additional source
Bieler, R.; Carter, J. G.; Coan, E. V. (2010). Classification of Bivalve families. Pp. 113-133, in: Bouchet P. & Rocroi J.-P. (2010), Nomenclator of Bivalve Families. <em>Malacologia.</em> 52(2): 1-184. [details]
From editor or global species database
Classification Tridacna has been shown to be a highly derived cardiid by Schneider (1998), therefore the group is downgraded to subfamily rank [details]