Subclass Protobranchia Pelseneer 1889
Synonym: Palaeotaxodonta Korobkov 1954
Parent taxon: Eubivalvia according to J. G. Carter et al. 2011
See also Bieler and Mikkelsen 2006, Bouchet et al. 2010, Coan and Valentich-Scott 2012, Cope 1997, Giribet and Wheeler 2002, Gliozzi and Malatesta 1983, Hinz-Schallreuter 2000, Kaim et al. 2014, Kiessling 2003, Mikkelsen and Bieler 2008, Nevesskaja 2009, Newell 1965, Scholz et al. 2008, Spencer et al. 2004, Squires 1984, Squires 1987, Stilwell and Zinsmeister 1992, Stilwell et al. 2004, Vokes 1980 and Ward and Blackwelder 1987
Sister taxon: Autobranchia
Subtaxa: Antactinodiontidae Nuculaniformii Nuculiformii Sareptoidea Solemyoida Zeehania