Class Echinoidea
(heart urchins, sand dollars, and sea urchins)

Confused by a class within a class or an order within an order? Please see our brief essay.

Scientific names for Aves taxonomy (family and below) are from The Howard and Moore Complete Checklist of the Birds of the World, Princeton University Press, copyright 2003. Used by permission.

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  Kingdom Animalia (animals)
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  Eumetazoa (metazoans)
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  Bilateria (bilaterally symmetrical animals)
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  Deuterostomia (deuterostomes)
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  Phylum Echinodermata (echinoderms)
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  Class Echinoidea (heart urchins, sand dollars, and sea urchins)
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  Subclass Euechinoidea
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  Superorder Atelostomata
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  Order Cassiduloida
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  Order Spatangoida (heart urchins)
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  Superorder Diadematacea
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  Order Diadematoida
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  Order Echinothurioida
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  Order Pedinoida
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  Superorder Echinacea
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  Order Arbacioida
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  Order Echinoida
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  Order Phymosomatoida
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  Order Salenioida
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  Order Temnopleuroida
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  Superorder Gnathostomata
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  Order Clypeasteroida (sand dollars)
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  Order Holectypoida
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  Subclass Perischoechinoidea
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  Order Cidaroida (pencil urchins)