Dinocardium robustum has a shell that reaches a length of 100–125 mm. This large and sturdy shell is obliquely ovate, with crenulate margins and about 32–36 rounded radialribs present on both the inside and the outside. The valves are symmetrical with one another. The basic color of the surface usually is creamywhite, mottled with reddish-brown markings, while the interior is pinkish. This cockle burrows into the substrate by means of its strongfoot, and like most bivalves feeds by filtering the water for plankton.