Characters of a phylum are given below. Read those carefully and answer the questions.
a. Spines of calcium carbonate are present on the body.
b. These animals are exclusively marine.
c. They perform the locomotion with the help of tube feet.
d. Their skeleton is made up of calcareous plates or spicules.
i. Animals of which phylum show the above characters?
ii. Give an example from that phylum.
iii. These animals can be classified with the help of which criteria of new system of animals classification?