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sand dollars

SCIENCE

What is the Difference between Sea Urchins and Sand Dollars?

Sand dollars and sea urchins both belong to the phylum Echinodermata, a group which contains other radially symmetrical animals such as starfish and sea cucumbers. Unlike starfish and sea cucumbers, sea urchins and sand dollars belong to the same class: Echinoidea. Members of this class are part of Echinodermata but have a few differences. The most notable differences are the solid test and spines, which starfish and sea cucumbers do not have. These tests form a hard, globose or discoidal shape and serve

  1 year ago ago
What is the Difference between Sea Urchins and Sand Dollars?