Acanthocardia spinosa, common name Sand Cockle, is a species of saltwater clams, marine bivalve molluscs in the family Cardiidae. The genus Acanthocardia is present from the Upper Oligocene to the Recent.
The shell of Acanthocardia spinosa can reach a size of 60-95 mm. This shell is robust, round with a heart-shaped profile, equivalve and inflated, with crenulated margins. The surface shows thick narrowly spaced radial ribs, with rows of pronounced thorny hooks. The basic external coloration is usually pale brown; the interior is white.
This species is present in sand and mud, from low waters to 120 m. Like almost all bivalves, these mollusks are phytoplankton feeders.