1. 
   Pteriomorphia
   (from the article `bivalve`) ...represented today by the superfamily Trigonioidea (placed in the subclass Palaeoheterodonta), which are an aberrant group of the subclass ... Of the various subclasses, two are most important ecologically: the Heterodonta, which are modern burrowers that feed primaril...
   Found op http://www.britannica.com/eb/a-z/p/128
   
   
2. 
   Pteriomorphia
   Pteriomorphia is a subclass of saltwater clams, marine bivalve mollusks. It contains several major orders and suborders: the Arcoida, Ostreoida, Pectinoida, Limoida, Mytiloida, and Pterioida, and it also contains some extinct and probably basal families, such as the Evyanidae, Colpomyidae, Bakevell...
   Found op http://en.wikipedia.org/wiki/Pteriomorphia
   
   

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