遠古龍屬

遠古龍屬; 化石時期：晚白堊世，72–68 Ma PreЄ Є O S D C P T J K Pg N ▼
	凱氏遠古龍的復原圖（英語：Life restoration）
科學分類
界：	動物界 Animalia
門：	脊索動物門 Chordata
綱：	爬蟲綱 Reptilia
目：	†蛇頸龍目 Plesiosauria
科：	†薄板龍科 Elasmosauridae
屬：	†遠古龍屬 Tuarangisaurus; Wiffen（英語：Joan Wiffen） & Moisley, 1986
模式種
	†凱氏遠古龍; Tuarangisaurus keyesi; Wiffen & Moisley, 1986

遠古龍（學名：Tuarangisaurus，毛利語：tuarangi［古代的］ + 希臘語：σαῦρος，羅馬化：sauros［蜥蜴］）是薄板龍科已滅絕的一個屬，化石發現於新西蘭。模式種兼唯一已知物種是凱氏遠古龍（Tuarangisaurus keyesi），由威芬（英語：Joan Wiffen）和莫伊斯利於1986年（英語：1986 in paleontology）命名。^[1]^[2]

發現

卡氏遠古龍（現視為分類不明的極泳龍亞科）的骨骼重建

已知化石包括正模標本NZGS（英語：New Zealand Geological Survey） CD425，含有幾乎完整的顱骨及下頜骨——及NZGS CD426，含前九節頸椎。一些幼龍顱後（英語：postocrania）遺骸亦歸入遠古龍，其中一件標本（NZGS CD427）含有至少30顆胃石。^[1]其收集於塔霍拉組（英語：Tahora Formation）曼加塔尼瓦砂岩段（Maungataniwha Sandstone Member），時間為晚白堊世坎帕階晚期至馬斯特里赫特階早期。^[2]

第二個種澳洲遠古龍（T. australis）於2005年命名，^[3]但於2007年移入新屬伊羅曼加龍，成為嵴頜伊羅曼加龍（E. carinognathus）的首異名。^[4]第三個種卡氏遠古龍（T.? cabazai）在原始描述中亦歸入本屬，^[1]但近期被重新歸為分類不明的極泳龍亞科。^[5]

2017年，一件原屬毛伊龍的完整標本（CM Zfr 115）被重新歸入該屬，^[6]2018年，奧特羅等人報告了一具幼龍標本，表明了這種蛇頸龍的個體發育。該標本具有很多與正模標本相同的特徵，但上頜骨方向及牙齒數目存在差異。^[7]

描述

遠古龍是種中型蛇頸龍，完整標本（CM Zfr 115）長度測為超過8公尺（26英尺）。^[8]顱骨保存部分長度測為37.0公分（1英尺2.6英寸）左右，完整長度估計為37.5公分（1英尺2.8英寸）。^[1]該屬可根據一個獨特的特徵組合及兩項此前未知的特徵，與所有其它薄板龍科區分開來：外翼骨有一個朝向背側的細長突起，下側有一大型骨質突起。正模標本中存在一個鐙骨，此前認為薄板龍科不具有這種骨骼。^[2]^[9]

分類

遠古龍最初被歸入薄板龍科，^[1]一項研究發現其為卡拉瓦亞龍的近親。^[10]奧戈曼等人2016年的系統發育分析再次確認其屬於薄板龍科，但否認其與卡拉瓦亞龍近緣。根據分析，該屬在薄板龍科中的位置如下。^[2]

薄板龍科 Elasmosauridae

格羅諾龍 Gronausaurus

斯皮頓黏土的蛇頸龍

貝茜尼可斯白浪泳龍 Wapuskanectes betsynicollsae

哥倫比亞卡拉瓦亞龍 Callawayasaurus colombiensis

	斯氏神河龍 Styxosaurus snowii

	鈴木雙葉龍 Futabasaurus suzukii

	范氏阿爾伯塔泳龍 Albertonectes vanderveldei

	凱氏遠古龍 Tuarangisaurus keyesi

	哈氏海霸龍 Thalassomedon haningtoni

	扁尾薄板龍 Elasmosaurus platyurus

龐泰克斯末泳龍 Terminonatator ponteixensis

亞歷山大水怪龍 Hydrotherosaurus alexandrae

摩氏西南泳龍 Libonectes morgani

海洋卡瓦泳龍 Kawanectes lafquenianum

莫氏維加龍 Vegasaurus molyi

斯氏莫雷諾龍 Morenosaurus stocki

	卡提基獵蛸龍 Kaiwhekea katiki

	小齒極泳龍 Aristonectes parvidens

	基里奎納極泳龍 Aristonectes quiriquinensis

參見

蛇頸龍列表
蛇頸龍類研究歷史（英語：Timeline of plesiosaur research）

參考資料

^ ^1.0 ^1.1 ^1.2 ^1.3 ^1.4 Wiffen, J.; Moisley, W.L. Late Cretaceous reptiles (Families Elasmosauridae and Pliosauridae) from the Mangahouanga Stream, North Island, New Zealand. New Zealand Journal of Geology and Geophysics. 1986, 29 (2): 205–252. Bibcode:1986NZJGG..29..205W. doi:10.1080/00288306.1986.10427535.
^ ^2.0 ^2.1 ^2.2 ^2.3 O'Gorman, J.P.; Otero, R.A.; Hiller, N.; Simes, J.; Terezow, M. Redescription of Tuarangisaurus keyesi (Sauropterygia; Elasmosauridae), a key species from the uppermost Cretaceous of the Weddellian Province: Internal skull anatomy and phylogenetic position. Cretaceous Research. 2016, 71: 118–136. doi:10.1016/j.cretres.2016.11.014.
^ Sachs, S. Tuarangisaurus australis sp. nov. (Plesiosauria: Elasmosauridae) from the Lower Cretaceous of northeastern Queensland, with additional notes on the phylogeny of the Elasmosauridae (PDF). Memoirs of the Queensland Museum. 2005, 50 (2): 425–440. （原始內容 (PDF)存檔於2011-09-28）.
^ Benjamin P. Kear. Taxonomic clarification of the Australian elasmosaurid genus Eromangasaurus, with reference to other austral elasmosaur taxa. Journal of Vertebrate Paleontology. 2007, 27 (1): 241–246. S2CID 86673814. doi:10.1671/0272-4634(2007)27[241:TCOTAE]2.0.CO;2.
^ O'Gorman, J.P.; Gasparini, Z.; Salgado, L. Reappraisal of Tuarangisaurus? cabazai (Elasmosauridae, Plesiosauria) from the Upper Maastrichtian of northern Patagonia, Argentina. Cretaceous Research. 2014, 47: 39–47. Bibcode:2014CrRes..47...39O. doi:10.1016/j.cretres.2013.10.003. hdl:11336/37287  .
^ Hiller, Norton; O'Gorman, José P.; Otero, Rodrigo A.; Mannering, Al A. A reappraisal of the Late Cretaceous Weddellian plesiosaur genus Mauisaurus Hector, 1874. New Zealand Journal of Geology and Geophysics. 2017, 60 (2): 112–128. Bibcode:2017NZJGG..60..112H. S2CID 132037930. doi:10.1080/00288306.2017.1281317.
^ Otero, R.A.; O'Gorman, J.P.; Moisley, W.L.; Terezow, M.; Mckee, J. A juvenile Tuarangisaurus keyesi Wiffen and Moisley, 1986 (Plesiosauria, Elasmosauridae) from the Upper Cretaceous of New Zealand, with Remarks on Its Skull Ontogeny. Cretaceous Research. 2018, 85: 214–231. Bibcode:2018CrRes..85..214O. doi:10.1016/j.cretres.2017.09.007. hdl:11336/99631  .
^ O'Gorman, J.P. A Small Body Sized Non-Aristonectine Elasmosaurid (Sauropterygia, Plesiosauria) from the Late Cretaceous of Patagonia with Comments on the Relationships of the Patagonian and Antarctic Elasmosaurids. Ameghiniana. 2016, 53 (3): 245–268. S2CID 133139689. doi:10.5710/AMGH.29.11.2015.2928.
^ Carpenter, K. Revision of North American elasmosaurs from the Cretaceous of the western interior. Paludicola. 1999, 2: 148–173.
^ Kubo, T.; Mitchell, M.T.; Henderson, D.M. Albertonectes vanderveldei, a new elasmosaur (Reptilia, Sauropterygia) from the Upper Cretaceous of Alberta. Journal of Vertebrate Paleontology. 2012, 32 (3): 557–572. Bibcode:2012JVPal..32..557K. S2CID 129500470. doi:10.1080/02724634.2012.658124.

[desc-1] 1.0 ^1.1 ^1.2 ^1.3 ^1.4 Wiffen, J.; Moisley, W.L. Late Cretaceous reptiles (Families Elasmosauridae and Pliosauridae) from the Mangahouanga Stream, North Island, New Zealand. New Zealand Journal of Geology and Geophysics. 1986, 29 (2): 205–252. Bibcode:1986NZJGG..29..205W. doi:10.1080/00288306.1986.10427535.

[redesc-2] 2.0 ^2.1 ^2.2 ^2.3 O'Gorman, J.P.; Otero, R.A.; Hiller, N.; Simes, J.; Terezow, M. Redescription of Tuarangisaurus keyesi (Sauropterygia; Elasmosauridae), a key species from the uppermost Cretaceous of the Weddellian Province: Internal skull anatomy and phylogenetic position. Cretaceous Research. 2016, 71: 118–136. doi:10.1016/j.cretres.2016.11.014.

[eromanga-3] Sachs, S. Tuarangisaurus australis sp. nov. (Plesiosauria: Elasmosauridae) from the Lower Cretaceous of northeastern Queensland, with additional notes on the phylogeny of the Elasmosauridae (PDF). Memoirs of the Queensland Museum. 2005, 50 (2): 425–440. （原始內容 (PDF)存檔於2011-09-28）.

[Eromangasaurus07-4] Benjamin P. Kear. Taxonomic clarification of the Australian elasmosaurid genus Eromangasaurus, with reference to other austral elasmosaur taxa. Journal of Vertebrate Paleontology. 2007, 27 (1): 241–246. S2CID 86673814. doi:10.1671/0272-4634(2007)27[241:TCOTAE]2.0.CO;2.

[cabazai-5] O'Gorman, J.P.; Gasparini, Z.; Salgado, L. Reappraisal of Tuarangisaurus? cabazai (Elasmosauridae, Plesiosauria) from the Upper Maastrichtian of northern Patagonia, Argentina. Cretaceous Research. 2014, 47: 39–47. Bibcode:2014CrRes..47...39O. doi:10.1016/j.cretres.2013.10.003. hdl:11336/37287  .

[6] Hiller, Norton; O'Gorman, José P.; Otero, Rodrigo A.; Mannering, Al A. A reappraisal of the Late Cretaceous Weddellian plesiosaur genus Mauisaurus Hector, 1874. New Zealand Journal of Geology and Geophysics. 2017, 60 (2): 112–128. Bibcode:2017NZJGG..60..112H. S2CID 132037930. doi:10.1080/00288306.2017.1281317.

[7] Otero, R.A.; O'Gorman, J.P.; Moisley, W.L.; Terezow, M.; Mckee, J. A juvenile Tuarangisaurus keyesi Wiffen and Moisley, 1986 (Plesiosauria, Elasmosauridae) from the Upper Cretaceous of New Zealand, with Remarks on Its Skull Ontogeny. Cretaceous Research. 2018, 85: 214–231. Bibcode:2018CrRes..85..214O. doi:10.1016/j.cretres.2017.09.007. hdl:11336/99631  .

[8] O'Gorman, J.P. A Small Body Sized Non-Aristonectine Elasmosaurid (Sauropterygia, Plesiosauria) from the Late Cretaceous of Patagonia with Comments on the Relationships of the Patagonian and Antarctic Elasmosaurids. Ameghiniana. 2016, 53 (3): 245–268. S2CID 133139689. doi:10.5710/AMGH.29.11.2015.2928.

[carpenter-9] Carpenter, K. Revision of North American elasmosaurs from the Cretaceous of the western interior. Paludicola. 1999, 2: 148–173.

[callawaya-10] Kubo, T.; Mitchell, M.T.; Henderson, D.M. Albertonectes vanderveldei, a new elasmosaur (Reptilia, Sauropterygia) from the Upper Cretaceous of Alberta. Journal of Vertebrate Paleontology. 2012, 32 (3): 557–572. Bibcode:2012JVPal..32..557K. S2CID 129500470. doi:10.1080/02724634.2012.658124.

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