Children (18 direct children, 18 direct and indirect children):
Echinocardium cordatum
Sea potato
Echinocardium pennatifidum
Echinocardium capense
Echinocardium lymani
Echinocardium laevigaster
Echinocardium flavescens
Echinocardium mortenseni
Echinocardium connectens
Echinocardium meteorense
Echinocardium fenauxi
Echinocardium keiense
Echinocardium mediterraneum
Echinocardium australe
New zealand heart urchin
Echinocardium kelloggi
Echinocardium leopolitanum
Echinocardium marylandiense
Echinocardium olisiponensis
Echinocardium peroni