾部的重建图（下）

倍甲龙估计身长3.58至4.16米及体重1.5至2.5吨。^[5]所有归入标本都是接近成熟的个体。^[6]

倍甲龙可由以下鉴定特征与其他甲龙科区别开来：荐部肋骨朝向前外侧；爪子背视为三角形；尾槌长度大于宽度。倍甲龙与刺甲龙不同处在于前者后髋臼突比例较小；尾部前部外侧有三角形皮内成骨。倍甲龙与包头龙差异在于前者骨盆第三荐椎有朝前外的腹横突，使荐骨孔呈蝴蝶形排列；坐骨与髂骨成直角。^[2]

倍甲龙正模标本保存了尾部骨化肌腱。尾槌在支柄处外背侧保存了三组肌腱，尾部腹侧远端则有四组。这些肌腱常于外背侧分成两组。^[6]^[1]2009年奥柏尔检验ROM 784标本来定义甲龙科的冲击力道，她发现倍甲龙可产生797至1127牛吨的冲击力与571牛吨的实际张力，如此程度尚不足以穿透骨头。主因是其尾槌略小于其他甲龙科。小体积尾槌代表甲龙科的这项构造的主要功能并非防御，考虑到成长过程晚期才发挥作用的构造，实际效益远比不上早期即有作用的武器。^[6]

正模左侧保存了皮肤和装甲残留物。皮肤印痕间镶嵌著小型约0.5至1公分完整亚圆形及亚三角形的皮内成骨。右侧皮肤印痕已受侵蚀遗失。^[2]

分类

1971年瓦特·库姆斯（Walter Coombs）将倍甲龙、刺甲龙、无齿甲龙定义为包头龙的异名，因为归入倍甲龙的四个下颌之一与包头龙标本的下颌一模一样，但没有指出其他作为异名的鉴定特征来解释。^[7]2009年维多莉亚·奥柏尔（英语：Victoria Arbour）等人发表了倍甲龙的重新描述，认为这是一个有效的物种，并解释之前是因为正模标本及其他包头龙标本的破碎状态而导致异名的观点。^[2]2011年汤普森等人证实彼此的独立性并将倍甲龙列为魔头绘龙的姊妹分类单元。^[8]2015年奥柏尔和菲力·柯里（英语：Phillip J. Currie）将倍甲龙与包含甲龙、包头龙、无齿甲龙、刺甲龙的演化支互成姊妹群。^[9]2017年奥柏尔和艾文思则让倍甲龙和祖鲁龙互为姊妹群。^[10]

以下取自2015年奥柏尔和柯里：^[9]

甲龙亚科 Ankylosaurinae

克氏盾龙 Crichtonpelta

白山龙 Tsagantegia

浙江龙 Zhejiangosaurus

绘龙 Pinacosaurus

美甲龙 Saichania

	多智龙 Tarchia

	猬甲龙 Zaraapelta

甲龙族 Ankylosaurini

倍甲龙 Dyoplosaurus

	篮尾龙 Talarurus

	结节头龙 Nodocephalosaurus

	甲龙 Ankylosaurus

	无齿甲龙 Anodontosaurus

包头龙 Euoplocephalus

	刺甲龙 Scolosaurus

	齐亚甲龙 Ziapelta

以下取自2017年奥柏尔和艾文思：^[10]

甲龙亚科 Ankylosaurinae

丽水浙江龙 Zhejiangosaurus lishuiensis

	谷氏绘龙 Pinacosaurus grangeri

	魔头绘龙 Pinacosaurus mephistocephalus

长头白山龙 Tsagantegia longicranialis

	皱棘篮尾龙 Talarurus plicatospineus

	科特兰结节头龙 Nodocephalosaurus kirtlandensis

胡山美甲龙 Saichania chulsanensis

	游牧猬甲龙 Zaraapelta nomadis

	凯氏多智龙Tarchia kielanae

甲龙族 Ankylosaurini

圣胡安齐亚甲龙 Ziapelta sanjuanensis

卫甲包头龙 Euoplocephalus tutus

大面甲龙 Ankylosaurus magniventris

赖氏无齿甲龙 Anodontosaurus lambei

库氏刺甲龙 Scolosaurus cutleri

	碎胫者祖鲁龙 Zuul crurivastator

	锐鳞倍甲龙 Dyoplosaurus acutosquameus

古生态

倍甲龙正模标本出土于恐龙公园层下部层位，地质年代可追溯至晚白垩世坎潘阶中期。^[2]当时环境主要为旱地，在低海拔处有排水不良形成的河道沉积物，常受到洪水侵袭，至于泛滥平原较远处则较少发生洪水。^[11]

倍甲龙与甲龙类的埃德蒙顿甲龙、包头龙、刺甲龙、角龙科的开角龙、鸭嘴龙科的冠龙、钩鼻龙、副栉龙、暴龙科的魔龙、^[2]奔龙科的西爪龙、^[12]伤齿龙科的潜猎龙、^[13]近颌龙科的近颌龙和纤手龙。^[14]

延伸阅读

甲龙类研究史（英语：Timeline of ankylosaur research）

参考来源

^ ^1.0 ^1.1 ^1.2 ^1.3 Parks, W. A. Dyoplosaurus acutosquameus, a new genus and species of armored dinosaur; and notes on a skeleton of Prosaurolophus maximus. University of Toronto Studies Geological Series. 1924, 18: 1–35.
^ ^2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 ^2.6 Arbour, V. M.; Burns, M. E.; Sissons, R. L. A redescription of the ankylosaurid dinosaur Dyoplosaurus acutosquameus Parks, 1924 (Ornithischia: Ankylosauria) and a revision of the genus. Journal of Vertebrate Paleontology. 2009, 29 (4): 1117. S2CID 85665879. doi:10.1671/039.029.0405.
^ Paul Penkalski. Revised systematics of the armoured dinosaur Euoplocephalus and its allies. Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 2018, 287 (3): 261–306. doi:10.1127/njgpa/2018/0717.
^ Victoria M. Arbour, Philip J. Currie and Demchig Badamgarav, 2014, "The ankylosaurid dinosaurs of the Upper Cretaceous Baruungoyot and Nemegt formations of Mongolia", Zoological Journal of the Linnean Society 172(3): 631–652|doi=https://doi.org/10.1111/zoj12185
^ Miyashita T, Arbour VM, Witmer LM, Currie PJ. The internal cranial morphology of an armoured dinosaur Euoplocephalus corroborated by X-ray computed tomographic reconstruction. Journal of Anatomy. 2011, 219 (6): 661–75. PMC 3237876  . PMID 21954840. doi:10.1111/j.1469-7580.2011.01427.x.
^ ^6.0 ^6.1 ^6.2 Arbour, V. M. Estimating Impact Forces of Tail Club Strikes by Ankylosaurid Dinosaurs. PLOS ONE. 2009, 4 (8): e6738. Bibcode:2009PLoSO...4.6738A. PMC 2726940  . PMID 19707581. doi:10.1371/journal.pone.0006738  . .
^ Coombs, Walter. The Ankylosauria. Columbia University. 1971.
^ Richard S. Thompson; Jolyon C. Parish; Susannah C. R. Maidment; Paul M. Barrett. Phylogeny of the ankylosaurian dinosaurs (Ornithischia: Thyreophora). Journal of Systematic Palaeontology. 2011, 10 (2): 301–312. S2CID 86002282. doi:10.1080/14772019.2011.569091.
^ ^9.0 ^9.1 Arbour, V. M.; Currie, P. J. Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs. Journal of Systematic Palaeontology. 2015, 14 (5): 1–60. S2CID 214625754. doi:10.1080/14772019.2015.1059985.
^ ^10.0 ^10.1 Arbour, Victoria M.; Evans, David C. A new ankylosaurine dinosaur from the Judith River Formation of Montana, USA, based on an exceptional skeleton with soft tissue preservation. Royal Society Open Science. 2017, 4 (5): 161086. Bibcode:2017RSOS....461086A. PMC 5451805  . PMID 28573004. doi:10.1098/rsos.161086.
^ Matson, C.C. Paleoenvironments of the Upper Cretaceous Dinosaur Park Formation in southern Alberta, Canada (学位论文). University of Calgary, Calgary, AB. 2010. doi:10.11575/PRISM/18677.
^ Longrich, N.R. and Currie, P.J. (2009). "A microraptorine (Dinosauria–Dromaeosauridae) from the Late Cretaceous of North America." Proceedings of the National Academy of Sciences 106(13): 5002–5007. doi: 10.1073/pnas.0811664106
^ van der Reest, A. J.; Currie, P. J. Troodontids (Theropoda) from the Dinosaur Park Formation, Alberta, with a description of a unique new taxon: implications for deinonychosaur diversity in North America. Canadian Journal of Earth Sciences. 2017, 54 (9): 919−935. Bibcode:2017CaJES..54..919V. doi:10.1139/cjes-2017-0031. hdl:1807/78296  .
^ Funston, Gregory. Caenagnathids of the Dinosaur Park Formation (Campanian) of Alberta, Canada: anatomy, osteohistology, taxonomy, and evolution. Vertebrate Anatomy Morphology Palaeontology. 2020-07-27, 8: 105–153. ISSN 2292-1389. doi:10.18435/vamp29362  .

[PWA24-1] 1.0 ^1.1 ^1.2 ^1.3 Parks, W. A. Dyoplosaurus acutosquameus, a new genus and species of armored dinosaur; and notes on a skeleton of Prosaurolophus maximus. University of Toronto Studies Geological Series. 1924, 18: 1–35.

[ABS09-2] 2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 ^2.6 Arbour, V. M.; Burns, M. E.; Sissons, R. L. A redescription of the ankylosaurid dinosaur Dyoplosaurus acutosquameus Parks, 1924 (Ornithischia: Ankylosauria) and a revision of the genus. Journal of Vertebrate Paleontology. 2009, 29 (4): 1117. S2CID 85665879. doi:10.1671/039.029.0405.

[Platypelta-3] Paul Penkalski. Revised systematics of the armoured dinosaur Euoplocephalus and its allies. Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 2018, 287 (3): 261–306. doi:10.1127/njgpa/2018/0717.

[Arbour2014-4] Victoria M. Arbour, Philip J. Currie and Demchig Badamgarav, 2014, "The ankylosaurid dinosaurs of the Upper Cretaceous Baruungoyot and Nemegt formations of Mongolia", Zoological Journal of the Linnean Society 172(3): 631–652|doi=https://doi.org/10.1111/zoj12185

[Miyashita2011-5] Miyashita T, Arbour VM, Witmer LM, Currie PJ. The internal cranial morphology of an armoured dinosaur Euoplocephalus corroborated by X-ray computed tomographic reconstruction. Journal of Anatomy. 2011, 219 (6): 661–75. PMC 3237876  . PMID 21954840. doi:10.1111/j.1469-7580.2011.01427.x.

[Arbor2009-6] 6.0 ^6.1 ^6.2 Arbour, V. M. Estimating Impact Forces of Tail Club Strikes by Ankylosaurid Dinosaurs. PLOS ONE. 2009, 4 (8): e6738. Bibcode:2009PLoSO...4.6738A. PMC 2726940  . PMID 19707581. doi:10.1371/journal.pone.0006738  . .

[7] Coombs, Walter. The Ankylosauria. Columbia University. 1971.

[ThompsonEtAl-8] Richard S. Thompson; Jolyon C. Parish; Susannah C. R. Maidment; Paul M. Barrett. Phylogeny of the ankylosaurian dinosaurs (Ornithischia: Thyreophora). Journal of Systematic Palaeontology. 2011, 10 (2): 301–312. S2CID 86002282. doi:10.1080/14772019.2011.569091.

[systematics_ankylosaurid-9] 9.0 ^9.1 Arbour, V. M.; Currie, P. J. Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs. Journal of Systematic Palaeontology. 2015, 14 (5): 1–60. S2CID 214625754. doi:10.1080/14772019.2015.1059985.

[Arbour2017-10] 10.0 ^10.1 Arbour, Victoria M.; Evans, David C. A new ankylosaurine dinosaur from the Judith River Formation of Montana, USA, based on an exceptional skeleton with soft tissue preservation. Royal Society Open Science. 2017, 4 (5): 161086. Bibcode:2017RSOS....461086A. PMC 5451805  . PMID 28573004. doi:10.1098/rsos.161086.

[11] Matson, C.C. Paleoenvironments of the Upper Cretaceous Dinosaur Park Formation in southern Alberta, Canada (学位论文). University of Calgary, Calgary, AB. 2010. doi:10.11575/PRISM/18677.

[longrich&currie2009-12] Longrich, N.R. and Currie, P.J. (2009). "A microraptorine (Dinosauria–Dromaeosauridae) from the Late Cretaceous of North America." Proceedings of the National Academy of Sciences 106(13): 5002–5007. doi: 10.1073/pnas.0811664106

[desc-13] van der Reest, A. J.; Currie, P. J. Troodontids (Theropoda) from the Dinosaur Park Formation, Alberta, with a description of a unique new taxon: implications for deinonychosaur diversity in North America. Canadian Journal of Earth Sciences. 2017, 54 (9): 919−935. Bibcode:2017CaJES..54..919V. doi:10.1139/cjes-2017-0031. hdl:1807/78296  .

[Citipes-14] Funston, Gregory. Caenagnathids of the Dinosaur Park Formation (Campanian) of Alberta, Canada: anatomy, osteohistology, taxonomy, and evolution. Vertebrate Anatomy Morphology Palaeontology. 2020-07-27, 8: 105–153. ISSN 2292-1389. doi:10.18435/vamp29362  .

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