Sea urchin

Sea urchins or urchins, sometimes cried sea hedgehogs, are smaa, spiny, globular animals which, wi thair close kin, such as saund dollars, constitute the class Echinoidea o the echinoderm phylum.

Sea urchin Temporal range: Ordovician–Present PreЄ Є O S D C P T J K Pg N
Tripneustes ventricosus an Echinometra viridis
Scientific classification
Kinrick:	Animalia
Phylum:	Echinodermata
Subphylum:	Echinozoa
Cless:	Echinoidea Leske, 1778
Subclasses
Subclass Perischoechinoidea Order Cidaroida (pencil urchins) Subclass Euechinoidea Superorder Atelostomata Order Cassiduloida Order Spatangoida (hert urchins) Superorder Diadematacea Order Diadematoida Order Echinothurioida Order Pedinoida Superorder Echinacea Order Arbacioida Order Echinoida Order Phymosomatoida Order Salenioida Order Temnopleuroida Superorder Gnathostomata Order Clypeasteroida (saund dollars) Order Holectypoida