Spatangoida

Heart urchins; Temporal range: Lower Cretaceous–recent PreꞒ Ꞓ O S D C P T J K Pg N
	Spatangus purpureus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Echinodermata
Class:	Echinoidea
Subclass:	Euechinoidea
Infraclass:	Irregularia
Superorder:	Atelostomata
Order:	Spatangoida; L. Agassiz, 1840
Suborders
	Brissidina; Micrasterina; Paleopneustina;

The heart urchins or Spatangoida are an order of sea urchins.

Their body is a somewhat elongated oval in form, and is distinguished by the mouth being placed towards one end of the animal, and the anus towards the other. As a result, heart urchins, unlike most other sea urchins, are bilaterally symmetrical, and have a distinct anterior surface. The presence and position of the mouth and anus typically give members of this group the distinct "heart" shape from which they get their name.

Heart urchins have no feeding lantern, and often have petaloids sunk into grooves. They are a relatively diverse order, with a number of varying species.

Taxonomy

According to World Register of Marine Species :

suborder Brissidina Stockley, Smith, Littlewood, Lessios & MacKenzie-Dodds, 2005
- family Asterostomatidae Pictet, 1857
- family Brissidae Gray, 1855
- family Palaeotropidae Lambert, 1896
- superfamily Spatangoidea Fischer, 1966
  - family Eupatagidae Lambert, 1905
  - family Eurypatagidae Kroh, 2007
  - family Loveniidae Lambert, 1905
  - family Macropneustidae Lambert, 1905
  - family Maretiidae Lambert, 1905
  - family Megapneustidae Fourtau, 1905 †
  - family Spatangidae Gray, 1825
family Hemiasteridae H. L. Clark, 1917
suborder Micrasterina Fischer, 1966
- family Aeropsidae Lambert, 1896
- family Micrasteridae Lambert, 1920a
family Palaeostomatidae Lovén, 1868
suborder Paleopneustina Markov & Solovjev, 2001
- superfamily Paleopneustoidea A. Agassiz, 1904
  - family Paleopneustidae A. Agassiz, 1904
  - family Pericosmidae Lambert, 1905
- family Prenasteridae Lambert, 1905
- family Schizasteridae Lambert, 1905
family Somaliasteridae Wagner & Durham, 1966a †
family Toxasteridae Lambert, 1920a †

Brissus latecarinatus (Brissidae)
Eupatagus mooreanus (Eupatagidae)
Echinocardium cordatum (Loveniidae)
Phrissocystis sp. (Macropneustidae)
Maretia planulata (Maretiidae)
Spatangus purpureus (Spatangidae)
Fossil of Palhemiaster comanchei (Hemiasteridae)
Aeropsis rostrata (Aeropsidae)
Fossil of Micraster leskei (Micrasteridae)
Prymnaster investigatoris (Schizasteridae)
Fossil of Heteraster oblongus (Toxasteridae)

References

Barnes, Robert D. (1982). Invertebrate Zoology. Philadelphia, PA: Holt-Saunders International. p. 981. ISBN 0-03-056747-5.
National History Museum. "Spatangoida". Retrieved 19 Dec 2009.

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Taxonomy

See also

References