Cambrian Pelecypoda (Mollusca)

The record of Cambrian bivalved organisms that have been placed in the Moll usca includes undoubted pelecypods and other bivalved shells. This record i s reviewed herein. Additional topotype material of Delgado's (1904, Communi cacoes da Commissao do Service Geologico de Portugal 5:307-374) Lower Cambr ian specimens from Portugal shows that they are distorted brachiopods. Rest udy of Zhang's (1980a, Bulletin Chinese Academy of Geological Sciences, Ser ies 8, 1:1-19; 1980b, 26th International Geological Congress 4:121-129) typ e specimens from the Lower Cambrian of China shows that most of them are al so brachiopods. New specimens of Tuarangia MacKinnon indicate that this gen us is a Middle-Upper Cambrian pelecypod.