Family Carditidae Férussac, 1822

Remarks. Some authors only recognize a few genera such as Venericardia Lamarck, 1801, and Cardita Bruguière, 1792, and a large number of subgenera (e.g. Claibornicardia Stenzel & Krause, 1957, Venericor Stewart, 1930, Megacardita Sacco, 1899); however, some of those taxa are ranked as genera by other authors (for comparisons of different approaches see Sacco 1899; Dall 1903; Chavan 1969; Moore 1992, McClure & Lockwood 2015). As the use of subgenera implies closer phylogenetic relationship within each group than between these groups (Dubois 1982), we will regard all supraspecific groups as genera, discarding a priori any phylogenetic inferences until a thorough phylogenetic study of the family is carried out.

Chavan (1969) outlined a classification with seven subfamilies mainly based on shell outline and hinge morphology. As a result, members of the venericardids of Harris (1919), Gardner & Bowles (1939) and Heaslip (1968) were indistinctly included in the subfamilies Carditamerinae, Venericardiinae or Carditesinae . In this paper, we reject Chavan’s (1969) approach because it ignores the phylogenetic proposals by Harris (1919) and Heaslip (1968). A comparison among genera discussed in the text is presented in Table 2.