Ophiocistioidea

The Ophiocistioidea is a class of extinct echinoderms from the Palaeozoic. Ophiocistioids had a flattened dome-shaped body encased in a solid test of calcareous plates, similar to that of a modern sea urchin. The mouth was at the apex of the dome, and surrounded by a set of five jaws. The animals apparently did not have an anus, but a madreporite ...
Found on http://en.wikipedia.org/wiki/Ophiocistioidea

Ophiocistioidea

(from the article `echinoderm`) ...Cambrian about 570,000,000 years ago; pear-shaped or spindle-shaped body with many plates arranged spirally.†Class OphiocistioideaLower Ordovician ...
Found on http://www.britannica.com/eb/a-z/o/23
No exact match found