(Sarah of the Clue Crew delivers the clue) Sea urchins' body symmetry makes their teeth fit together in a way that this pupil of Plato compared to a five-sided lantern.  2300 years later, it's still known as his lantern
[DOC] [TLE] Egypt Sea Urchin - Egypt Cairo [PAR] Egypt Sea Urchin The Sea urchins are interesting and attractive marine creatures 
... of the phylum Echinodermata family, together with the sea cucumbers, the 
crinoids, ... on the oral surface and is made from five jaws or calcium carbonate 
teeth.