Sea urchin
From Conservapedia
Sea urchins are marine animals of the class Echinoidea, echinoderms that have a soft body enclosed in a round, symmetrical, calcareous shell covered with long spines.
Sea urchins are marine animals of the class Echinoidea, echinoderms that have a soft body enclosed in a round, symmetrical, calcareous shell covered with long spines.