檢視極地鳥屬的原始碼

{| class="wikitable" style="float:right; margin: -10px 0px 10px 20px; text-align:left"
|<center>'''極地鳥屬'''<br><img src="https://upload.wikimedia.org/wikipedia/commons/thumb/e/ef/PacificLoon24.jpg/800px-PacificLoon24.jpg" width="280"></center><small>[https://carnivora.net/polarornis-gregorii-t273.html 圖片來自carnivora]</small> 
|}

'''極地鳥屬'''（[[學名]]：''Polarornis''）是[[雁形類]]（Anserimorphae）已[[滅絕]]的一個[[屬]]，屬[[維加鳥科]]，僅有'''''Polarornis gregorii'''''一種，其[[化石]]出土於[[南極洲]][[西摩島]]Lopez de Bertodano組，年代為距今約6600萬年白堊紀晚期的[[馬斯垂克期]]。極地鳥最早於1988年由古生物學家桑卡爾·柯特吉發現，但直到2002年才正式描述發表，不過他在1997年便在其著作''The Rise of Birds''中使用了本屬的學名。

==分類==
柯特吉將極地鳥屬歸入潛鳥科，認為其為潛鳥較早分支的類群，許多學者認同此觀點，但也有人反對，例如傑拉爾德·梅爾即認為極地鳥的解剖特徵和其他潛鳥差異過大<ref name=mayr2004>{{cite journal | last1 = Mayr | first1 = G | year = 2004 | title = A partial skeleton of a new fossil loon (Aves, Gaviiformes) from the early Oligocene of Germany with preserved stomach content | url = http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/colymboides.pdf | journal = Journal of Ornithology | volume = 145 | issue = 4 | pages = 281–286 | doi = 10.1007/s10336-004-0050-9 | access-date = 2006-11-07 | archive-url = https://web.archive.org/web/20150924100426/http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/colymboides.pdf | archive-date = 2015-09-24 }}</ref><ref name=feduccia1999>Feduccia, A. (1999). ''The Origin and Evolution of Birds''. 2nd edition. Yale University Press.</ref> 。2017年一篇研究將極地鳥與同出土於南極的白堊紀鳥類[[維加鳥屬]]、[[智利]]出土的白堊紀鳥類''Neogaeornis''、[[紐西蘭]]出土的[[古新世]]鳥類[[南鳥屬]]（''Australornis''）一起歸入新科[[維加鳥科]]，為雁形類較早分支的[[演化支]]<ref name="agnolínetal2017">{{cite journal | last1 = Agnolín | first1 = F.L. | last2 = Egli | first2 = F.B. | last3 = Chatterjee | first3 = S. | last4 = Marsà | first4 = J.A.G | year = 2017 | title = Vegaviidae, a new clade of southern diving birds that survived the K/T boundary | journal = The Science of Nature | volume = 104 | issue = 87 | pages = 87| doi=10.1007/s00114-017-1508-y| pmid = 28988276 }}</ref>。

==習性==
極地鳥應為以[[魚類]]與[[無脊椎動物]]為食的水鳥，其[[生態棲位]]可能與潛鴨和[[黃昏鳥]]相似。有研究顯示極地鳥的[[股骨]]中心密實，不同於多數鳥類中空的股骨，顯示極地鳥應不具（或接近不具）飛行能力，與[[企鵝]]和黃昏鳥相仿<ref name=Chinsamy>{{cite journal | last1 = Chinsamy | first1 = A. | last2 = Martin | first2 = L.D. | last3 = Dobson | first3 = P. | year = 1998 | title = Bone microstructure of the diving ''Hesperornis'' and the volant ''Ichthyornis'' from the Niobrara Chalk of western Kansas | url = | journal = Cretaceous Research | volume = 19 | issue = 2| pages = 225–235 | doi = 10.1006/cres.1997.0102 }}</ref>。

== 參考文獻 == 
{{reflist}}
[[Category: 380 動物學總論]]