Life (root) » Animalia (Animals) » Echinodermata (Echinoderms) » Echinozoa (sea urchins and sea cucumbers) » Echinoidea (Sea Urchins, Sand Dollars, and Heart Urchins) » Euechinoidea (sea urchins) » Acroechinoidea » Diadematoida » Diadematidae » Diadema » Diadema mexicanum