The heart urchins or Spatangoida are an
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...
of
sea urchin
Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) o ...
s.
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
''Asterostomatidae'' is an extinct family of sea urchins belonging to the order Spatangoida.
They are slow-moving, shallow infaunal, or sediment-dwelling organisms, and are deposit feeders or detritivores. They lived during the Eocene and Mioce ...
Pictet, 1857
** family
Brissidae Gray, 1855
** family
Palaeotropidae Lambert, 1896
** super-family
Spatangidea Fischer, 1966
*** family
Eupatagidae
Eupatagidae is a family of echinoderms
An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dolla ...
Lambert, 1905
*** family
Eurypatagidae Kroh, 2007
*** family
Loveniidae Lambert, 1905
*** family
Macropneustidae
Macropneustidae is a family of echinoderms belonging to the order Spatangoida
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 ...
Lambert, 1905
*** family
Maretiidae
Maretiidae is a family of echinoderms belonging to the order Spatangoida
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 ...
Lambert, 1905
*** family
Megapneustidae Fourtau, 1905 †
*** family
Spatangidae Gray, 1825
* family
Hemiasteridae
Hemiasteridae is a family of echinoderms belonging to the order Spatangoida
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 o ...
H. L. Clark, 1917
* suborder
Micrasterina Fischer, 1966
** family
Aeropsidae
Aeropsidae is a family of echinoderms belonging to the order Spatangoida. It contains one extant genus. There are also eight extinct genera, most of which fall in the subfamily Corasterinae.
History
Initially, a large number of genera were incl ...
Lambert, 1896
** family
Micrasteridae
Micrasteridae is a family of echinoderms belonging to the order Spatangoida
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 o ...
Lambert, 1920a
* family
Palaeostomatidae
Palaeostomatidae is a family of echinoderms belonging to the order Spatangoida
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 toward ...
Lovén, 1868
* suborder
Paleopneustina Markov & Solovjev, 2001
** superfamily
Paleopneustoidea A. Agassiz, 1904
*** family
Paleopneustidae
Paleopneustidae is a family of echinoderms belonging to the order Spatangoida
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 ...
A. Agassiz, 1904
*** family
Pericosmidae
Pericosmidae is a family of echinoderms belonging to the order Spatangoida
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 on ...
Lambert, 1905
** family
Prenasteridae
Prenasteridae is a family of echinoderms
An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dol ...
Lambert, 1905
** family
Schizasteridae
Schizasteridae is a family of echinoderms belonging to the order Spatangoida.
Genera:
* '' Abatus'' Troschel, 1851
* '' Aceste'' Thomson, 1877
* '' Agassizia'' Agassiz & Desor, 1847
* '' Aguayoaster'' Sanchez Roig, 1952
* '' Aliaster'' Valdin ...
Lambert, 1905
* family
Somaliasteridae Wagner & Durham, 1966a †
* family
Toxasteridae
''Toxasteridae'' is an extinct family of sea urchins.
These slow-moving shallow infaunal deposit feeder-detritivores lived during the Cretaceous period, from 145.5 to 61.7 Ma.
Genera
*''Adytaster''
*''Aphelaster''
*''Douvillaster''
*''Enallopn ...
Lambert, 1920a †
Image:Brissus latecarinatus.jpg , '' Brissus latecarinatus'' ( Brissidae)
Image:Eupatagus mooreanus fossil heart urchin (Eocene; Florida, USA) 1 (16765728703).jpg, '' Eupatagus mooreanus'' (Eupatagidae
Eupatagidae is a family of echinoderms
An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dolla ...
)
Image:Echinocardium_cordatum.jpg, '' Echinocardium cordatum'' ( Loveniidae)
Image:Phrissocystis.jpg, '' Phrissocystis sp.'' (Macropneustidae
Macropneustidae is a family of echinoderms belonging to the order Spatangoida
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 ...
)
Image:Tiny maretia heart urchin (Maretia planulata).jpg , '' Maretia planulata'' (Maretiidae
Maretiidae is a family of echinoderms belonging to the order Spatangoida
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 ...
)
Image:Spatangus purpureus.jpg, ''Spatangus purpureus
''Spatangus purpureus'', commonly known as the purple heart urchin, is a species of sea urchin in the family Spatangidae. It is found in the eastern Atlantic Ocean and the Mediterranean Sea, where it lives immersed in the sediment.
Description ...
'' ( Spatangidae)
Image:Palhemiastercomanchei.jpg, Fossil of '' Palhemiaster comanchei'' (Hemiasteridae
Hemiasteridae is a family of echinoderms belonging to the order Spatangoida
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 o ...
)
Image:Oliver2012 fig5 Aeropsis rostrata (Wyville Thomson, 1877) with Kelliola symmetros (Jeffreys, 1876).png, '' Aeropsis rostrata'' (Aeropsidae
Aeropsidae is a family of echinoderms belonging to the order Spatangoida. It contains one extant genus. There are also eight extinct genera, most of which fall in the subfamily Corasterinae.
History
Initially, a large number of genera were incl ...
)
Image:Micraster leskei MHNT Turonien Puys 76.jpg, Fossil of ''Micraster leskei
''Micraster'' is an extinct genus of echinoids from the Late Cretaceous to the early Eocene. Its remains have been found in Africa, Antarctica, Europe, and North America. Micraster was an infaunal echinoid living in a burrow below the sedi ...
'' (Micrasteridae
Micrasteridae is a family of echinoderms belonging to the order Spatangoida
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 o ...
)
Image:Prymnaster investigatoris dPNG12 2718.JPG, '' Prymnaster investigatoris'' (Schizasteridae
Schizasteridae is a family of echinoderms belonging to the order Spatangoida.
Genera:
* '' Abatus'' Troschel, 1851
* '' Aceste'' Thomson, 1877
* '' Agassizia'' Agassiz & Desor, 1847
* '' Aguayoaster'' Sanchez Roig, 1952
* '' Aliaster'' Valdin ...
)
Image:Heteraster oblongus.3 - Cretacico inferior.JPG, Fossil of '' Heteraster oblongus'' (Toxasteridae
''Toxasteridae'' is an extinct family of sea urchins.
These slow-moving shallow infaunal deposit feeder-detritivores lived during the Cretaceous period, from 145.5 to 61.7 Ma.
Genera
*''Adytaster''
*''Aphelaster''
*''Douvillaster''
*''Enallopn ...
)
See also
* ''
Abatus agassizii''
* ''
Meoma ventricosa''
References
*
*
Extant Early Cretaceous first appearances
{{echinoidea-stub