Echinocardium flavescens, sometimes called the yellow sea potato,[1][2] is a species of sea urchin in the family Loveniidae, chiefly found in the northeast Atlantic region.

It is yellow to the tube feet (hence the name flavescens, "yellowish")[4] and has spines on the underside of the body.

The frontal ambulacrum is not indented and there are larger spines in the interambulacral areas of the upper side of the test.

[5] Found in the waters off Great Britain, Ireland and associated islands.

[7] Echinocardium flavescens buries itself about 4 in (100 mm) deep in coarse gravel in the sublittoral,[8] up to depths of 200 m (660 ft),[7] sometimes associated with the sea cucumber Neopentadactyla mixta or the brittle star Ophiopsila annulosa.