Sea urchin

(Reguidit frae Echinoidea)

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
Tripneustes ventricosus (West Indian Sea Egg-top) and Echinometra viridis (Reef Urchin - bottom).jpg
Tripneustes ventricosus an Echinometra viridis
Scientific classification e
Kinrick: Animalia
Phylum: Echinodermata
Subphylum: Echinozoa
Cless: Echinoidea
Leske, 1778
Subclasses