Heart urchins Temporal range: Lower Cretaceous–recent
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S
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Spatangus purpureus | |
Scientific classification | |
Kingdom: | Animalia
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Phylum: | Echinodermata
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Class: | Echinoidea
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Superorder: | Atelostomata
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Order: | Spatangoida L. Agassiz, 1840
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Suborders | |
Asterostomatina |
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.
According to World Register of Marine Species :
Brissus latecarinatus ( Brissidae)
Eupatagus mooreanus ( Eupatagidae)
Echinocardium cordatum (Loveniidae)
Phrissocystis sp. ( Macropneustidae)
Maretia planulata ( Maretiidae)
Spatangus purpureus (Spatangidae)
Fossile of Palhemiaster comanchei ( Hemiasteridae)
Aeropsis rostrata ( Aeropsidae)
Fossile de Micraster leskei ( Micrasteridae)
Prymnaster investigatoris ( Schizasteridae)
Fossile d' Heteraster oblongus (Toxasteridae)