Sand dollar

Sand dollars Temporal range: 56–0 Ma PreꞒ Ꞓ O S D C P T J K Pg N Late Paleocene to Recent[1]
A live individual of Clypeaster reticulatus (Mayotte)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Echinodermata
Class:	Echinoidea
Superorder:	Gnathostomata
Order:	Clypeasteroida
Suborders and families
See text.

Sand dollars (also known as sea cookies or snapper biscuits in New Zealand and Brazil, or pansy shells in South Africa) are species of flat, burrowing sea urchins belonging to the order Clypeasteroida. Some species within the order, not quite as flat, are known as sea biscuits. Sand dollars can also be called "sand cakes" or "cake urchins".^[2]