平扭貝屬

平扭貝屬（學名：）是褶正形貝科下已滅絕的一個屬，生存於中奧陶紀至中志留紀，生活在海洋底部，利用短小的腳附著在沙質基底上。

特徵 
這類中等大小的腕足動物外型接近長方形，兩瓣突出明顯。沿著鉸線，殼能延展到最寬，而鉸則延展形成一個尖銳的耳狀骨。在腳狀瓣上有明顯的溝，在臂狀瓣上則有相應的褶。殼間的連接線在前緣有顯著折褶。眾多頂鋒銳利的翅脈向殼的邊緣方向散發。

物種 
Orthis (Platystrophia) cypha James, 1874
Orthis (Platystrophia) laticosta James, 1871
Platystrophia acutilirata Conrad, 1842
Platystrophia amoena McEwan, 1919
Platystrophia annieana Foerste, 1910
Platystrophia anomala Hiller, 1980
Platystrophia baltica Zuykov & Harper, 2007
Platystrophia biforatus Schlotheim, 1820
Platystrophia caelata Williams, 1974
Platystrophia chama Eichwald, 1861
Platystrophia clarksvillensis Foerste, 1910
Platystrophia colbiensis Foerste, 1910
Platystrophia costata Zuykov, 2000
Platystrophia costatus Pander, 1830
Platystrophia crassoplicata Alichova, 1951
Platystrophia cypha James, 1874
Platystrophia dentata Pander, 1830
Platystrophia elegantula McEwan, 1919
Platystrophia extensa McEwan, 1920
Platystrophia hongueda Li & Copper, 2006
Platystrophia hopensis Foerste, 1910
Platystrophia humilis Oraspold, 1959
Platystrophia jaaniensis Rübel, 1963
Platystrophia laticosta James, 1871
Platystrophia lutkevichi Alikhova, 1951
Platystrophia lynx Eichwald, 1830
Platystrophia orbiculata Oraspold, 1959
Platystrophia pogrebovi Zuykov & Harper, 2007
Platystrophia ponderosa Foerste, 1909
Platystrophia profundosulcata Meek, 1873
Platystrophia quadriplicata Alikhova, 1951
Platystrophia saxbyensis Oraspold, 1959
Platystrophia scotica Williams, 1962
Platystrophia trentonensis McEwan, 1919

參考文獻

外部連結 
Platystrophia  in the 

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美國化石