Spatangoida
Encyclopedia
The heart urchins or Spatangoida are an order
of sea urchin
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.
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of sea urchin
Sea urchin
Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...
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
Order Spatangoida- Suborder Asterostomatina
- Family Asterostomatidae
- Suborder Hemiasterina
- Family Aeropsidae
- Family Hemiasteridae
- Family Palaeostomatidae
- Family Pericosmidae
- Family Schizasteridae
- Suborder Holasterina
- Family Calymnidae
- Family Holasteridae
- Family Pourtalesiidae
- Family Urechinidae
- Suborder Micrasterina
- Family Brissidae
- Family Brissopsidae
- Family LoveniidaeLoveniidaeLoveniidae is a family of heart urchins in the order Spatangoida.-Genera:* Echinocardium Gray, 1825 * Lovenia Desor, 1847...
- Family SpatangidaeSpatangidaeThe Spatangidae are a family of heart urchins. There are four recognised genera within the family; Maretia, Paramaretia, Pseudomaretia and Spatangus...
- Suborder Toxasterina
- Family Toxasteridae