Arbacioida

Arbacioida Temporal range:
Arbacia lixula
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Echinodermata
Class:	Echinoidea
Superorder:	Echinacea
Order:	Arbacioida Gregory, 1900
Family:	Arbaciidae Gray, 1855

Arbacioida are an order of sea urchins, consisting of a single family, the Arbaciidae. They are distinguished from other sea urchins by the presence of five separate plates around the anus. Unlike their close relatives, the Salenioida, all of the tubercles on their tests are of similar size.

Genera:

• Arbacia Gray, 1835
• Arbaciella Mortensen, 1910a
• Arbia Cooke, 1948†
• Baueria Noetling, 1885†
• Codiopsis Agassiz, in Agassiz & Desor, 1846†
• Coelopleurus Agassiz, 1840a
• Cottaldia Desor, 1856 †
• Dialithocidaris Agassiz, 1898
• Habrocidaris Agassiz & Clark, 1907b
• Podocidaris Agassiz, 1869
• Pygmaeocidaris Döderlein, 1905
• Sexpyga Shigei, 1975
• Tetrapygus Agassiz, 1841b

References

• Barnes, Robert D. (1982). Invertebrate Zoology. Philadelphia, PA: Holt-Saunders International. p. 980. ISBN 0-03-056747-5.
• National History Museum. "Arbacioida". Retrieved 19 Dec 2009.