Edrioasteroidea is an extinct class of echinoderms that lived from the Ediacaran (if Arkarua was indeed an edrioasteroid) until the Permian, about {Ma|600-300}. The living animal would have resembled a pentamerously symmetrical disc or cushion. The body plan for this class was simple: a main body (theca), composed of many small plates, a periphera...
Found on
http://en.wikipedia.org/wiki/Edrioasteroidea
(from the article `echinoderm`) ...about 375,000,000–460,000,000 years ago; small, disk-shaped; theca composed of numerous plates; ambulacral system with multiple branching.†Class ...
Found on
http://www.britannica.com/eb/a-z/e/11
No exact match found.
