Taxonomic revision of the Indo-Pacific Vasticardium flavum species group (Bivalvia, Cardiidae)

The group of Vasticardium flavum (Trachycardiinae) includes four species of medium size, with a slightly elongate or rounded shell of circa thirty ribs, and a characteristic sculpture: rounded ribs elaborately ornamented with transverse ridges. The identity of Cardium flavum, until now rather enigmatic, is revised based on Linnés descriptions and the designation of a lectotype. Three subspecies of V. flavum are recognized: the nominal subspecies (Carolines to Eastern Indonesia and the Solomons), V. flavum subrugosum (India to the Philippines, China, South Japan) and V. flavum dupuchense (north-western Australia). Vasticardium pectiniforme (Born, 1780), better known as V. rugosum (Lamarck, 1819) and often erroneously considered a synonym of V. flavum, is the most common and widespread trachycardiine in the Indo-Pacific. Two additional species have restricted ranges in Australia: Vasticardium vertebratum (Jonas, 1845) [= V. reeveanum (Dunker, 1852)], and Vasticardium ornatum (Sowerby, 1877) [= V. fultoni (Sowerby, 1916)].