"Echinodermata are animals with spines like sea stars."
I think this needs to be changed; the word 'spines' has two meanings that apply to animals. For example, mammals also have spines, but a different kind of spine. Thus, they would fit into the echinodermata category by that definition. I don't know what it would be changed to, but something defining 'spines' in a better way.
- Perhaps it would be better to give a more obvious example, say "Crown of Thorns Starfish" or perhaps "Echidna"