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，利用短小的肉莖附著在石灰質或沙質基底上。

特徵
殼體大小中等，外形接近長方形，兩瓣殼突出明顯。殼體沿著鉸線延展到很寬的程度，而鉸則向兩邊延展形成一對尖銳的耳狀突起。腹殼上有明顯的溝，背殼上則有相應的褶。殼間的連接線在前緣有顯著折褶。眾多頂鋒銳利的肋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
[http://paleodb.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_no=26936 Platystrophia*] in the Paleobiology Database

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